From 9c6a0766be95fc197f4f30764a794eb4d50b649a Mon Sep 17 00:00:00 2001
From: Ibraheem Ahmed <ibraheem@ibraheem.ca>
Date: Thu, 29 Feb 2024 00:56:31 -0500
Subject: [PATCH 1/2] document potential memory leak in unbounded channel
---
library/std/src/sync/mpmc/list.rs | 3 +++
1 file changed, 3 insertions(+)
diff --git a/library/std/src/sync/mpmc/list.rs b/library/std/src/sync/mpmc/list.rs
index a1b275112a1ed..b6bae7dc50ce3 100644
--- a/library/std/src/sync/mpmc/list.rs
+++ b/library/std/src/sync/mpmc/list.rs
@@ -547,6 +547,9 @@ impl<T> Channel<T> {
}
let mut head = self.head.index.load(Ordering::Acquire);
+ // the channel may be uninitialized, so we have to swap to avoid overwriting any sender's attempts
+ // to initalize the first block before noticing that the receivers disconnected. late allocations
+ // will be deallocated by the sender in Drop
let mut block = self.head.block.swap(ptr::null_mut(), Ordering::AcqRel);
// If we're going to be dropping messages we need to synchronize with initialization
From 7c9fa952c3be1f7d0872fe9cd5f1f4a0327771b9 Mon Sep 17 00:00:00 2001
From: Ibraheem Ahmed <ibraheem@ibraheem.ca>
Date: Thu, 29 Feb 2024 01:33:02 -0500
Subject: [PATCH 2/2] fix typos
Co-authored-by: Ralf Jung <post@ralfj.de>
---
library/std/src/sync/mpmc/list.rs | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/library/std/src/sync/mpmc/list.rs b/library/std/src/sync/mpmc/list.rs
index b6bae7dc50ce3..9e7148c716cda 100644
--- a/library/std/src/sync/mpmc/list.rs
+++ b/library/std/src/sync/mpmc/list.rs
@@ -547,9 +547,9 @@ impl<T> Channel<T> {
}
let mut head = self.head.index.load(Ordering::Acquire);
- // the channel may be uninitialized, so we have to swap to avoid overwriting any sender's attempts
- // to initalize the first block before noticing that the receivers disconnected. late allocations
- // will be deallocated by the sender in Drop
+ // The channel may be uninitialized, so we have to swap to avoid overwriting any sender's attempts
+ // to initalize the first block before noticing that the receivers disconnected. Late allocations
+ // will be deallocated by the sender in Drop.
let mut block = self.head.block.swap(ptr::null_mut(), Ordering::AcqRel);
// If we're going to be dropping messages we need to synchronize with initialization