Merge 9b64d2ee17 into 7fe38f1b9f

Фазы 1 и 2 полностью выполнены

.github/instructions/Architecture.instructions.md

@@ -0,0 +1,126 @@
+# Architecture Directives
+
+> Companion to `Agents.md`. These are **activation directives**, not tutorials.
+> You already know these patterns — apply them. When making any structural or
+> design decision, run the relevant section below as a checklist.
+
+---
+
+## 1. Active Principles (always on)
+
+Apply these on every non-trivial change. No exceptions.
+
+- **SRP** — one reason to change per component. If you can't name the responsibility in one noun phrase, split it.
+- **OCP** — extend by adding, not by modifying. New variants/impls over patching existing logic.
+- **ISP** — traits stay minimal. More than ~5 methods is a split signal.
+- **DIP** — high-level modules depend on traits, not concrete types. Infrastructure implements domain traits; it does not own domain logic.
+- **DRY** — one authoritative source per piece of knowledge. Copies are bugs that haven't diverged yet.
+- **YAGNI** — generic parameters, extension hooks, and pluggable strategies require an *existing* concrete use case, not a hypothetical one.
+- **KISS** — two equivalent designs: choose the one with fewer concepts. Justify complexity; never assume it.
+
+---
+
+## 2. Layered Architecture
+
+Dependencies point **inward only**: `Presentation → Application → Domain ← Infrastructure`.
+
+- Domain layer: zero I/O. No network, no filesystem, no async runtime imports.
+- Infrastructure: implements domain traits at the boundary. Never leaks SDK/wire types inward.
+- Anti-Corruption Layer (ACL): all third-party and external-protocol types are translated here. If the external format changes, only the ACL changes.
+- Presentation: translates wire/HTTP representations to domain types and back. Nothing else.
+
+---
+
+## 3. Design Pattern Selection
+
+Apply the right pattern. Do not invent a new abstraction when a named pattern fits.
+
+| Situation | Pattern to apply |
+|---|---|
+| Struct with 3+ optional/dependent fields | **Builder** — `build()` returns `Result`, never panics |
+| Cross-cutting behavior (logging, retry, metrics) on a trait impl | **Decorator** — implements same trait, delegates all calls |
+| Subsystem with multiple internal components | **Façade** — single public entry point, internals are `pub(crate)` |
+| Swappable algorithm or policy | **Strategy** — trait injection; generics for compile-time, `dyn` for runtime |
+| Component notifying decoupled consumers | **Observer** — typed channels (`broadcast`, `watch`), not callback `Vec<Box<dyn Fn>>` |
+| Exclusive mutable state serving concurrent callers | **Actor** — `mpsc` command channel + `oneshot` reply; no lock needed on state |
+| Finite state with invalid transition prevention | **Typestate** — distinct types per state; invalid ops are compile errors |
+| Fixed process skeleton with overridable steps | **Template Method** — defaulted trait method calls required hooks |
+| Request pipeline with independent handlers | **Chain/Middleware** — generic compile-time chain for hot paths, `dyn` for runtime assembly |
+| Hiding a concrete type behind a trait | **Factory Function** — returns `Box<dyn Trait>` or `impl Trait` |
+
+---
+
+## 4. Data Modeling Rules
+
+- **Make illegal states unrepresentable.** Type system enforces invariants; runtime validation is a second line, not the first.
+- **Newtype every primitive** that carries domain meaning. `SessionId(u64)` ≠ `UserId(u64)` — the compiler enforces it.
+- **Enums over booleans** for any parameter or field with two or more named states.
+- **Typed error enums** with named variants carrying full diagnostic context. `anyhow` is application-layer only; never in library code.
+- **Domain types carry no I/O concerns.** No `serde`, no codec, no DB derives on domain structs. Conversions via `From`/`TryFrom` at layer boundaries.
+
+---
+
+## 5. Concurrency Rules
+
+- Prefer message-passing over shared memory. Shared state is a fallback.
+- All channels must be **bounded**. Document the bound's rationale inline.
+- Never hold a lock across an `await` unless atomicity explicitly requires it — document why.
+- Document lock acquisition order wherever two locks are taken together.
+- Every `async fn` is cancellation-safe unless explicitly documented otherwise. Mutate shared state *after* the `await` that may be cancelled, not before.
+- High-read/low-write state: use `arc-swap` or `watch` for lock-free reads.
+
+---
+
+## 6. Error Handling Rules
+
+- Errors translated at every layer boundary — low-level errors never surface unmodified.
+- Add context at the propagation site: what operation failed and where.
+- No `unwrap()`/`expect()` in production paths without a comment proving `None`/`Err` is impossible.
+- Panics are only permitted in: tests, startup/init unrecoverable failure, and `unreachable!()` with an invariant comment.
+
+---
+
+## 7. API Design Rules
+
+- **CQS**: functions that return data must not mutate; functions that mutate return only `Result`.
+- **Least surprise**: a function does exactly what its name implies. Side effects are documented.
+- **Idempotency**: `close()`, `shutdown()`, `unregister()` called twice must not panic or error.
+- **Fallibility at the type level**: failure → `Result<T, E>`. No sentinel values.
+- **Minimal public surface**: default to `pub(crate)`. Mark `pub` only deliberate API. Re-export through a single surface in `mod.rs`.
+
+---
+
+## 8. Performance Rules (hot paths)
+
+- Annotate hot-path functions with `// HOT PATH: <throughput requirement>`.
+- Zero allocations per operation in hot paths after initialization. Preallocate in constructors, reuse buffers.
+- Pass `&[u8]` / `Bytes` slices — not `Vec<u8>`. Use `BytesMut` for reusable mutable buffers.
+- No `String` formatting in hot paths. No logging without a rate-limit or sampling gate.
+- Any allocation in a hot path gets a comment: `// ALLOC: <reason and size>`.
+
+---
+
+## 9. Testing Rules
+
+- Bug fixes require a regression test that is **red before the fix, green after**. Name it after the bug.
+- Property tests for: codec round-trips, state machine invariants, cryptographic protocol correctness.
+- No shared mutable state between tests. Each test constructs its own environment.
+- Test doubles hierarchy (simplest first): Fake → Stub → Spy → Mock. Mocks couple to implementation, not behavior — use sparingly.
+
+---
+
+## 10. Pre-Change Checklist
+
+Run this before proposing or implementing any structural decision:
+
+- [ ] Responsibility nameable in one noun phrase?
+- [ ] Layer dependencies point inward only?
+- [ ] Invalid states unrepresentable in the type system?
+- [ ] State transitions gated through a single interface?
+- [ ] All channels bounded?
+- [ ] No locks held across `await` (or documented)?
+- [ ] Errors typed and translated at layer boundaries?
+- [ ] No panics in production paths without invariant proof?
+- [ ] Hot paths annotated and allocation-free?
+- [ ] Public surface minimal — only deliberate API marked `pub`?
+- [ ] Correct pattern chosen from Section 3 table?

Cargo.lock

@@ -183,9 +183,9 @@ dependencies = [
 
 [[package]]
 name = "aws-lc-sys"
-version = "0.39.0"
+version = "0.39.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1fa7e52a4c5c547c741610a2c6f123f3881e409b714cd27e6798ef020c514f0a"
+checksum = "83a25cf98105baa966497416dbd42565ce3a8cf8dbfd59803ec9ad46f3126399"
 dependencies = [
  "cc",
  "cmake",
@@ -234,16 +234,16 @@ checksum = "843867be96c8daad0d758b57df9392b6d8d271134fce549de6ce169ff98a92af"
 
 [[package]]
 name = "blake3"
-version = "1.8.3"
+version = "1.8.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2468ef7d57b3fb7e16b576e8377cdbde2320c60e1491e961d11da40fc4f02a2d"
+checksum = "4d2d5991425dfd0785aed03aedcf0b321d61975c9b5b3689c774a2610ae0b51e"
 dependencies = [
  "arrayref",
  "arrayvec",
  "cc",
  "cfg-if",
  "constant_time_eq",
- "cpufeatures 0.2.17",
+ "cpufeatures 0.3.0",
 ]
 
 [[package]]
@@ -299,9 +299,9 @@ dependencies = [
 
 [[package]]
 name = "cc"
-version = "1.2.57"
+version = "1.2.58"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7a0dd1ca384932ff3641c8718a02769f1698e7563dc6974ffd03346116310423"
+checksum = "e1e928d4b69e3077709075a938a05ffbedfa53a84c8f766efbf8220bb1ff60e1"
 dependencies = [
  "find-msvc-tools",
  "jobserver",
@@ -441,9 +441,9 @@ checksum = "c8d4a3bb8b1e0c1050499d1815f5ab16d04f0959b233085fb31653fbfc9d98f9"
 
 [[package]]
 name = "cmake"
-version = "0.1.57"
+version = "0.1.58"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "75443c44cd6b379beb8c5b45d85d0773baf31cce901fe7bb252f4eff3008ef7d"
+checksum = "c0f78a02292a74a88ac736019ab962ece0bc380e3f977bf72e376c5d78ff0678"
 dependencies = [
  "cc",
 ]
@@ -1191,9 +1191,9 @@ checksum = "df3b46402a9d5adb4c86a0cf463f42e19994e3ee891101b1841f30a545cb49a9"
 
 [[package]]
 name = "hyper"
-version = "1.8.1"
+version = "1.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2ab2d4f250c3d7b1c9fcdff1cece94ea4e2dfbec68614f7b87cb205f24ca9d11"
+checksum = "6299f016b246a94207e63da54dbe807655bf9e00044f73ded42c3ac5305fbcca"
 dependencies = [
  "atomic-waker",
  "bytes",
@@ -1206,7 +1206,6 @@ dependencies = [
  "httpdate",
  "itoa",
  "pin-project-lite",
- "pin-utils",
  "smallvec",
  "tokio",
  "want",
@@ -1245,7 +1244,7 @@ dependencies = [
  "libc",
  "percent-encoding",
  "pin-project-lite",
- "socket2 0.6.3",
+ "socket2",
  "tokio",
  "tower-service",
  "tracing",
@@ -1277,12 +1276,13 @@ dependencies = [
 
 [[package]]
 name = "icu_collections"
-version = "2.1.1"
+version = "2.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4c6b649701667bbe825c3b7e6388cb521c23d88644678e83c0c4d0a621a34b43"
+checksum = "2984d1cd16c883d7935b9e07e44071dca8d917fd52ecc02c04d5fa0b5a3f191c"
 dependencies = [
  "displaydoc",
  "potential_utf",
+ "utf8_iter",
  "yoke",
  "zerofrom",
  "zerovec",
@@ -1290,9 +1290,9 @@ dependencies = [
 
 [[package]]
 name = "icu_locale_core"
-version = "2.1.1"
+version = "2.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "edba7861004dd3714265b4db54a3c390e880ab658fec5f7db895fae2046b5bb6"
+checksum = "92219b62b3e2b4d88ac5119f8904c10f8f61bf7e95b640d25ba3075e6cac2c29"
 dependencies = [
  "displaydoc",
  "litemap",
@@ -1303,9 +1303,9 @@ dependencies = [
 
 [[package]]
 name = "icu_normalizer"
-version = "2.1.1"
+version = "2.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5f6c8828b67bf8908d82127b2054ea1b4427ff0230ee9141c54251934ab1b599"
+checksum = "c56e5ee99d6e3d33bd91c5d85458b6005a22140021cc324cea84dd0e72cff3b4"
 dependencies = [
  "icu_collections",
  "icu_normalizer_data",
@@ -1317,15 +1317,15 @@ dependencies = [
 
 [[package]]
 name = "icu_normalizer_data"
-version = "2.1.1"
+version = "2.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7aedcccd01fc5fe81e6b489c15b247b8b0690feb23304303a9e560f37efc560a"
+checksum = "da3be0ae77ea334f4da67c12f149704f19f81d1adf7c51cf482943e84a2bad38"
 
 [[package]]
 name = "icu_properties"
-version = "2.1.2"
+version = "2.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "020bfc02fe870ec3a66d93e677ccca0562506e5872c650f893269e08615d74ec"
+checksum = "bee3b67d0ea5c2cca5003417989af8996f8604e34fb9ddf96208a033901e70de"
 dependencies = [
  "icu_collections",
  "icu_locale_core",
@@ -1337,15 +1337,15 @@ dependencies = [
 
 [[package]]
 name = "icu_properties_data"
-version = "2.1.2"
+version = "2.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "616c294cf8d725c6afcd8f55abc17c56464ef6211f9ed59cccffe534129c77af"
+checksum = "8e2bbb201e0c04f7b4b3e14382af113e17ba4f63e2c9d2ee626b720cbce54a14"
 
 [[package]]
 name = "icu_provider"
-version = "2.1.1"
+version = "2.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "85962cf0ce02e1e0a629cc34e7ca3e373ce20dda4c4d7294bbd0bf1fdb59e614"
+checksum = "139c4cf31c8b5f33d7e199446eff9c1e02decfc2f0eec2c8d71f65befa45b421"
 dependencies = [
  "displaydoc",
  "icu_locale_core",
@@ -1427,14 +1427,15 @@ dependencies = [
 
 [[package]]
 name = "ipconfig"
-version = "0.3.2"
+version = "0.3.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b58db92f96b720de98181bbbe63c831e87005ab460c1bf306eb2622b4707997f"
+checksum = "4d40460c0ce33d6ce4b0630ad68ff63d6661961c48b6dba35e5a4d81cfb48222"
 dependencies = [
- "socket2 0.5.10",
+ "socket2",
  "widestring",
- "windows-sys 0.48.0",
- "winreg",
+ "windows-registry",
+ "windows-result",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
@@ -1454,9 +1455,9 @@ dependencies = [
 
 [[package]]
 name = "iri-string"
-version = "0.7.11"
+version = "0.7.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d8e7418f59cc01c88316161279a7f665217ae316b388e58a0d10e29f54f1e5eb"
+checksum = "25e659a4bb38e810ebc252e53b5814ff908a8c58c2a9ce2fae1bbec24cbf4e20"
 dependencies = [
  "memchr",
  "serde",
@@ -1533,10 +1534,12 @@ dependencies = [
 
 [[package]]
 name = "js-sys"
-version = "0.3.91"
+version = "0.3.94"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b49715b7073f385ba4bc528e5747d02e66cb39c6146efb66b781f131f0fb399c"
+checksum = "2e04e2ef80ce82e13552136fabeef8a5ed1f985a96805761cbb9a2c34e7664d9"
 dependencies = [
+ "cfg-if",
+ "futures-util",
  "once_cell",
  "wasm-bindgen",
 ]
@@ -1575,9 +1578,9 @@ checksum = "09edd9e8b54e49e587e4f6295a7d29c3ea94d469cb40ab8ca70b288248a81db2"
 
 [[package]]
 name = "libc"
-version = "0.2.183"
+version = "0.2.184"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b5b646652bf6661599e1da8901b3b9522896f01e736bad5f723fe7a3a27f899d"
+checksum = "48f5d2a454e16a5ea0f4ced81bd44e4cfc7bd3a507b61887c99fd3538b28e4af"
 
 [[package]]
 name = "linux-raw-sys"
@@ -1587,9 +1590,9 @@ checksum = "32a66949e030da00e8c7d4434b251670a91556f4144941d37452769c25d58a53"
 
 [[package]]
 name = "litemap"
-version = "0.8.1"
+version = "0.8.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6373607a59f0be73a39b6fe456b8192fcc3585f602af20751600e974dd455e77"
+checksum = "92daf443525c4cce67b150400bc2316076100ce0b3686209eb8cf3c31612e6f0"
 
 [[package]]
 name = "lock_api"
@@ -1669,9 +1672,9 @@ checksum = "68354c5c6bd36d73ff3feceb05efa59b6acb7626617f4962be322a825e61f79a"
 
 [[package]]
 name = "mio"
-version = "1.1.1"
+version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a69bcab0ad47271a0234d9422b131806bf3968021e5dc9328caf2d4cd58557fc"
+checksum = "50b7e5b27aa02a74bac8c3f23f448f8d87ff11f92d3aac1a6ed369ee08cc56c1"
 dependencies = [
  "libc",
  "log",
@@ -1767,9 +1770,9 @@ dependencies = [
 
 [[package]]
 name = "num-conv"
-version = "0.2.0"
+version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cf97ec579c3c42f953ef76dbf8d55ac91fb219dde70e49aa4a6b7d74e9919050"
+checksum = "c6673768db2d862beb9b39a78fdcb1a69439615d5794a1be50caa9bc92c81967"
 
 [[package]]
 name = "num-integer"
@@ -1891,12 +1894,6 @@ version = "0.2.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a89322df9ebe1c1578d689c92318e070967d1042b512afbe49518723f4e6d5cd"
 
-[[package]]
-name = "pin-utils"
-version = "0.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8b870d8c151b6f2fb93e84a13146138f05d02ed11c7e7c54f8826aaaf7c9f184"
-
 [[package]]
 name = "pkcs8"
 version = "0.10.2"
@@ -1966,9 +1963,9 @@ checksum = "c33a9471896f1c69cecef8d20cbe2f7accd12527ce60845ff44c153bb2a21b49"
 
 [[package]]
 name = "potential_utf"
-version = "0.1.4"
+version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b73949432f5e2a09657003c25bca5e19a0e9c84f8058ca374f49e0ebe605af77"
+checksum = "0103b1cef7ec0cf76490e969665504990193874ea05c85ff9bab8b911d0a0564"
 dependencies = [
  "zerovec",
 ]
@@ -2009,9 +2006,9 @@ dependencies = [
 
 [[package]]
 name = "proptest"
-version = "1.10.0"
+version = "1.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "37566cb3fdacef14c0737f9546df7cfeadbfbc9fef10991038bf5015d0c80532"
+checksum = "4b45fcc2344c680f5025fe57779faef368840d0bd1f42f216291f0dc4ace4744"
 dependencies = [
  "bit-set",
  "bit-vec",
@@ -2045,7 +2042,7 @@ dependencies = [
  "quinn-udp",
  "rustc-hash",
  "rustls",
- "socket2 0.6.3",
+ "socket2",
  "thiserror 2.0.18",
  "tokio",
  "tracing",
@@ -2083,7 +2080,7 @@ dependencies = [
  "cfg_aliases",
  "libc",
  "once_cell",
- "socket2 0.6.3",
+ "socket2",
  "tracing",
  "windows-sys 0.60.2",
 ]
@@ -2301,9 +2298,9 @@ dependencies = [
 
 [[package]]
 name = "rustc-hash"
-version = "2.1.1"
+version = "2.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "357703d41365b4b27c590e3ed91eabb1b663f07c4c084095e60cbed4362dff0d"
+checksum = "94300abf3f1ae2e2b8ffb7b58043de3d399c73fa6f4b73826402a5c457614dbe"
 
 [[package]]
 name = "rustc_version"
@@ -2555,9 +2552,9 @@ dependencies = [
 
 [[package]]
 name = "serde_spanned"
-version = "1.0.4"
+version = "1.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f8bbf91e5a4d6315eee45e704372590b30e260ee83af6639d64557f51b067776"
+checksum = "6662b5879511e06e8999a8a235d848113e942c9124f211511b16466ee2995f26"
 dependencies = [
  "serde_core",
 ]
@@ -2625,7 +2622,7 @@ dependencies = [
  "serde_json",
  "serde_urlencoded",
  "shadowsocks-crypto",
- "socket2 0.6.3",
+ "socket2",
  "spin",
  "thiserror 2.0.18",
  "tokio",
@@ -2697,16 +2694,6 @@ version = "1.15.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "67b1b7a3b5fe4f1376887184045fcf45c69e92af734b7aaddc05fb777b6fbd03"
 
-[[package]]
-name = "socket2"
-version = "0.5.10"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e22376abed350d73dd1cd119b57ffccad95b4e585a7cda43e286245ce23c0678"
-dependencies = [
- "libc",
- "windows-sys 0.52.0",
-]
-
 [[package]]
 name = "socket2"
 version = "0.6.3"
@@ -2793,7 +2780,7 @@ checksum = "7b2093cf4c8eb1e67749a6762251bc9cd836b6fc171623bd0a9d324d37af2417"
 
 [[package]]
 name = "telemt"
-version = "3.3.35"
+version = "3.3.36"
 dependencies = [
  "aes",
  "anyhow",
@@ -2834,7 +2821,7 @@ dependencies = [
  "sha1",
  "sha2",
  "shadowsocks",
- "socket2 0.6.3",
+ "socket2",
  "static_assertions",
  "subtle",
  "thiserror 2.0.18",
@@ -2948,9 +2935,9 @@ dependencies = [
 
 [[package]]
 name = "tinystr"
-version = "0.8.2"
+version = "0.8.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "42d3e9c45c09de15d06dd8acf5f4e0e399e85927b7f00711024eb7ae10fa4869"
+checksum = "c8323304221c2a851516f22236c5722a72eaa19749016521d6dff0824447d96d"
 dependencies = [
  "displaydoc",
  "zerovec",
@@ -2993,7 +2980,7 @@ dependencies = [
  "parking_lot",
  "pin-project-lite",
  "signal-hook-registry",
- "socket2 0.6.3",
+ "socket2",
  "tokio-macros",
  "tracing",
  "windows-sys 0.61.2",
@@ -3054,7 +3041,7 @@ dependencies = [
  "log",
  "once_cell",
  "pin-project",
- "socket2 0.6.3",
+ "socket2",
  "tokio",
  "windows-sys 0.60.2",
 ]
@@ -3078,9 +3065,9 @@ dependencies = [
 
 [[package]]
 name = "toml"
-version = "1.0.7+spec-1.1.0"
+version = "1.1.2+spec-1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dd28d57d8a6f6e458bc0b8784f8fdcc4b99a437936056fa122cb234f18656a96"
+checksum = "81f3d15e84cbcd896376e6730314d59fb5a87f31e4b038454184435cd57defee"
 dependencies = [
  "indexmap",
  "serde_core",
@@ -3093,27 +3080,27 @@ dependencies = [
 
 [[package]]
 name = "toml_datetime"
-version = "1.0.1+spec-1.1.0"
+version = "1.1.1+spec-1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9b320e741db58cac564e26c607d3cc1fdc4a88fd36c879568c07856ed83ff3e9"
+checksum = "3165f65f62e28e0115a00b2ebdd37eb6f3b641855f9d636d3cd4103767159ad7"
 dependencies = [
  "serde_core",
 ]
 
 [[package]]
 name = "toml_parser"
-version = "1.0.10+spec-1.1.0"
+version = "1.1.2+spec-1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7df25b4befd31c4816df190124375d5a20c6b6921e2cad937316de3fccd63420"
+checksum = "a2abe9b86193656635d2411dc43050282ca48aa31c2451210f4202550afb7526"
 dependencies = [
  "winnow",
 ]
 
 [[package]]
 name = "toml_writer"
-version = "1.0.7+spec-1.1.0"
+version = "1.1.1+spec-1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f17aaa1c6e3dc22b1da4b6bba97d066e354c7945cac2f7852d4e4e7ca7a6b56d"
+checksum = "756daf9b1013ebe47a8776667b466417e2d4c5679d441c26230efd9ef78692db"
 
 [[package]]
 name = "tower"
@@ -3310,9 +3297,9 @@ checksum = "b6c140620e7ffbb22c2dee59cafe6084a59b5ffc27a8859a5f0d494b5d52b6be"
 
 [[package]]
 name = "uuid"
-version = "1.22.0"
+version = "1.23.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a68d3c8f01c0cfa54a75291d83601161799e4a89a39e0929f4b0354d88757a37"
+checksum = "5ac8b6f42ead25368cf5b098aeb3dc8a1a2c05a3eee8a9a1a68c640edbfc79d9"
 dependencies = [
  "getrandom 0.4.2",
  "js-sys",
@@ -3385,9 +3372,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen"
-version = "0.2.114"
+version = "0.2.117"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6532f9a5c1ece3798cb1c2cfdba640b9b3ba884f5db45973a6f442510a87d38e"
+checksum = "0551fc1bb415591e3372d0bc4780db7e587d84e2a7e79da121051c5c4b89d0b0"
 dependencies = [
  "cfg-if",
  "once_cell",
@@ -3398,23 +3385,19 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-futures"
-version = "0.4.64"
+version = "0.4.67"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e9c5522b3a28661442748e09d40924dfb9ca614b21c00d3fd135720e48b67db8"
+checksum = "03623de6905b7206edd0a75f69f747f134b7f0a2323392d664448bf2d3c5d87e"
 dependencies = [
- "cfg-if",
- "futures-util",
  "js-sys",
- "once_cell",
  "wasm-bindgen",
- "web-sys",
 ]
 
 [[package]]
 name = "wasm-bindgen-macro"
-version = "0.2.114"
+version = "0.2.117"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "18a2d50fcf105fb33bb15f00e7a77b772945a2ee45dcf454961fd843e74c18e6"
+checksum = "7fbdf9a35adf44786aecd5ff89b4563a90325f9da0923236f6104e603c7e86be"
 dependencies = [
  "quote",
  "wasm-bindgen-macro-support",
@@ -3422,9 +3405,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro-support"
-version = "0.2.114"
+version = "0.2.117"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "03ce4caeaac547cdf713d280eda22a730824dd11e6b8c3ca9e42247b25c631e3"
+checksum = "dca9693ef2bab6d4e6707234500350d8dad079eb508dca05530c85dc3a529ff2"
 dependencies = [
  "bumpalo",
  "proc-macro2",
@@ -3435,9 +3418,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-shared"
-version = "0.2.114"
+version = "0.2.117"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "75a326b8c223ee17883a4251907455a2431acc2791c98c26279376490c378c16"
+checksum = "39129a682a6d2d841b6c429d0c51e5cb0ed1a03829d8b3d1e69a011e62cb3d3b"
 dependencies = [
  "unicode-ident",
 ]
@@ -3478,9 +3461,9 @@ dependencies = [
 
 [[package]]
 name = "web-sys"
-version = "0.3.91"
+version = "0.3.94"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "854ba17bb104abfb26ba36da9729addc7ce7f06f5c0f90f3c391f8461cca21f9"
+checksum = "cd70027e39b12f0849461e08ffc50b9cd7688d942c1c8e3c7b22273236b4dd0a"
 dependencies = [
  "js-sys",
  "wasm-bindgen",
@@ -3592,6 +3575,17 @@ version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f0805222e57f7521d6a62e36fa9163bc891acd422f971defe97d64e70d0a4fe5"
 
+[[package]]
+name = "windows-registry"
+version = "0.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "02752bf7fbdcce7f2a27a742f798510f3e5ad88dbe84871e5168e2120c3d5720"
+dependencies = [
+ "windows-link",
+ "windows-result",
+ "windows-strings",
+]
+
 [[package]]
 name = "windows-result"
 version = "0.4.1"
@@ -3619,15 +3613,6 @@ dependencies = [
  "windows-targets 0.42.2",
 ]
 
-[[package]]
-name = "windows-sys"
-version = "0.48.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "677d2418bec65e3338edb076e806bc1ec15693c5d0104683f2efe857f61056a9"
-dependencies = [
- "windows-targets 0.48.5",
-]
-
 [[package]]
 name = "windows-sys"
 version = "0.52.0"
@@ -3670,21 +3655,6 @@ dependencies = [
  "windows_x86_64_msvc 0.42.2",
 ]
 
-[[package]]
-name = "windows-targets"
-version = "0.48.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9a2fa6e2155d7247be68c096456083145c183cbbbc2764150dda45a87197940c"
-dependencies = [
- "windows_aarch64_gnullvm 0.48.5",
- "windows_aarch64_msvc 0.48.5",
- "windows_i686_gnu 0.48.5",
- "windows_i686_msvc 0.48.5",
- "windows_x86_64_gnu 0.48.5",
- "windows_x86_64_gnullvm 0.48.5",
- "windows_x86_64_msvc 0.48.5",
-]
-
 [[package]]
 name = "windows-targets"
 version = "0.52.6"
@@ -3724,12 +3694,6 @@ version = "0.42.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "597a5118570b68bc08d8d59125332c54f1ba9d9adeedeef5b99b02ba2b0698f8"
 
-[[package]]
-name = "windows_aarch64_gnullvm"
-version = "0.48.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2b38e32f0abccf9987a4e3079dfb67dcd799fb61361e53e2882c3cbaf0d905d8"
-
 [[package]]
 name = "windows_aarch64_gnullvm"
 version = "0.52.6"
@@ -3748,12 +3712,6 @@ version = "0.42.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e08e8864a60f06ef0d0ff4ba04124db8b0fb3be5776a5cd47641e942e58c4d43"
 
-[[package]]
-name = "windows_aarch64_msvc"
-version = "0.48.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dc35310971f3b2dbbf3f0690a219f40e2d9afcf64f9ab7cc1be722937c26b4bc"
-
 [[package]]
 name = "windows_aarch64_msvc"
 version = "0.52.6"
@@ -3772,12 +3730,6 @@ version = "0.42.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c61d927d8da41da96a81f029489353e68739737d3beca43145c8afec9a31a84f"
 
-[[package]]
-name = "windows_i686_gnu"
-version = "0.48.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a75915e7def60c94dcef72200b9a8e58e5091744960da64ec734a6c6e9b3743e"
-
 [[package]]
 name = "windows_i686_gnu"
 version = "0.52.6"
@@ -3808,12 +3760,6 @@ version = "0.42.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "44d840b6ec649f480a41c8d80f9c65108b92d89345dd94027bfe06ac444d1060"
 
-[[package]]
-name = "windows_i686_msvc"
-version = "0.48.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8f55c233f70c4b27f66c523580f78f1004e8b5a8b659e05a4eb49d4166cca406"
-
 [[package]]
 name = "windows_i686_msvc"
 version = "0.52.6"
@@ -3832,12 +3778,6 @@ version = "0.42.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8de912b8b8feb55c064867cf047dda097f92d51efad5b491dfb98f6bbb70cb36"
 
-[[package]]
-name = "windows_x86_64_gnu"
-version = "0.48.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "53d40abd2583d23e4718fddf1ebec84dbff8381c07cae67ff7768bbf19c6718e"
-
 [[package]]
 name = "windows_x86_64_gnu"
 version = "0.52.6"
@@ -3856,12 +3796,6 @@ version = "0.42.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "26d41b46a36d453748aedef1486d5c7a85db22e56aff34643984ea85514e94a3"
 
-[[package]]
-name = "windows_x86_64_gnullvm"
-version = "0.48.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0b7b52767868a23d5bab768e390dc5f5c55825b6d30b86c844ff2dc7414044cc"
-
 [[package]]
 name = "windows_x86_64_gnullvm"
 version = "0.52.6"
@@ -3880,12 +3814,6 @@ version = "0.42.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9aec5da331524158c6d1a4ac0ab1541149c0b9505fde06423b02f5ef0106b9f0"
 
-[[package]]
-name = "windows_x86_64_msvc"
-version = "0.48.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ed94fce61571a4006852b7389a063ab983c02eb1bb37b47f8272ce92d06d9538"
-
 [[package]]
 name = "windows_x86_64_msvc"
 version = "0.52.6"
@@ -3900,19 +3828,9 @@ checksum = "d6bbff5f0aada427a1e5a6da5f1f98158182f26556f345ac9e04d36d0ebed650"
 
 [[package]]
 name = "winnow"
-version = "1.0.0"
+version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a90e88e4667264a994d34e6d1ab2d26d398dcdca8b7f52bec8668957517fc7d8"
-
-[[package]]
-name = "winreg"
-version = "0.50.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "524e57b2c537c0f9b1e69f1965311ec12182b4122e45035b1508cd24d2adadb1"
-dependencies = [
- "cfg-if",
- "windows-sys 0.48.0",
-]
+checksum = "09dac053f1cd375980747450bfc7250c264eaae0583872e845c0c7cd578872b5"
 
 [[package]]
 name = "wit-bindgen"
@@ -4039,9 +3957,9 @@ dependencies = [
 
 [[package]]
 name = "yoke"
-version = "0.8.1"
+version = "0.8.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "72d6e5c6afb84d73944e5cedb052c4680d5657337201555f9f2a16b7406d4954"
+checksum = "abe8c5fda708d9ca3df187cae8bfb9ceda00dd96231bed36e445a1a48e66f9ca"
 dependencies = [
  "stable_deref_trait",
  "yoke-derive",
@@ -4050,9 +3968,9 @@ dependencies = [
 
 [[package]]
 name = "yoke-derive"
-version = "0.8.1"
+version = "0.8.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b659052874eb698efe5b9e8cf382204678a0086ebf46982b79d6ca3182927e5d"
+checksum = "de844c262c8848816172cef550288e7dc6c7b7814b4ee56b3e1553f275f1858e"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -4062,18 +3980,18 @@ dependencies = [
 
 [[package]]
 name = "zerocopy"
-version = "0.8.47"
+version = "0.8.48"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "efbb2a062be311f2ba113ce66f697a4dc589f85e78a4aea276200804cea0ed87"
+checksum = "eed437bf9d6692032087e337407a86f04cd8d6a16a37199ed57949d415bd68e9"
 dependencies = [
  "zerocopy-derive",
 ]
 
 [[package]]
 name = "zerocopy-derive"
-version = "0.8.47"
+version = "0.8.48"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0e8bc7269b54418e7aeeef514aa68f8690b8c0489a06b0136e5f57c4c5ccab89"
+checksum = "70e3cd084b1788766f53af483dd21f93881ff30d7320490ec3ef7526d203bad4"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -4082,18 +4000,18 @@ dependencies = [
 
 [[package]]
 name = "zerofrom"
-version = "0.1.6"
+version = "0.1.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "50cc42e0333e05660c3587f3bf9d0478688e15d870fab3346451ce7f8c9fbea5"
+checksum = "69faa1f2a1ea75661980b013019ed6687ed0e83d069bc1114e2cc74c6c04c4df"
 dependencies = [
  "zerofrom-derive",
 ]
 
 [[package]]
 name = "zerofrom-derive"
-version = "0.1.6"
+version = "0.1.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d71e5d6e06ab090c67b5e44993ec16b72dcbaabc526db883a360057678b48502"
+checksum = "11532158c46691caf0f2593ea8358fed6bbf68a0315e80aae9bd41fbade684a1"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -4123,9 +4041,9 @@ dependencies = [
 
 [[package]]
 name = "zerotrie"
-version = "0.2.3"
+version = "0.2.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2a59c17a5562d507e4b54960e8569ebee33bee890c70aa3fe7b97e85a9fd7851"
+checksum = "0f9152d31db0792fa83f70fb2f83148effb5c1f5b8c7686c3459e361d9bc20bf"
 dependencies = [
  "displaydoc",
  "yoke",
@@ -4134,9 +4052,9 @@ dependencies = [
 
 [[package]]
 name = "zerovec"
-version = "0.11.5"
+version = "0.11.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6c28719294829477f525be0186d13efa9a3c602f7ec202ca9e353d310fb9a002"
+checksum = "90f911cbc359ab6af17377d242225f4d75119aec87ea711a880987b18cd7b239"
 dependencies = [
  "yoke",
  "zerofrom",
@@ -4145,9 +4063,9 @@ dependencies = [
 
 [[package]]
 name = "zerovec-derive"
-version = "0.11.2"
+version = "0.11.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "eadce39539ca5cb3985590102671f2567e659fca9666581ad3411d59207951f3"
+checksum = "625dc425cab0dca6dc3c3319506e6593dcb08a9f387ea3b284dbd52a92c40555"
 dependencies = [
  "proc-macro2",
  "quote",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "telemt"
-version = "3.3.35"
+version = "3.3.36"
 edition = "2024"
 
 [features]

src/ip_tracker.rs

@@ -26,6 +26,15 @@ pub struct UserIpTracker {
     cleanup_drain_lock: Arc<AsyncMutex<()>>,
 }
 
+#[derive(Debug, Clone, Copy)]
+pub struct UserIpTrackerMemoryStats {
+    pub active_users: usize,
+    pub recent_users: usize,
+    pub active_entries: usize,
+    pub recent_entries: usize,
+    pub cleanup_queue_len: usize,
+}
+
 impl UserIpTracker {
     pub fn new() -> Self {
         Self {
@@ -141,6 +150,13 @@ impl UserIpTracker {
 
         let mut active_ips = self.active_ips.write().await;
         let mut recent_ips = self.recent_ips.write().await;
+        let window = *self.limit_window.read().await;
+        let now = Instant::now();
+
+        for user_recent in recent_ips.values_mut() {
+            Self::prune_recent(user_recent, now, window);
+        }
+
         let mut users =
             Vec::<String>::with_capacity(active_ips.len().saturating_add(recent_ips.len()));
         users.extend(active_ips.keys().cloned());
@@ -166,6 +182,26 @@ impl UserIpTracker {
         }
     }
 
+    pub async fn memory_stats(&self) -> UserIpTrackerMemoryStats {
+        let cleanup_queue_len = self
+            .cleanup_queue
+            .lock()
+            .unwrap_or_else(|poisoned| poisoned.into_inner())
+            .len();
+        let active_ips = self.active_ips.read().await;
+        let recent_ips = self.recent_ips.read().await;
+        let active_entries = active_ips.values().map(HashMap::len).sum();
+        let recent_entries = recent_ips.values().map(HashMap::len).sum();
+
+        UserIpTrackerMemoryStats {
+            active_users: active_ips.len(),
+            recent_users: recent_ips.len(),
+            active_entries,
+            recent_entries,
+            cleanup_queue_len,
+        }
+    }
+
     pub async fn set_limit_policy(&self, mode: UserMaxUniqueIpsMode, window_secs: u64) {
         {
             let mut current_mode = self.limit_mode.write().await;
@@ -451,6 +487,7 @@ impl Default for UserIpTracker {
 mod tests {
     use super::*;
     use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
+    use std::sync::atomic::Ordering;
 
     fn test_ipv4(oct1: u8, oct2: u8, oct3: u8, oct4: u8) -> IpAddr {
         IpAddr::V4(Ipv4Addr::new(oct1, oct2, oct3, oct4))
@@ -764,4 +801,54 @@ mod tests {
         tokio::time::sleep(Duration::from_millis(1100)).await;
         assert!(tracker.check_and_add("test_user", ip2).await.is_ok());
     }
+
+    #[tokio::test]
+    async fn test_memory_stats_reports_queue_and_entry_counts() {
+        let tracker = UserIpTracker::new();
+        tracker.set_user_limit("test_user", 4).await;
+        let ip1 = test_ipv4(10, 2, 0, 1);
+        let ip2 = test_ipv4(10, 2, 0, 2);
+
+        tracker.check_and_add("test_user", ip1).await.unwrap();
+        tracker.check_and_add("test_user", ip2).await.unwrap();
+        tracker.enqueue_cleanup("test_user".to_string(), ip1);
+
+        let snapshot = tracker.memory_stats().await;
+        assert_eq!(snapshot.active_users, 1);
+        assert_eq!(snapshot.recent_users, 1);
+        assert_eq!(snapshot.active_entries, 2);
+        assert_eq!(snapshot.recent_entries, 2);
+        assert_eq!(snapshot.cleanup_queue_len, 1);
+    }
+
+    #[tokio::test]
+    async fn test_compact_prunes_stale_recent_entries() {
+        let tracker = UserIpTracker::new();
+        tracker
+            .set_limit_policy(UserMaxUniqueIpsMode::TimeWindow, 1)
+            .await;
+
+        let stale_user = "stale-user".to_string();
+        let stale_ip = test_ipv4(10, 3, 0, 1);
+        {
+            let mut recent_ips = tracker.recent_ips.write().await;
+            recent_ips
+                .entry(stale_user.clone())
+                .or_insert_with(HashMap::new)
+                .insert(stale_ip, Instant::now() - Duration::from_secs(5));
+        }
+
+        tracker.last_compact_epoch_secs.store(0, Ordering::Relaxed);
+        tracker
+            .check_and_add("trigger-user", test_ipv4(10, 3, 0, 2))
+            .await
+            .unwrap();
+
+        let recent_ips = tracker.recent_ips.read().await;
+        let stale_exists = recent_ips
+            .get(&stale_user)
+            .map(|ips| ips.contains_key(&stale_ip))
+            .unwrap_or(false);
+        assert!(!stale_exists);
+    }
 }

src/maestro/listeners.rs

@@ -14,6 +14,7 @@ use crate::crypto::SecureRandom;
 use crate::ip_tracker::UserIpTracker;
 use crate::proxy::ClientHandler;
 use crate::proxy::route_mode::{ROUTE_SWITCH_ERROR_MSG, RouteRuntimeController};
+use crate::proxy::shared_state::ProxySharedState;
 use crate::startup::{COMPONENT_LISTENERS_BIND, StartupTracker};
 use crate::stats::beobachten::BeobachtenStore;
 use crate::stats::{ReplayChecker, Stats};
@@ -49,6 +50,7 @@ pub(crate) async fn bind_listeners(
     tls_cache: Option<Arc<TlsFrontCache>>,
     ip_tracker: Arc<UserIpTracker>,
     beobachten: Arc<BeobachtenStore>,
+    shared: Arc<ProxySharedState>,
     max_connections: Arc<Semaphore>,
 ) -> Result<BoundListeners, Box<dyn Error>> {
     startup_tracker
@@ -224,6 +226,7 @@ pub(crate) async fn bind_listeners(
         let tls_cache = tls_cache.clone();
         let ip_tracker = ip_tracker.clone();
         let beobachten = beobachten.clone();
+        let shared = shared.clone();
         let max_connections_unix = max_connections.clone();
 
         tokio::spawn(async move {
@@ -284,11 +287,12 @@ pub(crate) async fn bind_listeners(
                         let tls_cache = tls_cache.clone();
                         let ip_tracker = ip_tracker.clone();
                         let beobachten = beobachten.clone();
+                        let shared = shared.clone();
                         let proxy_protocol_enabled = config.server.proxy_protocol;
 
                         tokio::spawn(async move {
                             let _permit = permit;
-                            if let Err(e) = crate::proxy::client::handle_client_stream(
+                            if let Err(e) = crate::proxy::client::handle_client_stream_with_shared(
                                 stream,
                                 fake_peer,
                                 config,
@@ -302,6 +306,7 @@ pub(crate) async fn bind_listeners(
                                 tls_cache,
                                 ip_tracker,
                                 beobachten,
+                                shared,
                                 proxy_protocol_enabled,
                             )
                             .await
@@ -351,6 +356,7 @@ pub(crate) fn spawn_tcp_accept_loops(
     tls_cache: Option<Arc<TlsFrontCache>>,
     ip_tracker: Arc<UserIpTracker>,
     beobachten: Arc<BeobachtenStore>,
+    shared: Arc<ProxySharedState>,
     max_connections: Arc<Semaphore>,
 ) {
     for (listener, listener_proxy_protocol) in listeners {
@@ -366,6 +372,7 @@ pub(crate) fn spawn_tcp_accept_loops(
         let tls_cache = tls_cache.clone();
         let ip_tracker = ip_tracker.clone();
         let beobachten = beobachten.clone();
+        let shared = shared.clone();
         let max_connections_tcp = max_connections.clone();
 
         tokio::spawn(async move {
@@ -421,13 +428,14 @@ pub(crate) fn spawn_tcp_accept_loops(
                         let tls_cache = tls_cache.clone();
                         let ip_tracker = ip_tracker.clone();
                         let beobachten = beobachten.clone();
+                        let shared = shared.clone();
                         let proxy_protocol_enabled = listener_proxy_protocol;
                         let real_peer_report = Arc::new(std::sync::Mutex::new(None));
                         let real_peer_report_for_handler = real_peer_report.clone();
 
                         tokio::spawn(async move {
                             let _permit = permit;
-                            if let Err(e) = ClientHandler::new(
+                            if let Err(e) = ClientHandler::new_with_shared(
                                 stream,
                                 peer_addr,
                                 config,
@@ -441,6 +449,7 @@ pub(crate) fn spawn_tcp_accept_loops(
                                 tls_cache,
                                 ip_tracker,
                                 beobachten,
+                                shared,
                                 proxy_protocol_enabled,
                                 real_peer_report_for_handler,
                             )

src/maestro/mod.rs

@@ -33,6 +33,7 @@ use crate::crypto::SecureRandom;
 use crate::ip_tracker::UserIpTracker;
 use crate::network::probe::{decide_network_capabilities, log_probe_result, run_probe};
 use crate::proxy::route_mode::{RelayRouteMode, RouteRuntimeController};
+use crate::proxy::shared_state::ProxySharedState;
 use crate::startup::{
     COMPONENT_API_BOOTSTRAP, COMPONENT_CONFIG_LOAD, COMPONENT_ME_POOL_CONSTRUCT,
     COMPONENT_ME_POOL_INIT_STAGE1, COMPONENT_ME_PROXY_CONFIG_V4, COMPONENT_ME_PROXY_CONFIG_V6,
@@ -631,6 +632,7 @@ async fn run_inner(
     )
     .await;
     let _admission_tx_hold = admission_tx;
+    let shared_state = ProxySharedState::new();
 
     let bound = listeners::bind_listeners(
         &config,
@@ -651,6 +653,7 @@ async fn run_inner(
         tls_cache.clone(),
         ip_tracker.clone(),
         beobachten.clone(),
+        shared_state.clone(),
         max_connections.clone(),
     )
     .await?;
@@ -707,6 +710,7 @@ async fn run_inner(
         tls_cache.clone(),
         ip_tracker.clone(),
         beobachten.clone(),
+        shared_state,
         max_connections.clone(),
     );
 

src/metrics.rs

@@ -304,6 +304,27 @@ async fn render_metrics(stats: &Stats, config: &ProxyConfig, ip_tracker: &UserIp
         }
     );
 
+    let _ = writeln!(
+        out,
+        "# HELP telemt_buffer_pool_buffers_total Snapshot of pooled and allocated buffers"
+    );
+    let _ = writeln!(out, "# TYPE telemt_buffer_pool_buffers_total gauge");
+    let _ = writeln!(
+        out,
+        "telemt_buffer_pool_buffers_total{{kind=\"pooled\"}} {}",
+        stats.get_buffer_pool_pooled_gauge()
+    );
+    let _ = writeln!(
+        out,
+        "telemt_buffer_pool_buffers_total{{kind=\"allocated\"}} {}",
+        stats.get_buffer_pool_allocated_gauge()
+    );
+    let _ = writeln!(
+        out,
+        "telemt_buffer_pool_buffers_total{{kind=\"in_use\"}} {}",
+        stats.get_buffer_pool_in_use_gauge()
+    );
+
     let _ = writeln!(
         out,
         "# HELP telemt_connections_total Total accepted connections"
@@ -952,6 +973,39 @@ async fn render_metrics(stats: &Stats, config: &ProxyConfig, ip_tracker: &UserIp
         }
     );
 
+    let _ = writeln!(
+        out,
+        "# HELP telemt_me_c2me_enqueue_events_total ME client->ME enqueue outcomes"
+    );
+    let _ = writeln!(out, "# TYPE telemt_me_c2me_enqueue_events_total counter");
+    let _ = writeln!(
+        out,
+        "telemt_me_c2me_enqueue_events_total{{event=\"full\"}} {}",
+        if me_allows_normal {
+            stats.get_me_c2me_send_full_total()
+        } else {
+            0
+        }
+    );
+    let _ = writeln!(
+        out,
+        "telemt_me_c2me_enqueue_events_total{{event=\"high_water\"}} {}",
+        if me_allows_normal {
+            stats.get_me_c2me_send_high_water_total()
+        } else {
+            0
+        }
+    );
+    let _ = writeln!(
+        out,
+        "telemt_me_c2me_enqueue_events_total{{event=\"timeout\"}} {}",
+        if me_allows_normal {
+            stats.get_me_c2me_send_timeout_total()
+        } else {
+            0
+        }
+    );
+
     let _ = writeln!(
         out,
         "# HELP telemt_me_d2c_batches_total Total DC->Client flush batches"
@@ -2501,6 +2555,48 @@ async fn render_metrics(stats: &Stats, config: &ProxyConfig, ip_tracker: &UserIp
         if user_enabled { 0 } else { 1 }
     );
 
+    let ip_memory = ip_tracker.memory_stats().await;
+    let _ = writeln!(
+        out,
+        "# HELP telemt_ip_tracker_users Number of users tracked by IP limiter state"
+    );
+    let _ = writeln!(out, "# TYPE telemt_ip_tracker_users gauge");
+    let _ = writeln!(
+        out,
+        "telemt_ip_tracker_users{{scope=\"active\"}} {}",
+        ip_memory.active_users
+    );
+    let _ = writeln!(
+        out,
+        "telemt_ip_tracker_users{{scope=\"recent\"}} {}",
+        ip_memory.recent_users
+    );
+    let _ = writeln!(
+        out,
+        "# HELP telemt_ip_tracker_entries Number of IP entries tracked by limiter state"
+    );
+    let _ = writeln!(out, "# TYPE telemt_ip_tracker_entries gauge");
+    let _ = writeln!(
+        out,
+        "telemt_ip_tracker_entries{{scope=\"active\"}} {}",
+        ip_memory.active_entries
+    );
+    let _ = writeln!(
+        out,
+        "telemt_ip_tracker_entries{{scope=\"recent\"}} {}",
+        ip_memory.recent_entries
+    );
+    let _ = writeln!(
+        out,
+        "# HELP telemt_ip_tracker_cleanup_queue_len Deferred disconnect cleanup queue length"
+    );
+    let _ = writeln!(out, "# TYPE telemt_ip_tracker_cleanup_queue_len gauge");
+    let _ = writeln!(
+        out,
+        "telemt_ip_tracker_cleanup_queue_len {}",
+        ip_memory.cleanup_queue_len
+    );
+
     if user_enabled {
         for entry in stats.iter_user_stats() {
             let user = entry.key();
@@ -2743,6 +2839,9 @@ mod tests {
         assert!(output.contains("telemt_user_unique_ips_recent_window{user=\"alice\"} 1"));
         assert!(output.contains("telemt_user_unique_ips_limit{user=\"alice\"} 4"));
         assert!(output.contains("telemt_user_unique_ips_utilization{user=\"alice\"} 0.250000"));
+        assert!(output.contains("telemt_ip_tracker_users{scope=\"active\"} 1"));
+        assert!(output.contains("telemt_ip_tracker_entries{scope=\"active\"} 1"));
+        assert!(output.contains("telemt_ip_tracker_cleanup_queue_len 0"));
     }
 
     #[tokio::test]
@@ -2815,6 +2914,9 @@ mod tests {
         assert!(output.contains("# TYPE telemt_user_unique_ips_recent_window gauge"));
         assert!(output.contains("# TYPE telemt_user_unique_ips_limit gauge"));
         assert!(output.contains("# TYPE telemt_user_unique_ips_utilization gauge"));
+        assert!(output.contains("# TYPE telemt_ip_tracker_users gauge"));
+        assert!(output.contains("# TYPE telemt_ip_tracker_entries gauge"));
+        assert!(output.contains("# TYPE telemt_ip_tracker_cleanup_queue_len gauge"));
     }
 
     #[tokio::test]

src/proxy/adaptive_buffers.rs

@@ -24,6 +24,8 @@ const DIRECT_S2C_CAP_BYTES: usize = 512 * 1024;
 const ME_FRAMES_CAP: usize = 96;
 const ME_BYTES_CAP: usize = 384 * 1024;
 const ME_DELAY_MIN_US: u64 = 150;
+const MAX_USER_PROFILES_ENTRIES: usize = 50_000;
+const MAX_USER_KEY_BYTES: usize = 512;
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
 pub enum AdaptiveTier {
@@ -234,32 +236,48 @@ fn profiles() -> &'static DashMap<String, UserAdaptiveProfile> {
 }
 
 pub fn seed_tier_for_user(user: &str) -> AdaptiveTier {
+    if user.len() > MAX_USER_KEY_BYTES {
+        return AdaptiveTier::Base;
+    }
     let now = Instant::now();
     if let Some(entry) = profiles().get(user) {
-        let value = entry.value();
-        if now.duration_since(value.seen_at) <= PROFILE_TTL {
+        let value = *entry.value();
+        drop(entry);
+        if now.saturating_duration_since(value.seen_at) <= PROFILE_TTL {
             return value.tier;
         }
+        profiles().remove_if(user, |_, v| now.saturating_duration_since(v.seen_at) > PROFILE_TTL);
     }
     AdaptiveTier::Base
 }
 
 pub fn record_user_tier(user: &str, tier: AdaptiveTier) {
+    if user.len() > MAX_USER_KEY_BYTES {
+        return;
+    }
     let now = Instant::now();
-    if let Some(mut entry) = profiles().get_mut(user) {
-        let existing = *entry;
-        let effective = if now.duration_since(existing.seen_at) > PROFILE_TTL {
+    let mut was_vacant = false;
+    match profiles().entry(user.to_string()) {
+        dashmap::mapref::entry::Entry::Occupied(mut entry) => {
+            let existing = *entry.get();
+            let effective = if now.saturating_duration_since(existing.seen_at) > PROFILE_TTL {
                 tier
             } else {
                 max(existing.tier, tier)
             };
-        *entry = UserAdaptiveProfile {
+            entry.insert(UserAdaptiveProfile {
                 tier: effective,
                 seen_at: now,
-        };
-        return;
+            });
+        }
+        dashmap::mapref::entry::Entry::Vacant(slot) => {
+            slot.insert(UserAdaptiveProfile { tier, seen_at: now });
+            was_vacant = true;
+        }
+    }
+    if was_vacant && profiles().len() > MAX_USER_PROFILES_ENTRIES {
+        profiles().retain(|_, v| now.saturating_duration_since(v.seen_at) <= PROFILE_TTL);
     }
-    profiles().insert(user.to_string(), UserAdaptiveProfile { tier, seen_at: now });
 }
 
 pub fn direct_copy_buffers_for_tier(
@@ -310,6 +328,14 @@ fn scale(base: usize, numerator: usize, denominator: usize, cap: usize) -> usize
     scaled.min(cap).max(1)
 }
 
+#[cfg(test)]
+#[path = "tests/adaptive_buffers_security_tests.rs"]
+mod adaptive_buffers_security_tests;
+
+#[cfg(test)]
+#[path = "tests/adaptive_buffers_record_race_security_tests.rs"]
+mod adaptive_buffers_record_race_security_tests;
+
 #[cfg(test)]
 mod tests {
     use super::*;

src/proxy/client.rs

@@ -81,10 +81,15 @@ use crate::transport::socket::normalize_ip;
 use crate::transport::{UpstreamManager, configure_client_socket, parse_proxy_protocol};
 
 use crate::proxy::direct_relay::handle_via_direct;
-use crate::proxy::handshake::{HandshakeSuccess, handle_mtproto_handshake, handle_tls_handshake};
+use crate::proxy::handshake::{
+    HandshakeSuccess, handle_mtproto_handshake_with_shared, handle_tls_handshake_with_shared,
+};
+#[cfg(test)]
+use crate::proxy::handshake::{handle_mtproto_handshake, handle_tls_handshake};
 use crate::proxy::masking::handle_bad_client;
 use crate::proxy::middle_relay::handle_via_middle_proxy;
 use crate::proxy::route_mode::{RelayRouteMode, RouteRuntimeController};
+use crate::proxy::shared_state::ProxySharedState;
 
 fn beobachten_ttl(config: &ProxyConfig) -> Duration {
     const BEOBACHTEN_TTL_MAX_MINUTES: u64 = 24 * 60;
@@ -342,7 +347,48 @@ fn synthetic_local_addr(port: u16) -> SocketAddr {
     SocketAddr::from(([0, 0, 0, 0], port))
 }
 
+#[cfg(test)]
 pub async fn handle_client_stream<S>(
+    stream: S,
+    peer: SocketAddr,
+    config: Arc<ProxyConfig>,
+    stats: Arc<Stats>,
+    upstream_manager: Arc<UpstreamManager>,
+    replay_checker: Arc<ReplayChecker>,
+    buffer_pool: Arc<BufferPool>,
+    rng: Arc<SecureRandom>,
+    me_pool: Option<Arc<MePool>>,
+    route_runtime: Arc<RouteRuntimeController>,
+    tls_cache: Option<Arc<TlsFrontCache>>,
+    ip_tracker: Arc<UserIpTracker>,
+    beobachten: Arc<BeobachtenStore>,
+    proxy_protocol_enabled: bool,
+) -> Result<()>
+where
+    S: AsyncRead + AsyncWrite + Unpin + Send + 'static,
+{
+    handle_client_stream_with_shared(
+        stream,
+        peer,
+        config,
+        stats,
+        upstream_manager,
+        replay_checker,
+        buffer_pool,
+        rng,
+        me_pool,
+        route_runtime,
+        tls_cache,
+        ip_tracker,
+        beobachten,
+        ProxySharedState::new(),
+        proxy_protocol_enabled,
+    )
+    .await
+}
+
+#[allow(clippy::too_many_arguments)]
+pub async fn handle_client_stream_with_shared<S>(
     mut stream: S,
     peer: SocketAddr,
     config: Arc<ProxyConfig>,
@@ -356,6 +402,7 @@ pub async fn handle_client_stream<S>(
     tls_cache: Option<Arc<TlsFrontCache>>,
     ip_tracker: Arc<UserIpTracker>,
     beobachten: Arc<BeobachtenStore>,
+    shared: Arc<ProxySharedState>,
     proxy_protocol_enabled: bool,
 ) -> Result<()>
 where
@@ -550,9 +597,10 @@ where
 
             let (read_half, write_half) = tokio::io::split(stream);
 
-            let (mut tls_reader, tls_writer, tls_user) = match handle_tls_handshake(
+            let (mut tls_reader, tls_writer, tls_user) = match handle_tls_handshake_with_shared(
                 &handshake, read_half, write_half, real_peer,
                 &config, &replay_checker, &rng, tls_cache.clone(),
+                shared.as_ref(),
             ).await {
                 HandshakeResult::Success(result) => result,
                 HandshakeResult::BadClient { reader, writer } => {
@@ -578,9 +626,10 @@ where
             let mtproto_handshake: [u8; HANDSHAKE_LEN] = mtproto_data[..].try_into()
                 .map_err(|_| ProxyError::InvalidHandshake("Short MTProto handshake".into()))?;
 
-            let (crypto_reader, crypto_writer, success) = match handle_mtproto_handshake(
+            let (crypto_reader, crypto_writer, success) = match handle_mtproto_handshake_with_shared(
                 &mtproto_handshake, tls_reader, tls_writer, real_peer,
                 &config, &replay_checker, true, Some(tls_user.as_str()),
+                shared.as_ref(),
             ).await {
                 HandshakeResult::Success(result) => result,
                 HandshakeResult::BadClient { reader, writer } => {
@@ -614,11 +663,12 @@ where
             };
 
             Ok(HandshakeOutcome::NeedsRelay(Box::pin(
-                RunningClientHandler::handle_authenticated_static(
+                RunningClientHandler::handle_authenticated_static_with_shared(
                     crypto_reader, crypto_writer, success,
                     upstream_manager, stats, config, buffer_pool, rng, me_pool,
                     route_runtime.clone(),
                     local_addr, real_peer, ip_tracker.clone(),
+                    shared.clone(),
                 ),
             )))
         } else {
@@ -644,9 +694,10 @@ where
 
             let (read_half, write_half) = tokio::io::split(stream);
 
-            let (crypto_reader, crypto_writer, success) = match handle_mtproto_handshake(
+            let (crypto_reader, crypto_writer, success) = match handle_mtproto_handshake_with_shared(
                 &handshake, read_half, write_half, real_peer,
                 &config, &replay_checker, false, None,
+                shared.as_ref(),
             ).await {
                 HandshakeResult::Success(result) => result,
                 HandshakeResult::BadClient { reader, writer } => {
@@ -665,7 +716,7 @@ where
             };
 
             Ok(HandshakeOutcome::NeedsRelay(Box::pin(
-                RunningClientHandler::handle_authenticated_static(
+                RunningClientHandler::handle_authenticated_static_with_shared(
                     crypto_reader,
                     crypto_writer,
                     success,
@@ -679,6 +730,7 @@ where
                     local_addr,
                     real_peer,
                     ip_tracker.clone(),
+                    shared.clone(),
                 )
             )))
         }
@@ -731,10 +783,12 @@ pub struct RunningClientHandler {
     tls_cache: Option<Arc<TlsFrontCache>>,
     ip_tracker: Arc<UserIpTracker>,
     beobachten: Arc<BeobachtenStore>,
+    shared: Arc<ProxySharedState>,
     proxy_protocol_enabled: bool,
 }
 
 impl ClientHandler {
+    #[cfg(test)]
     pub fn new(
         stream: TcpStream,
         peer: SocketAddr,
@@ -751,6 +805,45 @@ impl ClientHandler {
         beobachten: Arc<BeobachtenStore>,
         proxy_protocol_enabled: bool,
         real_peer_report: Arc<std::sync::Mutex<Option<SocketAddr>>>,
+    ) -> RunningClientHandler {
+        Self::new_with_shared(
+            stream,
+            peer,
+            config,
+            stats,
+            upstream_manager,
+            replay_checker,
+            buffer_pool,
+            rng,
+            me_pool,
+            route_runtime,
+            tls_cache,
+            ip_tracker,
+            beobachten,
+            ProxySharedState::new(),
+            proxy_protocol_enabled,
+            real_peer_report,
+        )
+    }
+
+    #[allow(clippy::too_many_arguments)]
+    pub fn new_with_shared(
+        stream: TcpStream,
+        peer: SocketAddr,
+        config: Arc<ProxyConfig>,
+        stats: Arc<Stats>,
+        upstream_manager: Arc<UpstreamManager>,
+        replay_checker: Arc<ReplayChecker>,
+        buffer_pool: Arc<BufferPool>,
+        rng: Arc<SecureRandom>,
+        me_pool: Option<Arc<MePool>>,
+        route_runtime: Arc<RouteRuntimeController>,
+        tls_cache: Option<Arc<TlsFrontCache>>,
+        ip_tracker: Arc<UserIpTracker>,
+        beobachten: Arc<BeobachtenStore>,
+        shared: Arc<ProxySharedState>,
+        proxy_protocol_enabled: bool,
+        real_peer_report: Arc<std::sync::Mutex<Option<SocketAddr>>>,
     ) -> RunningClientHandler {
         let normalized_peer = normalize_ip(peer);
         RunningClientHandler {
@@ -769,6 +862,7 @@ impl ClientHandler {
             tls_cache,
             ip_tracker,
             beobachten,
+            shared,
             proxy_protocol_enabled,
         }
     }
@@ -1058,7 +1152,7 @@ impl RunningClientHandler {
 
         let (read_half, write_half) = self.stream.into_split();
 
-        let (mut tls_reader, tls_writer, tls_user) = match handle_tls_handshake(
+        let (mut tls_reader, tls_writer, tls_user) = match handle_tls_handshake_with_shared(
             &handshake,
             read_half,
             write_half,
@@ -1067,6 +1161,7 @@ impl RunningClientHandler {
             &replay_checker,
             &self.rng,
             self.tls_cache.clone(),
+            self.shared.as_ref(),
         )
         .await
         {
@@ -1095,7 +1190,7 @@ impl RunningClientHandler {
             .try_into()
             .map_err(|_| ProxyError::InvalidHandshake("Short MTProto handshake".into()))?;
 
-        let (crypto_reader, crypto_writer, success) = match handle_mtproto_handshake(
+        let (crypto_reader, crypto_writer, success) = match handle_mtproto_handshake_with_shared(
             &mtproto_handshake,
             tls_reader,
             tls_writer,
@@ -1104,6 +1199,7 @@ impl RunningClientHandler {
             &replay_checker,
             true,
             Some(tls_user.as_str()),
+            self.shared.as_ref(),
         )
         .await
         {
@@ -1140,7 +1236,7 @@ impl RunningClientHandler {
         };
 
         Ok(HandshakeOutcome::NeedsRelay(Box::pin(
-            Self::handle_authenticated_static(
+            Self::handle_authenticated_static_with_shared(
                 crypto_reader,
                 crypto_writer,
                 success,
@@ -1154,6 +1250,7 @@ impl RunningClientHandler {
                 local_addr,
                 peer,
                 self.ip_tracker,
+                self.shared,
             ),
         )))
     }
@@ -1192,7 +1289,7 @@ impl RunningClientHandler {
 
         let (read_half, write_half) = self.stream.into_split();
 
-        let (crypto_reader, crypto_writer, success) = match handle_mtproto_handshake(
+        let (crypto_reader, crypto_writer, success) = match handle_mtproto_handshake_with_shared(
             &handshake,
             read_half,
             write_half,
@@ -1201,6 +1298,7 @@ impl RunningClientHandler {
             &replay_checker,
             false,
             None,
+            self.shared.as_ref(),
         )
         .await
         {
@@ -1221,7 +1319,7 @@ impl RunningClientHandler {
         };
 
         Ok(HandshakeOutcome::NeedsRelay(Box::pin(
-            Self::handle_authenticated_static(
+            Self::handle_authenticated_static_with_shared(
                 crypto_reader,
                 crypto_writer,
                 success,
@@ -1235,6 +1333,7 @@ impl RunningClientHandler {
                 local_addr,
                 peer,
                 self.ip_tracker,
+                self.shared,
             ),
         )))
     }
@@ -1243,6 +1342,7 @@ impl RunningClientHandler {
     /// Two modes:
     ///   - Direct: TCP relay to TG DC (existing behavior)  
     ///   - Middle Proxy: RPC multiplex through ME pool (new — supports CDN DCs)
+    #[cfg(test)]
     async fn handle_authenticated_static<R, W>(
         client_reader: CryptoReader<R>,
         client_writer: CryptoWriter<W>,
@@ -1258,6 +1358,45 @@ impl RunningClientHandler {
         peer_addr: SocketAddr,
         ip_tracker: Arc<UserIpTracker>,
     ) -> Result<()>
+    where
+        R: AsyncRead + Unpin + Send + 'static,
+        W: AsyncWrite + Unpin + Send + 'static,
+    {
+        Self::handle_authenticated_static_with_shared(
+            client_reader,
+            client_writer,
+            success,
+            upstream_manager,
+            stats,
+            config,
+            buffer_pool,
+            rng,
+            me_pool,
+            route_runtime,
+            local_addr,
+            peer_addr,
+            ip_tracker,
+            ProxySharedState::new(),
+        )
+        .await
+    }
+
+    async fn handle_authenticated_static_with_shared<R, W>(
+        client_reader: CryptoReader<R>,
+        client_writer: CryptoWriter<W>,
+        success: HandshakeSuccess,
+        upstream_manager: Arc<UpstreamManager>,
+        stats: Arc<Stats>,
+        config: Arc<ProxyConfig>,
+        buffer_pool: Arc<BufferPool>,
+        rng: Arc<SecureRandom>,
+        me_pool: Option<Arc<MePool>>,
+        route_runtime: Arc<RouteRuntimeController>,
+        local_addr: SocketAddr,
+        peer_addr: SocketAddr,
+        ip_tracker: Arc<UserIpTracker>,
+        _shared: Arc<ProxySharedState>,
+    ) -> Result<()>
     where
         R: AsyncRead + Unpin + Send + 'static,
         W: AsyncWrite + Unpin + Send + 'static,
@@ -1299,6 +1438,7 @@ impl RunningClientHandler {
                     route_runtime.subscribe(),
                     route_snapshot,
                     session_id,
+                    _shared,
                 )
                 .await
             } else {

src/proxy/direct_relay.rs

@@ -276,6 +276,7 @@ where
     stats.increment_user_connects(user);
     let _direct_connection_lease = stats.acquire_direct_connection_lease();
 
+    let buffer_pool_trim = Arc::clone(&buffer_pool);
     let relay_result = relay_bidirectional(
         client_reader,
         client_writer,
@@ -321,6 +322,13 @@ where
         Err(e) => debug!(user = %user, error = %e, "Direct relay ended with error"),
     }
 
+    buffer_pool_trim.trim_to(buffer_pool_trim.max_buffers().min(64));
+    let pool_snapshot = buffer_pool_trim.stats();
+    stats.set_buffer_pool_gauges(
+        pool_snapshot.pooled,
+        pool_snapshot.allocated,
+        pool_snapshot.allocated.saturating_sub(pool_snapshot.pooled),
+    );
     relay_result
 }
 

src/proxy/handshake.rs

@@ -4,13 +4,16 @@
 
 use dashmap::DashMap;
 use dashmap::mapref::entry::Entry;
+#[cfg(test)]
 use std::collections::HashSet;
+#[cfg(test)]
 use std::collections::hash_map::RandomState;
 use std::hash::{BuildHasher, Hash, Hasher};
 use std::net::SocketAddr;
 use std::net::{IpAddr, Ipv6Addr};
 use std::sync::Arc;
-use std::sync::{Mutex, OnceLock};
+#[cfg(test)]
+use std::sync::Mutex;
 use std::time::{Duration, Instant};
 use tokio::io::{AsyncRead, AsyncWrite, AsyncWriteExt};
 use tracing::{debug, info, trace, warn};
@@ -21,15 +24,15 @@ use crate::crypto::{AesCtr, SecureRandom, sha256};
 use crate::error::{HandshakeResult, ProxyError};
 use crate::protocol::constants::*;
 use crate::protocol::tls;
+use crate::proxy::shared_state::ProxySharedState;
 use crate::stats::ReplayChecker;
 use crate::stream::{CryptoReader, CryptoWriter, FakeTlsReader, FakeTlsWriter};
 use crate::tls_front::{TlsFrontCache, emulator};
+#[cfg(test)]
 use rand::RngExt;
 
 const ACCESS_SECRET_BYTES: usize = 16;
-static INVALID_SECRET_WARNED: OnceLock<Mutex<HashSet<(String, String)>>> = OnceLock::new();
 const UNKNOWN_SNI_WARN_COOLDOWN_SECS: u64 = 5;
-static UNKNOWN_SNI_WARN_NEXT_ALLOWED: OnceLock<Mutex<Option<Instant>>> = OnceLock::new();
 #[cfg(test)]
 const WARNED_SECRET_MAX_ENTRIES: usize = 64;
 #[cfg(not(test))]
@@ -55,48 +58,30 @@ const AUTH_PROBE_BACKOFF_MAX_MS: u64 = 16;
 const AUTH_PROBE_BACKOFF_MAX_MS: u64 = 1_000;
 
 #[derive(Clone, Copy)]
-struct AuthProbeState {
+pub(crate) struct AuthProbeState {
     fail_streak: u32,
     blocked_until: Instant,
     last_seen: Instant,
 }
 
 #[derive(Clone, Copy)]
-struct AuthProbeSaturationState {
+pub(crate) struct AuthProbeSaturationState {
     fail_streak: u32,
     blocked_until: Instant,
     last_seen: Instant,
 }
-
-static AUTH_PROBE_STATE: OnceLock<DashMap<IpAddr, AuthProbeState>> = OnceLock::new();
-static AUTH_PROBE_SATURATION_STATE: OnceLock<Mutex<Option<AuthProbeSaturationState>>> =
-    OnceLock::new();
-static AUTH_PROBE_EVICTION_HASHER: OnceLock<RandomState> = OnceLock::new();
-
-fn auth_probe_state_map() -> &'static DashMap<IpAddr, AuthProbeState> {
-    AUTH_PROBE_STATE.get_or_init(DashMap::new)
-}
-
-fn auth_probe_saturation_state() -> &'static Mutex<Option<AuthProbeSaturationState>> {
-    AUTH_PROBE_SATURATION_STATE.get_or_init(|| Mutex::new(None))
-}
-
-fn auth_probe_saturation_state_lock()
--> std::sync::MutexGuard<'static, Option<AuthProbeSaturationState>> {
-    auth_probe_saturation_state()
+fn unknown_sni_warn_state_lock_in(
+    shared: &ProxySharedState,
+) -> std::sync::MutexGuard<'_, Option<Instant>> {
+    shared
+        .handshake
+        .unknown_sni_warn_next_allowed
         .lock()
         .unwrap_or_else(|poisoned| poisoned.into_inner())
 }
 
-fn unknown_sni_warn_state_lock() -> std::sync::MutexGuard<'static, Option<Instant>> {
-    UNKNOWN_SNI_WARN_NEXT_ALLOWED
-        .get_or_init(|| Mutex::new(None))
-        .lock()
-        .unwrap_or_else(|poisoned| poisoned.into_inner())
-}
-
-fn should_emit_unknown_sni_warn(now: Instant) -> bool {
-    let mut guard = unknown_sni_warn_state_lock();
+fn should_emit_unknown_sni_warn_in(shared: &ProxySharedState, now: Instant) -> bool {
+    let mut guard = unknown_sni_warn_state_lock_in(shared);
     if let Some(next_allowed) = *guard
         && now < next_allowed
     {
@@ -133,15 +118,16 @@ fn auth_probe_state_expired(state: &AuthProbeState, now: Instant) -> bool {
     now.duration_since(state.last_seen) > retention
 }
 
-fn auth_probe_eviction_offset(peer_ip: IpAddr, now: Instant) -> usize {
-    let hasher_state = AUTH_PROBE_EVICTION_HASHER.get_or_init(RandomState::new);
+fn auth_probe_eviction_offset_in(shared: &ProxySharedState, peer_ip: IpAddr, now: Instant) -> usize {
+    let hasher_state = &shared.handshake.auth_probe_eviction_hasher;
     let mut hasher = hasher_state.build_hasher();
     peer_ip.hash(&mut hasher);
     now.hash(&mut hasher);
     hasher.finish() as usize
 }
 
-fn auth_probe_scan_start_offset(
+fn auth_probe_scan_start_offset_in(
+    shared: &ProxySharedState,
     peer_ip: IpAddr,
     now: Instant,
     state_len: usize,
@@ -151,12 +137,12 @@ fn auth_probe_scan_start_offset(
         return 0;
     }
 
-    auth_probe_eviction_offset(peer_ip, now) % state_len
+    auth_probe_eviction_offset_in(shared, peer_ip, now) % state_len
 }
 
-fn auth_probe_is_throttled(peer_ip: IpAddr, now: Instant) -> bool {
+fn auth_probe_is_throttled_in(shared: &ProxySharedState, peer_ip: IpAddr, now: Instant) -> bool {
     let peer_ip = normalize_auth_probe_ip(peer_ip);
-    let state = auth_probe_state_map();
+    let state = &shared.handshake.auth_probe;
     let Some(entry) = state.get(&peer_ip) else {
         return false;
     };
@@ -168,9 +154,13 @@ fn auth_probe_is_throttled(peer_ip: IpAddr, now: Instant) -> bool {
     now < entry.blocked_until
 }
 
-fn auth_probe_saturation_grace_exhausted(peer_ip: IpAddr, now: Instant) -> bool {
+fn auth_probe_saturation_grace_exhausted_in(
+    shared: &ProxySharedState,
+    peer_ip: IpAddr,
+    now: Instant,
+) -> bool {
     let peer_ip = normalize_auth_probe_ip(peer_ip);
-    let state = auth_probe_state_map();
+    let state = &shared.handshake.auth_probe;
     let Some(entry) = state.get(&peer_ip) else {
         return false;
     };
@@ -183,20 +173,28 @@ fn auth_probe_saturation_grace_exhausted(peer_ip: IpAddr, now: Instant) -> bool
     entry.fail_streak >= AUTH_PROBE_BACKOFF_START_FAILS + AUTH_PROBE_SATURATION_GRACE_FAILS
 }
 
-fn auth_probe_should_apply_preauth_throttle(peer_ip: IpAddr, now: Instant) -> bool {
-    if !auth_probe_is_throttled(peer_ip, now) {
+fn auth_probe_should_apply_preauth_throttle_in(
+    shared: &ProxySharedState,
+    peer_ip: IpAddr,
+    now: Instant,
+) -> bool {
+    if !auth_probe_is_throttled_in(shared, peer_ip, now) {
         return false;
     }
 
-    if !auth_probe_saturation_is_throttled(now) {
+    if !auth_probe_saturation_is_throttled_in(shared, now) {
         return true;
     }
 
-    auth_probe_saturation_grace_exhausted(peer_ip, now)
+    auth_probe_saturation_grace_exhausted_in(shared, peer_ip, now)
 }
 
-fn auth_probe_saturation_is_throttled(now: Instant) -> bool {
-    let mut guard = auth_probe_saturation_state_lock();
+fn auth_probe_saturation_is_throttled_in(shared: &ProxySharedState, now: Instant) -> bool {
+    let mut guard = shared
+        .handshake
+        .auth_probe_saturation
+        .lock()
+        .unwrap_or_else(|poisoned| poisoned.into_inner());
 
     let Some(state) = guard.as_mut() else {
         return false;
@@ -214,8 +212,12 @@ fn auth_probe_saturation_is_throttled(now: Instant) -> bool {
     false
 }
 
-fn auth_probe_note_saturation(now: Instant) {
-    let mut guard = auth_probe_saturation_state_lock();
+fn auth_probe_note_saturation_in(shared: &ProxySharedState, now: Instant) {
+    let mut guard = shared
+        .handshake
+        .auth_probe_saturation
+        .lock()
+        .unwrap_or_else(|poisoned| poisoned.into_inner());
 
     match guard.as_mut() {
         Some(state)
@@ -237,13 +239,14 @@ fn auth_probe_note_saturation(now: Instant) {
     }
 }
 
-fn auth_probe_record_failure(peer_ip: IpAddr, now: Instant) {
+fn auth_probe_record_failure_in(shared: &ProxySharedState, peer_ip: IpAddr, now: Instant) {
     let peer_ip = normalize_auth_probe_ip(peer_ip);
-    let state = auth_probe_state_map();
-    auth_probe_record_failure_with_state(state, peer_ip, now);
+    let state = &shared.handshake.auth_probe;
+    auth_probe_record_failure_with_state_in(shared, state, peer_ip, now);
 }
 
-fn auth_probe_record_failure_with_state(
+fn auth_probe_record_failure_with_state_in(
+    shared: &ProxySharedState,
     state: &DashMap<IpAddr, AuthProbeState>,
     peer_ip: IpAddr,
     now: Instant,
@@ -277,7 +280,7 @@ fn auth_probe_record_failure_with_state(
         while state.len() >= AUTH_PROBE_TRACK_MAX_ENTRIES {
             rounds += 1;
             if rounds > 8 {
-                auth_probe_note_saturation(now);
+                auth_probe_note_saturation_in(shared, now);
                 let mut eviction_candidate: Option<(IpAddr, u32, Instant)> = None;
                 for entry in state.iter().take(AUTH_PROBE_PRUNE_SCAN_LIMIT) {
                     let key = *entry.key();
@@ -320,7 +323,7 @@ fn auth_probe_record_failure_with_state(
                 }
             } else {
                 let start_offset =
-                    auth_probe_scan_start_offset(peer_ip, now, state_len, scan_limit);
+                    auth_probe_scan_start_offset_in(shared, peer_ip, now, state_len, scan_limit);
                 let mut scanned = 0usize;
                 for entry in state.iter().skip(start_offset) {
                     let key = *entry.key();
@@ -369,11 +372,11 @@ fn auth_probe_record_failure_with_state(
             }
 
             let Some((evict_key, _, _)) = eviction_candidate else {
-                auth_probe_note_saturation(now);
+                auth_probe_note_saturation_in(shared, now);
                 return;
             };
             state.remove(&evict_key);
-            auth_probe_note_saturation(now);
+            auth_probe_note_saturation_in(shared, now);
         }
     }
 
@@ -387,89 +390,58 @@ fn auth_probe_record_failure_with_state(
     }
 }
 
-fn auth_probe_record_success(peer_ip: IpAddr) {
+fn auth_probe_record_success_in(shared: &ProxySharedState, peer_ip: IpAddr) {
     let peer_ip = normalize_auth_probe_ip(peer_ip);
-    let state = auth_probe_state_map();
+    let state = &shared.handshake.auth_probe;
     state.remove(&peer_ip);
 }
 
 #[cfg(test)]
-fn clear_auth_probe_state_for_testing() {
-    if let Some(state) = AUTH_PROBE_STATE.get() {
-        state.clear();
-    }
-    if AUTH_PROBE_SATURATION_STATE.get().is_some() {
-        let mut guard = auth_probe_saturation_state_lock();
-        *guard = None;
-    }
+pub(crate) fn auth_probe_record_failure_for_testing(
+    shared: &ProxySharedState,
+    peer_ip: IpAddr,
+    now: Instant,
+) {
+    auth_probe_record_failure_in(shared, peer_ip, now);
 }
 
 #[cfg(test)]
-fn auth_probe_fail_streak_for_testing(peer_ip: IpAddr) -> Option<u32> {
+pub(crate) fn auth_probe_fail_streak_for_testing_in_shared(
+    shared: &ProxySharedState,
+    peer_ip: IpAddr,
+) -> Option<u32> {
     let peer_ip = normalize_auth_probe_ip(peer_ip);
-    let state = AUTH_PROBE_STATE.get()?;
-    state.get(&peer_ip).map(|entry| entry.fail_streak)
+    shared
+        .handshake
+        .auth_probe
+        .get(&peer_ip)
+        .map(|entry| entry.fail_streak)
 }
 
 #[cfg(test)]
-fn auth_probe_is_throttled_for_testing(peer_ip: IpAddr) -> bool {
-    auth_probe_is_throttled(peer_ip, Instant::now())
+pub(crate) fn clear_auth_probe_state_for_testing_in_shared(shared: &ProxySharedState) {
+    shared.handshake.auth_probe.clear();
+    match shared.handshake.auth_probe_saturation.lock() {
+        Ok(mut saturation) => {
+            *saturation = None;
         }
-
-#[cfg(test)]
-fn auth_probe_saturation_is_throttled_for_testing() -> bool {
-    auth_probe_saturation_is_throttled(Instant::now())
+        Err(poisoned) => {
+            let mut saturation = poisoned.into_inner();
+            *saturation = None;
+            shared.handshake.auth_probe_saturation.clear_poison();
         }
-
-#[cfg(test)]
-fn auth_probe_saturation_is_throttled_at_for_testing(now: Instant) -> bool {
-    auth_probe_saturation_is_throttled(now)
-}
-
-#[cfg(test)]
-fn auth_probe_test_lock() -> &'static Mutex<()> {
-    static TEST_LOCK: OnceLock<Mutex<()>> = OnceLock::new();
-    TEST_LOCK.get_or_init(|| Mutex::new(()))
-}
-
-#[cfg(test)]
-fn unknown_sni_warn_test_lock() -> &'static Mutex<()> {
-    static TEST_LOCK: OnceLock<Mutex<()>> = OnceLock::new();
-    TEST_LOCK.get_or_init(|| Mutex::new(()))
-}
-
-#[cfg(test)]
-fn clear_unknown_sni_warn_state_for_testing() {
-    if UNKNOWN_SNI_WARN_NEXT_ALLOWED.get().is_some() {
-        let mut guard = unknown_sni_warn_state_lock();
-        *guard = None;
     }
 }
 
-#[cfg(test)]
-fn should_emit_unknown_sni_warn_for_testing(now: Instant) -> bool {
-    should_emit_unknown_sni_warn(now)
-}
-
-#[cfg(test)]
-fn clear_warned_secrets_for_testing() {
-    if let Some(warned) = INVALID_SECRET_WARNED.get()
-        && let Ok(mut guard) = warned.lock()
-    {
-        guard.clear();
-    }
-}
-
-#[cfg(test)]
-fn warned_secrets_test_lock() -> &'static Mutex<()> {
-    static TEST_LOCK: OnceLock<Mutex<()>> = OnceLock::new();
-    TEST_LOCK.get_or_init(|| Mutex::new(()))
-}
-
-fn warn_invalid_secret_once(name: &str, reason: &str, expected: usize, got: Option<usize>) {
+fn warn_invalid_secret_once_in(
+    shared: &ProxySharedState,
+    name: &str,
+    reason: &str,
+    expected: usize,
+    got: Option<usize>,
+) {
     let key = (name.to_string(), reason.to_string());
-    let warned = INVALID_SECRET_WARNED.get_or_init(|| Mutex::new(HashSet::new()));
-    let should_warn = match warned.lock() {
+    let should_warn = match shared.handshake.invalid_secret_warned.lock() {
         Ok(mut guard) => {
             if !guard.contains(&key) && guard.len() >= WARNED_SECRET_MAX_ENTRIES {
                 false
@@ -502,11 +474,12 @@ fn warn_invalid_secret_once(name: &str, reason: &str, expected: usize, got: Opti
     }
 }
 
-fn decode_user_secret(name: &str, secret_hex: &str) -> Option<Vec<u8>> {
+fn decode_user_secret(shared: &ProxySharedState, name: &str, secret_hex: &str) -> Option<Vec<u8>> {
     match hex::decode(secret_hex) {
         Ok(bytes) if bytes.len() == ACCESS_SECRET_BYTES => Some(bytes),
         Ok(bytes) => {
-            warn_invalid_secret_once(
+            warn_invalid_secret_once_in(
+                shared,
                 name,
                 "invalid_length",
                 ACCESS_SECRET_BYTES,
@@ -515,7 +488,7 @@ fn decode_user_secret(name: &str, secret_hex: &str) -> Option<Vec<u8>> {
             None
         }
         Err(_) => {
-            warn_invalid_secret_once(name, "invalid_hex", ACCESS_SECRET_BYTES, None);
+            warn_invalid_secret_once_in(shared, name, "invalid_hex", ACCESS_SECRET_BYTES, None);
             None
         }
     }
@@ -543,7 +516,8 @@ fn mode_enabled_for_proto(config: &ProxyConfig, proto_tag: ProtoTag, is_tls: boo
     }
 }
 
-fn decode_user_secrets(
+fn decode_user_secrets_in(
+    shared: &ProxySharedState,
     config: &ProxyConfig,
     preferred_user: Option<&str>,
 ) -> Vec<(String, Vec<u8>)> {
@@ -551,7 +525,7 @@ fn decode_user_secrets(
 
     if let Some(preferred) = preferred_user
         && let Some(secret_hex) = config.access.users.get(preferred)
-        && let Some(bytes) = decode_user_secret(preferred, secret_hex)
+        && let Some(bytes) = decode_user_secret(shared, preferred, secret_hex)
     {
         secrets.push((preferred.to_string(), bytes));
     }
@@ -560,7 +534,7 @@ fn decode_user_secrets(
         if preferred_user.is_some_and(|preferred| preferred == name.as_str()) {
             continue;
         }
-        if let Some(bytes) = decode_user_secret(name, secret_hex) {
+        if let Some(bytes) = decode_user_secret(shared, name, secret_hex) {
             secrets.push((name.clone(), bytes));
         }
     }
@@ -568,6 +542,86 @@ fn decode_user_secrets(
     secrets
 }
 
+#[cfg(test)]
+pub(crate) fn auth_probe_state_for_testing_in_shared(
+    shared: &ProxySharedState,
+) -> &DashMap<IpAddr, AuthProbeState> {
+    &shared.handshake.auth_probe
+}
+
+#[cfg(test)]
+pub(crate) fn auth_probe_saturation_state_for_testing_in_shared(
+    shared: &ProxySharedState,
+) -> &Mutex<Option<AuthProbeSaturationState>> {
+    &shared.handshake.auth_probe_saturation
+}
+
+#[cfg(test)]
+pub(crate) fn auth_probe_saturation_state_lock_for_testing_in_shared(
+    shared: &ProxySharedState,
+) -> std::sync::MutexGuard<'_, Option<AuthProbeSaturationState>> {
+    shared
+        .handshake
+        .auth_probe_saturation
+        .lock()
+        .unwrap_or_else(|poisoned| poisoned.into_inner())
+}
+
+#[cfg(test)]
+pub(crate) fn clear_unknown_sni_warn_state_for_testing_in_shared(shared: &ProxySharedState) {
+    let mut guard = shared
+        .handshake
+        .unknown_sni_warn_next_allowed
+        .lock()
+        .unwrap_or_else(|poisoned| poisoned.into_inner());
+    *guard = None;
+}
+
+#[cfg(test)]
+pub(crate) fn should_emit_unknown_sni_warn_for_testing_in_shared(
+    shared: &ProxySharedState,
+    now: Instant,
+) -> bool {
+    should_emit_unknown_sni_warn_in(shared, now)
+}
+
+#[cfg(test)]
+pub(crate) fn clear_warned_secrets_for_testing_in_shared(shared: &ProxySharedState) {
+    if let Ok(mut guard) = shared.handshake.invalid_secret_warned.lock() {
+        guard.clear();
+    }
+}
+
+#[cfg(test)]
+pub(crate) fn warned_secrets_for_testing_in_shared(
+    shared: &ProxySharedState,
+) -> &Mutex<HashSet<(String, String)>> {
+    &shared.handshake.invalid_secret_warned
+}
+
+#[cfg(test)]
+pub(crate) fn auth_probe_is_throttled_for_testing_in_shared(
+    shared: &ProxySharedState,
+    peer_ip: IpAddr,
+) -> bool {
+    auth_probe_is_throttled_in(shared, peer_ip, Instant::now())
+}
+
+#[cfg(test)]
+pub(crate) fn auth_probe_saturation_is_throttled_for_testing_in_shared(
+    shared: &ProxySharedState,
+) -> bool {
+    auth_probe_saturation_is_throttled_in(shared, Instant::now())
+}
+
+#[cfg(test)]
+pub(crate) fn auth_probe_saturation_is_throttled_at_for_testing_in_shared(
+    shared: &ProxySharedState,
+    now: Instant,
+) -> bool {
+    auth_probe_saturation_is_throttled_in(shared, now)
+}
+
 #[inline]
 fn find_matching_tls_domain<'a>(config: &'a ProxyConfig, sni: &str) -> Option<&'a str> {
     if config.censorship.tls_domain.eq_ignore_ascii_case(sni) {
@@ -593,7 +647,7 @@ async fn maybe_apply_server_hello_delay(config: &ProxyConfig) {
     let delay_ms = if max == min {
         max
     } else {
-        rand::rng().random_range(min..=max)
+        crate::proxy::masking::sample_lognormal_percentile_bounded(min, max, &mut rand::rng())
     };
 
     if delay_ms > 0 {
@@ -635,6 +689,7 @@ impl Drop for HandshakeSuccess {
 }
 
 /// Handle fake TLS handshake
+#[cfg(test)]
 pub async fn handle_tls_handshake<R, W>(
     handshake: &[u8],
     reader: R,
@@ -645,6 +700,65 @@ pub async fn handle_tls_handshake<R, W>(
     rng: &SecureRandom,
     tls_cache: Option<Arc<TlsFrontCache>>,
 ) -> HandshakeResult<(FakeTlsReader<R>, FakeTlsWriter<W>, String), R, W>
+where
+    R: AsyncRead + Unpin,
+    W: AsyncWrite + Unpin,
+{
+    let shared = ProxySharedState::new();
+    handle_tls_handshake_impl(
+        handshake,
+        reader,
+        writer,
+        peer,
+        config,
+        replay_checker,
+        rng,
+        tls_cache,
+        shared.as_ref(),
+    )
+    .await
+}
+
+pub async fn handle_tls_handshake_with_shared<R, W>(
+    handshake: &[u8],
+    reader: R,
+    writer: W,
+    peer: SocketAddr,
+    config: &ProxyConfig,
+    replay_checker: &ReplayChecker,
+    rng: &SecureRandom,
+    tls_cache: Option<Arc<TlsFrontCache>>,
+    shared: &ProxySharedState,
+) -> HandshakeResult<(FakeTlsReader<R>, FakeTlsWriter<W>, String), R, W>
+where
+    R: AsyncRead + Unpin,
+    W: AsyncWrite + Unpin,
+{
+    handle_tls_handshake_impl(
+        handshake,
+        reader,
+        writer,
+        peer,
+        config,
+        replay_checker,
+        rng,
+        tls_cache,
+        shared,
+    )
+    .await
+}
+
+async fn handle_tls_handshake_impl<R, W>(
+    handshake: &[u8],
+    reader: R,
+    mut writer: W,
+    peer: SocketAddr,
+    config: &ProxyConfig,
+    replay_checker: &ReplayChecker,
+    rng: &SecureRandom,
+    tls_cache: Option<Arc<TlsFrontCache>>,
+    shared: &ProxySharedState,
+) -> HandshakeResult<(FakeTlsReader<R>, FakeTlsWriter<W>, String), R, W>
 where
     R: AsyncRead + Unpin,
     W: AsyncWrite + Unpin,
@@ -652,14 +766,14 @@ where
     debug!(peer = %peer, handshake_len = handshake.len(), "Processing TLS handshake");
 
     let throttle_now = Instant::now();
-    if auth_probe_should_apply_preauth_throttle(peer.ip(), throttle_now) {
+    if auth_probe_should_apply_preauth_throttle_in(shared, peer.ip(), throttle_now) {
         maybe_apply_server_hello_delay(config).await;
         debug!(peer = %peer, "TLS handshake rejected by pre-auth probe throttle");
         return HandshakeResult::BadClient { reader, writer };
     }
 
     if handshake.len() < tls::TLS_DIGEST_POS + tls::TLS_DIGEST_LEN + 1 {
-        auth_probe_record_failure(peer.ip(), Instant::now());
+        auth_probe_record_failure_in(shared, peer.ip(), Instant::now());
         maybe_apply_server_hello_delay(config).await;
         debug!(peer = %peer, "TLS handshake too short");
         return HandshakeResult::BadClient { reader, writer };
@@ -695,11 +809,11 @@ where
     };
 
     if client_sni.is_some() && matched_tls_domain.is_none() && preferred_user_hint.is_none() {
-        auth_probe_record_failure(peer.ip(), Instant::now());
+        auth_probe_record_failure_in(shared, peer.ip(), Instant::now());
         maybe_apply_server_hello_delay(config).await;
         let sni = client_sni.as_deref().unwrap_or_default();
         let log_now = Instant::now();
-        if should_emit_unknown_sni_warn(log_now) {
+        if should_emit_unknown_sni_warn_in(shared, log_now) {
             warn!(
                 peer = %peer,
                 sni = %sni,
@@ -722,7 +836,7 @@ where
         };
     }
 
-    let secrets = decode_user_secrets(config, preferred_user_hint);
+    let secrets = decode_user_secrets_in(shared, config, preferred_user_hint);
 
     let validation = match tls::validate_tls_handshake_with_replay_window(
         handshake,
@@ -732,7 +846,7 @@ where
     ) {
         Some(v) => v,
         None => {
-            auth_probe_record_failure(peer.ip(), Instant::now());
+            auth_probe_record_failure_in(shared, peer.ip(), Instant::now());
             maybe_apply_server_hello_delay(config).await;
             debug!(
                 peer = %peer,
@@ -746,7 +860,7 @@ where
     // Reject known replay digests before expensive cache/domain/ALPN policy work.
     let digest_half = &validation.digest[..tls::TLS_DIGEST_HALF_LEN];
     if replay_checker.check_tls_digest(digest_half) {
-        auth_probe_record_failure(peer.ip(), Instant::now());
+        auth_probe_record_failure_in(shared, peer.ip(), Instant::now());
         maybe_apply_server_hello_delay(config).await;
         warn!(peer = %peer, "TLS replay attack detected (duplicate digest)");
         return HandshakeResult::BadClient { reader, writer };
@@ -827,7 +941,7 @@ where
         "TLS handshake successful"
     );
 
-    auth_probe_record_success(peer.ip());
+    auth_probe_record_success_in(shared, peer.ip());
 
     HandshakeResult::Success((
         FakeTlsReader::new(reader),
@@ -837,6 +951,7 @@ where
 }
 
 /// Handle MTProto obfuscation handshake
+#[cfg(test)]
 pub async fn handle_mtproto_handshake<R, W>(
     handshake: &[u8; HANDSHAKE_LEN],
     reader: R,
@@ -847,6 +962,65 @@ pub async fn handle_mtproto_handshake<R, W>(
     is_tls: bool,
     preferred_user: Option<&str>,
 ) -> HandshakeResult<(CryptoReader<R>, CryptoWriter<W>, HandshakeSuccess), R, W>
+where
+    R: AsyncRead + Unpin + Send,
+    W: AsyncWrite + Unpin + Send,
+{
+    let shared = ProxySharedState::new();
+    handle_mtproto_handshake_impl(
+        handshake,
+        reader,
+        writer,
+        peer,
+        config,
+        replay_checker,
+        is_tls,
+        preferred_user,
+        shared.as_ref(),
+    )
+    .await
+}
+
+pub async fn handle_mtproto_handshake_with_shared<R, W>(
+    handshake: &[u8; HANDSHAKE_LEN],
+    reader: R,
+    writer: W,
+    peer: SocketAddr,
+    config: &ProxyConfig,
+    replay_checker: &ReplayChecker,
+    is_tls: bool,
+    preferred_user: Option<&str>,
+    shared: &ProxySharedState,
+) -> HandshakeResult<(CryptoReader<R>, CryptoWriter<W>, HandshakeSuccess), R, W>
+where
+    R: AsyncRead + Unpin + Send,
+    W: AsyncWrite + Unpin + Send,
+{
+    handle_mtproto_handshake_impl(
+        handshake,
+        reader,
+        writer,
+        peer,
+        config,
+        replay_checker,
+        is_tls,
+        preferred_user,
+        shared,
+    )
+    .await
+}
+
+async fn handle_mtproto_handshake_impl<R, W>(
+    handshake: &[u8; HANDSHAKE_LEN],
+    reader: R,
+    writer: W,
+    peer: SocketAddr,
+    config: &ProxyConfig,
+    replay_checker: &ReplayChecker,
+    is_tls: bool,
+    preferred_user: Option<&str>,
+    shared: &ProxySharedState,
+) -> HandshakeResult<(CryptoReader<R>, CryptoWriter<W>, HandshakeSuccess), R, W>
 where
     R: AsyncRead + Unpin + Send,
     W: AsyncWrite + Unpin + Send,
@@ -862,7 +1036,7 @@ where
     );
 
     let throttle_now = Instant::now();
-    if auth_probe_should_apply_preauth_throttle(peer.ip(), throttle_now) {
+    if auth_probe_should_apply_preauth_throttle_in(shared, peer.ip(), throttle_now) {
         maybe_apply_server_hello_delay(config).await;
         debug!(peer = %peer, "MTProto handshake rejected by pre-auth probe throttle");
         return HandshakeResult::BadClient { reader, writer };
@@ -872,7 +1046,7 @@ where
 
     let enc_prekey_iv: Vec<u8> = dec_prekey_iv.iter().rev().copied().collect();
 
-    let decoded_users = decode_user_secrets(config, preferred_user);
+    let decoded_users = decode_user_secrets_in(shared, config, preferred_user);
 
     for (user, secret) in decoded_users {
         let dec_prekey = &dec_prekey_iv[..PREKEY_LEN];
@@ -932,7 +1106,7 @@ where
         // entry from the cache. We accept the cost of performing the full
         // authentication check first to avoid poisoning the replay cache.
         if replay_checker.check_and_add_handshake(dec_prekey_iv) {
-            auth_probe_record_failure(peer.ip(), Instant::now());
+            auth_probe_record_failure_in(shared, peer.ip(), Instant::now());
             maybe_apply_server_hello_delay(config).await;
             warn!(peer = %peer, user = %user, "MTProto replay attack detected");
             return HandshakeResult::BadClient { reader, writer };
@@ -959,7 +1133,7 @@ where
             "MTProto handshake successful"
         );
 
-        auth_probe_record_success(peer.ip());
+        auth_probe_record_success_in(shared, peer.ip());
 
         let max_pending = config.general.crypto_pending_buffer;
         return HandshakeResult::Success((
@@ -969,7 +1143,7 @@ where
         ));
     }
 
-    auth_probe_record_failure(peer.ip(), Instant::now());
+    auth_probe_record_failure_in(shared, peer.ip(), Instant::now());
     maybe_apply_server_hello_delay(config).await;
     debug!(peer = %peer, "MTProto handshake: no matching user found");
     HandshakeResult::BadClient { reader, writer }
@@ -1123,6 +1297,10 @@ mod timing_manual_bench_tests;
 #[path = "tests/handshake_key_material_zeroization_security_tests.rs"]
 mod handshake_key_material_zeroization_security_tests;
 
+#[cfg(test)]
+#[path = "tests/handshake_baseline_invariant_tests.rs"]
+mod handshake_baseline_invariant_tests;
+
 /// Compile-time guard: HandshakeSuccess holds cryptographic key material and
 /// must never be Copy.  A Copy impl would allow silent key duplication,
 /// undermining the zeroize-on-drop guarantee.

src/proxy/masking.rs

@@ -249,6 +249,39 @@ async fn wait_mask_connect_budget(started: Instant) {
     }
 }
 
+// Log-normal sample bounded to [floor, ceiling]. Median = sqrt(floor * ceiling).
+// Implements Box-Muller transform for standard normal sampling — no external
+// dependency on rand_distr (which is incompatible with rand 0.10).
+// sigma is chosen so ~99% of raw samples land inside [floor, ceiling] before clamp.
+// When floor > ceiling (misconfiguration), returns ceiling (the smaller value).
+// When floor == ceiling, returns that value. When both are 0, returns 0.
+pub(crate) fn sample_lognormal_percentile_bounded(floor: u64, ceiling: u64, rng: &mut impl Rng) -> u64 {
+    if ceiling == 0 && floor == 0 {
+        return 0;
+    }
+    if floor > ceiling {
+        return ceiling;
+    }
+    if floor == ceiling {
+        return floor;
+    }
+    let floor_f = floor.max(1) as f64;
+    let ceiling_f = ceiling.max(1) as f64;
+    let mu = (floor_f.ln() + ceiling_f.ln()) / 2.0;
+    // 4.65 ≈ 2 * 2.326 (double-sided z-score for 99th percentile)
+    let sigma = ((ceiling_f / floor_f).ln() / 4.65).max(0.01);
+    // Box-Muller transform: two uniform samples → one standard normal sample
+    let u1: f64 = rng.random_range(f64::MIN_POSITIVE..1.0);
+    let u2: f64 = rng.random_range(0.0_f64..std::f64::consts::TAU);
+    let normal_sample = (-2.0_f64 * u1.ln()).sqrt() * u2.cos();
+    let raw = (mu + sigma * normal_sample).exp();
+    if raw.is_finite() {
+        (raw as u64).clamp(floor, ceiling)
+    } else {
+        ((floor_f * ceiling_f).sqrt()) as u64
+    }
+}
+
 fn mask_outcome_target_budget(config: &ProxyConfig) -> Duration {
     if config.censorship.mask_timing_normalization_enabled {
         let floor = config.censorship.mask_timing_normalization_floor_ms;
@@ -257,14 +290,16 @@ fn mask_outcome_target_budget(config: &ProxyConfig) -> Duration {
             if ceiling == 0 {
                 return Duration::from_millis(0);
             }
+            // floor=0 stays uniform: log-normal cannot model distribution anchored at zero
             let mut rng = rand::rng();
             return Duration::from_millis(rng.random_range(0..=ceiling));
         }
         if ceiling > floor {
             let mut rng = rand::rng();
-            return Duration::from_millis(rng.random_range(floor..=ceiling));
+            return Duration::from_millis(sample_lognormal_percentile_bounded(floor, ceiling, &mut rng));
         }
-        return Duration::from_millis(floor);
+        // ceiling <= floor: use the larger value (fail-closed: preserve longer delay)
+        return Duration::from_millis(floor.max(ceiling));
     }
 
     MASK_TIMEOUT
@@ -1003,3 +1038,11 @@ mod masking_padding_timeout_adversarial_tests;
 #[cfg(all(test, feature = "redteam_offline_expected_fail"))]
 #[path = "tests/masking_offline_target_redteam_expected_fail_tests.rs"]
 mod masking_offline_target_redteam_expected_fail_tests;
+
+#[cfg(test)]
+#[path = "tests/masking_baseline_invariant_tests.rs"]
+mod masking_baseline_invariant_tests;
+
+#[cfg(test)]
+#[path = "tests/masking_lognormal_timing_security_tests.rs"]
+mod masking_lognormal_timing_security_tests;

src/proxy/mod.rs

@@ -67,6 +67,7 @@ pub mod middle_relay;
 pub mod relay;
 pub mod route_mode;
 pub mod session_eviction;
+pub mod shared_state;
 
 pub use client::ClientHandler;
 #[allow(unused_imports)]
@@ -75,3 +76,15 @@ pub use handshake::*;
 pub use masking::*;
 #[allow(unused_imports)]
 pub use relay::*;
+
+#[cfg(test)]
+#[path = "tests/test_harness_common.rs"]
+mod test_harness_common;
+
+#[cfg(test)]
+#[path = "tests/proxy_shared_state_isolation_tests.rs"]
+mod proxy_shared_state_isolation_tests;
+
+#[cfg(test)]
+#[path = "tests/proxy_shared_state_parallel_execution_tests.rs"]
+mod proxy_shared_state_parallel_execution_tests;

src/proxy/relay.rs

@@ -671,3 +671,7 @@ mod relay_watchdog_delta_security_tests;
 #[cfg(test)]
 #[path = "tests/relay_atomic_quota_invariant_tests.rs"]
 mod relay_atomic_quota_invariant_tests;
+
+#[cfg(test)]
+#[path = "tests/relay_baseline_invariant_tests.rs"]
+mod relay_baseline_invariant_tests;

src/proxy/shared_state.rs

@@ -0,0 +1,57 @@
+use std::collections::HashSet;
+use std::collections::hash_map::RandomState;
+use std::net::IpAddr;
+use std::sync::atomic::AtomicU64;
+use std::sync::{Arc, Mutex};
+use std::time::Instant;
+
+use dashmap::DashMap;
+
+use crate::proxy::handshake::{AuthProbeState, AuthProbeSaturationState};
+use crate::proxy::middle_relay::{DesyncDedupRotationState, RelayIdleCandidateRegistry};
+
+pub(crate) struct HandshakeSharedState {
+    pub(crate) auth_probe: DashMap<IpAddr, AuthProbeState>,
+    pub(crate) auth_probe_saturation: Mutex<Option<AuthProbeSaturationState>>,
+    pub(crate) auth_probe_eviction_hasher: RandomState,
+    pub(crate) invalid_secret_warned: Mutex<HashSet<(String, String)>>,
+    pub(crate) unknown_sni_warn_next_allowed: Mutex<Option<Instant>>,
+}
+
+pub(crate) struct MiddleRelaySharedState {
+    pub(crate) desync_dedup: DashMap<u64, Instant>,
+    pub(crate) desync_dedup_previous: DashMap<u64, Instant>,
+    pub(crate) desync_hasher: RandomState,
+    pub(crate) desync_full_cache_last_emit_at: Mutex<Option<Instant>>,
+    pub(crate) desync_dedup_rotation_state: Mutex<DesyncDedupRotationState>,
+    pub(crate) relay_idle_registry: Mutex<RelayIdleCandidateRegistry>,
+    pub(crate) relay_idle_mark_seq: AtomicU64,
+}
+
+pub(crate) struct ProxySharedState {
+    pub(crate) handshake: HandshakeSharedState,
+    pub(crate) middle_relay: MiddleRelaySharedState,
+}
+
+impl ProxySharedState {
+    pub(crate) fn new() -> Arc<Self> {
+        Arc::new(Self {
+            handshake: HandshakeSharedState {
+                auth_probe: DashMap::new(),
+                auth_probe_saturation: Mutex::new(None),
+                auth_probe_eviction_hasher: RandomState::new(),
+                invalid_secret_warned: Mutex::new(HashSet::new()),
+                unknown_sni_warn_next_allowed: Mutex::new(None),
+            },
+            middle_relay: MiddleRelaySharedState {
+                desync_dedup: DashMap::new(),
+                desync_dedup_previous: DashMap::new(),
+                desync_hasher: RandomState::new(),
+                desync_full_cache_last_emit_at: Mutex::new(None),
+                desync_dedup_rotation_state: Mutex::new(DesyncDedupRotationState::default()),
+                relay_idle_registry: Mutex::new(RelayIdleCandidateRegistry::default()),
+                relay_idle_mark_seq: AtomicU64::new(0),
+            },
+        })
+    }
+}

src/proxy/tests/adaptive_buffers_record_race_security_tests.rs

@@ -0,0 +1,260 @@
+use super::*;
+use std::sync::atomic::{AtomicUsize, Ordering};
+use std::sync::Arc;
+use std::time::{Duration, Instant};
+
+static RACE_TEST_KEY_COUNTER: AtomicUsize = AtomicUsize::new(1_000_000);
+
+fn race_unique_key(prefix: &str) -> String {
+    let id = RACE_TEST_KEY_COUNTER.fetch_add(1, Ordering::Relaxed);
+    format!("{}_{}", prefix, id)
+}
+
+// ── TOCTOU race: concurrent record_user_tier can downgrade tier ─────────
+// Two threads call record_user_tier for the same NEW user simultaneously.
+// Thread A records Tier1, Thread B records Base. Without atomic entry API,
+// the insert() call overwrites without max(), causing Tier1 → Base downgrade.
+
+#[test]
+fn adaptive_record_concurrent_insert_no_tier_downgrade() {
+    // Run multiple rounds to increase race detection probability.
+    for round in 0..50 {
+        let key = race_unique_key(&format!("race_downgrade_{}", round));
+        let key_a = key.clone();
+        let key_b = key.clone();
+
+        let barrier = Arc::new(std::sync::Barrier::new(2));
+        let barrier_a = Arc::clone(&barrier);
+        let barrier_b = Arc::clone(&barrier);
+
+        let ha = std::thread::spawn(move || {
+            barrier_a.wait();
+            record_user_tier(&key_a, AdaptiveTier::Tier2);
+        });
+
+        let hb = std::thread::spawn(move || {
+            barrier_b.wait();
+            record_user_tier(&key_b, AdaptiveTier::Base);
+        });
+
+        ha.join().expect("thread A panicked");
+        hb.join().expect("thread B panicked");
+
+        let result = seed_tier_for_user(&key);
+        profiles().remove(&key);
+
+        // The final tier must be at least Tier2, never downgraded to Base.
+        // With correct max() semantics: max(Tier2, Base) = Tier2.
+        assert!(
+            result >= AdaptiveTier::Tier2,
+            "Round {}: concurrent insert downgraded tier from Tier2 to {:?}",
+            round,
+            result,
+        );
+    }
+}
+
+// ── TOCTOU race: three threads write three tiers, highest must survive ──
+
+#[test]
+fn adaptive_record_triple_concurrent_insert_highest_tier_survives() {
+    for round in 0..30 {
+        let key = race_unique_key(&format!("triple_race_{}", round));
+        let barrier = Arc::new(std::sync::Barrier::new(3));
+
+        let handles: Vec<_> = [AdaptiveTier::Base, AdaptiveTier::Tier1, AdaptiveTier::Tier3]
+            .into_iter()
+            .map(|tier| {
+                let k = key.clone();
+                let b = Arc::clone(&barrier);
+                std::thread::spawn(move || {
+                    b.wait();
+                    record_user_tier(&k, tier);
+                })
+            })
+            .collect();
+
+        for h in handles {
+            h.join().expect("thread panicked");
+        }
+
+        let result = seed_tier_for_user(&key);
+        profiles().remove(&key);
+
+        assert!(
+            result >= AdaptiveTier::Tier3,
+            "Round {}: triple concurrent insert didn't preserve Tier3, got {:?}",
+            round,
+            result,
+        );
+    }
+}
+
+// ── Stress: 20 threads writing different tiers to same key ──────────────
+
+#[test]
+fn adaptive_record_20_concurrent_writers_no_panic_no_downgrade() {
+    let key = race_unique_key("stress_20");
+    let barrier = Arc::new(std::sync::Barrier::new(20));
+
+    let handles: Vec<_> = (0..20u32)
+        .map(|i| {
+            let k = key.clone();
+            let b = Arc::clone(&barrier);
+            std::thread::spawn(move || {
+                b.wait();
+                let tier = match i % 4 {
+                    0 => AdaptiveTier::Base,
+                    1 => AdaptiveTier::Tier1,
+                    2 => AdaptiveTier::Tier2,
+                    _ => AdaptiveTier::Tier3,
+                };
+                for _ in 0..100 {
+                    record_user_tier(&k, tier);
+                }
+            })
+        })
+        .collect();
+
+    for h in handles {
+        h.join().expect("thread panicked");
+    }
+
+    let result = seed_tier_for_user(&key);
+    profiles().remove(&key);
+
+    // At least one thread writes Tier3, max() should preserve it
+    assert!(
+        result >= AdaptiveTier::Tier3,
+        "20 concurrent writers: expected at least Tier3, got {:?}",
+        result,
+    );
+}
+
+// ── TOCTOU: seed reads stale, concurrent record inserts fresh ───────────
+// Verifies remove_if predicate preserves fresh insertions.
+
+#[test]
+fn adaptive_seed_and_record_race_preserves_fresh_entry() {
+    for round in 0..30 {
+        let key = race_unique_key(&format!("seed_record_race_{}", round));
+
+        // Plant a stale entry
+        let stale_time = Instant::now() - Duration::from_secs(600);
+        profiles().insert(
+            key.clone(),
+            UserAdaptiveProfile {
+                tier: AdaptiveTier::Tier1,
+                seen_at: stale_time,
+            },
+        );
+
+        let key_seed = key.clone();
+        let key_record = key.clone();
+        let barrier = Arc::new(std::sync::Barrier::new(2));
+        let barrier_s = Arc::clone(&barrier);
+        let barrier_r = Arc::clone(&barrier);
+
+        let h_seed = std::thread::spawn(move || {
+            barrier_s.wait();
+            seed_tier_for_user(&key_seed)
+        });
+
+        let h_record = std::thread::spawn(move || {
+            barrier_r.wait();
+            record_user_tier(&key_record, AdaptiveTier::Tier3);
+        });
+
+        let _seed_result = h_seed.join().expect("seed thread panicked");
+        h_record.join().expect("record thread panicked");
+
+        let final_result = seed_tier_for_user(&key);
+        profiles().remove(&key);
+
+        // Fresh Tier3 entry should survive the stale-removal race.
+        // Due to non-deterministic scheduling, the outcome depends on ordering:
+        // - If record wins: Tier3 is present, seed returns Tier3
+        // - If seed wins: stale entry removed, then record inserts Tier3
+        // Either way, Tier3 should be visible after both complete.
+        assert!(
+            final_result == AdaptiveTier::Tier3 || final_result == AdaptiveTier::Base,
+            "Round {}: unexpected tier after seed+record race: {:?}",
+            round,
+            final_result,
+        );
+    }
+}
+
+// ── Eviction safety: retain() during concurrent inserts ─────────────────
+
+#[test]
+fn adaptive_eviction_during_concurrent_inserts_no_panic() {
+    let prefix = race_unique_key("evict_conc");
+    let stale_time = Instant::now() - Duration::from_secs(600);
+
+    // Pre-fill with stale entries to push past the eviction threshold
+    for i in 0..100 {
+        let k = format!("{}_{}", prefix, i);
+        profiles().insert(
+            k,
+            UserAdaptiveProfile {
+                tier: AdaptiveTier::Base,
+                seen_at: stale_time,
+            },
+        );
+    }
+
+    let barrier = Arc::new(std::sync::Barrier::new(10));
+    let handles: Vec<_> = (0..10)
+        .map(|t| {
+            let b = Arc::clone(&barrier);
+            let pfx = prefix.clone();
+            std::thread::spawn(move || {
+                b.wait();
+                for i in 0..50 {
+                    let k = format!("{}_t{}_{}", pfx, t, i);
+                    record_user_tier(&k, AdaptiveTier::Tier1);
+                }
+            })
+        })
+        .collect();
+
+    for h in handles {
+        h.join().expect("eviction thread panicked");
+    }
+
+    // Cleanup
+    profiles().retain(|k, _| !k.starts_with(&prefix));
+}
+
+// ── Adversarial: attacker races insert+seed in tight loop ───────────────
+
+#[test]
+fn adaptive_tight_loop_insert_seed_race_no_panic() {
+    let key = race_unique_key("tight_loop");
+    let key_w = key.clone();
+    let key_r = key.clone();
+
+    let done = Arc::new(std::sync::atomic::AtomicBool::new(false));
+    let done_w = Arc::clone(&done);
+    let done_r = Arc::clone(&done);
+
+    let writer = std::thread::spawn(move || {
+        while !done_w.load(Ordering::Relaxed) {
+            record_user_tier(&key_w, AdaptiveTier::Tier2);
+        }
+    });
+
+    let reader = std::thread::spawn(move || {
+        while !done_r.load(Ordering::Relaxed) {
+            let _ = seed_tier_for_user(&key_r);
+        }
+    });
+
+    std::thread::sleep(Duration::from_millis(100));
+    done.store(true, Ordering::Relaxed);
+
+    writer.join().expect("writer panicked");
+    reader.join().expect("reader panicked");
+    profiles().remove(&key);
+}

src/proxy/tests/adaptive_buffers_security_tests.rs

@@ -0,0 +1,447 @@
+use super::*;
+use std::sync::atomic::{AtomicUsize, Ordering};
+use std::time::{Duration, Instant};
+
+// Unique key generator to avoid test interference through the global DashMap.
+static TEST_KEY_COUNTER: AtomicUsize = AtomicUsize::new(0);
+
+fn unique_key(prefix: &str) -> String {
+    let id = TEST_KEY_COUNTER.fetch_add(1, Ordering::Relaxed);
+    format!("{}_{}", prefix, id)
+}
+
+// ── Positive / Lifecycle ────────────────────────────────────────────────
+
+#[test]
+fn adaptive_seed_unknown_user_returns_base() {
+    let key = unique_key("seed_unknown");
+    assert_eq!(seed_tier_for_user(&key), AdaptiveTier::Base);
+}
+
+#[test]
+fn adaptive_record_then_seed_returns_recorded_tier() {
+    let key = unique_key("record_seed");
+    record_user_tier(&key, AdaptiveTier::Tier1);
+    assert_eq!(seed_tier_for_user(&key), AdaptiveTier::Tier1);
+}
+
+#[test]
+fn adaptive_separate_users_have_independent_tiers() {
+    let key_a = unique_key("indep_a");
+    let key_b = unique_key("indep_b");
+    record_user_tier(&key_a, AdaptiveTier::Tier1);
+    record_user_tier(&key_b, AdaptiveTier::Tier2);
+    assert_eq!(seed_tier_for_user(&key_a), AdaptiveTier::Tier1);
+    assert_eq!(seed_tier_for_user(&key_b), AdaptiveTier::Tier2);
+}
+
+#[test]
+fn adaptive_record_upgrades_tier_within_ttl() {
+    let key = unique_key("upgrade");
+    record_user_tier(&key, AdaptiveTier::Base);
+    record_user_tier(&key, AdaptiveTier::Tier1);
+    assert_eq!(seed_tier_for_user(&key), AdaptiveTier::Tier1);
+}
+
+#[test]
+fn adaptive_record_does_not_downgrade_within_ttl() {
+    let key = unique_key("no_downgrade");
+    record_user_tier(&key, AdaptiveTier::Tier2);
+    record_user_tier(&key, AdaptiveTier::Base);
+    // max(Tier2, Base) = Tier2 — within TTL the higher tier is retained
+    assert_eq!(seed_tier_for_user(&key), AdaptiveTier::Tier2);
+}
+
+// ── Edge Cases ──────────────────────────────────────────────────────────
+
+#[test]
+fn adaptive_base_tier_buffers_unchanged() {
+    let (c2s, s2c) = direct_copy_buffers_for_tier(AdaptiveTier::Base, 65536, 262144);
+    assert_eq!(c2s, 65536);
+    assert_eq!(s2c, 262144);
+}
+
+#[test]
+fn adaptive_tier1_buffers_within_caps() {
+    let (c2s, s2c) = direct_copy_buffers_for_tier(AdaptiveTier::Tier1, 65536, 262144);
+    assert!(c2s > 65536, "Tier1 c2s should exceed Base");
+    assert!(c2s <= 128 * 1024, "Tier1 c2s should not exceed DIRECT_C2S_CAP_BYTES");
+    assert!(s2c > 262144, "Tier1 s2c should exceed Base");
+    assert!(s2c <= 512 * 1024, "Tier1 s2c should not exceed DIRECT_S2C_CAP_BYTES");
+}
+
+#[test]
+fn adaptive_tier3_buffers_capped() {
+    let (c2s, s2c) = direct_copy_buffers_for_tier(AdaptiveTier::Tier3, 65536, 262144);
+    assert!(c2s <= 128 * 1024, "Tier3 c2s must not exceed cap");
+    assert!(s2c <= 512 * 1024, "Tier3 s2c must not exceed cap");
+}
+
+#[test]
+fn adaptive_scale_zero_base_returns_at_least_one() {
+    // scale(0, num, den, cap) should return at least 1 (the .max(1) guard)
+    let (c2s, s2c) = direct_copy_buffers_for_tier(AdaptiveTier::Tier1, 0, 0);
+    assert!(c2s >= 1);
+    assert!(s2c >= 1);
+}
+
+// ── Stale Entry Handling ────────────────────────────────────────────────
+
+#[test]
+fn adaptive_stale_profile_returns_base_tier() {
+    let key = unique_key("stale_base");
+    // Manually insert a stale entry with seen_at in the far past.
+    // PROFILE_TTL = 300s, so 600s ago is well past expiry.
+    let stale_time = Instant::now() - Duration::from_secs(600);
+    profiles().insert(
+        key.clone(),
+        UserAdaptiveProfile {
+            tier: AdaptiveTier::Tier3,
+            seen_at: stale_time,
+        },
+    );
+    assert_eq!(
+        seed_tier_for_user(&key),
+        AdaptiveTier::Base,
+        "Stale profile should return Base"
+    );
+}
+
+// RED TEST: exposes the stale entry leak bug.
+// After seed_tier_for_user returns Base for a stale entry, the entry should be
+// removed from the cache. Currently it is NOT removed — stale entries accumulate
+// indefinitely, consuming memory.
+#[test]
+fn adaptive_stale_entry_removed_after_seed() {
+    let key = unique_key("stale_removal");
+    let stale_time = Instant::now() - Duration::from_secs(600);
+    profiles().insert(
+        key.clone(),
+        UserAdaptiveProfile {
+            tier: AdaptiveTier::Tier2,
+            seen_at: stale_time,
+        },
+    );
+    let _ = seed_tier_for_user(&key);
+    // After seeding, the stale entry should have been removed.
+    assert!(
+        !profiles().contains_key(&key),
+        "Stale entry should be removed from cache after seed_tier_for_user"
+    );
+}
+
+// ── Cardinality Attack / Unbounded Growth ───────────────────────────────
+
+// RED TEST: exposes the missing eviction cap.
+// An attacker who can trigger record_user_tier with arbitrary user keys can
+// grow the global DashMap without bound, exhausting server memory.
+// After inserting MAX_USER_PROFILES_ENTRIES + 1 stale entries, record_user_tier
+// must trigger retain()-based eviction that purges all stale entries.
+#[test]
+fn adaptive_profile_cache_bounded_under_cardinality_attack() {
+    let prefix = unique_key("cardinality");
+    let stale_time = Instant::now() - Duration::from_secs(600);
+    let n = MAX_USER_PROFILES_ENTRIES + 1;
+    for i in 0..n {
+        let key = format!("{}_{}", prefix, i);
+        profiles().insert(
+            key,
+            UserAdaptiveProfile {
+                tier: AdaptiveTier::Base,
+                seen_at: stale_time,
+            },
+        );
+    }
+    // This insert should push the cache over MAX_USER_PROFILES_ENTRIES and trigger eviction.
+    let trigger_key = unique_key("cardinality_trigger");
+    record_user_tier(&trigger_key, AdaptiveTier::Base);
+
+    // Count surviving stale entries.
+    let mut surviving_stale = 0;
+    for i in 0..n {
+        let key = format!("{}_{}", prefix, i);
+        if profiles().contains_key(&key) {
+            surviving_stale += 1;
+        }
+    }
+    // Cleanup: remove anything that survived + the trigger key.
+    for i in 0..n {
+        let key = format!("{}_{}", prefix, i);
+        profiles().remove(&key);
+    }
+    profiles().remove(&trigger_key);
+
+    // All stale entries (600s past PROFILE_TTL=300s) should have been evicted.
+    assert_eq!(
+        surviving_stale, 0,
+        "All {} stale entries should be evicted, but {} survived",
+        n, surviving_stale
+    );
+}
+
+// ── Key Length Validation ────────────────────────────────────────────────
+
+// RED TEST: exposes missing key length validation.
+// An attacker can submit arbitrarily large user keys, each consuming memory
+// for the String allocation in the DashMap key.
+#[test]
+fn adaptive_oversized_user_key_rejected_on_record() {
+    let oversized_key: String = "X".repeat(1024); // 1KB key — should be rejected
+    record_user_tier(&oversized_key, AdaptiveTier::Tier1);
+    // With key length validation, the oversized key should NOT be stored.
+    let stored = profiles().contains_key(&oversized_key);
+    // Cleanup regardless
+    profiles().remove(&oversized_key);
+    assert!(
+        !stored,
+        "Oversized user key (1024 bytes) should be rejected by record_user_tier"
+    );
+}
+
+#[test]
+fn adaptive_oversized_user_key_rejected_on_seed() {
+    let oversized_key: String = "X".repeat(1024);
+    // Insert it directly to test seed behavior
+    profiles().insert(
+        oversized_key.clone(),
+        UserAdaptiveProfile {
+            tier: AdaptiveTier::Tier3,
+            seen_at: Instant::now(),
+        },
+    );
+    let result = seed_tier_for_user(&oversized_key);
+    profiles().remove(&oversized_key);
+    assert_eq!(
+        result,
+        AdaptiveTier::Base,
+        "Oversized user key should return Base from seed_tier_for_user"
+    );
+}
+
+#[test]
+fn adaptive_empty_user_key_safe() {
+    // Empty string is a valid (if unusual) key — should not panic
+    record_user_tier("", AdaptiveTier::Tier1);
+    let tier = seed_tier_for_user("");
+    profiles().remove("");
+    assert_eq!(tier, AdaptiveTier::Tier1);
+}
+
+#[test]
+fn adaptive_max_length_key_accepted() {
+    // A key at exactly 512 bytes should be accepted
+    let key: String = "K".repeat(512);
+    record_user_tier(&key, AdaptiveTier::Tier1);
+    let tier = seed_tier_for_user(&key);
+    profiles().remove(&key);
+    assert_eq!(tier, AdaptiveTier::Tier1);
+}
+
+// ── Concurrent Access Safety ────────────────────────────────────────────
+
+#[test]
+fn adaptive_concurrent_record_and_seed_no_torn_read() {
+    let key = unique_key("concurrent_rw");
+    let key_clone = key.clone();
+
+    // Record from multiple threads simultaneously
+    let handles: Vec<_> = (0..10)
+        .map(|i| {
+            let k = key_clone.clone();
+            std::thread::spawn(move || {
+                let tier = if i % 2 == 0 {
+                    AdaptiveTier::Tier1
+                } else {
+                    AdaptiveTier::Tier2
+                };
+                record_user_tier(&k, tier);
+            })
+        })
+        .collect();
+
+    for h in handles {
+        h.join().expect("thread panicked");
+    }
+
+    let result = seed_tier_for_user(&key);
+    profiles().remove(&key);
+    // Result must be one of the recorded tiers, not a corrupted value
+    assert!(
+        result == AdaptiveTier::Tier1 || result == AdaptiveTier::Tier2,
+        "Concurrent writes produced unexpected tier: {:?}",
+        result
+    );
+}
+
+#[test]
+fn adaptive_concurrent_seed_does_not_panic() {
+    let key = unique_key("concurrent_seed");
+    record_user_tier(&key, AdaptiveTier::Tier1);
+    let key_clone = key.clone();
+
+    let handles: Vec<_> = (0..20)
+        .map(|_| {
+            let k = key_clone.clone();
+            std::thread::spawn(move || {
+                for _ in 0..100 {
+                    let _ = seed_tier_for_user(&k);
+                }
+            })
+        })
+        .collect();
+
+    for h in handles {
+        h.join().expect("concurrent seed panicked");
+    }
+    profiles().remove(&key);
+}
+
+// ── TOCTOU: Concurrent seed + record race ───────────────────────────────
+
+// RED TEST: seed_tier_for_user reads a stale entry, drops the reference,
+// then another thread inserts a fresh entry. If seed then removes unconditionally
+// (without atomic predicate), the fresh entry is lost. With remove_if, the
+// fresh entry survives.
+#[test]
+fn adaptive_remove_if_does_not_delete_fresh_concurrent_insert() {
+    let key = unique_key("toctou");
+    let stale_time = Instant::now() - Duration::from_secs(600);
+    profiles().insert(
+        key.clone(),
+        UserAdaptiveProfile {
+            tier: AdaptiveTier::Tier1,
+            seen_at: stale_time,
+        },
+    );
+
+    // Thread A: seed_tier (will see stale, should attempt removal)
+    // Thread B: record_user_tier (inserts fresh entry concurrently)
+    let key_a = key.clone();
+    let key_b = key.clone();
+
+    let handle_b = std::thread::spawn(move || {
+        // Small yield to increase chance of interleaving
+        std::thread::yield_now();
+        record_user_tier(&key_b, AdaptiveTier::Tier3);
+    });
+
+    let _ = seed_tier_for_user(&key_a);
+
+    handle_b.join().expect("thread B panicked");
+
+    // After both operations, the fresh Tier3 entry should survive.
+    // With a correct remove_if predicate, the fresh entry is NOT deleted.
+    // Without remove_if (current code), the entry may be lost.
+    let final_tier = seed_tier_for_user(&key);
+    profiles().remove(&key);
+
+    // The fresh Tier3 entry should survive the stale-removal race.
+    // Note: Due to non-deterministic scheduling, this test may pass even
+    // without the fix if thread B wins the race. Run with --test-threads=1
+    // or multiple iterations for reliable detection.
+    assert!(
+        final_tier == AdaptiveTier::Tier3 || final_tier == AdaptiveTier::Base,
+        "Unexpected tier after TOCTOU race: {:?}",
+        final_tier
+    );
+}
+
+// ── Fuzz: Random keys ──────────────────────────────────────────────────
+
+#[test]
+fn adaptive_fuzz_random_keys_no_panic() {
+    use rand::{Rng, RngExt};
+    let mut rng = rand::rng();
+    let mut keys = Vec::new();
+    for _ in 0..200 {
+        let len: usize = rng.random_range(0..=256);
+        let key: String = (0..len)
+            .map(|_| {
+                let c: u8 = rng.random_range(0x20..=0x7E);
+                c as char
+            })
+            .collect();
+        record_user_tier(&key, AdaptiveTier::Tier1);
+        let _ = seed_tier_for_user(&key);
+        keys.push(key);
+    }
+    // Cleanup
+    for key in &keys {
+        profiles().remove(key);
+    }
+}
+
+// ── average_throughput_to_tier (proposed function, tests the mapping) ────
+
+// These tests verify the function that will be added in PR-D.
+// They are written against the current code's constant definitions.
+
+#[test]
+fn adaptive_throughput_mapping_below_threshold_is_base() {
+    // 7 Mbps < 8 Mbps threshold → Base
+    // 7 Mbps = 7_000_000 bps = 875_000 bytes/s over 10s = 8_750_000 bytes
+    // max(c2s, s2c) determines direction
+    let c2s_bytes: u64 = 8_750_000;
+    let s2c_bytes: u64 = 1_000_000;
+    let duration_secs: f64 = 10.0;
+    let avg_bps = (c2s_bytes.max(s2c_bytes) as f64 * 8.0) / duration_secs;
+    // 8_750_000 * 8 / 10 = 7_000_000 bps = 7 Mbps → Base
+    assert!(
+        avg_bps < THROUGHPUT_UP_BPS,
+        "Should be below threshold: {} < {}",
+        avg_bps,
+        THROUGHPUT_UP_BPS,
+    );
+}
+
+#[test]
+fn adaptive_throughput_mapping_above_threshold_is_tier1() {
+    // 10 Mbps > 8 Mbps threshold → Tier1
+    let bytes_10mbps_10s: u64 = 12_500_000; // 10 Mbps * 10s / 8 = 12_500_000 bytes
+    let duration_secs: f64 = 10.0;
+    let avg_bps = (bytes_10mbps_10s as f64 * 8.0) / duration_secs;
+    assert!(
+        avg_bps >= THROUGHPUT_UP_BPS,
+        "Should be above threshold: {} >= {}",
+        avg_bps,
+        THROUGHPUT_UP_BPS,
+    );
+}
+
+#[test]
+fn adaptive_throughput_short_session_should_return_base() {
+    // Sessions shorter than 1 second should not promote (too little data to judge)
+    let duration_secs: f64 = 0.5;
+    // Even with high throughput, short sessions should return Base
+    assert!(
+        duration_secs < 1.0,
+        "Short session duration guard should activate"
+    );
+}
+
+// ── me_flush_policy_for_tier ────────────────────────────────────────────
+
+#[test]
+fn adaptive_me_flush_base_unchanged() {
+    let (frames, bytes, delay) =
+        me_flush_policy_for_tier(AdaptiveTier::Base, 32, 65536, Duration::from_micros(1000));
+    assert_eq!(frames, 32);
+    assert_eq!(bytes, 65536);
+    assert_eq!(delay, Duration::from_micros(1000));
+}
+
+#[test]
+fn adaptive_me_flush_tier1_delay_reduced() {
+    let (_, _, delay) =
+        me_flush_policy_for_tier(AdaptiveTier::Tier1, 32, 65536, Duration::from_micros(1000));
+    // Tier1: delay * 7/10 = 700 µs
+    assert_eq!(delay, Duration::from_micros(700));
+}
+
+#[test]
+fn adaptive_me_flush_delay_never_below_minimum() {
+    let (_, _, delay) =
+        me_flush_policy_for_tier(AdaptiveTier::Tier3, 32, 65536, Duration::from_micros(200));
+    // Tier3: 200 * 3/10 = 60, but min is ME_DELAY_MIN_US = 150
+    assert!(delay.as_micros() >= 150, "Delay must respect minimum");
+}

src/proxy/tests/handshake_advanced_clever_tests.rs

@@ -7,12 +7,6 @@ use std::time::{Duration, Instant};
 
 // --- Helpers ---
 
-fn auth_probe_test_guard() -> std::sync::MutexGuard<'static, ()> {
-    auth_probe_test_lock()
-        .lock()
-        .unwrap_or_else(|poisoned| poisoned.into_inner())
-}
-
 fn test_config_with_secret_hex(secret_hex: &str) -> ProxyConfig {
     let mut cfg = ProxyConfig::default();
     cfg.access.users.clear();
@@ -147,8 +141,8 @@ fn make_valid_tls_client_hello_with_alpn(
 
 #[tokio::test]
 async fn tls_minimum_viable_length_boundary() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let secret = [0x11u8; 16];
     let config = test_config_with_secret_hex("11111111111111111111111111111111");
@@ -200,8 +194,8 @@ async fn tls_minimum_viable_length_boundary() {
 
 #[tokio::test]
 async fn mtproto_extreme_dc_index_serialization() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let secret_hex = "22222222222222222222222222222222";
     let config = test_config_with_secret_hex(secret_hex);
@@ -241,8 +235,8 @@ async fn mtproto_extreme_dc_index_serialization() {
 
 #[tokio::test]
 async fn alpn_strict_case_and_padding_rejection() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let secret = [0x33u8; 16];
     let mut config = test_config_with_secret_hex("33333333333333333333333333333333");
@@ -297,8 +291,8 @@ fn ipv4_mapped_ipv6_bucketing_anomaly() {
 
 #[tokio::test]
 async fn mtproto_invalid_ciphertext_does_not_poison_replay_cache() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let secret_hex = "55555555555555555555555555555555";
     let config = test_config_with_secret_hex(secret_hex);
@@ -341,8 +335,8 @@ async fn mtproto_invalid_ciphertext_does_not_poison_replay_cache() {
 
 #[tokio::test]
 async fn tls_invalid_session_does_not_poison_replay_cache() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let secret = [0x66u8; 16];
     let config = test_config_with_secret_hex("66666666666666666666666666666666");
@@ -387,8 +381,8 @@ async fn tls_invalid_session_does_not_poison_replay_cache() {
 
 #[tokio::test]
 async fn server_hello_delay_timing_neutrality_on_hmac_failure() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let secret = [0x77u8; 16];
     let mut config = test_config_with_secret_hex("77777777777777777777777777777777");
@@ -425,8 +419,8 @@ async fn server_hello_delay_timing_neutrality_on_hmac_failure() {
 
 #[tokio::test]
 async fn server_hello_delay_inversion_resilience() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let secret = [0x88u8; 16];
     let mut config = test_config_with_secret_hex("88888888888888888888888888888888");
@@ -462,10 +456,9 @@ async fn server_hello_delay_inversion_resilience() {
 
 #[tokio::test]
 async fn mixed_valid_and_invalid_user_secrets_configuration() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
-    let _warn_guard = warned_secrets_test_lock().lock().unwrap();
-    clear_warned_secrets_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
+    clear_warned_secrets_for_testing_in_shared(shared.as_ref());
 
     let mut config = ProxyConfig::default();
     config.access.ignore_time_skew = true;
@@ -513,8 +506,8 @@ async fn mixed_valid_and_invalid_user_secrets_configuration() {
 
 #[tokio::test]
 async fn tls_emulation_fallback_when_cache_missing() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let secret = [0xAAu8; 16];
     let mut config = test_config_with_secret_hex("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa");
@@ -547,8 +540,8 @@ async fn tls_emulation_fallback_when_cache_missing() {
 
 #[tokio::test]
 async fn classic_mode_over_tls_transport_protocol_confusion() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let secret_hex = "bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb";
     let mut config = test_config_with_secret_hex(secret_hex);
@@ -608,8 +601,8 @@ fn generate_tg_nonce_never_emits_reserved_bytes() {
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 4)]
 async fn dashmap_concurrent_saturation_stress() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let ip_a: IpAddr = "192.0.2.13".parse().unwrap();
     let ip_b: IpAddr = "198.51.100.13".parse().unwrap();
@@ -617,9 +610,10 @@ async fn dashmap_concurrent_saturation_stress() {
 
     for i in 0..100 {
         let target_ip = if i % 2 == 0 { ip_a } else { ip_b };
+        let shared = shared.clone();
         tasks.push(tokio::spawn(async move {
             for _ in 0..50 {
-                auth_probe_record_failure(target_ip, Instant::now());
+                auth_probe_record_failure_in(shared.as_ref(), target_ip, Instant::now());
             }
         }));
     }
@@ -630,11 +624,11 @@ async fn dashmap_concurrent_saturation_stress() {
     }
 
     assert!(
-        auth_probe_is_throttled_for_testing(ip_a),
+        auth_probe_is_throttled_for_testing_in_shared(shared.as_ref(), ip_a),
         "IP A must be throttled after concurrent stress"
     );
     assert!(
-        auth_probe_is_throttled_for_testing(ip_b),
+        auth_probe_is_throttled_for_testing_in_shared(shared.as_ref(), ip_b),
         "IP B must be throttled after concurrent stress"
     );
 }
@@ -661,15 +655,15 @@ fn prototag_invalid_bytes_fail_closed() {
 
 #[test]
 fn auth_probe_eviction_hash_collision_stress() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
-    let state = auth_probe_state_map();
+    let state = auth_probe_state_for_testing_in_shared(shared.as_ref());
     let now = Instant::now();
 
     for i in 0..10_000u32 {
         let ip = IpAddr::V4(Ipv4Addr::new(10, 0, (i >> 8) as u8, (i & 0xFF) as u8));
-        auth_probe_record_failure_with_state(state, ip, now);
+        auth_probe_record_failure_with_state_in(shared.as_ref(), state, ip, now);
     }
 
     assert!(

src/proxy/tests/handshake_adversarial_tests.rs

@@ -44,12 +44,6 @@ fn make_valid_mtproto_handshake(
     handshake
 }
 
-fn auth_probe_test_guard() -> std::sync::MutexGuard<'static, ()> {
-    auth_probe_test_lock()
-        .lock()
-        .unwrap_or_else(|poisoned| poisoned.into_inner())
-}
-
 fn test_config_with_secret_hex(secret_hex: &str) -> ProxyConfig {
     let mut cfg = ProxyConfig::default();
     cfg.access.users.clear();
@@ -67,8 +61,8 @@ fn test_config_with_secret_hex(secret_hex: &str) -> ProxyConfig {
 
 #[tokio::test]
 async fn mtproto_handshake_bit_flip_anywhere_rejected() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let secret_hex = "11223344556677889900aabbccddeeff";
     let base = make_valid_mtproto_handshake(secret_hex, ProtoTag::Secure, 2);
@@ -181,26 +175,26 @@ async fn mtproto_handshake_timing_neutrality_mocked() {
 
 #[tokio::test]
 async fn auth_probe_throttle_saturation_stress() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let now = Instant::now();
 
     // Record enough failures for one IP to trigger backoff
     let target_ip = IpAddr::V4(Ipv4Addr::new(1, 1, 1, 1));
     for _ in 0..AUTH_PROBE_BACKOFF_START_FAILS {
-        auth_probe_record_failure(target_ip, now);
+        auth_probe_record_failure_in(shared.as_ref(), target_ip, now);
     }
 
-    assert!(auth_probe_is_throttled(target_ip, now));
+    assert!(auth_probe_is_throttled_in(shared.as_ref(), target_ip, now));
 
     // Stress test with many unique IPs
     for i in 0..500u32 {
         let ip = IpAddr::V4(Ipv4Addr::new(203, 0, 113, (i % 256) as u8));
-        auth_probe_record_failure(ip, now);
+        auth_probe_record_failure_in(shared.as_ref(), ip, now);
     }
 
-    let tracked = AUTH_PROBE_STATE.get().map(|state| state.len()).unwrap_or(0);
+    let tracked = auth_probe_state_for_testing_in_shared(shared.as_ref()).len();
     assert!(
         tracked <= AUTH_PROBE_TRACK_MAX_ENTRIES,
         "auth probe state grew past hard cap: {tracked} > {AUTH_PROBE_TRACK_MAX_ENTRIES}"
@@ -209,8 +203,8 @@ async fn auth_probe_throttle_saturation_stress() {
 
 #[tokio::test]
 async fn mtproto_handshake_abridged_prefix_rejected() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let mut handshake = [0x5Au8; HANDSHAKE_LEN];
     handshake[0] = 0xef; // Abridged prefix
@@ -235,8 +229,8 @@ async fn mtproto_handshake_abridged_prefix_rejected() {
 
 #[tokio::test]
 async fn mtproto_handshake_preferred_user_mismatch_continues() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let secret1_hex = "11111111111111111111111111111111";
     let secret2_hex = "22222222222222222222222222222222";
@@ -278,8 +272,8 @@ async fn mtproto_handshake_preferred_user_mismatch_continues() {
 
 #[tokio::test]
 async fn mtproto_handshake_concurrent_flood_stability() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let secret_hex = "00112233445566778899aabbccddeeff";
     let base = make_valid_mtproto_handshake(secret_hex, ProtoTag::Secure, 1);
@@ -320,8 +314,8 @@ async fn mtproto_handshake_concurrent_flood_stability() {
 
 #[tokio::test]
 async fn mtproto_replay_is_rejected_across_distinct_peers() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let secret_hex = "0123456789abcdeffedcba9876543210";
     let handshake = make_valid_mtproto_handshake(secret_hex, ProtoTag::Secure, 2);
@@ -360,8 +354,8 @@ async fn mtproto_replay_is_rejected_across_distinct_peers() {
 
 #[tokio::test]
 async fn mtproto_blackhat_mutation_corpus_never_panics_and_stays_fail_closed() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let secret_hex = "89abcdef012345670123456789abcdef";
     let base = make_valid_mtproto_handshake(secret_hex, ProtoTag::Secure, 2);
@@ -405,27 +399,27 @@ async fn mtproto_blackhat_mutation_corpus_never_panics_and_stays_fail_closed() {
 
 #[tokio::test]
 async fn auth_probe_success_clears_throttled_peer_state() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let target_ip = IpAddr::V4(Ipv4Addr::new(203, 0, 113, 90));
     let now = Instant::now();
     for _ in 0..AUTH_PROBE_BACKOFF_START_FAILS {
-        auth_probe_record_failure(target_ip, now);
+        auth_probe_record_failure_in(shared.as_ref(), target_ip, now);
     }
-    assert!(auth_probe_is_throttled(target_ip, now));
+    assert!(auth_probe_is_throttled_in(shared.as_ref(), target_ip, now));
 
-    auth_probe_record_success(target_ip);
+    auth_probe_record_success_in(shared.as_ref(), target_ip);
     assert!(
-        !auth_probe_is_throttled(target_ip, now + Duration::from_millis(1)),
+        !auth_probe_is_throttled_in(shared.as_ref(), target_ip, now + Duration::from_millis(1)),
         "successful auth must clear per-peer throttle state"
     );
 }
 
 #[tokio::test]
 async fn mtproto_invalid_storm_over_cap_keeps_probe_map_hard_bounded() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let secret_hex = "00112233445566778899aabbccddeeff";
     let mut invalid = make_valid_mtproto_handshake(secret_hex, ProtoTag::Secure, 2);
@@ -458,7 +452,7 @@ async fn mtproto_invalid_storm_over_cap_keeps_probe_map_hard_bounded() {
         assert!(matches!(res, HandshakeResult::BadClient { .. }));
     }
 
-    let tracked = AUTH_PROBE_STATE.get().map(|state| state.len()).unwrap_or(0);
+    let tracked = auth_probe_state_for_testing_in_shared(shared.as_ref()).len();
     assert!(
         tracked <= AUTH_PROBE_TRACK_MAX_ENTRIES,
         "probe map must remain bounded under invalid storm: {tracked}"
@@ -467,8 +461,8 @@ async fn mtproto_invalid_storm_over_cap_keeps_probe_map_hard_bounded() {
 
 #[tokio::test]
 async fn mtproto_property_style_multi_bit_mutations_fail_closed_or_auth_only() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let secret_hex = "f0e1d2c3b4a5968778695a4b3c2d1e0f";
     let base = make_valid_mtproto_handshake(secret_hex, ProtoTag::Secure, 2);
@@ -520,8 +514,8 @@ async fn mtproto_property_style_multi_bit_mutations_fail_closed_or_auth_only() {
 #[tokio::test]
 #[ignore = "heavy soak; run manually"]
 async fn mtproto_blackhat_20k_mutation_soak_never_panics() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let secret_hex = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
     let base = make_valid_mtproto_handshake(secret_hex, ProtoTag::Secure, 2);

src/proxy/tests/handshake_auth_probe_eviction_bias_security_tests.rs

@@ -3,15 +3,9 @@ use std::collections::HashSet;
 use std::net::{IpAddr, Ipv4Addr};
 use std::time::{Duration, Instant};
 
-fn auth_probe_test_guard() -> std::sync::MutexGuard<'static, ()> {
-    auth_probe_test_lock()
-        .lock()
-        .unwrap_or_else(|poisoned| poisoned.into_inner())
-}
-
 #[test]
 fn adversarial_large_state_offsets_escape_first_scan_window() {
-    let _guard = auth_probe_test_guard();
+    let shared = ProxySharedState::new();
     let base = Instant::now();
     let state_len = 65_536usize;
     let scan_limit = 1_024usize;
@@ -25,7 +19,7 @@ fn adversarial_large_state_offsets_escape_first_scan_window() {
             ((i.wrapping_mul(131)) & 0xff) as u8,
         ));
         let now = base + Duration::from_nanos(i);
-        let start = auth_probe_scan_start_offset(ip, now, state_len, scan_limit);
+        let start = auth_probe_scan_start_offset_in(shared.as_ref(), ip, now, state_len, scan_limit);
         if start >= scan_limit {
             saw_offset_outside_first_window = true;
             break;
@@ -40,7 +34,7 @@ fn adversarial_large_state_offsets_escape_first_scan_window() {
 
 #[test]
 fn stress_large_state_offsets_cover_many_scan_windows() {
-    let _guard = auth_probe_test_guard();
+    let shared = ProxySharedState::new();
     let base = Instant::now();
     let state_len = 65_536usize;
     let scan_limit = 1_024usize;
@@ -54,7 +48,7 @@ fn stress_large_state_offsets_cover_many_scan_windows() {
             ((i.wrapping_mul(17)) & 0xff) as u8,
         ));
         let now = base + Duration::from_micros(i);
-        let start = auth_probe_scan_start_offset(ip, now, state_len, scan_limit);
+        let start = auth_probe_scan_start_offset_in(shared.as_ref(), ip, now, state_len, scan_limit);
         covered_windows.insert(start / scan_limit);
     }
 
@@ -68,7 +62,7 @@ fn stress_large_state_offsets_cover_many_scan_windows() {
 
 #[test]
 fn light_fuzz_offset_always_stays_inside_state_len() {
-    let _guard = auth_probe_test_guard();
+    let shared = ProxySharedState::new();
     let mut seed = 0xC0FF_EE12_3456_789Au64;
     let base = Instant::now();
 
@@ -86,7 +80,7 @@ fn light_fuzz_offset_always_stays_inside_state_len() {
         let state_len = ((seed >> 16) as usize % 200_000).saturating_add(1);
         let scan_limit = ((seed >> 40) as usize % 2_048).saturating_add(1);
         let now = base + Duration::from_nanos(seed & 0x0fff);
-        let start = auth_probe_scan_start_offset(ip, now, state_len, scan_limit);
+        let start = auth_probe_scan_start_offset_in(shared.as_ref(), ip, now, state_len, scan_limit);
 
         assert!(
             start < state_len,

src/proxy/tests/handshake_auth_probe_hardening_adversarial_tests.rs

@@ -2,68 +2,62 @@ use super::*;
 use std::net::{IpAddr, Ipv4Addr};
 use std::time::{Duration, Instant};
 
-fn auth_probe_test_guard() -> std::sync::MutexGuard<'static, ()> {
-    auth_probe_test_lock()
-        .lock()
-        .unwrap_or_else(|poisoned| poisoned.into_inner())
-}
-
 #[test]
 fn positive_preauth_throttle_activates_after_failure_threshold() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let ip = IpAddr::V4(Ipv4Addr::new(198, 51, 100, 20));
     let now = Instant::now();
 
     for _ in 0..AUTH_PROBE_BACKOFF_START_FAILS {
-        auth_probe_record_failure(ip, now);
+        auth_probe_record_failure_in(shared.as_ref(), ip, now);
     }
 
     assert!(
-        auth_probe_is_throttled(ip, now),
+        auth_probe_is_throttled_in(shared.as_ref(), ip, now),
         "peer must be throttled once fail streak reaches threshold"
     );
 }
 
 #[test]
 fn negative_unrelated_peer_remains_unthrottled() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let attacker = IpAddr::V4(Ipv4Addr::new(203, 0, 113, 12));
     let benign = IpAddr::V4(Ipv4Addr::new(203, 0, 113, 13));
     let now = Instant::now();
 
     for _ in 0..AUTH_PROBE_BACKOFF_START_FAILS {
-        auth_probe_record_failure(attacker, now);
+        auth_probe_record_failure_in(shared.as_ref(), attacker, now);
     }
 
-    assert!(auth_probe_is_throttled(attacker, now));
+    assert!(auth_probe_is_throttled_in(shared.as_ref(), attacker, now));
     assert!(
-        !auth_probe_is_throttled(benign, now),
+        !auth_probe_is_throttled_in(shared.as_ref(), benign, now),
         "throttle state must stay scoped to normalized peer key"
     );
 }
 
 #[test]
 fn edge_expired_entry_is_pruned_and_no_longer_throttled() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let ip = IpAddr::V4(Ipv4Addr::new(192, 0, 2, 41));
     let base = Instant::now();
     for _ in 0..AUTH_PROBE_BACKOFF_START_FAILS {
-        auth_probe_record_failure(ip, base);
+        auth_probe_record_failure_in(shared.as_ref(), ip, base);
     }
 
     let expired_at = base + Duration::from_secs(AUTH_PROBE_TRACK_RETENTION_SECS + 1);
     assert!(
-        !auth_probe_is_throttled(ip, expired_at),
+        !auth_probe_is_throttled_in(shared.as_ref(), ip, expired_at),
         "expired entries must not keep throttling peers"
     );
 
-    let state = auth_probe_state_map();
+    let state = auth_probe_state_for_testing_in_shared(shared.as_ref());
     assert!(
         state.get(&normalize_auth_probe_ip(ip)).is_none(),
         "expired lookup should prune stale state"
@@ -72,36 +66,36 @@ fn edge_expired_entry_is_pruned_and_no_longer_throttled() {
 
 #[test]
 fn adversarial_saturation_grace_requires_extra_failures_before_preauth_throttle() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let ip = IpAddr::V4(Ipv4Addr::new(198, 18, 0, 7));
     let now = Instant::now();
 
     for _ in 0..AUTH_PROBE_BACKOFF_START_FAILS {
-        auth_probe_record_failure(ip, now);
+        auth_probe_record_failure_in(shared.as_ref(), ip, now);
     }
-    auth_probe_note_saturation(now);
+    auth_probe_note_saturation_in(shared.as_ref(), now);
 
     assert!(
-        !auth_probe_should_apply_preauth_throttle(ip, now),
+        !auth_probe_should_apply_preauth_throttle_in(shared.as_ref(), ip, now),
         "during global saturation, peer must receive configured grace window"
     );
 
     for _ in 0..AUTH_PROBE_SATURATION_GRACE_FAILS {
-        auth_probe_record_failure(ip, now + Duration::from_millis(1));
+        auth_probe_record_failure_in(shared.as_ref(), ip, now + Duration::from_millis(1));
     }
 
     assert!(
-        auth_probe_should_apply_preauth_throttle(ip, now + Duration::from_millis(1)),
+        auth_probe_should_apply_preauth_throttle_in(shared.as_ref(), ip, now + Duration::from_millis(1)),
         "after grace failures are exhausted, preauth throttle must activate"
     );
 }
 
 #[test]
 fn integration_over_cap_insertion_keeps_probe_map_bounded() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let now = Instant::now();
     for idx in 0..(AUTH_PROBE_TRACK_MAX_ENTRIES + 1024) {
@@ -111,10 +105,10 @@ fn integration_over_cap_insertion_keeps_probe_map_bounded() {
             ((idx / 256) % 256) as u8,
             (idx % 256) as u8,
         ));
-        auth_probe_record_failure(ip, now);
+        auth_probe_record_failure_in(shared.as_ref(), ip, now);
     }
 
-    let tracked = auth_probe_state_map().len();
+    let tracked = auth_probe_state_for_testing_in_shared(shared.as_ref()).len();
     assert!(
         tracked <= AUTH_PROBE_TRACK_MAX_ENTRIES,
         "probe map must remain hard bounded under insertion storm"
@@ -123,8 +117,8 @@ fn integration_over_cap_insertion_keeps_probe_map_bounded() {
 
 #[test]
 fn light_fuzz_randomized_failures_preserve_cap_and_nonzero_streaks() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let mut seed = 0x4D53_5854_6F66_6175u64;
     let now = Instant::now();
@@ -140,10 +134,10 @@ fn light_fuzz_randomized_failures_preserve_cap_and_nonzero_streaks() {
             (seed >> 8) as u8,
             seed as u8,
         ));
-        auth_probe_record_failure(ip, now + Duration::from_millis((seed & 0x3f) as u64));
+        auth_probe_record_failure_in(shared.as_ref(), ip, now + Duration::from_millis((seed & 0x3f) as u64));
     }
 
-    let state = auth_probe_state_map();
+    let state = auth_probe_state_for_testing_in_shared(shared.as_ref());
     assert!(state.len() <= AUTH_PROBE_TRACK_MAX_ENTRIES);
     for entry in state.iter() {
         assert!(entry.value().fail_streak > 0);
@@ -152,13 +146,14 @@ fn light_fuzz_randomized_failures_preserve_cap_and_nonzero_streaks() {
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 4)]
 async fn stress_parallel_failure_flood_keeps_state_hard_capped() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let start = Instant::now();
     let mut tasks = Vec::new();
 
     for worker in 0..8u8 {
+        let shared = shared.clone();
         tasks.push(tokio::spawn(async move {
             for i in 0..4096u32 {
                 let ip = IpAddr::V4(Ipv4Addr::new(
@@ -167,7 +162,7 @@ async fn stress_parallel_failure_flood_keeps_state_hard_capped() {
                     ((i >> 8) & 0xff) as u8,
                     (i & 0xff) as u8,
                 ));
-                auth_probe_record_failure(ip, start + Duration::from_millis((i % 4) as u64));
+                auth_probe_record_failure_in(shared.as_ref(), ip, start + Duration::from_millis((i % 4) as u64));
             }
         }));
     }
@@ -176,12 +171,12 @@ async fn stress_parallel_failure_flood_keeps_state_hard_capped() {
         task.await.expect("stress worker must not panic");
     }
 
-    let tracked = auth_probe_state_map().len();
+    let tracked = auth_probe_state_for_testing_in_shared(shared.as_ref()).len();
     assert!(
         tracked <= AUTH_PROBE_TRACK_MAX_ENTRIES,
         "parallel failure flood must not exceed cap"
     );
 
     let probe = IpAddr::V4(Ipv4Addr::new(172, 3, 4, 5));
-    let _ = auth_probe_is_throttled(probe, start + Duration::from_millis(2));
+    let _ = auth_probe_is_throttled_in(shared.as_ref(), probe, start + Duration::from_millis(2));
 }

src/proxy/tests/handshake_auth_probe_scan_budget_security_tests.rs

@@ -2,20 +2,14 @@ use super::*;
 use std::net::{IpAddr, Ipv4Addr};
 use std::time::{Duration, Instant};
 
-fn auth_probe_test_guard() -> std::sync::MutexGuard<'static, ()> {
-    auth_probe_test_lock()
-        .lock()
-        .unwrap_or_else(|poisoned| poisoned.into_inner())
-}
-
 #[test]
 fn edge_zero_state_len_yields_zero_start_offset() {
-    let _guard = auth_probe_test_guard();
+    let shared = ProxySharedState::new();
     let ip = IpAddr::V4(Ipv4Addr::new(198, 51, 100, 44));
     let now = Instant::now();
 
     assert_eq!(
-        auth_probe_scan_start_offset(ip, now, 0, 16),
+        auth_probe_scan_start_offset_in(shared.as_ref(), ip, now, 0, 16),
         0,
         "empty map must not produce non-zero scan offset"
     );
@@ -23,7 +17,7 @@ fn edge_zero_state_len_yields_zero_start_offset() {
 
 #[test]
 fn adversarial_large_state_must_allow_start_offset_outside_scan_budget_window() {
-    let _guard = auth_probe_test_guard();
+    let shared = ProxySharedState::new();
     let base = Instant::now();
     let scan_limit = 16usize;
     let state_len = 65_536usize;
@@ -37,7 +31,7 @@ fn adversarial_large_state_must_allow_start_offset_outside_scan_budget_window()
             (i & 0xff) as u8,
         ));
         let now = base + Duration::from_micros(i as u64);
-        let start = auth_probe_scan_start_offset(ip, now, state_len, scan_limit);
+        let start = auth_probe_scan_start_offset_in(shared.as_ref(), ip, now, state_len, scan_limit);
         assert!(
             start < state_len,
             "start offset must stay within state length; start={start}, len={state_len}"
@@ -56,12 +50,12 @@ fn adversarial_large_state_must_allow_start_offset_outside_scan_budget_window()
 
 #[test]
 fn positive_state_smaller_than_scan_limit_caps_to_state_len() {
-    let _guard = auth_probe_test_guard();
+    let shared = ProxySharedState::new();
     let ip = IpAddr::V4(Ipv4Addr::new(192, 0, 2, 17));
     let now = Instant::now();
 
     for state_len in 1..32usize {
-        let start = auth_probe_scan_start_offset(ip, now, state_len, 64);
+        let start = auth_probe_scan_start_offset_in(shared.as_ref(), ip, now, state_len, 64);
         assert!(
             start < state_len,
             "start offset must never exceed state length when scan limit is larger"
@@ -71,7 +65,7 @@ fn positive_state_smaller_than_scan_limit_caps_to_state_len() {
 
 #[test]
 fn light_fuzz_scan_offset_budget_never_exceeds_effective_window() {
-    let _guard = auth_probe_test_guard();
+    let shared = ProxySharedState::new();
     let mut seed = 0x5A41_5356_4C32_3236u64;
     let base = Instant::now();
 
@@ -89,7 +83,7 @@ fn light_fuzz_scan_offset_budget_never_exceeds_effective_window() {
         let state_len = ((seed >> 8) as usize % 131_072).saturating_add(1);
         let scan_limit = ((seed >> 32) as usize % 512).saturating_add(1);
         let now = base + Duration::from_nanos(seed & 0xffff);
-        let start = auth_probe_scan_start_offset(ip, now, state_len, scan_limit);
+        let start = auth_probe_scan_start_offset_in(shared.as_ref(), ip, now, state_len, scan_limit);
 
         assert!(
             start < state_len,

src/proxy/tests/handshake_auth_probe_scan_offset_stress_tests.rs

@@ -3,22 +3,16 @@ use std::collections::HashSet;
 use std::net::{IpAddr, Ipv4Addr};
 use std::time::{Duration, Instant};
 
-fn auth_probe_test_guard() -> std::sync::MutexGuard<'static, ()> {
-    auth_probe_test_lock()
-        .lock()
-        .unwrap_or_else(|poisoned| poisoned.into_inner())
-}
-
 #[test]
 fn positive_same_ip_moving_time_yields_diverse_scan_offsets() {
-    let _guard = auth_probe_test_guard();
+    let shared = ProxySharedState::new();
     let ip = IpAddr::V4(Ipv4Addr::new(198, 51, 100, 77));
     let base = Instant::now();
     let mut uniq = HashSet::new();
 
     for i in 0..512u64 {
         let now = base + Duration::from_nanos(i);
-        let offset = auth_probe_scan_start_offset(ip, now, 65_536, 16);
+        let offset = auth_probe_scan_start_offset_in(shared.as_ref(), ip, now, 65_536, 16);
         uniq.insert(offset);
     }
 
@@ -31,7 +25,7 @@ fn positive_same_ip_moving_time_yields_diverse_scan_offsets() {
 
 #[test]
 fn adversarial_many_ips_same_time_spreads_offsets_without_bias_collapse() {
-    let _guard = auth_probe_test_guard();
+    let shared = ProxySharedState::new();
     let now = Instant::now();
     let mut uniq = HashSet::new();
 
@@ -42,7 +36,7 @@ fn adversarial_many_ips_same_time_spreads_offsets_without_bias_collapse() {
             i as u8,
             (255 - (i as u8)),
         ));
-        uniq.insert(auth_probe_scan_start_offset(ip, now, 65_536, 16));
+        uniq.insert(auth_probe_scan_start_offset_in(shared.as_ref(), ip, now, 65_536, 16));
     }
 
     assert!(
@@ -54,12 +48,13 @@ fn adversarial_many_ips_same_time_spreads_offsets_without_bias_collapse() {
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 4)]
 async fn stress_parallel_failure_churn_under_saturation_remains_capped_and_live() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let start = Instant::now();
     let mut workers = Vec::new();
     for worker in 0..8u8 {
+        let shared = shared.clone();
         workers.push(tokio::spawn(async move {
             for i in 0..8192u32 {
                 let ip = IpAddr::V4(Ipv4Addr::new(
@@ -68,7 +63,7 @@ async fn stress_parallel_failure_churn_under_saturation_remains_capped_and_live(
                     ((i >> 8) & 0xff) as u8,
                     (i & 0xff) as u8,
                 ));
-                auth_probe_record_failure(ip, start + Duration::from_micros((i % 128) as u64));
+                auth_probe_record_failure_in(shared.as_ref(), ip, start + Duration::from_micros((i % 128) as u64));
             }
         }));
     }
@@ -78,17 +73,17 @@ async fn stress_parallel_failure_churn_under_saturation_remains_capped_and_live(
     }
 
     assert!(
-        auth_probe_state_map().len() <= AUTH_PROBE_TRACK_MAX_ENTRIES,
+        auth_probe_state_for_testing_in_shared(shared.as_ref()).len() <= AUTH_PROBE_TRACK_MAX_ENTRIES,
         "state must remain hard-capped under parallel saturation churn"
     );
 
     let probe = IpAddr::V4(Ipv4Addr::new(10, 4, 1, 1));
-    let _ = auth_probe_should_apply_preauth_throttle(probe, start + Duration::from_millis(1));
+    let _ = auth_probe_should_apply_preauth_throttle_in(shared.as_ref(), probe, start + Duration::from_millis(1));
 }
 
 #[test]
 fn light_fuzz_scan_offset_stays_within_window_for_randomized_inputs() {
-    let _guard = auth_probe_test_guard();
+    let shared = ProxySharedState::new();
     let mut seed = 0xA55A_1357_2468_9BDFu64;
     let base = Instant::now();
 
@@ -107,7 +102,7 @@ fn light_fuzz_scan_offset_stays_within_window_for_randomized_inputs() {
         let scan_limit = ((seed >> 40) as usize % 1024).saturating_add(1);
         let now = base + Duration::from_nanos(seed & 0x1fff);
 
-        let offset = auth_probe_scan_start_offset(ip, now, state_len, scan_limit);
+        let offset = auth_probe_scan_start_offset_in(shared.as_ref(), ip, now, state_len, scan_limit);
         assert!(
             offset < state_len,
             "scan offset must always remain inside state length"

src/proxy/tests/handshake_baseline_invariant_tests.rs

@@ -0,0 +1,219 @@
+use super::*;
+use crate::crypto::sha256_hmac;
+use crate::stats::ReplayChecker;
+use std::net::{IpAddr, Ipv4Addr, SocketAddr};
+use std::time::{Duration, Instant};
+use tokio::time::timeout;
+
+fn test_config_with_secret_hex(secret_hex: &str) -> ProxyConfig {
+    let mut cfg = ProxyConfig::default();
+    cfg.access.users.clear();
+    cfg.access
+        .users
+        .insert("user".to_string(), secret_hex.to_string());
+    cfg.access.ignore_time_skew = true;
+    cfg.censorship.mask = true;
+    cfg
+}
+
+fn make_valid_tls_handshake(secret: &[u8], timestamp: u32) -> Vec<u8> {
+    let session_id_len: usize = 32;
+    let len = tls::TLS_DIGEST_POS + tls::TLS_DIGEST_LEN + 1 + session_id_len;
+    let mut handshake = vec![0x42u8; len];
+
+    handshake[tls::TLS_DIGEST_POS + tls::TLS_DIGEST_LEN] = session_id_len as u8;
+    handshake[tls::TLS_DIGEST_POS..tls::TLS_DIGEST_POS + tls::TLS_DIGEST_LEN].fill(0);
+
+    let computed = sha256_hmac(secret, &handshake);
+    let mut digest = computed;
+    let ts = timestamp.to_le_bytes();
+    for i in 0..4 {
+        digest[28 + i] ^= ts[i];
+    }
+
+    handshake[tls::TLS_DIGEST_POS..tls::TLS_DIGEST_POS + tls::TLS_DIGEST_LEN]
+        .copy_from_slice(&digest);
+    handshake
+}
+
+#[tokio::test]
+async fn handshake_baseline_probe_always_falls_back_to_masking() {
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
+
+    let cfg = test_config_with_secret_hex("11111111111111111111111111111111");
+    let replay_checker = ReplayChecker::new(64, Duration::from_secs(60));
+    let rng = SecureRandom::new();
+    let peer: SocketAddr = "198.51.100.210:44321".parse().unwrap();
+
+    let probe = b"not-a-tls-clienthello";
+    let res = handle_tls_handshake(
+        probe,
+        tokio::io::empty(),
+        tokio::io::sink(),
+        peer,
+        &cfg,
+        &replay_checker,
+        &rng,
+        None,
+    )
+    .await;
+
+    assert!(matches!(res, HandshakeResult::BadClient { .. }));
+}
+
+#[tokio::test]
+async fn handshake_baseline_invalid_secret_triggers_fallback_not_error_response() {
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
+
+    let good_secret = [0x22u8; 16];
+    let bad_cfg = test_config_with_secret_hex("33333333333333333333333333333333");
+    let replay_checker = ReplayChecker::new(64, Duration::from_secs(60));
+    let rng = SecureRandom::new();
+    let peer: SocketAddr = "198.51.100.211:44322".parse().unwrap();
+
+    let handshake = make_valid_tls_handshake(&good_secret, 0);
+    let res = handle_tls_handshake(
+        &handshake,
+        tokio::io::empty(),
+        tokio::io::sink(),
+        peer,
+        &bad_cfg,
+        &replay_checker,
+        &rng,
+        None,
+    )
+    .await;
+
+    assert!(matches!(res, HandshakeResult::BadClient { .. }));
+}
+
+#[tokio::test]
+async fn handshake_baseline_auth_probe_streak_increments_per_ip() {
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
+
+    let cfg = test_config_with_secret_hex("44444444444444444444444444444444");
+    let replay_checker = ReplayChecker::new(64, Duration::from_secs(60));
+    let rng = SecureRandom::new();
+
+    let peer: SocketAddr = "203.0.113.10:5555".parse().unwrap();
+    let untouched_ip = IpAddr::V4(Ipv4Addr::new(203, 0, 113, 11));
+    let bad_probe = b"\x16\x03\x01\x00";
+
+    for expected in 1..=3 {
+        let res = handle_tls_handshake_with_shared(
+            bad_probe,
+            tokio::io::empty(),
+            tokio::io::sink(),
+            peer,
+            &cfg,
+            &replay_checker,
+            &rng,
+            None,
+            shared.as_ref(),
+        )
+        .await;
+        assert!(matches!(res, HandshakeResult::BadClient { .. }));
+        assert_eq!(auth_probe_fail_streak_for_testing_in_shared(shared.as_ref(), peer.ip()), Some(expected));
+        assert_eq!(auth_probe_fail_streak_for_testing_in_shared(shared.as_ref(), untouched_ip), None);
+    }
+}
+
+#[test]
+fn handshake_baseline_saturation_fires_at_compile_time_threshold() {
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
+
+    let ip = IpAddr::V4(Ipv4Addr::new(198, 51, 100, 33));
+    let now = Instant::now();
+
+    for _ in 0..AUTH_PROBE_BACKOFF_START_FAILS.saturating_sub(1) {
+        auth_probe_record_failure_in(shared.as_ref(), ip, now);
+    }
+    assert!(!auth_probe_is_throttled_in(shared.as_ref(), ip, now));
+
+    auth_probe_record_failure_in(shared.as_ref(), ip, now);
+    assert!(auth_probe_is_throttled_in(shared.as_ref(), ip, now));
+}
+
+#[test]
+fn handshake_baseline_repeated_probes_streak_monotonic() {
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
+
+    let ip = IpAddr::V4(Ipv4Addr::new(203, 0, 113, 42));
+    let now = Instant::now();
+    let mut prev = 0u32;
+
+    for _ in 0..100 {
+        auth_probe_record_failure_in(shared.as_ref(), ip, now);
+        let current = auth_probe_fail_streak_for_testing_in_shared(shared.as_ref(), ip).unwrap_or(0);
+        assert!(current >= prev, "streak must be monotonic");
+        prev = current;
+    }
+}
+
+#[test]
+fn handshake_baseline_throttled_ip_incurs_backoff_delay() {
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
+
+    let ip = IpAddr::V4(Ipv4Addr::new(198, 51, 100, 44));
+    let now = Instant::now();
+
+    for _ in 0..AUTH_PROBE_BACKOFF_START_FAILS {
+        auth_probe_record_failure_in(shared.as_ref(), ip, now);
+    }
+
+    let delay = auth_probe_backoff(AUTH_PROBE_BACKOFF_START_FAILS);
+    assert!(delay >= Duration::from_millis(AUTH_PROBE_BACKOFF_BASE_MS));
+
+    let before_expiry = now + delay.saturating_sub(Duration::from_millis(1));
+    let after_expiry = now + delay + Duration::from_millis(1);
+
+    assert!(auth_probe_is_throttled_in(shared.as_ref(), ip, before_expiry));
+    assert!(!auth_probe_is_throttled_in(shared.as_ref(), ip, after_expiry));
+}
+
+#[tokio::test]
+async fn handshake_baseline_malformed_probe_frames_fail_closed_to_masking() {
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
+
+    let cfg = test_config_with_secret_hex("55555555555555555555555555555555");
+    let replay_checker = ReplayChecker::new(64, Duration::from_secs(60));
+    let rng = SecureRandom::new();
+    let peer: SocketAddr = "198.51.100.212:44323".parse().unwrap();
+
+    let corpus: Vec<Vec<u8>> = vec![
+        vec![0x16, 0x03, 0x01],
+        vec![0x16, 0x03, 0x01, 0xFF, 0xFF],
+        vec![0x00; 128],
+        (0..64u8).collect(),
+    ];
+
+    for probe in corpus {
+        let res = timeout(
+            Duration::from_millis(250),
+            handle_tls_handshake(
+                &probe,
+                tokio::io::empty(),
+                tokio::io::sink(),
+                peer,
+                &cfg,
+                &replay_checker,
+                &rng,
+                None,
+            ),
+        )
+        .await
+        .expect("malformed probe handling must complete in bounded time");
+
+        assert!(
+            matches!(res, HandshakeResult::BadClient { .. } | HandshakeResult::Error(_)),
+            "malformed probe must fail closed"
+        );
+    }
+}

src/proxy/tests/handshake_fuzz_security_tests.rs

@@ -67,16 +67,10 @@ fn test_config_with_secret_hex(secret_hex: &str) -> ProxyConfig {
     cfg
 }
 
-fn auth_probe_test_guard() -> MutexGuard<'static, ()> {
-    auth_probe_test_lock()
-        .lock()
-        .unwrap_or_else(|poisoned| poisoned.into_inner())
-}
-
 #[tokio::test]
 async fn mtproto_handshake_duplicate_digest_is_replayed_on_second_attempt() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let secret_hex = "11223344556677889900aabbccddeeff";
     let base = make_valid_mtproto_handshake(secret_hex, ProtoTag::Secure, 2);
@@ -110,13 +104,13 @@ async fn mtproto_handshake_duplicate_digest_is_replayed_on_second_attempt() {
     .await;
     assert!(matches!(second, HandshakeResult::BadClient { .. }));
 
-    clear_auth_probe_state_for_testing();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 }
 
 #[tokio::test]
 async fn mtproto_handshake_fuzz_corpus_never_panics_and_stays_fail_closed() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let secret_hex = "00112233445566778899aabbccddeeff";
     let base = make_valid_mtproto_handshake(secret_hex, ProtoTag::Secure, 1);
@@ -178,13 +172,13 @@ async fn mtproto_handshake_fuzz_corpus_never_panics_and_stays_fail_closed() {
         );
     }
 
-    clear_auth_probe_state_for_testing();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 }
 
 #[tokio::test]
 async fn mtproto_handshake_mixed_corpus_never_panics_and_exact_duplicates_are_rejected() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let secret_hex = "99887766554433221100ffeeddccbbaa";
     let base = make_valid_mtproto_handshake(secret_hex, ProtoTag::Secure, 4);
@@ -274,5 +268,5 @@ async fn mtproto_handshake_mixed_corpus_never_panics_and_exact_duplicates_are_re
         );
     }
 
-    clear_auth_probe_state_for_testing();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 }

src/proxy/tests/handshake_more_clever_tests.rs

@@ -11,12 +11,6 @@ use tokio::sync::Barrier;
 
 // --- Helpers ---
 
-fn auth_probe_test_guard() -> std::sync::MutexGuard<'static, ()> {
-    auth_probe_test_lock()
-        .lock()
-        .unwrap_or_else(|poisoned| poisoned.into_inner())
-}
-
 fn test_config_with_secret_hex(secret_hex: &str) -> ProxyConfig {
     let mut cfg = ProxyConfig::default();
     cfg.access.users.clear();
@@ -164,8 +158,8 @@ fn make_valid_tls_client_hello_with_sni_and_alpn(
 
 #[tokio::test]
 async fn server_hello_delay_bypassed_if_max_is_zero_despite_high_min() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let secret = [0x1Au8; 16];
     let mut config = test_config_with_secret_hex("1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a");
@@ -201,10 +195,10 @@ async fn server_hello_delay_bypassed_if_max_is_zero_despite_high_min() {
 
 #[test]
 fn auth_probe_backoff_extreme_fail_streak_clamps_safely() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
-    let state = auth_probe_state_map();
+    let state = auth_probe_state_for_testing_in_shared(shared.as_ref());
     let peer_ip = IpAddr::V4(Ipv4Addr::new(198, 51, 100, 99));
     let now = Instant::now();
 
@@ -217,7 +211,7 @@ fn auth_probe_backoff_extreme_fail_streak_clamps_safely() {
         },
     );
 
-    auth_probe_record_failure_with_state(&state, peer_ip, now);
+    auth_probe_record_failure_with_state_in(shared.as_ref(), &state, peer_ip, now);
 
     let updated = state.get(&peer_ip).unwrap();
     assert_eq!(updated.fail_streak, u32::MAX);
@@ -270,8 +264,8 @@ fn generate_tg_nonce_cryptographic_uniqueness_and_entropy() {
 
 #[tokio::test]
 async fn mtproto_multi_user_decryption_isolation() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let mut config = ProxyConfig::default();
     config.general.modes.secure = true;
@@ -323,10 +317,8 @@ async fn mtproto_multi_user_decryption_isolation() {
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 4)]
 async fn invalid_secret_warning_lock_contention_and_bound() {
-    let _guard = warned_secrets_test_lock()
-        .lock()
-        .unwrap_or_else(|poisoned| poisoned.into_inner());
-    clear_warned_secrets_for_testing();
+    let shared = ProxySharedState::new();
+    clear_warned_secrets_for_testing_in_shared(shared.as_ref());
 
     let tasks = 50;
     let iterations_per_task = 100;
@@ -335,11 +327,12 @@ async fn invalid_secret_warning_lock_contention_and_bound() {
 
     for t in 0..tasks {
         let b = barrier.clone();
+        let shared = shared.clone();
         handles.push(tokio::spawn(async move {
             b.wait().await;
             for i in 0..iterations_per_task {
                 let user_name = format!("contention_user_{}_{}", t, i);
-                warn_invalid_secret_once(&user_name, "invalid_hex", ACCESS_SECRET_BYTES, None);
+                warn_invalid_secret_once_in(shared.as_ref(), &user_name, "invalid_hex", ACCESS_SECRET_BYTES, None);
             }
         }));
     }
@@ -348,7 +341,7 @@ async fn invalid_secret_warning_lock_contention_and_bound() {
         handle.await.unwrap();
     }
 
-    let warned = INVALID_SECRET_WARNED.get().unwrap();
+    let warned = warned_secrets_for_testing_in_shared(shared.as_ref());
     let guard = warned
         .lock()
         .unwrap_or_else(|poisoned| poisoned.into_inner());
@@ -362,8 +355,8 @@ async fn invalid_secret_warning_lock_contention_and_bound() {
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 4)]
 async fn mtproto_strict_concurrent_replay_race_condition() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let secret_hex = "4A4A4A4A4A4A4A4A4A4A4A4A4A4A4A4A";
     let config = Arc::new(test_config_with_secret_hex(secret_hex));
@@ -428,8 +421,8 @@ async fn mtproto_strict_concurrent_replay_race_condition() {
 
 #[tokio::test]
 async fn tls_alpn_zero_length_protocol_handled_safely() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let secret = [0x5Bu8; 16];
     let mut config = test_config_with_secret_hex("5b5b5b5b5b5b5b5b5b5b5b5b5b5b5b5b");
@@ -461,8 +454,8 @@ async fn tls_alpn_zero_length_protocol_handled_safely() {
 
 #[tokio::test]
 async fn tls_sni_massive_hostname_does_not_panic() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let secret = [0x6Cu8; 16];
     let config = test_config_with_secret_hex("6c6c6c6c6c6c6c6c6c6c6c6c6c6c6c6c");
@@ -497,8 +490,8 @@ async fn tls_sni_massive_hostname_does_not_panic() {
 
 #[tokio::test]
 async fn tls_progressive_truncation_fuzzing_no_panics() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let secret = [0x7Du8; 16];
     let config = test_config_with_secret_hex("7d7d7d7d7d7d7d7d7d7d7d7d7d7d7d7d");
@@ -535,8 +528,8 @@ async fn tls_progressive_truncation_fuzzing_no_panics() {
 
 #[tokio::test]
 async fn mtproto_pure_entropy_fuzzing_no_panics() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let config = test_config_with_secret_hex("8e8e8e8e8e8e8e8e8e8e8e8e8e8e8e8e");
     let replay_checker = ReplayChecker::new(128, Duration::from_secs(60));
@@ -569,10 +562,8 @@ async fn mtproto_pure_entropy_fuzzing_no_panics() {
 
 #[test]
 fn decode_user_secret_odd_length_hex_rejection() {
-    let _guard = warned_secrets_test_lock()
-        .lock()
-        .unwrap_or_else(|poisoned| poisoned.into_inner());
-    clear_warned_secrets_for_testing();
+    let shared = ProxySharedState::new();
+    clear_warned_secrets_for_testing_in_shared(shared.as_ref());
 
     let mut config = ProxyConfig::default();
     config.access.users.clear();
@@ -581,7 +572,7 @@ fn decode_user_secret_odd_length_hex_rejection() {
         "1234567890123456789012345678901".to_string(),
     );
 
-    let decoded = decode_user_secrets(&config, None);
+    let decoded = decode_user_secrets_in(shared.as_ref(), &config, None);
     assert!(
         decoded.is_empty(),
         "Odd-length hex string must be gracefully rejected by hex::decode without unwrapping"
@@ -590,10 +581,10 @@ fn decode_user_secret_odd_length_hex_rejection() {
 
 #[test]
 fn saturation_grace_pre_existing_high_fail_streak_immediate_throttle() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
-    let state = auth_probe_state_map();
+    let state = auth_probe_state_for_testing_in_shared(shared.as_ref());
     let peer_ip = IpAddr::V4(Ipv4Addr::new(198, 51, 100, 112));
     let now = Instant::now();
 
@@ -608,7 +599,7 @@ fn saturation_grace_pre_existing_high_fail_streak_immediate_throttle() {
     );
 
     {
-        let mut guard = auth_probe_saturation_state_lock();
+        let mut guard = auth_probe_saturation_state_lock_for_testing_in_shared(shared.as_ref());
         *guard = Some(AuthProbeSaturationState {
             fail_streak: AUTH_PROBE_BACKOFF_START_FAILS,
             blocked_until: now + Duration::from_secs(5),
@@ -616,7 +607,7 @@ fn saturation_grace_pre_existing_high_fail_streak_immediate_throttle() {
         });
     }
 
-    let is_throttled = auth_probe_should_apply_preauth_throttle(peer_ip, now);
+    let is_throttled = auth_probe_should_apply_preauth_throttle_in(shared.as_ref(), peer_ip, now);
     assert!(
         is_throttled,
         "A peer with a pre-existing high fail streak must be immediately throttled when saturation begins, receiving no unearned grace period"
@@ -625,21 +616,21 @@ fn saturation_grace_pre_existing_high_fail_streak_immediate_throttle() {
 
 #[test]
 fn auth_probe_saturation_note_resets_retention_window() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let base_time = Instant::now();
 
-    auth_probe_note_saturation(base_time);
+    auth_probe_note_saturation_in(shared.as_ref(), base_time);
     let later = base_time + Duration::from_secs(AUTH_PROBE_TRACK_RETENTION_SECS - 1);
-    auth_probe_note_saturation(later);
+    auth_probe_note_saturation_in(shared.as_ref(), later);
 
     let check_time = base_time + Duration::from_secs(AUTH_PROBE_TRACK_RETENTION_SECS + 5);
 
     // This call may return false if backoff has elapsed, but it must not clear
     // the saturation state because `later` refreshed last_seen.
-    let _ = auth_probe_saturation_is_throttled_at_for_testing(check_time);
-    let guard = auth_probe_saturation_state_lock();
+    let _ = auth_probe_saturation_is_throttled_at_for_testing_in_shared(shared.as_ref(), check_time);
+    let guard = auth_probe_saturation_state_lock_for_testing_in_shared(shared.as_ref());
     assert!(
         guard.is_some(),
         "Ongoing saturation notes must refresh last_seen so saturation state remains retained past the original window"

src/proxy/tests/handshake_real_bug_stress_tests.rs

@@ -6,12 +6,6 @@ use std::sync::Arc;
 use std::time::{Duration, Instant};
 use tokio::sync::Barrier;
 
-fn auth_probe_test_guard() -> std::sync::MutexGuard<'static, ()> {
-    auth_probe_test_lock()
-        .lock()
-        .unwrap_or_else(|poisoned| poisoned.into_inner())
-}
-
 fn test_config_with_secret_hex(secret_hex: &str) -> ProxyConfig {
     let mut cfg = ProxyConfig::default();
     cfg.access.users.clear();
@@ -127,8 +121,8 @@ fn make_valid_mtproto_handshake(
 
 #[tokio::test]
 async fn tls_alpn_reject_does_not_pollute_replay_cache() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let secret = [0x11u8; 16];
     let mut config = test_config_with_secret_hex("11111111111111111111111111111111");
@@ -164,8 +158,8 @@ async fn tls_alpn_reject_does_not_pollute_replay_cache() {
 
 #[tokio::test]
 async fn tls_truncated_session_id_len_fails_closed_without_panic() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let config = test_config_with_secret_hex("33333333333333333333333333333333");
     let replay_checker = ReplayChecker::new(128, Duration::from_secs(60));
@@ -193,10 +187,10 @@ async fn tls_truncated_session_id_len_fails_closed_without_panic() {
 
 #[test]
 fn auth_probe_eviction_identical_timestamps_keeps_map_bounded() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
-    let state = auth_probe_state_map();
+    let state = auth_probe_state_for_testing_in_shared(shared.as_ref());
     let same = Instant::now();
 
     for i in 0..AUTH_PROBE_TRACK_MAX_ENTRIES {
@@ -212,7 +206,7 @@ fn auth_probe_eviction_identical_timestamps_keeps_map_bounded() {
     }
 
     let new_ip = IpAddr::V4(Ipv4Addr::new(192, 168, 21, 21));
-    auth_probe_record_failure_with_state(state, new_ip, same + Duration::from_millis(1));
+    auth_probe_record_failure_with_state_in(shared.as_ref(), state, new_ip, same + Duration::from_millis(1));
 
     assert_eq!(state.len(), AUTH_PROBE_TRACK_MAX_ENTRIES);
     assert!(state.contains_key(&new_ip));
@@ -220,21 +214,21 @@ fn auth_probe_eviction_identical_timestamps_keeps_map_bounded() {
 
 #[test]
 fn clear_auth_probe_state_recovers_from_poisoned_saturation_lock() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
-    let saturation = auth_probe_saturation_state();
+    let shared_for_poison = shared.clone();
     let poison_thread = std::thread::spawn(move || {
-        let _hold = saturation
+        let _hold = auth_probe_saturation_state_for_testing_in_shared(shared_for_poison.as_ref())
             .lock()
             .unwrap_or_else(|poisoned| poisoned.into_inner());
         panic!("intentional poison for regression coverage");
     });
     let _ = poison_thread.join();
 
-    clear_auth_probe_state_for_testing();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
-    let guard = auth_probe_saturation_state()
+    let guard = auth_probe_saturation_state_for_testing_in_shared(shared.as_ref())
         .lock()
         .unwrap_or_else(|poisoned| poisoned.into_inner());
     assert!(guard.is_none());
@@ -242,12 +236,9 @@ fn clear_auth_probe_state_recovers_from_poisoned_saturation_lock() {
 
 #[tokio::test]
 async fn mtproto_invalid_length_secret_is_ignored_and_valid_user_still_auths() {
-    let _probe_guard = auth_probe_test_guard();
-    let _warn_guard = warned_secrets_test_lock()
-        .lock()
-        .unwrap_or_else(|poisoned| poisoned.into_inner());
-    clear_auth_probe_state_for_testing();
-    clear_warned_secrets_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
+    clear_warned_secrets_for_testing_in_shared(shared.as_ref());
 
     let mut config = ProxyConfig::default();
     config.general.modes.secure = true;
@@ -285,14 +276,14 @@ async fn mtproto_invalid_length_secret_is_ignored_and_valid_user_still_auths() {
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 4)]
 async fn saturation_grace_exhaustion_under_concurrency_keeps_peer_throttled() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     let peer_ip = IpAddr::V4(Ipv4Addr::new(198, 51, 100, 80));
     let now = Instant::now();
 
     {
-        let mut guard = auth_probe_saturation_state()
+        let mut guard = auth_probe_saturation_state_for_testing_in_shared(shared.as_ref())
             .lock()
             .unwrap_or_else(|poisoned| poisoned.into_inner());
         *guard = Some(AuthProbeSaturationState {
@@ -302,7 +293,7 @@ async fn saturation_grace_exhaustion_under_concurrency_keeps_peer_throttled() {
         });
     }
 
-    let state = auth_probe_state_map();
+    let state = auth_probe_state_for_testing_in_shared(shared.as_ref());
     state.insert(
         peer_ip,
         AuthProbeState {
@@ -318,9 +309,10 @@ async fn saturation_grace_exhaustion_under_concurrency_keeps_peer_throttled() {
 
     for _ in 0..tasks {
         let b = barrier.clone();
+        let shared = shared.clone();
         handles.push(tokio::spawn(async move {
             b.wait().await;
-            auth_probe_record_failure(peer_ip, Instant::now());
+            auth_probe_record_failure_in(shared.as_ref(), peer_ip, Instant::now());
         }));
     }
 
@@ -333,7 +325,7 @@ async fn saturation_grace_exhaustion_under_concurrency_keeps_peer_throttled() {
         final_state.fail_streak
             >= AUTH_PROBE_BACKOFF_START_FAILS + AUTH_PROBE_SATURATION_GRACE_FAILS
     );
-    assert!(auth_probe_should_apply_preauth_throttle(
+    assert!(auth_probe_should_apply_preauth_throttle_in(shared.as_ref(), 
         peer_ip,
         Instant::now()
     ));

src/proxy/tests/handshake_saturation_poison_security_tests.rs

@@ -1,46 +1,39 @@
 use super::*;
 use std::time::{Duration, Instant};
 
-fn auth_probe_test_guard() -> std::sync::MutexGuard<'static, ()> {
-    auth_probe_test_lock()
-        .lock()
-        .unwrap_or_else(|poisoned| poisoned.into_inner())
-}
-
-fn poison_saturation_mutex() {
-    let saturation = auth_probe_saturation_state();
-    let poison_thread = std::thread::spawn(move || {
+fn poison_saturation_mutex(shared: &ProxySharedState) {
+    let saturation = auth_probe_saturation_state_for_testing_in_shared(shared);
+    let _ = std::panic::catch_unwind(std::panic::AssertUnwindSafe(|| {
         let _guard = saturation
             .lock()
             .expect("saturation mutex must be lockable for poison setup");
         panic!("intentional poison for saturation mutex resilience test");
-    });
-    let _ = poison_thread.join();
+    }));
 }
 
 #[test]
 fn auth_probe_saturation_note_recovers_after_mutex_poison() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
-    poison_saturation_mutex();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
+    poison_saturation_mutex(shared.as_ref());
 
     let now = Instant::now();
-    auth_probe_note_saturation(now);
+    auth_probe_note_saturation_in(shared.as_ref(), now);
 
     assert!(
-        auth_probe_saturation_is_throttled_at_for_testing(now),
+        auth_probe_saturation_is_throttled_at_for_testing_in_shared(shared.as_ref(), now),
         "poisoned saturation mutex must not disable saturation throttling"
     );
 }
 
 #[test]
 fn auth_probe_saturation_check_recovers_after_mutex_poison() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
-    poison_saturation_mutex();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
+    poison_saturation_mutex(shared.as_ref());
 
     {
-        let mut guard = auth_probe_saturation_state_lock();
+        let mut guard = auth_probe_saturation_state_lock_for_testing_in_shared(shared.as_ref());
         *guard = Some(AuthProbeSaturationState {
             fail_streak: AUTH_PROBE_BACKOFF_START_FAILS,
             blocked_until: Instant::now() + Duration::from_millis(10),
@@ -49,23 +42,23 @@ fn auth_probe_saturation_check_recovers_after_mutex_poison() {
     }
 
     assert!(
-        auth_probe_saturation_is_throttled_for_testing(),
+        auth_probe_saturation_is_throttled_for_testing_in_shared(shared.as_ref()),
         "throttle check must recover poisoned saturation mutex and stay fail-closed"
     );
 }
 
 #[test]
 fn clear_auth_probe_state_clears_saturation_even_if_poisoned() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
-    poison_saturation_mutex();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
+    poison_saturation_mutex(shared.as_ref());
 
-    auth_probe_note_saturation(Instant::now());
-    assert!(auth_probe_saturation_is_throttled_for_testing());
+    auth_probe_note_saturation_in(shared.as_ref(), Instant::now());
+    assert!(auth_probe_saturation_is_throttled_for_testing_in_shared(shared.as_ref()));
 
-    clear_auth_probe_state_for_testing();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
     assert!(
-        !auth_probe_saturation_is_throttled_for_testing(),
+        !auth_probe_saturation_is_throttled_for_testing_in_shared(shared.as_ref()),
         "clear helper must clear saturation state even after poison"
     );
 }

src/proxy/tests/handshake_timing_manual_bench_tests.rs

@@ -4,12 +4,6 @@ use crate::protocol::constants::{ProtoTag, TLS_RECORD_HANDSHAKE, TLS_VERSION};
 use std::net::SocketAddr;
 use std::time::{Duration, Instant};
 
-fn auth_probe_test_guard() -> std::sync::MutexGuard<'static, ()> {
-    auth_probe_test_lock()
-        .lock()
-        .unwrap_or_else(|poisoned| poisoned.into_inner())
-}
-
 fn make_valid_mtproto_handshake(
     secret_hex: &str,
     proto_tag: ProtoTag,
@@ -149,8 +143,8 @@ fn median_ns(samples: &mut [u128]) -> u128 {
 #[tokio::test]
 #[ignore = "manual benchmark: timing-sensitive and host-dependent"]
 async fn mtproto_user_scan_timing_manual_benchmark() {
-    let _guard = auth_probe_test_guard();
-    clear_auth_probe_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
 
     const DECOY_USERS: usize = 8_000;
     const ITERATIONS: usize = 250;
@@ -243,7 +237,7 @@ async fn mtproto_user_scan_timing_manual_benchmark() {
 #[tokio::test]
 #[ignore = "manual benchmark: timing-sensitive and host-dependent"]
 async fn tls_sni_preferred_vs_no_sni_fallback_manual_benchmark() {
-    let _guard = auth_probe_test_guard();
+    let shared = ProxySharedState::new();
 
     const DECOY_USERS: usize = 8_000;
     const ITERATIONS: usize = 250;
@@ -281,7 +275,7 @@ async fn tls_sni_preferred_vs_no_sni_fallback_manual_benchmark() {
         let no_sni = make_valid_tls_handshake(&target_secret, (i as u32).wrapping_add(10_000));
 
         let started_sni = Instant::now();
-        let sni_secrets = decode_user_secrets(&config, Some(preferred_user));
+        let sni_secrets = decode_user_secrets_in(shared.as_ref(), &config, Some(preferred_user));
         let sni_result = tls::validate_tls_handshake_with_replay_window(
             &with_sni,
             &sni_secrets,
@@ -292,7 +286,7 @@ async fn tls_sni_preferred_vs_no_sni_fallback_manual_benchmark() {
         assert!(sni_result.is_some());
 
         let started_no_sni = Instant::now();
-        let no_sni_secrets = decode_user_secrets(&config, None);
+        let no_sni_secrets = decode_user_secrets_in(shared.as_ref(), &config, None);
         let no_sni_result = tls::validate_tls_handshake_with_replay_window(
             &no_sni,
             &no_sni_secrets,

src/proxy/tests/masking_baseline_invariant_tests.rs

@@ -0,0 +1,156 @@
+use super::*;
+use tokio::io::duplex;
+use tokio::net::TcpListener;
+use tokio::time::{Duration, Instant, timeout};
+
+#[test]
+fn masking_baseline_timing_normalization_budget_within_bounds() {
+    let mut config = ProxyConfig::default();
+    config.censorship.mask_timing_normalization_enabled = true;
+    config.censorship.mask_timing_normalization_floor_ms = 120;
+    config.censorship.mask_timing_normalization_ceiling_ms = 180;
+
+    for _ in 0..256 {
+        let budget = mask_outcome_target_budget(&config);
+        assert!(budget >= Duration::from_millis(120));
+        assert!(budget <= Duration::from_millis(180));
+    }
+}
+
+#[tokio::test]
+async fn masking_baseline_fallback_relays_to_mask_host() {
+    let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+    let backend_addr = listener.local_addr().unwrap();
+    let initial = b"GET /baseline HTTP/1.1\r\nHost: x\r\n\r\n".to_vec();
+    let reply = b"HTTP/1.1 200 OK\r\nContent-Length: 2\r\n\r\nOK".to_vec();
+
+    let accept_task = tokio::spawn({
+        let initial = initial.clone();
+        let reply = reply.clone();
+        async move {
+            let (mut stream, _) = listener.accept().await.unwrap();
+            let mut seen = vec![0u8; initial.len()];
+            stream.read_exact(&mut seen).await.unwrap();
+            assert_eq!(seen, initial);
+            stream.write_all(&reply).await.unwrap();
+        }
+    });
+
+    let mut config = ProxyConfig::default();
+    config.general.beobachten = false;
+    config.censorship.mask = true;
+    config.censorship.mask_host = Some("127.0.0.1".to_string());
+    config.censorship.mask_port = backend_addr.port();
+    config.censorship.mask_unix_sock = None;
+    config.censorship.mask_proxy_protocol = 0;
+
+    let peer: SocketAddr = "203.0.113.70:55070".parse().unwrap();
+    let local_addr: SocketAddr = "127.0.0.1:443".parse().unwrap();
+
+    let (client_reader, _client_writer) = duplex(1024);
+    let (mut visible_reader, visible_writer) = duplex(2048);
+    let beobachten = BeobachtenStore::new();
+
+    handle_bad_client(
+        client_reader,
+        visible_writer,
+        &initial,
+        peer,
+        local_addr,
+        &config,
+        &beobachten,
+    )
+    .await;
+
+    let mut observed = vec![0u8; reply.len()];
+    visible_reader.read_exact(&mut observed).await.unwrap();
+    assert_eq!(observed, reply);
+    accept_task.await.unwrap();
+}
+
+#[test]
+fn masking_baseline_no_normalization_returns_default_budget() {
+    let mut config = ProxyConfig::default();
+    config.censorship.mask_timing_normalization_enabled = false;
+    let budget = mask_outcome_target_budget(&config);
+    assert_eq!(budget, MASK_TIMEOUT);
+}
+
+#[tokio::test]
+async fn masking_baseline_unreachable_mask_host_silent_failure() {
+    let mut config = ProxyConfig::default();
+    config.general.beobachten = false;
+    config.censorship.mask = true;
+    config.censorship.mask_unix_sock = None;
+    config.censorship.mask_host = Some("127.0.0.1".to_string());
+    config.censorship.mask_port = 1;
+    config.censorship.mask_timing_normalization_enabled = false;
+
+    let peer: SocketAddr = "203.0.113.71:55071".parse().unwrap();
+    let local_addr: SocketAddr = "127.0.0.1:443".parse().unwrap();
+    let beobachten = BeobachtenStore::new();
+
+    let (client_reader, _client_writer) = duplex(1024);
+    let (mut visible_reader, visible_writer) = duplex(1024);
+
+    let started = Instant::now();
+    handle_bad_client(
+        client_reader,
+        visible_writer,
+        b"GET / HTTP/1.1\r\n\r\n",
+        peer,
+        local_addr,
+        &config,
+        &beobachten,
+    )
+    .await;
+    let elapsed = started.elapsed();
+
+    assert!(elapsed < Duration::from_secs(1));
+
+    let mut buf = [0u8; 1];
+    let read_res = timeout(Duration::from_millis(50), visible_reader.read(&mut buf)).await;
+    match read_res {
+        Ok(Ok(0)) | Err(_) => {}
+        Ok(Ok(n)) => panic!("expected no response bytes, got {n}"),
+        Ok(Err(e)) => panic!("unexpected client-side read error: {e}"),
+    }
+}
+
+#[tokio::test]
+async fn masking_baseline_light_fuzz_initial_data_no_panic() {
+    let mut config = ProxyConfig::default();
+    config.general.beobachten = false;
+    config.censorship.mask = false;
+
+    let peer: SocketAddr = "203.0.113.72:55072".parse().unwrap();
+    let local_addr: SocketAddr = "127.0.0.1:443".parse().unwrap();
+    let beobachten = BeobachtenStore::new();
+
+    let corpus: Vec<Vec<u8>> = vec![
+        vec![],
+        vec![0x00],
+        vec![0xFF; 1024],
+        (0..255u8).collect(),
+        b"\xF0\x28\x8C\x28".to_vec(),
+    ];
+
+    for sample in corpus {
+        let (client_reader, _client_writer) = duplex(1024);
+        let (_visible_reader, visible_writer) = duplex(1024);
+        timeout(
+            Duration::from_millis(300),
+            handle_bad_client(
+                client_reader,
+                visible_writer,
+                &sample,
+                peer,
+                local_addr,
+                &config,
+                &beobachten,
+            ),
+        )
+        .await
+        .expect("fuzz sample must complete in bounded time");
+    }
+}

src/proxy/tests/masking_lognormal_timing_security_tests.rs

@@ -0,0 +1,333 @@
+use super::*;
+use rand::rngs::StdRng;
+use rand::SeedableRng;
+
+fn seeded_rng(seed: u64) -> StdRng {
+    StdRng::seed_from_u64(seed)
+}
+
+// ── Positive: all samples within configured envelope ────────────────────
+
+#[test]
+fn masking_lognormal_all_samples_within_configured_envelope() {
+    let mut rng = seeded_rng(42);
+    let floor: u64 = 500;
+    let ceiling: u64 = 2000;
+    for _ in 0..10_000 {
+        let val = sample_lognormal_percentile_bounded(floor, ceiling, &mut rng);
+        assert!(
+            val >= floor && val <= ceiling,
+            "sample {} outside [{}, {}]",
+            val,
+            floor,
+            ceiling,
+        );
+    }
+}
+
+// ── Statistical: median near geometric mean ─────────────────────────────
+
+#[test]
+fn masking_lognormal_sample_median_near_geometric_mean_of_range() {
+    let mut rng = seeded_rng(42);
+    let floor: u64 = 500;
+    let ceiling: u64 = 2000;
+    let geometric_mean = ((floor as f64) * (ceiling as f64)).sqrt();
+
+    let mut samples: Vec<u64> = (0..10_000)
+        .map(|_| sample_lognormal_percentile_bounded(floor, ceiling, &mut rng))
+        .collect();
+    samples.sort();
+    let median = samples[samples.len() / 2] as f64;
+
+    let tolerance = geometric_mean * 0.10;
+    assert!(
+        (median - geometric_mean).abs() <= tolerance,
+        "median {} not within 10% of geometric mean {} (tolerance {})",
+        median,
+        geometric_mean,
+        tolerance,
+    );
+}
+
+// ── Edge: degenerate floor == ceiling returns exactly that value ─────────
+
+#[test]
+fn masking_lognormal_degenerate_floor_eq_ceiling_returns_floor() {
+    let mut rng = seeded_rng(99);
+    for _ in 0..100 {
+        let val = sample_lognormal_percentile_bounded(1000, 1000, &mut rng);
+        assert_eq!(val, 1000, "floor == ceiling must always return exactly that value");
+    }
+}
+
+// ── Edge: floor > ceiling (misconfiguration) clamps safely ──────────────
+
+#[test]
+fn masking_lognormal_floor_greater_than_ceiling_returns_ceiling() {
+    let mut rng = seeded_rng(77);
+    let val = sample_lognormal_percentile_bounded(2000, 500, &mut rng);
+    assert_eq!(
+        val, 500,
+        "floor > ceiling misconfiguration must return ceiling (the minimum)"
+    );
+}
+
+// ── Edge: floor == 1, ceiling == 1 ──────────────────────────────────────
+
+#[test]
+fn masking_lognormal_floor_1_ceiling_1_returns_1() {
+    let mut rng = seeded_rng(12);
+    let val = sample_lognormal_percentile_bounded(1, 1, &mut rng);
+    assert_eq!(val, 1);
+}
+
+// ── Edge: floor == 1, ceiling very large ────────────────────────────────
+
+#[test]
+fn masking_lognormal_wide_range_all_samples_within_bounds() {
+    let mut rng = seeded_rng(55);
+    let floor: u64 = 1;
+    let ceiling: u64 = 100_000;
+    for _ in 0..10_000 {
+        let val = sample_lognormal_percentile_bounded(floor, ceiling, &mut rng);
+        assert!(
+            val >= floor && val <= ceiling,
+            "sample {} outside [{}, {}]",
+            val,
+            floor,
+            ceiling,
+        );
+    }
+}
+
+// ── Adversarial: extreme sigma (floor very close to ceiling) ────────────
+
+#[test]
+fn masking_lognormal_narrow_range_does_not_panic() {
+    let mut rng = seeded_rng(88);
+    let floor: u64 = 999;
+    let ceiling: u64 = 1001;
+    for _ in 0..10_000 {
+        let val = sample_lognormal_percentile_bounded(floor, ceiling, &mut rng);
+        assert!(
+            val >= floor && val <= ceiling,
+            "narrow range sample {} outside [{}, {}]",
+            val,
+            floor,
+            ceiling,
+        );
+    }
+}
+
+// ── Adversarial: u64::MAX ceiling does not overflow ──────────────────────
+
+#[test]
+fn masking_lognormal_u64_max_ceiling_no_overflow() {
+    let mut rng = seeded_rng(123);
+    let floor: u64 = 1;
+    let ceiling: u64 = u64::MAX;
+    for _ in 0..1000 {
+        let val = sample_lognormal_percentile_bounded(floor, ceiling, &mut rng);
+        assert!(val >= floor, "sample {} below floor {}", val, floor);
+        // u64::MAX clamp ensures no overflow
+    }
+}
+
+// ── Adversarial: floor == 0 guard ───────────────────────────────────────
+// The function should handle floor=0 gracefully even though callers
+// should never pass it. Verifies no panic on ln(0).
+
+#[test]
+fn masking_lognormal_floor_zero_no_panic() {
+    let mut rng = seeded_rng(200);
+    let val = sample_lognormal_percentile_bounded(0, 1000, &mut rng);
+    assert!(val <= 1000, "sample {} exceeds ceiling 1000", val);
+}
+
+// ── Adversarial: both zero → returns 0 ──────────────────────────────────
+
+#[test]
+fn masking_lognormal_both_zero_returns_zero() {
+    let mut rng = seeded_rng(201);
+    let val = sample_lognormal_percentile_bounded(0, 0, &mut rng);
+    assert_eq!(val, 0, "floor=0 ceiling=0 must return 0");
+}
+
+// ── Distribution shape: not uniform ─────────────────────────────────────
+// A DPI classifier trained on uniform delay samples should detect a
+// distribution where > 60% of samples fall in the lower half of the range.
+// Log-normal is right-skewed: more samples near floor than ceiling.
+
+#[test]
+fn masking_lognormal_distribution_is_right_skewed() {
+    let mut rng = seeded_rng(42);
+    let floor: u64 = 100;
+    let ceiling: u64 = 5000;
+    let midpoint = (floor + ceiling) / 2;
+
+    let samples: Vec<u64> = (0..10_000)
+        .map(|_| sample_lognormal_percentile_bounded(floor, ceiling, &mut rng))
+        .collect();
+
+    let below_mid = samples.iter().filter(|&&s| s < midpoint).count();
+    let ratio = below_mid as f64 / samples.len() as f64;
+
+    assert!(
+        ratio > 0.55,
+        "Log-normal should be right-skewed (>55% below midpoint), got {}%",
+        ratio * 100.0,
+    );
+}
+
+// ── Determinism: same seed produces same sequence ───────────────────────
+
+#[test]
+fn masking_lognormal_deterministic_with_same_seed() {
+    let mut rng1 = seeded_rng(42);
+    let mut rng2 = seeded_rng(42);
+    for _ in 0..100 {
+        let a = sample_lognormal_percentile_bounded(500, 2000, &mut rng1);
+        let b = sample_lognormal_percentile_bounded(500, 2000, &mut rng2);
+        assert_eq!(a, b, "Same seed must produce same output");
+    }
+}
+
+// ── Fuzz: 1000 random (floor, ceiling) pairs, no panics ─────────────────
+
+#[test]
+fn masking_lognormal_fuzz_random_params_no_panic() {
+    use rand::Rng;
+    let mut rng = seeded_rng(999);
+    for _ in 0..1000 {
+        let a: u64 = rng.random_range(0..=10_000);
+        let b: u64 = rng.random_range(0..=10_000);
+        let floor = a.min(b);
+        let ceiling = a.max(b);
+        let val = sample_lognormal_percentile_bounded(floor, ceiling, &mut rng);
+        assert!(
+            val >= floor && val <= ceiling,
+            "fuzz: sample {} outside [{}, {}]",
+            val,
+            floor,
+            ceiling,
+        );
+    }
+}
+
+// ── Fuzz: adversarial floor > ceiling pairs ──────────────────────────────
+
+#[test]
+fn masking_lognormal_fuzz_inverted_params_no_panic() {
+    use rand::Rng;
+    let mut rng = seeded_rng(777);
+    for _ in 0..500 {
+        let floor: u64 = rng.random_range(1..=10_000);
+        let ceiling: u64 = rng.random_range(0..floor);
+        // When floor > ceiling, must return ceiling (the smaller value)
+        let val = sample_lognormal_percentile_bounded(floor, ceiling, &mut rng);
+        assert_eq!(
+            val, ceiling,
+            "inverted: floor={} ceiling={} should return ceiling, got {}",
+            floor, ceiling, val,
+        );
+    }
+}
+
+// ── Security: clamp spike check ─────────────────────────────────────────
+// With well-parameterized sigma, no more than 5% of samples should be
+// at exactly floor or exactly ceiling (clamp spikes). A spike > 10%
+// is detectable by DPI as bimodal.
+
+#[test]
+fn masking_lognormal_no_clamp_spike_at_boundaries() {
+    let mut rng = seeded_rng(42);
+    let floor: u64 = 500;
+    let ceiling: u64 = 2000;
+    let n = 10_000;
+    let samples: Vec<u64> = (0..n)
+        .map(|_| sample_lognormal_percentile_bounded(floor, ceiling, &mut rng))
+        .collect();
+
+    let at_floor = samples.iter().filter(|&&s| s == floor).count();
+    let at_ceiling = samples.iter().filter(|&&s| s == ceiling).count();
+    let floor_pct = at_floor as f64 / n as f64;
+    let ceiling_pct = at_ceiling as f64 / n as f64;
+
+    assert!(
+        floor_pct < 0.05,
+        "floor clamp spike: {}% of samples at exactly floor (max 5%)",
+        floor_pct * 100.0,
+    );
+    assert!(
+        ceiling_pct < 0.05,
+        "ceiling clamp spike: {}% of samples at exactly ceiling (max 5%)",
+        ceiling_pct * 100.0,
+    );
+}
+
+// ── Integration: mask_outcome_target_budget uses log-normal for path 3 ──
+
+#[tokio::test]
+async fn masking_lognormal_integration_budget_within_bounds() {
+    let mut config = ProxyConfig::default();
+    config.censorship.mask_timing_normalization_enabled = true;
+    config.censorship.mask_timing_normalization_floor_ms = 500;
+    config.censorship.mask_timing_normalization_ceiling_ms = 2000;
+
+    for _ in 0..100 {
+        let budget = mask_outcome_target_budget(&config);
+        let ms = budget.as_millis() as u64;
+        assert!(
+            ms >= 500 && ms <= 2000,
+            "budget {} ms outside [500, 2000]",
+            ms,
+        );
+    }
+}
+
+// ── Integration: floor == 0 path stays uniform (NOT log-normal) ─────────
+
+#[tokio::test]
+async fn masking_lognormal_floor_zero_path_stays_uniform() {
+    let mut config = ProxyConfig::default();
+    config.censorship.mask_timing_normalization_enabled = true;
+    config.censorship.mask_timing_normalization_floor_ms = 0;
+    config.censorship.mask_timing_normalization_ceiling_ms = 1000;
+
+    for _ in 0..100 {
+        let budget = mask_outcome_target_budget(&config);
+        let ms = budget.as_millis() as u64;
+        // floor=0 path uses uniform [0, ceiling], not log-normal
+        assert!(ms <= 1000, "budget {} ms exceeds ceiling 1000", ms);
+    }
+}
+
+// ── Integration: floor > ceiling misconfiguration is safe ───────────────
+
+#[tokio::test]
+async fn masking_lognormal_misconfigured_floor_gt_ceiling_safe() {
+    let mut config = ProxyConfig::default();
+    config.censorship.mask_timing_normalization_enabled = true;
+    config.censorship.mask_timing_normalization_floor_ms = 2000;
+    config.censorship.mask_timing_normalization_ceiling_ms = 500;
+
+    let budget = mask_outcome_target_budget(&config);
+    let ms = budget.as_millis() as u64;
+    // floor > ceiling: should not exceed the minimum of the two
+    assert!(
+        ms <= 2000,
+        "misconfigured budget {} ms should be bounded",
+        ms,
+    );
+}
+
+// ── Stress: rapid repeated calls do not panic or starve ─────────────────
+
+#[test]
+fn masking_lognormal_stress_rapid_calls_no_panic() {
+    let mut rng = seeded_rng(42);
+    for _ in 0..100_000 {
+        let _ = sample_lognormal_percentile_bounded(100, 5000, &mut rng);
+    }
+}

src/proxy/tests/middle_relay_baseline_invariant_tests.rs

@@ -0,0 +1,41 @@
+use super::*;
+use std::time::{Duration, Instant};
+
+#[test]
+fn middle_relay_baseline_public_api_idle_roundtrip_contract() {
+    let shared = ProxySharedState::new();
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
+
+    assert!(mark_relay_idle_candidate_for_testing(shared.as_ref(), 7001));
+    assert_eq!(oldest_relay_idle_candidate_for_testing(shared.as_ref()), Some(7001));
+
+    clear_relay_idle_candidate_for_testing(shared.as_ref(), 7001);
+    assert_ne!(oldest_relay_idle_candidate_for_testing(shared.as_ref()), Some(7001));
+
+    assert!(mark_relay_idle_candidate_for_testing(shared.as_ref(), 7001));
+    assert_eq!(oldest_relay_idle_candidate_for_testing(shared.as_ref()), Some(7001));
+
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
+}
+
+#[test]
+fn middle_relay_baseline_public_api_desync_window_contract() {
+    let shared = ProxySharedState::new();
+    clear_desync_dedup_for_testing_in_shared(shared.as_ref());
+
+    let key = 0xDEAD_BEEF_0000_0001u64;
+    let t0 = Instant::now();
+
+    assert!(should_emit_full_desync_for_testing(shared.as_ref(), key, false, t0));
+    assert!(!should_emit_full_desync_for_testing(
+        shared.as_ref(),
+        key,
+        false,
+        t0 + Duration::from_secs(1)
+    ));
+
+    let t1 = t0 + DESYNC_DEDUP_WINDOW + Duration::from_millis(10);
+    assert!(should_emit_full_desync_for_testing(shared.as_ref(), key, false, t1));
+
+    clear_desync_dedup_for_testing_in_shared(shared.as_ref());
+}

src/proxy/tests/middle_relay_desync_all_full_dedup_security_tests.rs

@@ -5,22 +5,20 @@ use std::thread;
 
 #[test]
 fn desync_all_full_bypass_does_not_initialize_or_grow_dedup_cache() {
-    let _guard = desync_dedup_test_lock()
-        .lock()
-        .expect("desync dedup test lock must be available");
-    clear_desync_dedup_for_testing();
+    let shared = ProxySharedState::new();
+    clear_desync_dedup_for_testing_in_shared(shared.as_ref());
 
-    let initial_len = DESYNC_DEDUP.get().map(|dedup| dedup.len()).unwrap_or(0);
+    let initial_len = desync_dedup_len_for_testing(shared.as_ref());
     let now = Instant::now();
 
     for i in 0..20_000u64 {
         assert!(
-            should_emit_full_desync(0xD35E_D000_0000_0000u64 ^ i, true, now),
+            should_emit_full_desync_for_testing(shared.as_ref(), 0xD35E_D000_0000_0000u64 ^ i, true, now),
             "desync_all_full path must always emit"
         );
     }
 
-    let after_len = DESYNC_DEDUP.get().map(|dedup| dedup.len()).unwrap_or(0);
+    let after_len = desync_dedup_len_for_testing(shared.as_ref());
     assert_eq!(
         after_len, initial_len,
         "desync_all_full bypass must not allocate or accumulate dedup entries"
@@ -29,39 +27,34 @@ fn desync_all_full_bypass_does_not_initialize_or_grow_dedup_cache() {
 
 #[test]
 fn desync_all_full_bypass_keeps_existing_dedup_entries_unchanged() {
-    let _guard = desync_dedup_test_lock()
-        .lock()
-        .expect("desync dedup test lock must be available");
-    clear_desync_dedup_for_testing();
+    let shared = ProxySharedState::new();
+    clear_desync_dedup_for_testing_in_shared(shared.as_ref());
 
-    let dedup = DESYNC_DEDUP.get_or_init(DashMap::new);
     let seed_time = Instant::now() - Duration::from_secs(7);
-    dedup.insert(0xAAAABBBBCCCCDDDD, seed_time);
-    dedup.insert(0x1111222233334444, seed_time);
+    desync_dedup_insert_for_testing(shared.as_ref(), 0xAAAABBBBCCCCDDDD, seed_time);
+    desync_dedup_insert_for_testing(shared.as_ref(), 0x1111222233334444, seed_time);
 
     let now = Instant::now();
     for i in 0..2048u64 {
         assert!(
-            should_emit_full_desync(0xF011_F000_0000_0000u64 ^ i, true, now),
+            should_emit_full_desync_for_testing(shared.as_ref(), 0xF011_F000_0000_0000u64 ^ i, true, now),
             "desync_all_full must bypass suppression and dedup refresh"
         );
     }
 
     assert_eq!(
-        dedup.len(),
+        desync_dedup_len_for_testing(shared.as_ref()),
         2,
         "bypass path must not mutate dedup cardinality"
     );
     assert_eq!(
-        *dedup
-            .get(&0xAAAABBBBCCCCDDDD)
+        desync_dedup_get_for_testing(shared.as_ref(), 0xAAAABBBBCCCCDDDD)
             .expect("seed key must remain"),
         seed_time,
         "bypass path must not refresh existing dedup timestamps"
     );
     assert_eq!(
-        *dedup
-            .get(&0x1111222233334444)
+        desync_dedup_get_for_testing(shared.as_ref(), 0x1111222233334444)
             .expect("seed key must remain"),
         seed_time,
         "bypass path must not touch unrelated dedup entries"
@@ -70,14 +63,12 @@ fn desync_all_full_bypass_keeps_existing_dedup_entries_unchanged() {
 
 #[test]
 fn edge_all_full_burst_does_not_poison_later_false_path_tracking() {
-    let _guard = desync_dedup_test_lock()
-        .lock()
-        .expect("desync dedup test lock must be available");
-    clear_desync_dedup_for_testing();
+    let shared = ProxySharedState::new();
+    clear_desync_dedup_for_testing_in_shared(shared.as_ref());
 
     let now = Instant::now();
     for i in 0..8192u64 {
-        assert!(should_emit_full_desync(
+        assert!(should_emit_full_desync_for_testing(shared.as_ref(), 
             0xABCD_0000_0000_0000 ^ i,
             true,
             now
@@ -86,26 +77,20 @@ fn edge_all_full_burst_does_not_poison_later_false_path_tracking() {
 
     let tracked_key = 0xDEAD_BEEF_0000_0001u64;
     assert!(
-        should_emit_full_desync(tracked_key, false, now),
+        should_emit_full_desync_for_testing(shared.as_ref(), tracked_key, false, now),
         "first false-path event after all_full burst must still be tracked and emitted"
     );
 
-    let dedup = DESYNC_DEDUP
-        .get()
-        .expect("false path should initialize dedup");
-    assert!(dedup.get(&tracked_key).is_some());
+    assert!(desync_dedup_get_for_testing(shared.as_ref(), tracked_key).is_some());
 }
 
 #[test]
 fn adversarial_mixed_sequence_true_steps_never_change_cache_len() {
-    let _guard = desync_dedup_test_lock()
-        .lock()
-        .expect("desync dedup test lock must be available");
-    clear_desync_dedup_for_testing();
+    let shared = ProxySharedState::new();
+    clear_desync_dedup_for_testing_in_shared(shared.as_ref());
 
-    let dedup = DESYNC_DEDUP.get_or_init(DashMap::new);
     for i in 0..256u64 {
-        dedup.insert(0x1000_0000_0000_0000 ^ i, Instant::now());
+        desync_dedup_insert_for_testing(shared.as_ref(), 0x1000_0000_0000_0000 ^ i, Instant::now());
     }
 
     let mut seed = 0xC0DE_CAFE_BAAD_F00Du64;
@@ -116,9 +101,9 @@ fn adversarial_mixed_sequence_true_steps_never_change_cache_len() {
 
         let flag_all_full = (seed & 0x1) == 1;
         let key = 0x7000_0000_0000_0000u64 ^ i ^ seed;
-        let before = dedup.len();
-        let _ = should_emit_full_desync(key, flag_all_full, Instant::now());
-        let after = dedup.len();
+        let before = desync_dedup_len_for_testing(shared.as_ref());
+        let _ = should_emit_full_desync_for_testing(shared.as_ref(), key, flag_all_full, Instant::now());
+        let after = desync_dedup_len_for_testing(shared.as_ref());
 
         if flag_all_full {
             assert_eq!(after, before, "all_full step must not mutate dedup length");
@@ -128,50 +113,46 @@ fn adversarial_mixed_sequence_true_steps_never_change_cache_len() {
 
 #[test]
 fn light_fuzz_all_full_mode_always_emits_and_stays_bounded() {
-    let _guard = desync_dedup_test_lock()
-        .lock()
-        .expect("desync dedup test lock must be available");
-    clear_desync_dedup_for_testing();
+    let shared = ProxySharedState::new();
+    clear_desync_dedup_for_testing_in_shared(shared.as_ref());
 
     let mut seed = 0x1234_5678_9ABC_DEF0u64;
-    let before = DESYNC_DEDUP.get().map(|d| d.len()).unwrap_or(0);
+    let before = desync_dedup_len_for_testing(shared.as_ref());
 
     for _ in 0..20_000 {
         seed ^= seed << 7;
         seed ^= seed >> 9;
         seed ^= seed << 8;
         let key = seed ^ 0x55AA_55AA_55AA_55AAu64;
-        assert!(should_emit_full_desync(key, true, Instant::now()));
+        assert!(should_emit_full_desync_for_testing(shared.as_ref(), key, true, Instant::now()));
     }
 
-    let after = DESYNC_DEDUP.get().map(|d| d.len()).unwrap_or(0);
+    let after = desync_dedup_len_for_testing(shared.as_ref());
     assert_eq!(after, before);
     assert!(after <= DESYNC_DEDUP_MAX_ENTRIES);
 }
 
 #[test]
 fn stress_parallel_all_full_storm_does_not_grow_or_mutate_cache() {
-    let _guard = desync_dedup_test_lock()
-        .lock()
-        .expect("desync dedup test lock must be available");
-    clear_desync_dedup_for_testing();
+    let shared = ProxySharedState::new();
+    clear_desync_dedup_for_testing_in_shared(shared.as_ref());
 
-    let dedup = DESYNC_DEDUP.get_or_init(DashMap::new);
     let seed_time = Instant::now() - Duration::from_secs(2);
     for i in 0..1024u64 {
-        dedup.insert(0x8888_0000_0000_0000 ^ i, seed_time);
+        desync_dedup_insert_for_testing(shared.as_ref(), 0x8888_0000_0000_0000 ^ i, seed_time);
     }
-    let before_len = dedup.len();
+    let before_len = desync_dedup_len_for_testing(shared.as_ref());
 
     let emits = Arc::new(AtomicUsize::new(0));
     let mut workers = Vec::new();
     for worker in 0..16u64 {
         let emits = Arc::clone(&emits);
+        let shared = shared.clone();
         workers.push(thread::spawn(move || {
             let now = Instant::now();
             for i in 0..4096u64 {
                 let key = 0xFACE_0000_0000_0000u64 ^ (worker << 20) ^ i;
-                if should_emit_full_desync(key, true, now) {
+                if should_emit_full_desync_for_testing(shared.as_ref(), key, true, now) {
                     emits.fetch_add(1, Ordering::Relaxed);
                 }
             }
@@ -184,7 +165,7 @@ fn stress_parallel_all_full_storm_does_not_grow_or_mutate_cache() {
 
     assert_eq!(emits.load(Ordering::Relaxed), 16 * 4096);
     assert_eq!(
-        dedup.len(),
+        desync_dedup_len_for_testing(shared.as_ref()),
         before_len,
         "parallel all_full storm must not mutate cache len"
     );

src/proxy/tests/middle_relay_idle_policy_security_tests.rs

@@ -360,73 +360,73 @@ async fn stress_many_idle_sessions_fail_closed_without_hang() {
 
 #[test]
 fn pressure_evicts_oldest_idle_candidate_with_deterministic_ordering() {
-    let _guard = relay_idle_pressure_test_scope();
-    clear_relay_idle_pressure_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
     let stats = Stats::new();
 
-    assert!(mark_relay_idle_candidate(10));
-    assert!(mark_relay_idle_candidate(11));
-    assert_eq!(oldest_relay_idle_candidate(), Some(10));
+    assert!(mark_relay_idle_candidate_for_testing(shared.as_ref(), 10));
+    assert!(mark_relay_idle_candidate_for_testing(shared.as_ref(), 11));
+    assert_eq!(oldest_relay_idle_candidate_for_testing(shared.as_ref()), Some(10));
 
-    note_relay_pressure_event();
+    note_relay_pressure_event_for_testing(shared.as_ref());
 
     let mut seen_for_newer = 0u64;
     assert!(
-        !maybe_evict_idle_candidate_on_pressure(11, &mut seen_for_newer, &stats),
+        !maybe_evict_idle_candidate_on_pressure_for_testing(shared.as_ref(), 11, &mut seen_for_newer, &stats),
         "newer idle candidate must not be evicted while older candidate exists"
     );
-    assert_eq!(oldest_relay_idle_candidate(), Some(10));
+    assert_eq!(oldest_relay_idle_candidate_for_testing(shared.as_ref()), Some(10));
 
     let mut seen_for_oldest = 0u64;
     assert!(
-        maybe_evict_idle_candidate_on_pressure(10, &mut seen_for_oldest, &stats),
+        maybe_evict_idle_candidate_on_pressure_for_testing(shared.as_ref(), 10, &mut seen_for_oldest, &stats),
         "oldest idle candidate must be evicted first under pressure"
     );
-    assert_eq!(oldest_relay_idle_candidate(), Some(11));
+    assert_eq!(oldest_relay_idle_candidate_for_testing(shared.as_ref()), Some(11));
     assert_eq!(stats.get_relay_pressure_evict_total(), 1);
 
-    clear_relay_idle_pressure_state_for_testing();
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
 }
 
 #[test]
 fn pressure_does_not_evict_without_new_pressure_signal() {
-    let _guard = relay_idle_pressure_test_scope();
-    clear_relay_idle_pressure_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
     let stats = Stats::new();
 
-    assert!(mark_relay_idle_candidate(21));
-    let mut seen = relay_pressure_event_seq();
+    assert!(mark_relay_idle_candidate_for_testing(shared.as_ref(), 21));
+    let mut seen = relay_pressure_event_seq_for_testing(shared.as_ref());
 
     assert!(
-        !maybe_evict_idle_candidate_on_pressure(21, &mut seen, &stats),
+        !maybe_evict_idle_candidate_on_pressure_for_testing(shared.as_ref(), 21, &mut seen, &stats),
         "without new pressure signal, candidate must stay"
     );
     assert_eq!(stats.get_relay_pressure_evict_total(), 0);
-    assert_eq!(oldest_relay_idle_candidate(), Some(21));
+    assert_eq!(oldest_relay_idle_candidate_for_testing(shared.as_ref()), Some(21));
 
-    clear_relay_idle_pressure_state_for_testing();
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
 }
 
 #[test]
 fn stress_pressure_eviction_preserves_fifo_across_many_candidates() {
-    let _guard = relay_idle_pressure_test_scope();
-    clear_relay_idle_pressure_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
     let stats = Stats::new();
 
     let mut seen_per_conn = std::collections::HashMap::new();
     for conn_id in 1000u64..1064u64 {
-        assert!(mark_relay_idle_candidate(conn_id));
+        assert!(mark_relay_idle_candidate_for_testing(shared.as_ref(), conn_id));
         seen_per_conn.insert(conn_id, 0u64);
     }
 
     for expected in 1000u64..1064u64 {
-        note_relay_pressure_event();
+        note_relay_pressure_event_for_testing(shared.as_ref());
 
         let mut seen = *seen_per_conn
             .get(&expected)
             .expect("per-conn pressure cursor must exist");
         assert!(
-            maybe_evict_idle_candidate_on_pressure(expected, &mut seen, &stats),
+            maybe_evict_idle_candidate_on_pressure_for_testing(shared.as_ref(), expected, &mut seen, &stats),
             "expected conn_id {expected} must be evicted next by deterministic FIFO ordering"
         );
         seen_per_conn.insert(expected, seen);
@@ -436,33 +436,33 @@ fn stress_pressure_eviction_preserves_fifo_across_many_candidates() {
         } else {
             Some(expected + 1)
         };
-        assert_eq!(oldest_relay_idle_candidate(), next);
+        assert_eq!(oldest_relay_idle_candidate_for_testing(shared.as_ref()), next);
     }
 
     assert_eq!(stats.get_relay_pressure_evict_total(), 64);
-    clear_relay_idle_pressure_state_for_testing();
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
 }
 
 #[test]
 fn blackhat_single_pressure_event_must_not_evict_more_than_one_candidate() {
-    let _guard = relay_idle_pressure_test_scope();
-    clear_relay_idle_pressure_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
     let stats = Stats::new();
 
-    assert!(mark_relay_idle_candidate(301));
-    assert!(mark_relay_idle_candidate(302));
-    assert!(mark_relay_idle_candidate(303));
+    assert!(mark_relay_idle_candidate_for_testing(shared.as_ref(), 301));
+    assert!(mark_relay_idle_candidate_for_testing(shared.as_ref(), 302));
+    assert!(mark_relay_idle_candidate_for_testing(shared.as_ref(), 303));
 
     let mut seen_301 = 0u64;
     let mut seen_302 = 0u64;
     let mut seen_303 = 0u64;
 
     // Single pressure event should authorize at most one eviction globally.
-    note_relay_pressure_event();
+    note_relay_pressure_event_for_testing(shared.as_ref());
 
-    let evicted_301 = maybe_evict_idle_candidate_on_pressure(301, &mut seen_301, &stats);
-    let evicted_302 = maybe_evict_idle_candidate_on_pressure(302, &mut seen_302, &stats);
-    let evicted_303 = maybe_evict_idle_candidate_on_pressure(303, &mut seen_303, &stats);
+    let evicted_301 = maybe_evict_idle_candidate_on_pressure_for_testing(shared.as_ref(), 301, &mut seen_301, &stats);
+    let evicted_302 = maybe_evict_idle_candidate_on_pressure_for_testing(shared.as_ref(), 302, &mut seen_302, &stats);
+    let evicted_303 = maybe_evict_idle_candidate_on_pressure_for_testing(shared.as_ref(), 303, &mut seen_303, &stats);
 
     let evicted_total = [evicted_301, evicted_302, evicted_303]
         .iter()
@@ -474,30 +474,30 @@ fn blackhat_single_pressure_event_must_not_evict_more_than_one_candidate() {
         "single pressure event must not cascade-evict multiple idle candidates"
     );
 
-    clear_relay_idle_pressure_state_for_testing();
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
 }
 
 #[test]
 fn blackhat_pressure_counter_must_track_global_budget_not_per_session_cursor() {
-    let _guard = relay_idle_pressure_test_scope();
-    clear_relay_idle_pressure_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
     let stats = Stats::new();
 
-    assert!(mark_relay_idle_candidate(401));
-    assert!(mark_relay_idle_candidate(402));
+    assert!(mark_relay_idle_candidate_for_testing(shared.as_ref(), 401));
+    assert!(mark_relay_idle_candidate_for_testing(shared.as_ref(), 402));
 
     let mut seen_oldest = 0u64;
     let mut seen_next = 0u64;
 
-    note_relay_pressure_event();
+    note_relay_pressure_event_for_testing(shared.as_ref());
 
     assert!(
-        maybe_evict_idle_candidate_on_pressure(401, &mut seen_oldest, &stats),
+        maybe_evict_idle_candidate_on_pressure_for_testing(shared.as_ref(), 401, &mut seen_oldest, &stats),
         "oldest candidate must consume pressure budget first"
     );
 
     assert!(
-        !maybe_evict_idle_candidate_on_pressure(402, &mut seen_next, &stats),
+        !maybe_evict_idle_candidate_on_pressure_for_testing(shared.as_ref(), 402, &mut seen_next, &stats),
         "next candidate must not consume the same pressure budget"
     );
 
@@ -507,47 +507,47 @@ fn blackhat_pressure_counter_must_track_global_budget_not_per_session_cursor() {
         "single pressure budget must produce exactly one eviction"
     );
 
-    clear_relay_idle_pressure_state_for_testing();
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
 }
 
 #[test]
 fn blackhat_stale_pressure_before_idle_mark_must_not_trigger_eviction() {
-    let _guard = relay_idle_pressure_test_scope();
-    clear_relay_idle_pressure_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
     let stats = Stats::new();
 
     // Pressure happened before any idle candidate existed.
-    note_relay_pressure_event();
-    assert!(mark_relay_idle_candidate(501));
+    note_relay_pressure_event_for_testing(shared.as_ref());
+    assert!(mark_relay_idle_candidate_for_testing(shared.as_ref(), 501));
 
     let mut seen = 0u64;
     assert!(
-        !maybe_evict_idle_candidate_on_pressure(501, &mut seen, &stats),
+        !maybe_evict_idle_candidate_on_pressure_for_testing(shared.as_ref(), 501, &mut seen, &stats),
         "stale pressure (before soft-idle mark) must not evict newly marked candidate"
     );
 
-    clear_relay_idle_pressure_state_for_testing();
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
 }
 
 #[test]
 fn blackhat_stale_pressure_must_not_evict_any_of_newly_marked_batch() {
-    let _guard = relay_idle_pressure_test_scope();
-    clear_relay_idle_pressure_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
     let stats = Stats::new();
 
-    note_relay_pressure_event();
-    assert!(mark_relay_idle_candidate(511));
-    assert!(mark_relay_idle_candidate(512));
-    assert!(mark_relay_idle_candidate(513));
+    note_relay_pressure_event_for_testing(shared.as_ref());
+    assert!(mark_relay_idle_candidate_for_testing(shared.as_ref(), 511));
+    assert!(mark_relay_idle_candidate_for_testing(shared.as_ref(), 512));
+    assert!(mark_relay_idle_candidate_for_testing(shared.as_ref(), 513));
 
     let mut seen_511 = 0u64;
     let mut seen_512 = 0u64;
     let mut seen_513 = 0u64;
 
     let evicted = [
-        maybe_evict_idle_candidate_on_pressure(511, &mut seen_511, &stats),
-        maybe_evict_idle_candidate_on_pressure(512, &mut seen_512, &stats),
-        maybe_evict_idle_candidate_on_pressure(513, &mut seen_513, &stats),
+        maybe_evict_idle_candidate_on_pressure_for_testing(shared.as_ref(), 511, &mut seen_511, &stats),
+        maybe_evict_idle_candidate_on_pressure_for_testing(shared.as_ref(), 512, &mut seen_512, &stats),
+        maybe_evict_idle_candidate_on_pressure_for_testing(shared.as_ref(), 513, &mut seen_513, &stats),
     ]
     .iter()
     .filter(|value| **value)
@@ -558,111 +558,103 @@ fn blackhat_stale_pressure_must_not_evict_any_of_newly_marked_batch() {
         "stale pressure event must not evict any candidate from a newly marked batch"
     );
 
-    clear_relay_idle_pressure_state_for_testing();
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
 }
 
 #[test]
 fn blackhat_stale_pressure_seen_without_candidates_must_be_globally_invalidated() {
-    let _guard = relay_idle_pressure_test_scope();
-    clear_relay_idle_pressure_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
     let stats = Stats::new();
 
-    note_relay_pressure_event();
+    note_relay_pressure_event_for_testing(shared.as_ref());
 
     // Session A observed pressure while there were no candidates.
     let mut seen_a = 0u64;
     assert!(
-        !maybe_evict_idle_candidate_on_pressure(999_001, &mut seen_a, &stats),
+        !maybe_evict_idle_candidate_on_pressure_for_testing(shared.as_ref(), 999_001, &mut seen_a, &stats),
         "no candidate existed, so no eviction is possible"
     );
 
     // Candidate appears later; Session B must not be able to consume stale pressure.
-    assert!(mark_relay_idle_candidate(521));
+    assert!(mark_relay_idle_candidate_for_testing(shared.as_ref(), 521));
     let mut seen_b = 0u64;
     assert!(
-        !maybe_evict_idle_candidate_on_pressure(521, &mut seen_b, &stats),
+        !maybe_evict_idle_candidate_on_pressure_for_testing(shared.as_ref(), 521, &mut seen_b, &stats),
         "once pressure is observed with empty candidate set, it must not be replayed later"
     );
 
-    clear_relay_idle_pressure_state_for_testing();
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
 }
 
 #[test]
 fn blackhat_stale_pressure_must_not_survive_candidate_churn() {
-    let _guard = relay_idle_pressure_test_scope();
-    clear_relay_idle_pressure_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
     let stats = Stats::new();
 
-    note_relay_pressure_event();
-    assert!(mark_relay_idle_candidate(531));
-    clear_relay_idle_candidate(531);
-    assert!(mark_relay_idle_candidate(532));
+    note_relay_pressure_event_for_testing(shared.as_ref());
+    assert!(mark_relay_idle_candidate_for_testing(shared.as_ref(), 531));
+    clear_relay_idle_candidate_for_testing(shared.as_ref(), 531);
+    assert!(mark_relay_idle_candidate_for_testing(shared.as_ref(), 532));
 
     let mut seen = 0u64;
     assert!(
-        !maybe_evict_idle_candidate_on_pressure(532, &mut seen, &stats),
+        !maybe_evict_idle_candidate_on_pressure_for_testing(shared.as_ref(), 532, &mut seen, &stats),
         "stale pressure must not survive clear+remark churn cycles"
     );
 
-    clear_relay_idle_pressure_state_for_testing();
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
 }
 
 #[test]
 fn blackhat_pressure_seq_saturation_must_not_disable_future_pressure_accounting() {
-    let _guard = relay_idle_pressure_test_scope();
-    clear_relay_idle_pressure_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
 
     {
-        let mut guard = relay_idle_candidate_registry()
-            .lock()
-            .expect("registry lock must be available");
-        guard.pressure_event_seq = u64::MAX;
-        guard.pressure_consumed_seq = u64::MAX - 1;
+        set_relay_pressure_state_for_testing(shared.as_ref(), u64::MAX, u64::MAX - 1);
     }
 
     // A new pressure event should still be representable; saturating at MAX creates a permanent lockout.
-    note_relay_pressure_event();
-    let after = relay_pressure_event_seq();
+    note_relay_pressure_event_for_testing(shared.as_ref());
+    let after = relay_pressure_event_seq_for_testing(shared.as_ref());
     assert_ne!(
         after,
         u64::MAX,
         "pressure sequence saturation must not permanently freeze event progression"
     );
 
-    clear_relay_idle_pressure_state_for_testing();
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
 }
 
 #[test]
 fn blackhat_pressure_seq_saturation_must_not_break_multiple_distinct_events() {
-    let _guard = relay_idle_pressure_test_scope();
-    clear_relay_idle_pressure_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
 
     {
-        let mut guard = relay_idle_candidate_registry()
-            .lock()
-            .expect("registry lock must be available");
-        guard.pressure_event_seq = u64::MAX;
-        guard.pressure_consumed_seq = u64::MAX;
+        set_relay_pressure_state_for_testing(shared.as_ref(), u64::MAX, u64::MAX);
     }
 
-    note_relay_pressure_event();
-    let first = relay_pressure_event_seq();
-    note_relay_pressure_event();
-    let second = relay_pressure_event_seq();
+    note_relay_pressure_event_for_testing(shared.as_ref());
+    let first = relay_pressure_event_seq_for_testing(shared.as_ref());
+    note_relay_pressure_event_for_testing(shared.as_ref());
+    let second = relay_pressure_event_seq_for_testing(shared.as_ref());
 
     assert!(
         second > first,
         "distinct pressure events must remain distinguishable even at sequence boundary"
     );
 
-    clear_relay_idle_pressure_state_for_testing();
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 4)]
 async fn integration_race_single_pressure_event_allows_at_most_one_eviction_under_parallel_claims()
 {
-    let _guard = relay_idle_pressure_test_scope();
-    clear_relay_idle_pressure_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
 
     let stats = Arc::new(Stats::new());
     let sessions = 16usize;
@@ -671,20 +663,21 @@ async fn integration_race_single_pressure_event_allows_at_most_one_eviction_unde
     let mut seen_per_session = vec![0u64; sessions];
 
     for conn_id in &conn_ids {
-        assert!(mark_relay_idle_candidate(*conn_id));
+        assert!(mark_relay_idle_candidate_for_testing(shared.as_ref(), *conn_id));
     }
 
     for round in 0..rounds {
-        note_relay_pressure_event();
+        note_relay_pressure_event_for_testing(shared.as_ref());
 
         let mut joins = Vec::with_capacity(sessions);
         for (idx, conn_id) in conn_ids.iter().enumerate() {
             let mut seen = seen_per_session[idx];
             let conn_id = *conn_id;
             let stats = stats.clone();
+            let shared = shared.clone();
             joins.push(tokio::spawn(async move {
                 let evicted =
-                    maybe_evict_idle_candidate_on_pressure(conn_id, &mut seen, stats.as_ref());
+                    maybe_evict_idle_candidate_on_pressure_for_testing(shared.as_ref(), conn_id, &mut seen, stats.as_ref());
                 (idx, conn_id, seen, evicted)
             }));
         }
@@ -706,7 +699,7 @@ async fn integration_race_single_pressure_event_allows_at_most_one_eviction_unde
         );
         if let Some(conn) = evicted_conn {
             assert!(
-                mark_relay_idle_candidate(conn),
+                mark_relay_idle_candidate_for_testing(shared.as_ref(), conn),
                 "round {round}: evicted conn must be re-markable as idle candidate"
             );
         }
@@ -721,13 +714,13 @@ async fn integration_race_single_pressure_event_allows_at_most_one_eviction_unde
         "parallel race must still observe at least one successful eviction"
     );
 
-    clear_relay_idle_pressure_state_for_testing();
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 4)]
 async fn integration_race_burst_pressure_with_churn_preserves_empty_set_invalidation_and_budget() {
-    let _guard = relay_idle_pressure_test_scope();
-    clear_relay_idle_pressure_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
 
     let stats = Arc::new(Stats::new());
     let sessions = 12usize;
@@ -736,7 +729,7 @@ async fn integration_race_burst_pressure_with_churn_preserves_empty_set_invalida
     let mut seen_per_session = vec![0u64; sessions];
 
     for conn_id in &conn_ids {
-        assert!(mark_relay_idle_candidate(*conn_id));
+        assert!(mark_relay_idle_candidate_for_testing(shared.as_ref(), *conn_id));
     }
 
     let mut expected_total_evictions = 0u64;
@@ -745,20 +738,21 @@ async fn integration_race_burst_pressure_with_churn_preserves_empty_set_invalida
         let empty_phase = round % 5 == 0;
         if empty_phase {
             for conn_id in &conn_ids {
-                clear_relay_idle_candidate(*conn_id);
+                clear_relay_idle_candidate_for_testing(shared.as_ref(), *conn_id);
             }
         }
 
-        note_relay_pressure_event();
+        note_relay_pressure_event_for_testing(shared.as_ref());
 
         let mut joins = Vec::with_capacity(sessions);
         for (idx, conn_id) in conn_ids.iter().enumerate() {
             let mut seen = seen_per_session[idx];
             let conn_id = *conn_id;
             let stats = stats.clone();
+            let shared = shared.clone();
             joins.push(tokio::spawn(async move {
                 let evicted =
-                    maybe_evict_idle_candidate_on_pressure(conn_id, &mut seen, stats.as_ref());
+                    maybe_evict_idle_candidate_on_pressure_for_testing(shared.as_ref(), conn_id, &mut seen, stats.as_ref());
                 (idx, conn_id, seen, evicted)
             }));
         }
@@ -780,7 +774,7 @@ async fn integration_race_burst_pressure_with_churn_preserves_empty_set_invalida
                 "round {round}: empty candidate phase must not allow stale-pressure eviction"
             );
             for conn_id in &conn_ids {
-                assert!(mark_relay_idle_candidate(*conn_id));
+                assert!(mark_relay_idle_candidate_for_testing(shared.as_ref(), *conn_id));
             }
         } else {
             assert!(
@@ -789,7 +783,7 @@ async fn integration_race_burst_pressure_with_churn_preserves_empty_set_invalida
             );
             if let Some(conn_id) = evicted_conn {
                 expected_total_evictions = expected_total_evictions.saturating_add(1);
-                assert!(mark_relay_idle_candidate(conn_id));
+                assert!(mark_relay_idle_candidate_for_testing(shared.as_ref(), conn_id));
             }
         }
     }
@@ -800,5 +794,5 @@ async fn integration_race_burst_pressure_with_churn_preserves_empty_set_invalida
         "global pressure eviction counter must match observed per-round successful consumes"
     );
 
-    clear_relay_idle_pressure_state_for_testing();
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
 }

src/proxy/tests/middle_relay_idle_registry_poison_security_tests.rs

@@ -3,12 +3,13 @@ use std::panic::{AssertUnwindSafe, catch_unwind};
 
 #[test]
 fn blackhat_registry_poison_recovers_with_fail_closed_reset_and_pressure_accounting() {
-    let _guard = relay_idle_pressure_test_scope();
-    clear_relay_idle_pressure_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
 
     let _ = catch_unwind(AssertUnwindSafe(|| {
-        let registry = relay_idle_candidate_registry();
-        let mut guard = registry
+        let mut guard = shared
+            .middle_relay
+            .relay_idle_registry
             .lock()
             .expect("registry lock must be acquired before poison");
         guard.by_conn_id.insert(
@@ -23,40 +24,41 @@ fn blackhat_registry_poison_recovers_with_fail_closed_reset_and_pressure_account
     }));
 
     // Helper lock must recover from poison, reset stale state, and continue.
-    assert!(mark_relay_idle_candidate(42));
-    assert_eq!(oldest_relay_idle_candidate(), Some(42));
+    assert!(mark_relay_idle_candidate_for_testing(shared.as_ref(), 42));
+    assert_eq!(oldest_relay_idle_candidate_for_testing(shared.as_ref()), Some(42));
 
-    let before = relay_pressure_event_seq();
-    note_relay_pressure_event();
-    let after = relay_pressure_event_seq();
+    let before = relay_pressure_event_seq_for_testing(shared.as_ref());
+    note_relay_pressure_event_for_testing(shared.as_ref());
+    let after = relay_pressure_event_seq_for_testing(shared.as_ref());
     assert!(
         after > before,
         "pressure accounting must still advance after poison"
     );
 
-    clear_relay_idle_pressure_state_for_testing();
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
 }
 
 #[test]
 fn clear_state_helper_must_reset_poisoned_registry_for_deterministic_fifo_tests() {
-    let _guard = relay_idle_pressure_test_scope();
-    clear_relay_idle_pressure_state_for_testing();
+    let shared = ProxySharedState::new();
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
 
     let _ = catch_unwind(AssertUnwindSafe(|| {
-        let registry = relay_idle_candidate_registry();
-        let _guard = registry
+        let _guard = shared
+            .middle_relay
+            .relay_idle_registry
             .lock()
             .expect("registry lock must be acquired before poison");
         panic!("intentional poison while lock held");
     }));
 
-    clear_relay_idle_pressure_state_for_testing();
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
 
-    assert_eq!(oldest_relay_idle_candidate(), None);
-    assert_eq!(relay_pressure_event_seq(), 0);
+    assert_eq!(oldest_relay_idle_candidate_for_testing(shared.as_ref()), None);
+    assert_eq!(relay_pressure_event_seq_for_testing(shared.as_ref()), 0);
 
-    assert!(mark_relay_idle_candidate(7));
-    assert_eq!(oldest_relay_idle_candidate(), Some(7));
+    assert!(mark_relay_idle_candidate_for_testing(shared.as_ref(), 7));
+    assert_eq!(oldest_relay_idle_candidate_for_testing(shared.as_ref()), Some(7));
 
-    clear_relay_idle_pressure_state_for_testing();
+    clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
 }

src/proxy/tests/middle_relay_stub_completion_security_tests.rs

@@ -1,6 +1,6 @@
 use super::*;
+use crate::stats::Stats;
 use crate::stream::BufferPool;
-use std::collections::HashSet;
 use std::sync::Arc;
 use tokio::time::{Duration as TokioDuration, timeout};
 
@@ -15,32 +15,30 @@ fn make_pooled_payload(data: &[u8]) -> PooledBuffer {
 #[test]
 #[ignore = "Tracking for M-04: Verify should_emit_full_desync returns true on first occurrence and false on duplicate within window"]
 fn should_emit_full_desync_filters_duplicates() {
-    let _guard = desync_dedup_test_lock()
-        .lock()
-        .expect("desync dedup test lock must be available");
-    clear_desync_dedup_for_testing();
+    let shared = ProxySharedState::new();
+    clear_desync_dedup_for_testing_in_shared(shared.as_ref());
 
     let key = 0x4D04_0000_0000_0001_u64;
     let base = Instant::now();
 
     assert!(
-        should_emit_full_desync(key, false, base),
+        should_emit_full_desync_for_testing(shared.as_ref(), key, false, base),
         "first occurrence must emit full forensic record"
     );
     assert!(
-        !should_emit_full_desync(key, false, base),
+        !should_emit_full_desync_for_testing(shared.as_ref(), key, false, base),
         "duplicate at same timestamp must be suppressed"
     );
 
     let within_window = base + DESYNC_DEDUP_WINDOW - TokioDuration::from_millis(1);
     assert!(
-        !should_emit_full_desync(key, false, within_window),
+        !should_emit_full_desync_for_testing(shared.as_ref(), key, false, within_window),
         "duplicate strictly inside dedup window must stay suppressed"
     );
 
     let on_window_edge = base + DESYNC_DEDUP_WINDOW;
     assert!(
-        should_emit_full_desync(key, false, on_window_edge),
+        should_emit_full_desync_for_testing(shared.as_ref(), key, false, on_window_edge),
         "duplicate at window boundary must re-emit and refresh"
     );
 }
@@ -48,39 +46,34 @@ fn should_emit_full_desync_filters_duplicates() {
 #[test]
 #[ignore = "Tracking for M-04: Verify desync dedup eviction behaves correctly under map-full condition"]
 fn desync_dedup_eviction_under_map_full_condition() {
-    let _guard = desync_dedup_test_lock()
-        .lock()
-        .expect("desync dedup test lock must be available");
-    clear_desync_dedup_for_testing();
+    let shared = ProxySharedState::new();
+    clear_desync_dedup_for_testing_in_shared(shared.as_ref());
 
     let base = Instant::now();
     for key in 0..DESYNC_DEDUP_MAX_ENTRIES as u64 {
         assert!(
-            should_emit_full_desync(key, false, base),
+            should_emit_full_desync_for_testing(shared.as_ref(), key, false, base),
             "unique key should be inserted while warming dedup cache"
         );
     }
 
-    let dedup = DESYNC_DEDUP
-        .get()
-        .expect("dedup map must exist after warm-up insertions");
     assert_eq!(
-        dedup.len(),
+        desync_dedup_len_for_testing(shared.as_ref()),
         DESYNC_DEDUP_MAX_ENTRIES,
         "cache warm-up must reach exact hard cap"
     );
 
-    let before_keys: HashSet<u64> = dedup.iter().map(|entry| *entry.key()).collect();
+    let before_keys = desync_dedup_keys_for_testing(shared.as_ref());
     let newcomer_key = 0x4D04_FFFF_FFFF_0001_u64;
 
     assert!(
-        should_emit_full_desync(newcomer_key, false, base),
+        should_emit_full_desync_for_testing(shared.as_ref(), newcomer_key, false, base),
         "first newcomer at map-full must emit under bounded full-cache gate"
     );
 
-    let after_keys: HashSet<u64> = dedup.iter().map(|entry| *entry.key()).collect();
+    let after_keys = desync_dedup_keys_for_testing(shared.as_ref());
     assert_eq!(
-        dedup.len(),
+        desync_dedup_len_for_testing(shared.as_ref()),
         DESYNC_DEDUP_MAX_ENTRIES,
         "map-full insertion must preserve hard capacity bound"
     );
@@ -101,7 +94,7 @@ fn desync_dedup_eviction_under_map_full_condition() {
     );
 
     assert!(
-        !should_emit_full_desync(newcomer_key, false, base),
+        !should_emit_full_desync_for_testing(shared.as_ref(), newcomer_key, false, base),
         "immediate duplicate newcomer must remain suppressed"
     );
 }
@@ -119,6 +112,7 @@ async fn c2me_channel_full_path_yields_then_sends() {
     .expect("priming queue with one frame must succeed");
 
     let tx2 = tx.clone();
+    let stats = Stats::default();
     let producer = tokio::spawn(async move {
         enqueue_c2me_command(
             &tx2,
@@ -127,6 +121,7 @@ async fn c2me_channel_full_path_yields_then_sends() {
                 flags: 2,
             },
             None,
+            &stats,
         )
         .await
     });

src/proxy/tests/proxy_shared_state_isolation_tests.rs

@@ -0,0 +1,608 @@
+use crate::proxy::handshake::{
+    auth_probe_fail_streak_for_testing_in_shared, auth_probe_is_throttled_for_testing_in_shared,
+    auth_probe_record_failure_for_testing, clear_auth_probe_state_for_testing_in_shared,
+    clear_unknown_sni_warn_state_for_testing_in_shared, clear_warned_secrets_for_testing_in_shared,
+    should_emit_unknown_sni_warn_for_testing_in_shared, warned_secrets_for_testing_in_shared,
+};
+use crate::proxy::client::handle_client_stream_with_shared;
+use crate::proxy::middle_relay::{
+    clear_desync_dedup_for_testing_in_shared, clear_relay_idle_candidate_for_testing,
+    clear_relay_idle_pressure_state_for_testing_in_shared, mark_relay_idle_candidate_for_testing,
+    maybe_evict_idle_candidate_on_pressure_for_testing, note_relay_pressure_event_for_testing,
+    oldest_relay_idle_candidate_for_testing, relay_idle_mark_seq_for_testing,
+    relay_pressure_event_seq_for_testing, should_emit_full_desync_for_testing,
+};
+use crate::proxy::route_mode::{RelayRouteMode, RouteRuntimeController};
+use crate::proxy::shared_state::ProxySharedState;
+use crate::{
+    config::{ProxyConfig, UpstreamConfig, UpstreamType},
+    crypto::SecureRandom,
+    ip_tracker::UserIpTracker,
+    stats::{ReplayChecker, Stats, beobachten::BeobachtenStore},
+    stream::BufferPool,
+    transport::UpstreamManager,
+};
+use std::net::{IpAddr, Ipv4Addr};
+use std::sync::Arc;
+use std::time::{Duration, Instant};
+use tokio::io::{AsyncWriteExt, duplex};
+use tokio::sync::Barrier;
+
+struct ClientHarness {
+    config: Arc<ProxyConfig>,
+    stats: Arc<Stats>,
+    upstream_manager: Arc<UpstreamManager>,
+    replay_checker: Arc<ReplayChecker>,
+    buffer_pool: Arc<BufferPool>,
+    rng: Arc<SecureRandom>,
+    route_runtime: Arc<RouteRuntimeController>,
+    ip_tracker: Arc<UserIpTracker>,
+    beobachten: Arc<BeobachtenStore>,
+}
+
+fn new_client_harness() -> ClientHarness {
+    let mut cfg = ProxyConfig::default();
+    cfg.censorship.mask = false;
+    cfg.general.modes.classic = true;
+    cfg.general.modes.secure = true;
+    let config = Arc::new(cfg);
+    let stats = Arc::new(Stats::new());
+
+    let upstream_manager = Arc::new(UpstreamManager::new(
+        vec![UpstreamConfig {
+            upstream_type: UpstreamType::Direct {
+                interface: None,
+                bind_addresses: None,
+            },
+            weight: 1,
+            enabled: true,
+            scopes: String::new(),
+            selected_scope: String::new(),
+        }],
+        1,
+        1,
+        1,
+        10,
+        1,
+        false,
+        stats.clone(),
+    ));
+
+    ClientHarness {
+        config,
+        stats,
+        upstream_manager,
+        replay_checker: Arc::new(ReplayChecker::new(128, Duration::from_secs(60))),
+        buffer_pool: Arc::new(BufferPool::new()),
+        rng: Arc::new(SecureRandom::new()),
+        route_runtime: Arc::new(RouteRuntimeController::new(RelayRouteMode::Direct)),
+        ip_tracker: Arc::new(UserIpTracker::new()),
+        beobachten: Arc::new(BeobachtenStore::new()),
+    }
+}
+
+async fn drive_invalid_mtproto_handshake(shared: Arc<ProxySharedState>, peer: std::net::SocketAddr) {
+    let harness = new_client_harness();
+    let (server_side, mut client_side) = duplex(4096);
+    let invalid = [0u8; 64];
+
+    let task = tokio::spawn(handle_client_stream_with_shared(
+        server_side,
+        peer,
+        harness.config,
+        harness.stats,
+        harness.upstream_manager,
+        harness.replay_checker,
+        harness.buffer_pool,
+        harness.rng,
+        None,
+        harness.route_runtime,
+        None,
+        harness.ip_tracker,
+        harness.beobachten,
+        shared,
+        false,
+    ));
+
+    client_side
+        .write_all(&invalid)
+        .await
+        .expect("failed to write invalid handshake");
+    client_side.shutdown().await.expect("failed to shutdown client");
+    let _ = tokio::time::timeout(Duration::from_secs(3), task)
+        .await
+        .expect("client task timed out")
+        .expect("client task join failed");
+}
+
+#[test]
+fn proxy_shared_state_two_instances_do_not_share_auth_probe_state() {
+    let a = ProxySharedState::new();
+    let b = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(a.as_ref());
+
+    let ip = IpAddr::V4(Ipv4Addr::new(198, 51, 100, 10));
+    auth_probe_record_failure_for_testing(a.as_ref(), ip, Instant::now());
+
+    assert_eq!(
+        auth_probe_fail_streak_for_testing_in_shared(a.as_ref(), ip),
+        Some(1)
+    );
+    assert_eq!(auth_probe_fail_streak_for_testing_in_shared(b.as_ref(), ip), None);
+}
+
+#[test]
+fn proxy_shared_state_two_instances_do_not_share_desync_dedup() {
+    let a = ProxySharedState::new();
+    let b = ProxySharedState::new();
+    clear_desync_dedup_for_testing_in_shared(a.as_ref());
+
+    let now = Instant::now();
+    let key = 0xA5A5_u64;
+    assert!(should_emit_full_desync_for_testing(a.as_ref(), key, false, now));
+    assert!(should_emit_full_desync_for_testing(b.as_ref(), key, false, now));
+}
+
+#[test]
+fn proxy_shared_state_two_instances_do_not_share_idle_registry() {
+    let a = ProxySharedState::new();
+    let b = ProxySharedState::new();
+    clear_relay_idle_pressure_state_for_testing_in_shared(a.as_ref());
+
+    assert!(mark_relay_idle_candidate_for_testing(a.as_ref(), 111));
+    assert_eq!(oldest_relay_idle_candidate_for_testing(a.as_ref()), Some(111));
+    assert_eq!(oldest_relay_idle_candidate_for_testing(b.as_ref()), None);
+}
+
+#[test]
+fn proxy_shared_state_reset_in_one_instance_does_not_affect_another() {
+    let a = ProxySharedState::new();
+    let b = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(a.as_ref());
+
+    let ip_a = IpAddr::V4(Ipv4Addr::new(203, 0, 113, 1));
+    let ip_b = IpAddr::V4(Ipv4Addr::new(203, 0, 113, 2));
+    let now = Instant::now();
+
+    auth_probe_record_failure_for_testing(a.as_ref(), ip_a, now);
+    auth_probe_record_failure_for_testing(b.as_ref(), ip_b, now);
+    clear_auth_probe_state_for_testing_in_shared(a.as_ref());
+
+    assert_eq!(auth_probe_fail_streak_for_testing_in_shared(a.as_ref(), ip_a), None);
+    assert_eq!(
+        auth_probe_fail_streak_for_testing_in_shared(b.as_ref(), ip_b),
+        Some(1)
+    );
+}
+
+#[test]
+fn proxy_shared_state_parallel_auth_probe_updates_stay_per_instance() {
+    let a = ProxySharedState::new();
+    let b = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(a.as_ref());
+
+    let ip = IpAddr::V4(Ipv4Addr::new(192, 0, 2, 77));
+    let now = Instant::now();
+
+    for _ in 0..5 {
+        auth_probe_record_failure_for_testing(a.as_ref(), ip, now);
+    }
+    for _ in 0..3 {
+        auth_probe_record_failure_for_testing(b.as_ref(), ip, now + Duration::from_millis(1));
+    }
+
+    assert_eq!(auth_probe_fail_streak_for_testing_in_shared(a.as_ref(), ip), Some(5));
+    assert_eq!(auth_probe_fail_streak_for_testing_in_shared(b.as_ref(), ip), Some(3));
+}
+
+#[tokio::test]
+async fn proxy_shared_state_client_pipeline_records_probe_failures_in_instance_state() {
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
+    let peer_ip = IpAddr::V4(Ipv4Addr::new(198, 51, 100, 200));
+    let peer = std::net::SocketAddr::new(peer_ip, 54001);
+
+    drive_invalid_mtproto_handshake(shared.clone(), peer).await;
+
+    assert_eq!(
+        auth_probe_fail_streak_for_testing_in_shared(shared.as_ref(), peer_ip),
+        Some(1),
+        "invalid handshake in client pipeline must update injected shared auth-probe state"
+    );
+}
+
+#[tokio::test]
+async fn proxy_shared_state_client_pipeline_keeps_auth_probe_isolated_between_instances() {
+    let shared_a = ProxySharedState::new();
+    let shared_b = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared_a.as_ref());
+    clear_auth_probe_state_for_testing_in_shared(shared_b.as_ref());
+
+    let peer_a_ip = IpAddr::V4(Ipv4Addr::new(203, 0, 113, 210));
+    let peer_b_ip = IpAddr::V4(Ipv4Addr::new(203, 0, 113, 211));
+
+    drive_invalid_mtproto_handshake(
+        shared_a.clone(),
+        std::net::SocketAddr::new(peer_a_ip, 54110),
+    )
+    .await;
+    drive_invalid_mtproto_handshake(
+        shared_b.clone(),
+        std::net::SocketAddr::new(peer_b_ip, 54111),
+    )
+    .await;
+
+    assert_eq!(
+        auth_probe_fail_streak_for_testing_in_shared(shared_a.as_ref(), peer_a_ip),
+        Some(1)
+    );
+    assert_eq!(
+        auth_probe_fail_streak_for_testing_in_shared(shared_b.as_ref(), peer_b_ip),
+        Some(1)
+    );
+    assert_eq!(
+        auth_probe_fail_streak_for_testing_in_shared(shared_a.as_ref(), peer_b_ip),
+        None
+    );
+    assert_eq!(
+        auth_probe_fail_streak_for_testing_in_shared(shared_b.as_ref(), peer_a_ip),
+        None
+    );
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 4)]
+async fn proxy_shared_state_client_pipeline_high_contention_same_ip_stays_lossless_per_instance() {
+    let shared_a = ProxySharedState::new();
+    let shared_b = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared_a.as_ref());
+    clear_auth_probe_state_for_testing_in_shared(shared_b.as_ref());
+
+    let ip = IpAddr::V4(Ipv4Addr::new(198, 51, 100, 250));
+    let workers = 48u16;
+    let barrier = Arc::new(Barrier::new((workers as usize) * 2));
+    let mut tasks = Vec::new();
+
+    for i in 0..workers {
+        let shared_a = shared_a.clone();
+        let barrier_a = barrier.clone();
+        let peer_a = std::net::SocketAddr::new(ip, 56000 + i);
+        tasks.push(tokio::spawn(async move {
+            barrier_a.wait().await;
+            drive_invalid_mtproto_handshake(shared_a, peer_a).await;
+        }));
+
+        let shared_b = shared_b.clone();
+        let barrier_b = barrier.clone();
+        let peer_b = std::net::SocketAddr::new(ip, 56100 + i);
+        tasks.push(tokio::spawn(async move {
+            barrier_b.wait().await;
+            drive_invalid_mtproto_handshake(shared_b, peer_b).await;
+        }));
+    }
+
+    for task in tasks {
+        task.await.expect("pipeline task join failed");
+    }
+
+    let streak_a = auth_probe_fail_streak_for_testing_in_shared(shared_a.as_ref(), ip)
+        .expect("instance A must track probe failures");
+    let streak_b = auth_probe_fail_streak_for_testing_in_shared(shared_b.as_ref(), ip)
+        .expect("instance B must track probe failures");
+
+    assert!(streak_a > 0);
+    assert!(streak_b > 0);
+
+    clear_auth_probe_state_for_testing_in_shared(shared_a.as_ref());
+    assert_eq!(
+        auth_probe_fail_streak_for_testing_in_shared(shared_a.as_ref(), ip),
+        None,
+        "clearing one instance must reset only that instance"
+    );
+    assert!(
+        auth_probe_fail_streak_for_testing_in_shared(shared_b.as_ref(), ip).is_some(),
+        "clearing one instance must not clear the other instance"
+    );
+}
+
+#[test]
+fn proxy_shared_state_auth_saturation_does_not_bleed_across_instances() {
+    let a = ProxySharedState::new();
+    let b = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(a.as_ref());
+    clear_auth_probe_state_for_testing_in_shared(b.as_ref());
+
+    let ip = IpAddr::V4(Ipv4Addr::new(203, 0, 113, 77));
+    let future_now = Instant::now() + Duration::from_secs(1);
+    for _ in 0..8 {
+        auth_probe_record_failure_for_testing(a.as_ref(), ip, future_now);
+    }
+
+    assert!(auth_probe_is_throttled_for_testing_in_shared(a.as_ref(), ip));
+    assert!(!auth_probe_is_throttled_for_testing_in_shared(b.as_ref(), ip));
+}
+
+#[test]
+fn proxy_shared_state_poison_clear_in_one_instance_does_not_affect_other_instance() {
+    let a = ProxySharedState::new();
+    let b = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(a.as_ref());
+    clear_auth_probe_state_for_testing_in_shared(b.as_ref());
+
+    let ip_a = IpAddr::V4(Ipv4Addr::new(203, 0, 113, 31));
+    let ip_b = IpAddr::V4(Ipv4Addr::new(203, 0, 113, 32));
+    let now = Instant::now();
+
+    auth_probe_record_failure_for_testing(a.as_ref(), ip_a, now);
+    auth_probe_record_failure_for_testing(b.as_ref(), ip_b, now);
+
+    let a_for_poison = a.clone();
+    let _ = std::thread::spawn(move || {
+        let _hold = a_for_poison
+            .handshake
+            .auth_probe_saturation
+            .lock()
+            .unwrap_or_else(|poisoned| poisoned.into_inner());
+        panic!("intentional poison for per-instance isolation regression coverage");
+    })
+    .join();
+
+    clear_auth_probe_state_for_testing_in_shared(a.as_ref());
+
+    assert_eq!(auth_probe_fail_streak_for_testing_in_shared(a.as_ref(), ip_a), None);
+    assert_eq!(
+        auth_probe_fail_streak_for_testing_in_shared(b.as_ref(), ip_b),
+        Some(1),
+        "poison recovery and clear in one instance must not touch other instance state"
+    );
+}
+
+#[test]
+fn proxy_shared_state_unknown_sni_cooldown_does_not_bleed_across_instances() {
+    let a = ProxySharedState::new();
+    let b = ProxySharedState::new();
+    clear_unknown_sni_warn_state_for_testing_in_shared(a.as_ref());
+    clear_unknown_sni_warn_state_for_testing_in_shared(b.as_ref());
+
+    let now = Instant::now();
+    assert!(should_emit_unknown_sni_warn_for_testing_in_shared(
+        a.as_ref(),
+        now
+    ));
+    assert!(should_emit_unknown_sni_warn_for_testing_in_shared(
+        b.as_ref(),
+        now
+    ));
+}
+
+#[test]
+fn proxy_shared_state_warned_secret_cache_does_not_bleed_across_instances() {
+    let a = ProxySharedState::new();
+    let b = ProxySharedState::new();
+    clear_warned_secrets_for_testing_in_shared(a.as_ref());
+    clear_warned_secrets_for_testing_in_shared(b.as_ref());
+
+    let key = ("isolation-user".to_string(), "invalid_hex".to_string());
+    {
+        let warned = warned_secrets_for_testing_in_shared(a.as_ref());
+        let mut guard = warned
+            .lock()
+            .unwrap_or_else(|poisoned| poisoned.into_inner());
+        guard.insert(key.clone());
+    }
+
+    let contains_in_a = {
+        let warned = warned_secrets_for_testing_in_shared(a.as_ref());
+        let guard = warned
+            .lock()
+            .unwrap_or_else(|poisoned| poisoned.into_inner());
+        guard.contains(&key)
+    };
+    let contains_in_b = {
+        let warned = warned_secrets_for_testing_in_shared(b.as_ref());
+        let guard = warned
+            .lock()
+            .unwrap_or_else(|poisoned| poisoned.into_inner());
+        guard.contains(&key)
+    };
+
+    assert!(contains_in_a);
+    assert!(!contains_in_b);
+}
+
+#[test]
+fn proxy_shared_state_idle_mark_seq_is_per_instance() {
+    let a = ProxySharedState::new();
+    let b = ProxySharedState::new();
+    clear_relay_idle_pressure_state_for_testing_in_shared(a.as_ref());
+    clear_relay_idle_pressure_state_for_testing_in_shared(b.as_ref());
+
+    assert_eq!(relay_idle_mark_seq_for_testing(a.as_ref()), 0);
+    assert_eq!(relay_idle_mark_seq_for_testing(b.as_ref()), 0);
+
+    assert!(mark_relay_idle_candidate_for_testing(a.as_ref(), 9001));
+    assert_eq!(relay_idle_mark_seq_for_testing(a.as_ref()), 1);
+    assert_eq!(relay_idle_mark_seq_for_testing(b.as_ref()), 0);
+
+    assert!(mark_relay_idle_candidate_for_testing(b.as_ref(), 9002));
+    assert_eq!(relay_idle_mark_seq_for_testing(a.as_ref()), 1);
+    assert_eq!(relay_idle_mark_seq_for_testing(b.as_ref()), 1);
+}
+
+#[test]
+fn proxy_shared_state_unknown_sni_clear_in_one_instance_does_not_reset_other() {
+    let a = ProxySharedState::new();
+    let b = ProxySharedState::new();
+    clear_unknown_sni_warn_state_for_testing_in_shared(a.as_ref());
+    clear_unknown_sni_warn_state_for_testing_in_shared(b.as_ref());
+
+    let now = Instant::now();
+    assert!(should_emit_unknown_sni_warn_for_testing_in_shared(
+        a.as_ref(),
+        now
+    ));
+    assert!(should_emit_unknown_sni_warn_for_testing_in_shared(
+        b.as_ref(),
+        now
+    ));
+
+    clear_unknown_sni_warn_state_for_testing_in_shared(a.as_ref());
+    assert!(should_emit_unknown_sni_warn_for_testing_in_shared(
+        a.as_ref(),
+        now + Duration::from_millis(1)
+    ));
+    assert!(!should_emit_unknown_sni_warn_for_testing_in_shared(
+        b.as_ref(),
+        now + Duration::from_millis(1)
+    ));
+}
+
+#[test]
+fn proxy_shared_state_warned_secret_clear_in_one_instance_does_not_clear_other() {
+    let a = ProxySharedState::new();
+    let b = ProxySharedState::new();
+    clear_warned_secrets_for_testing_in_shared(a.as_ref());
+    clear_warned_secrets_for_testing_in_shared(b.as_ref());
+
+    let key = ("clear-isolation-user".to_string(), "invalid_length".to_string());
+    {
+        let warned_a = warned_secrets_for_testing_in_shared(a.as_ref());
+        let mut guard_a = warned_a
+            .lock()
+            .unwrap_or_else(|poisoned| poisoned.into_inner());
+        guard_a.insert(key.clone());
+
+        let warned_b = warned_secrets_for_testing_in_shared(b.as_ref());
+        let mut guard_b = warned_b
+            .lock()
+            .unwrap_or_else(|poisoned| poisoned.into_inner());
+        guard_b.insert(key.clone());
+    }
+
+    clear_warned_secrets_for_testing_in_shared(a.as_ref());
+
+    let has_a = {
+        let warned = warned_secrets_for_testing_in_shared(a.as_ref());
+        let guard = warned
+            .lock()
+            .unwrap_or_else(|poisoned| poisoned.into_inner());
+        guard.contains(&key)
+    };
+    let has_b = {
+        let warned = warned_secrets_for_testing_in_shared(b.as_ref());
+        let guard = warned
+            .lock()
+            .unwrap_or_else(|poisoned| poisoned.into_inner());
+        guard.contains(&key)
+    };
+
+    assert!(!has_a);
+    assert!(has_b);
+}
+
+#[test]
+fn proxy_shared_state_desync_duplicate_suppression_is_instance_scoped() {
+    let a = ProxySharedState::new();
+    let b = ProxySharedState::new();
+    clear_desync_dedup_for_testing_in_shared(a.as_ref());
+    clear_desync_dedup_for_testing_in_shared(b.as_ref());
+
+    let now = Instant::now();
+    let key = 0xBEEF_0000_0000_0001u64;
+    assert!(should_emit_full_desync_for_testing(a.as_ref(), key, false, now));
+    assert!(!should_emit_full_desync_for_testing(
+        a.as_ref(),
+        key,
+        false,
+        now + Duration::from_millis(1)
+    ));
+    assert!(should_emit_full_desync_for_testing(b.as_ref(), key, false, now));
+}
+
+#[test]
+fn proxy_shared_state_desync_clear_in_one_instance_does_not_clear_other() {
+    let a = ProxySharedState::new();
+    let b = ProxySharedState::new();
+    clear_desync_dedup_for_testing_in_shared(a.as_ref());
+    clear_desync_dedup_for_testing_in_shared(b.as_ref());
+
+    let now = Instant::now();
+    let key = 0xCAFE_0000_0000_0001u64;
+    assert!(should_emit_full_desync_for_testing(a.as_ref(), key, false, now));
+    assert!(should_emit_full_desync_for_testing(b.as_ref(), key, false, now));
+
+    clear_desync_dedup_for_testing_in_shared(a.as_ref());
+
+    assert!(should_emit_full_desync_for_testing(
+        a.as_ref(),
+        key,
+        false,
+        now + Duration::from_millis(2)
+    ));
+    assert!(!should_emit_full_desync_for_testing(
+        b.as_ref(),
+        key,
+        false,
+        now + Duration::from_millis(2)
+    ));
+}
+
+#[test]
+fn proxy_shared_state_idle_candidate_clear_in_one_instance_does_not_affect_other() {
+    let a = ProxySharedState::new();
+    let b = ProxySharedState::new();
+    clear_relay_idle_pressure_state_for_testing_in_shared(a.as_ref());
+    clear_relay_idle_pressure_state_for_testing_in_shared(b.as_ref());
+
+    assert!(mark_relay_idle_candidate_for_testing(a.as_ref(), 1001));
+    assert!(mark_relay_idle_candidate_for_testing(b.as_ref(), 2002));
+    clear_relay_idle_candidate_for_testing(a.as_ref(), 1001);
+
+    assert_eq!(oldest_relay_idle_candidate_for_testing(a.as_ref()), None);
+    assert_eq!(oldest_relay_idle_candidate_for_testing(b.as_ref()), Some(2002));
+}
+
+#[test]
+fn proxy_shared_state_pressure_seq_increments_are_instance_scoped() {
+    let a = ProxySharedState::new();
+    let b = ProxySharedState::new();
+    clear_relay_idle_pressure_state_for_testing_in_shared(a.as_ref());
+    clear_relay_idle_pressure_state_for_testing_in_shared(b.as_ref());
+
+    assert_eq!(relay_pressure_event_seq_for_testing(a.as_ref()), 0);
+    assert_eq!(relay_pressure_event_seq_for_testing(b.as_ref()), 0);
+
+    note_relay_pressure_event_for_testing(a.as_ref());
+    note_relay_pressure_event_for_testing(a.as_ref());
+
+    assert_eq!(relay_pressure_event_seq_for_testing(a.as_ref()), 2);
+    assert_eq!(relay_pressure_event_seq_for_testing(b.as_ref()), 0);
+}
+
+#[test]
+fn proxy_shared_state_pressure_consumption_does_not_cross_instances() {
+    let a = ProxySharedState::new();
+    let b = ProxySharedState::new();
+    clear_relay_idle_pressure_state_for_testing_in_shared(a.as_ref());
+    clear_relay_idle_pressure_state_for_testing_in_shared(b.as_ref());
+
+    assert!(mark_relay_idle_candidate_for_testing(a.as_ref(), 7001));
+    assert!(mark_relay_idle_candidate_for_testing(b.as_ref(), 7001));
+    note_relay_pressure_event_for_testing(a.as_ref());
+
+    let stats = Stats::new();
+    let mut seen_a = 0u64;
+    let mut seen_b = 0u64;
+
+    assert!(maybe_evict_idle_candidate_on_pressure_for_testing(
+        a.as_ref(),
+        7001,
+        &mut seen_a,
+        &stats
+    ));
+    assert!(!maybe_evict_idle_candidate_on_pressure_for_testing(
+        b.as_ref(),
+        7001,
+        &mut seen_b,
+        &stats
+    ));
+}

src/proxy/tests/proxy_shared_state_parallel_execution_tests.rs

@@ -0,0 +1,255 @@
+use crate::proxy::handshake::{
+    auth_probe_fail_streak_for_testing_in_shared, auth_probe_record_failure_for_testing,
+    clear_auth_probe_state_for_testing_in_shared, clear_unknown_sni_warn_state_for_testing_in_shared,
+    should_emit_unknown_sni_warn_for_testing_in_shared,
+};
+use crate::proxy::middle_relay::{
+    clear_desync_dedup_for_testing_in_shared, clear_relay_idle_pressure_state_for_testing_in_shared,
+    mark_relay_idle_candidate_for_testing, oldest_relay_idle_candidate_for_testing,
+    should_emit_full_desync_for_testing,
+};
+use crate::proxy::shared_state::ProxySharedState;
+use rand::SeedableRng;
+use rand::RngExt;
+use rand::rngs::StdRng;
+use std::net::{IpAddr, Ipv4Addr};
+use std::sync::Arc;
+use std::time::Instant;
+use tokio::sync::Barrier;
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 4)]
+async fn proxy_shared_state_50_concurrent_instances_no_counter_bleed() {
+    let mut handles = Vec::new();
+    for i in 0..50_u8 {
+        handles.push(tokio::spawn(async move {
+            let shared = ProxySharedState::new();
+            clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
+            let ip = IpAddr::V4(Ipv4Addr::new(198, 51, 100, 200));
+            auth_probe_record_failure_for_testing(shared.as_ref(), ip, Instant::now());
+            auth_probe_fail_streak_for_testing_in_shared(shared.as_ref(), ip)
+        }));
+    }
+
+    for handle in handles {
+        let streak = handle.await.expect("task join failed");
+        assert_eq!(streak, Some(1));
+    }
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 4)]
+async fn proxy_shared_state_desync_rotation_concurrent_20_instances() {
+    let now = Instant::now();
+    let key = 0xD35E_D35E_u64;
+    let mut handles = Vec::new();
+    for _ in 0..20_u64 {
+        handles.push(tokio::spawn(async move {
+            let shared = ProxySharedState::new();
+            clear_desync_dedup_for_testing_in_shared(shared.as_ref());
+            should_emit_full_desync_for_testing(shared.as_ref(), key, false, now)
+        }));
+    }
+
+    for handle in handles {
+        let emitted = handle.await.expect("task join failed");
+        assert!(emitted);
+    }
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 4)]
+async fn proxy_shared_state_idle_registry_concurrent_10_instances() {
+    let mut handles = Vec::new();
+    let conn_id = 42_u64;
+    for _ in 1..=10_u64 {
+        handles.push(tokio::spawn(async move {
+            let shared = ProxySharedState::new();
+            clear_relay_idle_pressure_state_for_testing_in_shared(shared.as_ref());
+            let marked = mark_relay_idle_candidate_for_testing(shared.as_ref(), conn_id);
+            let oldest = oldest_relay_idle_candidate_for_testing(shared.as_ref());
+            (marked, oldest)
+        }));
+    }
+
+    for (i, handle) in handles.into_iter().enumerate() {
+        let (marked, oldest) = handle.await.expect("task join failed");
+        assert!(marked, "instance {} failed to mark", i);
+        assert_eq!(oldest, Some(conn_id));
+    }
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 4)]
+async fn proxy_shared_state_dual_instance_same_ip_high_contention_no_counter_bleed() {
+    let a = ProxySharedState::new();
+    let b = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(a.as_ref());
+    clear_auth_probe_state_for_testing_in_shared(b.as_ref());
+
+    let ip = IpAddr::V4(Ipv4Addr::new(203, 0, 113, 200));
+    let mut handles = Vec::new();
+
+    for _ in 0..64 {
+        let a = a.clone();
+        let b = b.clone();
+        handles.push(tokio::spawn(async move {
+            auth_probe_record_failure_for_testing(a.as_ref(), ip, Instant::now());
+            auth_probe_record_failure_for_testing(b.as_ref(), ip, Instant::now());
+        }));
+    }
+
+    for handle in handles {
+        handle.await.expect("task join failed");
+    }
+
+    assert_eq!(auth_probe_fail_streak_for_testing_in_shared(a.as_ref(), ip), Some(64));
+    assert_eq!(auth_probe_fail_streak_for_testing_in_shared(b.as_ref(), ip), Some(64));
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 4)]
+async fn proxy_shared_state_unknown_sni_parallel_instances_no_cross_cooldown() {
+    let mut handles = Vec::new();
+    let now = Instant::now();
+
+    for _ in 0..32 {
+        handles.push(tokio::spawn(async move {
+            let shared = ProxySharedState::new();
+            clear_unknown_sni_warn_state_for_testing_in_shared(shared.as_ref());
+            let first = should_emit_unknown_sni_warn_for_testing_in_shared(shared.as_ref(), now);
+            let second = should_emit_unknown_sni_warn_for_testing_in_shared(
+                shared.as_ref(),
+                now + std::time::Duration::from_millis(1),
+            );
+            (first, second)
+        }));
+    }
+
+    for handle in handles {
+        let (first, second) = handle.await.expect("task join failed");
+        assert!(first);
+        assert!(!second);
+    }
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 4)]
+async fn proxy_shared_state_auth_probe_high_contention_increments_are_lossless() {
+    let shared = ProxySharedState::new();
+    clear_auth_probe_state_for_testing_in_shared(shared.as_ref());
+
+    let ip = IpAddr::V4(Ipv4Addr::new(198, 51, 100, 33));
+    let workers = 128usize;
+    let rounds = 20usize;
+
+    for _ in 0..rounds {
+        let start = Arc::new(Barrier::new(workers));
+        let mut handles = Vec::with_capacity(workers);
+
+        for _ in 0..workers {
+            let shared = shared.clone();
+            let start = start.clone();
+            handles.push(tokio::spawn(async move {
+                start.wait().await;
+                auth_probe_record_failure_for_testing(shared.as_ref(), ip, Instant::now());
+            }));
+        }
+
+        for handle in handles {
+            handle.await.expect("task join failed");
+        }
+    }
+
+    let expected = (workers * rounds) as u32;
+    assert_eq!(
+        auth_probe_fail_streak_for_testing_in_shared(shared.as_ref(), ip),
+        Some(expected),
+        "auth probe fail streak must account for every concurrent update"
+    );
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 4)]
+async fn proxy_shared_state_seed_matrix_concurrency_isolation_no_counter_bleed() {
+    let seeds: [u64; 8] = [
+        0x0000_0000_0000_0001,
+        0x1111_1111_1111_1111,
+        0xA5A5_A5A5_A5A5_A5A5,
+        0xDEAD_BEEF_CAFE_BABE,
+        0x0123_4567_89AB_CDEF,
+        0xFEDC_BA98_7654_3210,
+        0x0F0F_F0F0_55AA_AA55,
+        0x1357_9BDF_2468_ACE0,
+    ];
+
+    for seed in seeds {
+        let mut rng = StdRng::seed_from_u64(seed);
+        let shared_a = ProxySharedState::new();
+        let shared_b = ProxySharedState::new();
+        clear_auth_probe_state_for_testing_in_shared(shared_a.as_ref());
+        clear_auth_probe_state_for_testing_in_shared(shared_b.as_ref());
+
+        let ip = IpAddr::V4(Ipv4Addr::new(
+            198,
+            51,
+            100,
+            rng.random_range(1_u8..=250_u8),
+        ));
+        let workers = rng.random_range(16_usize..=48_usize);
+        let rounds = rng.random_range(4_usize..=10_usize);
+
+        let mut expected_a: u32 = 0;
+        let mut expected_b: u32 = 0;
+
+        for _ in 0..rounds {
+            let start = Arc::new(Barrier::new(workers * 2));
+            let mut handles = Vec::with_capacity(workers * 2);
+
+            for _ in 0..workers {
+                let a_ops = rng.random_range(1_u32..=3_u32);
+                let b_ops = rng.random_range(1_u32..=3_u32);
+                expected_a = expected_a.saturating_add(a_ops);
+                expected_b = expected_b.saturating_add(b_ops);
+
+                let shared_a = shared_a.clone();
+                let start_a = start.clone();
+                handles.push(tokio::spawn(async move {
+                    start_a.wait().await;
+                    for _ in 0..a_ops {
+                        auth_probe_record_failure_for_testing(shared_a.as_ref(), ip, Instant::now());
+                    }
+                }));
+
+                let shared_b = shared_b.clone();
+                let start_b = start.clone();
+                handles.push(tokio::spawn(async move {
+                    start_b.wait().await;
+                    for _ in 0..b_ops {
+                        auth_probe_record_failure_for_testing(shared_b.as_ref(), ip, Instant::now());
+                    }
+                }));
+            }
+
+            for handle in handles {
+                handle.await.expect("task join failed");
+            }
+        }
+
+        assert_eq!(
+            auth_probe_fail_streak_for_testing_in_shared(shared_a.as_ref(), ip),
+            Some(expected_a),
+            "seed {seed:#x}: instance A streak mismatch"
+        );
+        assert_eq!(
+            auth_probe_fail_streak_for_testing_in_shared(shared_b.as_ref(), ip),
+            Some(expected_b),
+            "seed {seed:#x}: instance B streak mismatch"
+        );
+
+        clear_auth_probe_state_for_testing_in_shared(shared_a.as_ref());
+        assert_eq!(
+            auth_probe_fail_streak_for_testing_in_shared(shared_a.as_ref(), ip),
+            None,
+            "seed {seed:#x}: clearing A must reset only A"
+        );
+        assert_eq!(
+            auth_probe_fail_streak_for_testing_in_shared(shared_b.as_ref(), ip),
+            Some(expected_b),
+            "seed {seed:#x}: clearing A must not mutate B"
+        );
+    }
+}

src/proxy/tests/relay_baseline_invariant_tests.rs

@@ -0,0 +1,275 @@
+use super::*;
+use crate::error::ProxyError;
+use crate::stats::Stats;
+use crate::stream::BufferPool;
+use std::io;
+use std::sync::Arc;
+use tokio::io::{AsyncRead, AsyncReadExt, AsyncWrite, AsyncWriteExt, ReadBuf, duplex};
+use tokio::time::{Duration, timeout};
+
+struct BrokenPipeWriter;
+
+impl AsyncWrite for BrokenPipeWriter {
+    fn poll_write(
+        self: Pin<&mut Self>,
+        _cx: &mut Context<'_>,
+        _buf: &[u8],
+    ) -> Poll<io::Result<usize>> {
+        Poll::Ready(Err(io::Error::new(
+            io::ErrorKind::BrokenPipe,
+            "forced broken pipe",
+        )))
+    }
+
+    fn poll_flush(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<io::Result<()>> {
+        Poll::Ready(Ok(()))
+    }
+
+    fn poll_shutdown(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<io::Result<()>> {
+        Poll::Ready(Ok(()))
+    }
+}
+
+#[tokio::test(start_paused = true)]
+async fn relay_baseline_activity_timeout_fires_after_inactivity() {
+    let stats = Arc::new(Stats::new());
+    let user = "relay-baseline-idle-timeout";
+
+    let (_client_peer, relay_client) = duplex(1024);
+    let (_server_peer, relay_server) = duplex(1024);
+
+    let (client_reader, client_writer) = tokio::io::split(relay_client);
+    let (server_reader, server_writer) = tokio::io::split(relay_server);
+
+    let relay_task = tokio::spawn(relay_bidirectional(
+        client_reader,
+        client_writer,
+        server_reader,
+        server_writer,
+        1024,
+        1024,
+        user,
+        Arc::clone(&stats),
+        None,
+        Arc::new(BufferPool::new()),
+    ));
+
+    tokio::task::yield_now().await;
+    tokio::time::advance(ACTIVITY_TIMEOUT.saturating_sub(Duration::from_secs(1))).await;
+    tokio::task::yield_now().await;
+    assert!(
+        !relay_task.is_finished(),
+        "relay must stay alive before inactivity timeout"
+    );
+
+    tokio::time::advance(WATCHDOG_INTERVAL + Duration::from_secs(2)).await;
+
+    let done = timeout(Duration::from_secs(1), relay_task)
+        .await
+        .expect("relay must complete after inactivity timeout")
+        .expect("relay task must not panic");
+
+    assert!(done.is_ok(), "relay must return Ok(()) after inactivity timeout");
+}
+
+#[tokio::test]
+async fn relay_baseline_zero_bytes_returns_ok_and_counters_zero() {
+    let stats = Arc::new(Stats::new());
+    let user = "relay-baseline-zero-bytes";
+
+    let (client_peer, relay_client) = duplex(1024);
+    let (server_peer, relay_server) = duplex(1024);
+
+    let (client_reader, client_writer) = tokio::io::split(relay_client);
+    let (server_reader, server_writer) = tokio::io::split(relay_server);
+
+    let relay_task = tokio::spawn(relay_bidirectional(
+        client_reader,
+        client_writer,
+        server_reader,
+        server_writer,
+        1024,
+        1024,
+        user,
+        Arc::clone(&stats),
+        None,
+        Arc::new(BufferPool::new()),
+    ));
+
+    drop(client_peer);
+    drop(server_peer);
+
+    let done = timeout(Duration::from_secs(2), relay_task)
+        .await
+        .expect("relay must stop after both peers close")
+        .expect("relay task must not panic");
+
+    assert!(done.is_ok(), "relay must return Ok(()) on immediate EOF");
+    assert_eq!(stats.get_user_total_octets(user), 0);
+}
+
+#[tokio::test]
+async fn relay_baseline_bidirectional_bytes_counted_symmetrically() {
+    let stats = Arc::new(Stats::new());
+    let user = "relay-baseline-bidir-counters";
+
+    let (mut client_peer, relay_client) = duplex(16 * 1024);
+    let (relay_server, mut server_peer) = duplex(16 * 1024);
+
+    let (client_reader, client_writer) = tokio::io::split(relay_client);
+    let (server_reader, server_writer) = tokio::io::split(relay_server);
+
+    let relay_task = tokio::spawn(relay_bidirectional(
+        client_reader,
+        client_writer,
+        server_reader,
+        server_writer,
+        4096,
+        4096,
+        user,
+        Arc::clone(&stats),
+        None,
+        Arc::new(BufferPool::new()),
+    ));
+
+    let c2s = vec![0xAA; 4096];
+    let s2c = vec![0xBB; 2048];
+
+    client_peer.write_all(&c2s).await.unwrap();
+    server_peer.write_all(&s2c).await.unwrap();
+
+    let mut seen_c2s = vec![0u8; c2s.len()];
+    let mut seen_s2c = vec![0u8; s2c.len()];
+    server_peer.read_exact(&mut seen_c2s).await.unwrap();
+    client_peer.read_exact(&mut seen_s2c).await.unwrap();
+
+    assert_eq!(seen_c2s, c2s);
+    assert_eq!(seen_s2c, s2c);
+
+    drop(client_peer);
+    drop(server_peer);
+
+    let done = timeout(Duration::from_secs(2), relay_task)
+        .await
+        .expect("relay must complete after both peers close")
+        .expect("relay task must not panic");
+    assert!(done.is_ok());
+
+    assert_eq!(stats.get_user_total_octets(user), (c2s.len() + s2c.len()) as u64);
+}
+
+#[tokio::test]
+async fn relay_baseline_both_sides_close_simultaneously_no_panic() {
+    let stats = Arc::new(Stats::new());
+
+    let (client_peer, relay_client) = duplex(1024);
+    let (relay_server, server_peer) = duplex(1024);
+
+    let (client_reader, client_writer) = tokio::io::split(relay_client);
+    let (server_reader, server_writer) = tokio::io::split(relay_server);
+
+    let relay_task = tokio::spawn(relay_bidirectional(
+        client_reader,
+        client_writer,
+        server_reader,
+        server_writer,
+        1024,
+        1024,
+        "relay-baseline-sim-close",
+        Arc::clone(&stats),
+        None,
+        Arc::new(BufferPool::new()),
+    ));
+
+    drop(client_peer);
+    drop(server_peer);
+
+    let done = timeout(Duration::from_secs(2), relay_task)
+        .await
+        .expect("relay must complete")
+        .expect("relay task must not panic");
+    assert!(done.is_ok());
+}
+
+#[tokio::test]
+async fn relay_baseline_broken_pipe_midtransfer_returns_error() {
+    let stats = Arc::new(Stats::new());
+    let user = "relay-baseline-broken-pipe";
+
+    let (mut client_peer, relay_client) = duplex(1024);
+    let (client_reader, client_writer) = tokio::io::split(relay_client);
+
+    let relay_task = tokio::spawn(relay_bidirectional(
+        client_reader,
+        client_writer,
+        tokio::io::empty(),
+        BrokenPipeWriter,
+        1024,
+        1024,
+        user,
+        Arc::clone(&stats),
+        None,
+        Arc::new(BufferPool::new()),
+    ));
+
+    client_peer.write_all(b"trigger").await.unwrap();
+
+    let done = timeout(Duration::from_secs(2), relay_task)
+        .await
+        .expect("relay must return after broken pipe")
+        .expect("relay task must not panic");
+
+    match done {
+        Err(ProxyError::Io(err)) => {
+            assert!(
+                matches!(err.kind(), io::ErrorKind::BrokenPipe | io::ErrorKind::ConnectionReset),
+                "expected BrokenPipe/ConnectionReset, got {:?}",
+                err.kind()
+            );
+        }
+        other => panic!("expected ProxyError::Io, got {other:?}"),
+    }
+}
+
+#[tokio::test]
+async fn relay_baseline_many_small_writes_exact_counter() {
+    let stats = Arc::new(Stats::new());
+    let user = "relay-baseline-many-small";
+
+    let (mut client_peer, relay_client) = duplex(4096);
+    let (relay_server, mut server_peer) = duplex(4096);
+
+    let (client_reader, client_writer) = tokio::io::split(relay_client);
+    let (server_reader, server_writer) = tokio::io::split(relay_server);
+
+    let relay_task = tokio::spawn(relay_bidirectional(
+        client_reader,
+        client_writer,
+        server_reader,
+        server_writer,
+        1024,
+        1024,
+        user,
+        Arc::clone(&stats),
+        None,
+        Arc::new(BufferPool::new()),
+    ));
+
+    for i in 0..10_000u32 {
+        let b = [(i & 0xFF) as u8];
+        client_peer.write_all(&b).await.unwrap();
+        let mut seen = [0u8; 1];
+        server_peer.read_exact(&mut seen).await.unwrap();
+        assert_eq!(seen, b);
+    }
+
+    drop(client_peer);
+    drop(server_peer);
+
+    let done = timeout(Duration::from_secs(3), relay_task)
+        .await
+        .expect("relay must complete for many small writes")
+        .expect("relay task must not panic");
+    assert!(done.is_ok());
+    assert_eq!(stats.get_user_total_octets(user), 10_000);
+}

src/proxy/tests/test_harness_common.rs

@@ -0,0 +1,202 @@
+use crate::config::ProxyConfig;
+use rand::rngs::StdRng;
+use rand::SeedableRng;
+use std::io;
+use std::pin::Pin;
+use std::sync::Arc;
+use std::task::{Context, Poll};
+use tokio::io::AsyncWrite;
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::sync::Arc;
+    use std::sync::atomic::{AtomicUsize, Ordering};
+    use std::task::{RawWaker, RawWakerVTable, Waker};
+
+    unsafe fn wake_counter_clone(data: *const ()) -> RawWaker {
+        let arc = Arc::<AtomicUsize>::from_raw(data.cast::<AtomicUsize>());
+        let cloned = Arc::clone(&arc);
+        let _ = Arc::into_raw(arc);
+        RawWaker::new(Arc::into_raw(cloned).cast::<()>(), &WAKE_COUNTER_WAKER_VTABLE)
+    }
+
+    unsafe fn wake_counter_wake(data: *const ()) {
+        let arc = Arc::<AtomicUsize>::from_raw(data.cast::<AtomicUsize>());
+        arc.fetch_add(1, Ordering::SeqCst);
+    }
+
+    unsafe fn wake_counter_wake_by_ref(data: *const ()) {
+        let arc = Arc::<AtomicUsize>::from_raw(data.cast::<AtomicUsize>());
+        arc.fetch_add(1, Ordering::SeqCst);
+        let _ = Arc::into_raw(arc);
+    }
+
+    unsafe fn wake_counter_drop(data: *const ()) {
+        let _ = Arc::<AtomicUsize>::from_raw(data.cast::<AtomicUsize>());
+    }
+
+    static WAKE_COUNTER_WAKER_VTABLE: RawWakerVTable = RawWakerVTable::new(
+        wake_counter_clone,
+        wake_counter_wake,
+        wake_counter_wake_by_ref,
+        wake_counter_drop,
+    );
+
+    fn wake_counter_waker(counter: Arc<AtomicUsize>) -> Waker {
+        let raw = RawWaker::new(
+            Arc::into_raw(counter).cast::<()>(),
+            &WAKE_COUNTER_WAKER_VTABLE,
+        );
+        // SAFETY: `raw` points to a valid `Arc<AtomicUsize>` and uses a vtable
+        // that preserves Arc reference-counting semantics.
+        unsafe { Waker::from_raw(raw) }
+    }
+
+    #[test]
+    fn pending_count_writer_write_pending_does_not_spurious_wake() {
+        let counter = Arc::new(AtomicUsize::new(0));
+        let waker = wake_counter_waker(Arc::clone(&counter));
+        let mut cx = Context::from_waker(&waker);
+
+        let mut writer = PendingCountWriter::new(RecordingWriter::new(), 1, 0);
+        let poll = Pin::new(&mut writer).poll_write(&mut cx, b"x");
+
+        assert!(matches!(poll, Poll::Pending));
+        assert_eq!(counter.load(Ordering::SeqCst), 0);
+    }
+
+    #[test]
+    fn pending_count_writer_flush_pending_does_not_spurious_wake() {
+        let counter = Arc::new(AtomicUsize::new(0));
+        let waker = wake_counter_waker(Arc::clone(&counter));
+        let mut cx = Context::from_waker(&waker);
+
+        let mut writer = PendingCountWriter::new(RecordingWriter::new(), 0, 1);
+        let poll = Pin::new(&mut writer).poll_flush(&mut cx);
+
+        assert!(matches!(poll, Poll::Pending));
+        assert_eq!(counter.load(Ordering::SeqCst), 0);
+    }
+}
+
+// In-memory AsyncWrite that records both per-write and per-flush granularity.
+pub struct RecordingWriter {
+    pub writes: Vec<Vec<u8>>,
+    pub flushed: Vec<Vec<u8>>,
+    current_record: Vec<u8>,
+}
+
+impl RecordingWriter {
+    pub fn new() -> Self {
+        Self {
+            writes: Vec::new(),
+            flushed: Vec::new(),
+            current_record: Vec::new(),
+        }
+    }
+
+    pub fn total_bytes(&self) -> usize {
+        self.writes.iter().map(|w| w.len()).sum()
+    }
+}
+
+impl Default for RecordingWriter {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl AsyncWrite for RecordingWriter {
+    fn poll_write(
+        mut self: Pin<&mut Self>,
+        _cx: &mut Context<'_>,
+        buf: &[u8],
+    ) -> Poll<io::Result<usize>> {
+        let me = self.as_mut().get_mut();
+        me.writes.push(buf.to_vec());
+        me.current_record.extend_from_slice(buf);
+        Poll::Ready(Ok(buf.len()))
+    }
+
+    fn poll_flush(mut self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<io::Result<()>> {
+        let me = self.as_mut().get_mut();
+        let record = std::mem::take(&mut me.current_record);
+        if !record.is_empty() {
+            me.flushed.push(record);
+        }
+        Poll::Ready(Ok(()))
+    }
+
+    fn poll_shutdown(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<io::Result<()>> {
+        Poll::Ready(Ok(()))
+    }
+}
+
+// Returns Poll::Pending for the first N write/flush calls, then delegates.
+pub struct PendingCountWriter<W> {
+    pub inner: W,
+    pub write_pending_remaining: usize,
+    pub flush_pending_remaining: usize,
+}
+
+impl<W> PendingCountWriter<W> {
+    pub fn new(inner: W, write_pending: usize, flush_pending: usize) -> Self {
+        Self {
+            inner,
+            write_pending_remaining: write_pending,
+            flush_pending_remaining: flush_pending,
+        }
+    }
+}
+
+impl<W: AsyncWrite + Unpin> AsyncWrite for PendingCountWriter<W> {
+    fn poll_write(
+        mut self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+        buf: &[u8],
+    ) -> Poll<io::Result<usize>> {
+        let me = self.as_mut().get_mut();
+        if me.write_pending_remaining > 0 {
+            me.write_pending_remaining -= 1;
+            return Poll::Pending;
+        }
+        Pin::new(&mut me.inner).poll_write(cx, buf)
+    }
+
+    fn poll_flush(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
+        let me = self.as_mut().get_mut();
+        if me.flush_pending_remaining > 0 {
+            me.flush_pending_remaining -= 1;
+            return Poll::Pending;
+        }
+        Pin::new(&mut me.inner).poll_flush(cx)
+    }
+
+    fn poll_shutdown(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
+        Pin::new(&mut self.inner).poll_shutdown(cx)
+    }
+}
+
+pub fn seeded_rng(seed: u64) -> StdRng {
+    StdRng::seed_from_u64(seed)
+}
+
+pub fn tls_only_config() -> Arc<ProxyConfig> {
+    let mut cfg = ProxyConfig::default();
+    cfg.general.modes.tls = true;
+    Arc::new(cfg)
+}
+
+pub fn handshake_test_config(secret_hex: &str) -> ProxyConfig {
+    let mut cfg = ProxyConfig::default();
+    cfg.access.users.clear();
+    cfg.access
+        .users
+        .insert("test-user".to_string(), secret_hex.to_string());
+    cfg.access.ignore_time_skew = true;
+    cfg.censorship.mask = true;
+    cfg.censorship.mask_host = Some("127.0.0.1".to_string());
+    cfg.censorship.mask_port = 0;
+    cfg
+}

src/stats/mod.rs

@@ -200,6 +200,14 @@ pub struct Stats {
     me_d2c_flush_duration_us_bucket_1001_5000: AtomicU64,
     me_d2c_flush_duration_us_bucket_5001_20000: AtomicU64,
     me_d2c_flush_duration_us_bucket_gt_20000: AtomicU64,
+    // Buffer pool gauges
+    buffer_pool_pooled_gauge: AtomicU64,
+    buffer_pool_allocated_gauge: AtomicU64,
+    buffer_pool_in_use_gauge: AtomicU64,
+    // C2ME enqueue observability
+    me_c2me_send_full_total: AtomicU64,
+    me_c2me_send_high_water_total: AtomicU64,
+    me_c2me_send_timeout_total: AtomicU64,
     me_d2c_batch_timeout_armed_total: AtomicU64,
     me_d2c_batch_timeout_fired_total: AtomicU64,
     me_writer_pick_sorted_rr_success_try_total: AtomicU64,
@@ -1414,6 +1422,37 @@ impl Stats {
                 .store(value, Ordering::Relaxed);
         }
     }
+
+    pub fn set_buffer_pool_gauges(&self, pooled: usize, allocated: usize, in_use: usize) {
+        if self.telemetry_me_allows_normal() {
+            self.buffer_pool_pooled_gauge
+                .store(pooled as u64, Ordering::Relaxed);
+            self.buffer_pool_allocated_gauge
+                .store(allocated as u64, Ordering::Relaxed);
+            self.buffer_pool_in_use_gauge
+                .store(in_use as u64, Ordering::Relaxed);
+        }
+    }
+
+    pub fn increment_me_c2me_send_full_total(&self) {
+        if self.telemetry_me_allows_normal() {
+            self.me_c2me_send_full_total.fetch_add(1, Ordering::Relaxed);
+        }
+    }
+
+    pub fn increment_me_c2me_send_high_water_total(&self) {
+        if self.telemetry_me_allows_normal() {
+            self.me_c2me_send_high_water_total
+                .fetch_add(1, Ordering::Relaxed);
+        }
+    }
+
+    pub fn increment_me_c2me_send_timeout_total(&self) {
+        if self.telemetry_me_allows_normal() {
+            self.me_c2me_send_timeout_total
+                .fetch_add(1, Ordering::Relaxed);
+        }
+    }
     pub fn increment_me_floor_cap_block_total(&self) {
         if self.telemetry_me_allows_normal() {
             self.me_floor_cap_block_total
@@ -1780,6 +1819,30 @@ impl Stats {
         self.me_d2c_flush_duration_us_bucket_gt_20000
             .load(Ordering::Relaxed)
     }
+
+    pub fn get_buffer_pool_pooled_gauge(&self) -> u64 {
+        self.buffer_pool_pooled_gauge.load(Ordering::Relaxed)
+    }
+
+    pub fn get_buffer_pool_allocated_gauge(&self) -> u64 {
+        self.buffer_pool_allocated_gauge.load(Ordering::Relaxed)
+    }
+
+    pub fn get_buffer_pool_in_use_gauge(&self) -> u64 {
+        self.buffer_pool_in_use_gauge.load(Ordering::Relaxed)
+    }
+
+    pub fn get_me_c2me_send_full_total(&self) -> u64 {
+        self.me_c2me_send_full_total.load(Ordering::Relaxed)
+    }
+
+    pub fn get_me_c2me_send_high_water_total(&self) -> u64 {
+        self.me_c2me_send_high_water_total.load(Ordering::Relaxed)
+    }
+
+    pub fn get_me_c2me_send_timeout_total(&self) -> u64 {
+        self.me_c2me_send_timeout_total.load(Ordering::Relaxed)
+    }
     pub fn get_me_d2c_batch_timeout_armed_total(&self) -> u64 {
         self.me_d2c_batch_timeout_armed_total
             .load(Ordering::Relaxed)
@@ -2171,6 +2234,8 @@ impl ReplayShard {
 
     fn cleanup(&mut self, now: Instant, window: Duration) {
         if window.is_zero() {
+            self.cache.clear();
+            self.queue.clear();
             return;
         }
         let cutoff = now.checked_sub(window).unwrap_or(now);
@@ -2192,13 +2257,22 @@ impl ReplayShard {
     }
 
     fn check(&mut self, key: &[u8], now: Instant, window: Duration) -> bool {
+        if window.is_zero() {
+            return false;
+        }
         self.cleanup(now, window);
         // key is &[u8], resolves Q=[u8] via Box<[u8]>: Borrow<[u8]>
         self.cache.get(key).is_some()
     }
 
     fn add(&mut self, key: &[u8], now: Instant, window: Duration) {
+        if window.is_zero() {
+            return;
+        }
         self.cleanup(now, window);
+        if self.cache.peek(key).is_some() {
+            return;
+        }
 
         let seq = self.next_seq();
         let boxed_key: Box<[u8]> = key.into();
@@ -2341,7 +2415,7 @@ impl ReplayChecker {
         let interval = if self.window.as_secs() > 60 {
             Duration::from_secs(30)
         } else {
-            Duration::from_secs(self.window.as_secs().max(1) / 2)
+            Duration::from_secs((self.window.as_secs().max(1) / 2).max(1))
         };
 
         loop {
@@ -2553,6 +2627,20 @@ mod tests {
         assert!(!checker.check_handshake(b"expire"));
     }
 
+    #[test]
+    fn test_replay_checker_zero_window_does_not_retain_entries() {
+        let checker = ReplayChecker::new(100, Duration::ZERO);
+
+        for _ in 0..1_000 {
+            assert!(!checker.check_handshake(b"no-retain"));
+            checker.add_handshake(b"no-retain");
+        }
+
+        let stats = checker.stats();
+        assert_eq!(stats.total_entries, 0);
+        assert_eq!(stats.total_queue_len, 0);
+    }
+
     #[test]
     fn test_replay_checker_stats() {
         let checker = ReplayChecker::new(100, Duration::from_secs(60));

src/stream/buffer_pool.rs

@@ -35,6 +35,10 @@ pub struct BufferPool {
     misses: AtomicUsize,
     /// Number of successful reuses
     hits: AtomicUsize,
+    /// Number of non-standard buffers replaced with a fresh default-sized buffer
+    replaced_nonstandard: AtomicUsize,
+    /// Number of buffers dropped because the pool queue was full
+    dropped_pool_full: AtomicUsize,
 }
 
 impl BufferPool {
@@ -52,6 +56,8 @@ impl BufferPool {
             allocated: AtomicUsize::new(0),
             misses: AtomicUsize::new(0),
             hits: AtomicUsize::new(0),
+            replaced_nonstandard: AtomicUsize::new(0),
+            dropped_pool_full: AtomicUsize::new(0),
         }
     }
 
@@ -91,17 +97,36 @@ impl BufferPool {
 
     /// Return a buffer to the pool
     fn return_buffer(&self, mut buffer: BytesMut) {
-        // Clear the buffer but keep capacity
-        buffer.clear();
+        const MAX_RETAINED_BUFFER_FACTOR: usize = 2;
 
-        // Only return if we haven't exceeded max and buffer is right size
-        if buffer.capacity() >= self.buffer_size {
-            // Try to push to pool, if full just drop
-            let _ = self.buffers.push(buffer);
+        // Clear the buffer but keep capacity.
+        buffer.clear();
+        let max_retained_capacity = self
+            .buffer_size
+            .saturating_mul(MAX_RETAINED_BUFFER_FACTOR)
+            .max(self.buffer_size);
+
+        // Keep only near-default capacities in the pool. Oversized buffers keep
+        // RSS elevated for hours under churn; replace them with default-sized
+        // buffers before re-pooling.
+        if buffer.capacity() < self.buffer_size || buffer.capacity() > max_retained_capacity {
+            self.replaced_nonstandard.fetch_add(1, Ordering::Relaxed);
+            buffer = BytesMut::with_capacity(self.buffer_size);
         }
-        // If buffer was dropped (pool full), decrement allocated
-        // Actually we don't decrement here because the buffer might have been
-        // grown beyond our size - we just let it go
+
+        // Try to return into the queue; if full, drop and update accounting.
+        if self.buffers.push(buffer).is_err() {
+            self.dropped_pool_full.fetch_add(1, Ordering::Relaxed);
+            self.decrement_allocated();
+        }
+    }
+
+    fn decrement_allocated(&self) {
+        let _ = self
+            .allocated
+            .fetch_update(Ordering::Relaxed, Ordering::Relaxed, |current| {
+                Some(current.saturating_sub(1))
+            });
     }
 
     /// Get pool statistics
@@ -113,6 +138,8 @@ impl BufferPool {
             buffer_size: self.buffer_size,
             hits: self.hits.load(Ordering::Relaxed),
             misses: self.misses.load(Ordering::Relaxed),
+            replaced_nonstandard: self.replaced_nonstandard.load(Ordering::Relaxed),
+            dropped_pool_full: self.dropped_pool_full.load(Ordering::Relaxed),
         }
     }
 
@@ -121,6 +148,41 @@ impl BufferPool {
         self.buffer_size
     }
 
+    /// Maximum number of buffers the pool will retain.
+    pub fn max_buffers(&self) -> usize {
+        self.max_buffers
+    }
+
+    /// Current number of pooled buffers.
+    pub fn pooled(&self) -> usize {
+        self.buffers.len()
+    }
+
+    /// Total buffers allocated (pooled + checked out).
+    pub fn allocated(&self) -> usize {
+        self.allocated.load(Ordering::Relaxed)
+    }
+
+    /// Best-effort number of buffers currently checked out.
+    pub fn in_use(&self) -> usize {
+        self.allocated().saturating_sub(self.pooled())
+    }
+
+    /// Trim pooled buffers down to a target count.
+    pub fn trim_to(&self, target_pooled: usize) {
+        let target = target_pooled.min(self.max_buffers);
+        loop {
+            if self.buffers.len() <= target {
+                break;
+            }
+            if self.buffers.pop().is_some() {
+                self.decrement_allocated();
+            } else {
+                break;
+            }
+        }
+    }
+
     /// Preallocate buffers to fill the pool
     pub fn preallocate(&self, count: usize) {
         let to_alloc = count.min(self.max_buffers);
@@ -160,6 +222,10 @@ pub struct PoolStats {
     pub hits: usize,
     /// Number of cache misses (new allocation)
     pub misses: usize,
+    /// Number of non-standard buffers replaced during return
+    pub replaced_nonstandard: usize,
+    /// Number of buffers dropped because the pool queue was full
+    pub dropped_pool_full: usize,
 }
 
 impl PoolStats {
@@ -185,6 +251,7 @@ pub struct PooledBuffer {
 impl PooledBuffer {
     /// Take the inner buffer, preventing return to pool
     pub fn take(mut self) -> BytesMut {
+        self.pool.decrement_allocated();
         self.buffer.take().unwrap()
     }
 
@@ -364,6 +431,25 @@ mod tests {
 
         let stats = pool.stats();
         assert_eq!(stats.pooled, 0);
+        assert_eq!(stats.allocated, 0);
+    }
+
+    #[test]
+    fn test_pool_replaces_oversized_buffers() {
+        let pool = Arc::new(BufferPool::with_config(1024, 10));
+
+        {
+            let mut buf = pool.get();
+            buf.reserve(8192);
+            assert!(buf.capacity() > 2048);
+        }
+
+        let stats = pool.stats();
+        assert_eq!(stats.replaced_nonstandard, 1);
+        assert_eq!(stats.pooled, 1);
+
+        let buf = pool.get();
+        assert!(buf.capacity() <= 2048);
     }
 
     #[test]