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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-30 03:59:35 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-30 03:59:35 +0000 |
commit | d1b2d29528b7794b41e66fc2136e395a02f8529b (patch) | |
tree | a4a17504b260206dec3cf55b2dca82929a348ac2 /library/std/src/sys_common/thread_parking | |
parent | Releasing progress-linux version 1.72.1+dfsg1-1~progress7.99u1. (diff) | |
download | rustc-d1b2d29528b7794b41e66fc2136e395a02f8529b.tar.xz rustc-d1b2d29528b7794b41e66fc2136e395a02f8529b.zip |
Merging upstream version 1.73.0+dfsg1.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'library/std/src/sys_common/thread_parking')
-rw-r--r-- | library/std/src/sys_common/thread_parking/id.rs | 17 |
1 files changed, 6 insertions, 11 deletions
diff --git a/library/std/src/sys_common/thread_parking/id.rs b/library/std/src/sys_common/thread_parking/id.rs index 15042fc3b..046674396 100644 --- a/library/std/src/sys_common/thread_parking/id.rs +++ b/library/std/src/sys_common/thread_parking/id.rs @@ -56,18 +56,14 @@ impl Parker { self.init_tid(); // Changes NOTIFIED to EMPTY and EMPTY to PARKED. - let mut state = self.state.fetch_sub(1, Acquire).wrapping_sub(1); - if state == PARKED { + let state = self.state.fetch_sub(1, Acquire); + if state == EMPTY { // Loop to guard against spurious wakeups. - while state == PARKED { + // The state must be reset with acquire ordering to ensure that all + // calls to `unpark` synchronize with this thread. + while self.state.compare_exchange(NOTIFIED, EMPTY, Acquire, Relaxed).is_err() { park(self.state.as_ptr().addr()); - state = self.state.load(Acquire); } - - // Since the state change has already been observed with acquire - // ordering, the state can be reset with a relaxed store instead - // of a swap. - self.state.store(EMPTY, Relaxed); } } @@ -78,8 +74,7 @@ impl Parker { if state == PARKED { park_timeout(dur, self.state.as_ptr().addr()); // Swap to ensure that we observe all state changes with acquire - // ordering, even if the state has been changed after the timeout - // occurred. + // ordering. self.state.swap(EMPTY, Acquire); } } |