Auto merge of #155689 - zetanumbers:lock_latch_thread_local, r=<try>

bors · bors · commit 2ca292ba1c7d · 2026-04-23T15:25:23.000Z
Const initialize `LOCK_LATCH` thread local
diff --git a/compiler/rustc_thread_pool/src/latch.rs b/compiler/rustc_thread_pool/src/latch.rs
@@ -220,7 +220,7 @@ pub(super) struct LockLatch {
 
 impl LockLatch {
     #[inline]
-    pub(super) fn new() -> LockLatch {
+    pub(super) const fn new() -> LockLatch {
         LockLatch { m: Mutex::new(false), v: Condvar::new() }
     }
 
diff --git a/compiler/rustc_thread_pool/src/registry.rs b/compiler/rustc_thread_pool/src/registry.rs
@@ -524,7 +524,7 @@ impl Registry {
         OP: FnOnce(&WorkerThread, bool) -> R + Send,
         R: Send,
     {
-        thread_local!(static LOCK_LATCH: LockLatch = LockLatch::new());
+        thread_local!(static LOCK_LATCH: LockLatch = const { LockLatch::new() });
 
         LOCK_LATCH.with(|l| {
             // This thread isn't a member of *any* thread pool, so just block.

Original file line number	Diff line number	Diff line change
`@@ -220,7 +220,7 @@ pub(super) struct LockLatch {`
`220`	`220`
`221`	`221`	`impl LockLatch {`
`222`	`222`	`#[inline]`
`223`		`- pub(super) fn new() -> LockLatch {`
	`223`	`+ pub(super) const fn new() -> LockLatch {`
`224`	`224`	`LockLatch { m: Mutex::new(false), v: Condvar::new() }`
`225`	`225`	`}`
`226`	`226`
Original file line number	Diff line number	Diff line change
`@@ -524,7 +524,7 @@ impl Registry {`
`524`	`524`	`OP: FnOnce(&WorkerThread, bool) -> R + Send,`
`525`	`525`	`R: Send,`
`526`	`526`	`{`
`527`		`- thread_local!(static LOCK_LATCH: LockLatch = LockLatch::new());`
	`527`	`+ thread_local!(static LOCK_LATCH: LockLatch = const { LockLatch::new() });`
`528`	`528`
`529`	`529`	`LOCK_LATCH.with(\|l\| {`
`530`	`530`	`// This thread isn't a member of any thread pool, so just block.`