Files
rust/compiler/rustc_thread_pool
Josh Stone 29ccf67f77 rustc_thread_pool: Make CoreLatch::set use SeqCst instead of AcqRel
Every other modification of this variable uses `SeqCst`, which is
justified in the sleep README. This particular choice of `AcqRel` was
not discussed during its addition in rayon-rs/rayon#746, nor
rayon-rs/rfcs#5, so I suspect was simply an oversight from earlier
development. We probably do want this to participate in the same
sequential consistency.

The only other ordering difference is `CoreLatch::probe`'s load with
`Acquire`, which should be fine because this doesn't need consistency
with the sleep counters.

See also rayon-rs/rayon#1297. As I commented there, I think in practice
this would be quite rare to cause any problems, but it *could* be a
source of non-deterministic bugs on targets with weak memory ordering.
2026-04-21 10:41:56 -07:00
..
2025-06-28 17:58:21 +08:00
2025-06-16 12:27:47 -07:00

Note: This is an unstable fork made for use in rustc

Rayon-core represents the "core, stable" APIs of Rayon: join, scope, and so forth, as well as the ability to create custom thread-pools with ThreadPool.

Maybe worth mentioning: users are not necessarily intended to directly access rustc_thread_pool; all its APIs are mirrored in the rayon crate. To that end, the examples in the docs use rayon::join and so forth rather than rayon_core::join.

Please see Rayon Docs for details about using Rayon.