CI runs cargo miri test -p bevy_ecs (bevyengine#4310)

# Objective

Fixes bevyengine#1529
Run bevy_ecs in miri

## Solution

- Don't set thread names when running in miri rust-lang/miri/issues/1717
- Update `event-listener` to `2.5.2` as previous versions have UB that is detected by miri: [event-listener commit](smol-rs/event-listener@1fa31c5)
- Ignore memory leaks when running in miri as they are impossible to track down rust-lang/miri/issues/1481
- Make `table_add_remove_many` test less "many" because miri is really quite slow :)
- Make CI run `RUSTFLAGS="-Zrandomize-layout" MIRIFLAGS="-Zmiri-ignore-leaks -Zmiri-tag-raw-pointers -Zmiri-disable-isolation" cargo +nightly miri test -p bevy_ecs`

.github/bors.toml

@@ -13,6 +13,7 @@ status = [
  "check-missing-examples-in-docs",
  "check-unused-dependencies",
  "ci",
+ "miri",
  "check-benches",
 ]
 

.github/workflows/ci.yml

@@ -70,6 +70,38 @@ jobs:
  # See tools/ci/src/main.rs for the commands this runs
  run: cargo run -p ci -- nonlocal
 
+ miri:
+ runs-on: ubuntu-latest
+ steps:
+ - uses: actions/checkout@v3
+ - uses: actions/cache@v2
+ with:
+ path: |
+ ~/.cargo/bin/
+ ~/.cargo/registry/index/
+ ~/.cargo/registry/cache/
+ ~/.cargo/git/db/
+ target/
+ key: ${{ runner.os }}-cargo-ci-${{ hashFiles('**/Cargo.toml') }}
+ - uses: actions-rs/toolchain@v1
+ with:
+ toolchain: nightly
+ components: miri
+ override: true
+ - name: Install alsa and udev
+ run: sudo apt-get update; sudo apt-get install --no-install-recommends libasound2-dev libudev-dev libwayland-dev libxkbcommon-dev
+ - name: CI job
+ run: cargo miri test -p bevy_ecs
+ env:
+ # -Zrandomize-layout makes sure we dont rely on the layout of anything that might change
+ RUSTFLAGS: -Zrandomize-layout
+ # -Zmiri-disable-isolation is needed because our executor uses `fastrand` which accesses system time.
+ # -Zmiri-ignore-leaks is needed because running bevy_ecs tests finds a memory leak but its impossible
+ # to track down because allocids are nondeterministic.
+ # -Zmiri-tag-raw-pointers is not strictly "necessary" but enables a lot of extra UB checks relating
+ # to raw pointer aliasing rules that we should be trying to uphold.
+ MIRIFLAGS: -Zmiri-disable-isolation -Zmiri-ignore-leaks -Zmiri-tag-raw-pointers
+
  check-benches:
  runs-on: ubuntu-latest
  needs: ci

crates/bevy_ecs/src/lib.rs

@@ -637,8 +637,18 @@ mod tests {
  #[test]
  fn table_add_remove_many() {
  let mut world = World::default();
- let mut entities = Vec::with_capacity(10_000);
- for _ in 0..1000 {
+ #[cfg(miri)]
+ let (mut entities, to) = {
+ let to = 10;
+ (Vec::with_capacity(to), to)
+ };
+ #[cfg(not(miri))]
+ let (mut entities, to) = {
+ let to = 10_000;
+ (Vec::with_capacity(to), to)
+ };
+
+ for _ in 0..to {
  entities.push(world.spawn().insert(B(0)).id());
  }
 

crates/bevy_tasks/Cargo.toml

@@ -10,7 +10,7 @@ keywords = ["bevy"]
 
 [dependencies]
 futures-lite = "1.4.0"
-event-listener = "2.4.0"
+event-listener = "2.5.2"
 async-executor = "1.3.0"
 async-channel = "1.4.2"
 num_cpus = "1.0.1"

crates/bevy_tasks/src/task_pool.rs

@@ -121,13 +121,23 @@ impl TaskPool {
  let ex = Arc::clone(&executor);
  let shutdown_rx = shutdown_rx.clone();
 
- let thread_name = if let Some(thread_name) = thread_name {
- format!("{} ({})", thread_name, i)
- } else {
- format!("TaskPool ({})", i)
+ // miri does not support setting thread names
+ // TODO: change back when https:/rust-lang/miri/issues/1717 is fixed
+ #[cfg(not(miri))]
+ let mut thread_builder = {
+ let thread_name = if let Some(thread_name) = thread_name {
+ format!("{} ({})", thread_name, i)
+ } else {
+ format!("TaskPool ({})", i)
+ };
+ thread::Builder::new().name(thread_name)
+ };
+ #[cfg(miri)]
+ let mut thread_builder = {
+ let _ = i;
+ let _ = thread_name;
+ thread::Builder::new()
  };
-
- let mut thread_builder = thread::Builder::new().name(thread_name);
 
  if let Some(stack_size) = stack_size {
  thread_builder = thread_builder.stack_size(stack_size);