add Miri CI job

.github/workflows/rust.yml

@@ -66,3 +66,8 @@ jobs:
           cd benchmark
           cargo run --release --bin mutex -- 2 1 0 1 2
           cargo run --release --bin rwlock -- 1 1 1 0 1 2
+  miri:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - run: bash ci/miri.sh

ci/miri.sh

@@ -0,0 +1,22 @@
+#!/usr/bin/env bash
+
+set -ex
+
+export CARGO_NET_RETRY=5
+export CARGO_NET_TIMEOUT=10
+
+rustup toolchain install nightly --component miri
+rustup override set nightly
+cargo miri setup
+
+# We use different seeds for the different features to get a bit more test coverage.
+SEED=0
+for FEATURE in arc_lock serde deadlock_detection nightly hardware-lock-elision; do
+    export MIRIFLAGS="-Zmiri-strict-provenance -Zmiri-seed=$SEED"
+    if [ "$FEATURE" = "deadlock_detection" ]; then
+        # There's a background thread that never goes away, so Miri can't check for leaks.
+        MIRIFLAGS="$MIRIFLAGS -Zmiri-ignore-leaks"
+    fi
+    cargo miri test --features=$FEATURE
+    SEED=$(( $SEED+1 ))
+done

src/condvar.rs

@@ -916,6 +916,7 @@ mod tests {
 /// This module contains an integration test that is heavily inspired from WebKit's own integration
 /// tests for it's own Condvar.
 #[cfg(test)]
+#[cfg(not(miri))] // Miri is too slow
 mod webkit_queue_test {
     use crate::{Condvar, Mutex, MutexGuard};
     use std::{collections::VecDeque, sync::Arc, thread, time::Duration};

src/fair_mutex.rs

@@ -122,7 +122,7 @@ mod tests {
 
     #[test]
     fn lots_and_lots() {
-        const J: u32 = 1000;
+        const J: u32 = if cfg!(miri) { 200 } else { 1000 };
         const K: u32 = 3;
 
         let m = Arc::new(FairMutex::new(0));

src/mutex.rs

@@ -138,7 +138,7 @@ mod tests {
 
     #[test]
     fn lots_and_lots() {
-        const J: u32 = 1000;
+        const J: u32 = if cfg!(miri) { 200 } else { 1000 };
         const K: u32 = 3;
 
         let m = Arc::new(Mutex::new(0));

src/rwlock.rs

@@ -154,7 +154,7 @@ mod tests {
     #[test]
     fn frob() {
         const N: u32 = 10;
-        const M: u32 = 1000;
+        const M: u32 = if cfg!(miri) { 100 } else { 1000 };
 
         let r = Arc::new(RwLock::new(()));