v1.1.3: portable-atomic polyfill so mipsel-softfloat compiles (#46)

v1.1.2 reached cargo build inside the mipsel docker this time
(YAML-fold bug finally out of the way) and surfaced the real
underlying problem: MIPS32 has no native 64-bit atomic instructions,
so std::sync::atomic::AtomicU64 doesn't exist on
mipsel-unknown-linux-musl. Three call sites (DomainFronter stats
counters + the request-cache) failed to resolve the import.

Fix: depend on `portable-atomic` with the `fallback` feature and
import AtomicU64 from there instead of std. The API is identical
(same associated methods, same Ordering accepted), so the two
touched files change only the `use` line. On 64-bit targets
portable-atomic compiles down to the native 64-bit atomic insns
with no overhead; on MIPS32 it uses a global spinlock, which is
fine for counter increments that happen a few times per relay.

Cache.rs and domain_fronter.rs both updated. No other callers of
AtomicU64 in non-cfg-gated code (android_jni.rs has it but is
gated `#![cfg(target_os = "android")]`, so mipsel-linux-musl
never sees it).

`cargo test --lib` / `cargo build` still pass on host.

Cargo.lock

@@ -2199,6 +2199,7 @@ dependencies = [
  "httparse",
  "jni 0.21.1",
  "libc",
+ "portable-atomic",
  "rand 0.8.6",
  "rcgen",
  "rustls",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "mhrv-rs"
-version = "1.1.2"
+version = "1.1.3"
 edition = "2021"
 description = "Rust port of MasterHttpRelayVPN -- DPI bypass via Google Apps Script relay with domain fronting"
 license = "MIT"
@@ -49,6 +49,14 @@ http = "1"
 flate2 = "1"
 directories = "5"
 futures-util = { version = "0.3", default-features = false, features = ["std"] }
+# 64-bit atomics on 32-bit MIPS/ARMv5 targets. Rust's std AtomicU64 is
+# only available on targets that expose native 64-bit atomics, which
+# mipsel-unknown-linux-musl does not — `AtomicU64` resolves to "no
+# such name in sync::atomic" and the whole crate fails to build. The
+# `fallback` feature uses a global spinlock when the target can't do
+# 64-bit atomically; on x86_64 / aarch64 / armv7 / etc. it compiles
+# down to the native instructions with no overhead.
+portable-atomic = { version = "1", features = ["fallback"] }
 
 # Optional UI dep: only pulled in when --features ui is set.
 # Both `glow` (OpenGL 2+) and `wgpu` (DX12/Vulkan/Metal) are compiled in;

android/app/build.gradle.kts

@@ -14,8 +14,8 @@ android {
         applicationId = "com.therealaleph.mhrv"
         minSdk = 24 // Android 7.0 — covers 99%+ of live devices.
         targetSdk = 34
-        versionCode = 112
-        versionName = "1.1.2"
+        versionCode = 113
+        versionName = "1.1.3"
 
         // Ship all four mainstream Android ABIs:
         //   - arm64-v8a      — 95%+ of real-world Android phones since 2019

src/cache.rs

@@ -1,5 +1,11 @@
 use std::collections::{HashMap, VecDeque};
-use std::sync::atomic::{AtomicU64, Ordering};
+// AtomicU64 polyfill via portable-atomic — mipsel is MIPS32 with no
+// native 64-bit atomic instructions, so std::sync::atomic::AtomicU64
+// doesn't exist on that target. portable-atomic falls back to a
+// global spinlock on 32-bit MIPS; compiles to native insns on x86_64
+// and aarch64.
+use portable_atomic::AtomicU64;
+use std::sync::atomic::Ordering;
 use std::sync::Mutex;
 use std::time::{Duration, Instant};
 

src/domain_fronter.rs

@@ -10,7 +10,12 @@
 //! TODO: add parallel range-based downloads.
 
 use std::collections::HashMap;
-use std::sync::atomic::{AtomicU64, AtomicUsize, Ordering};
+// AtomicU64 via portable-atomic: native on 64-bit / armv7, spinlock-
+// backed on mipsel (MIPS32 has no 64-bit atomic instructions). API
+// is identical to std::sync::atomic::AtomicU64 so call sites need
+// no other changes.
+use portable_atomic::AtomicU64;
+use std::sync::atomic::{AtomicUsize, Ordering};
 use std::sync::Arc;
 use std::time::{Duration, Instant};