diff options
| author | FUJITA Tomonori <fujita.tomonori@gmail.com> | 2026-01-01 12:49:21 +0900 |
|---|---|---|
| committer | Boqun Feng <boqun.feng@gmail.com> | 2026-01-09 19:01:41 +0800 |
| commit | 06bd0e52bfd78eae1c7dd5db163ce64161b495e7 (patch) | |
| tree | 68a613821344088db66c43055c2e2dc28960a9b7 /rust/kernel | |
| parent | 584f286f822afecc1a6521a27b3caf3e2f515d41 (diff) | |
rust: sync: atomic: Add atomic bool support via i8 representation
Add `bool` support, `Atomic<bool>` by using `i8` as its underlying
representation.
Rust specifies that `bool` has size 1 and alignment 1 [1], so it
matches `i8` on layout; keep `static_assert!()` checks to enforce this
assumption at build time.
[boqun: Remove the unnecessary impl AtomicImpl for bool]
Link: https://doc.rust-lang.org/reference/types/boolean.html [1]
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://patch.msgid.link/20260101034922.2020334-2-fujita.tomonori@gmail.com
Diffstat (limited to 'rust/kernel')
| -rw-r--r-- | rust/kernel/sync/atomic/predefine.rs | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/rust/kernel/sync/atomic/predefine.rs b/rust/kernel/sync/atomic/predefine.rs index 248d26555ccf..3fc99174b086 100644 --- a/rust/kernel/sync/atomic/predefine.rs +++ b/rust/kernel/sync/atomic/predefine.rs @@ -5,6 +5,17 @@ use crate::static_assert; use core::mem::{align_of, size_of}; +// Ensure size and alignment requirements are checked. +static_assert!(size_of::<bool>() == size_of::<i8>()); +static_assert!(align_of::<bool>() == align_of::<i8>()); + +// SAFETY: `bool` has the same size and alignment as `i8`, and Rust guarantees that `bool` has +// only two valid bit patterns: 0 (false) and 1 (true). Those are valid `i8` values, so `bool` is +// round-trip transmutable to `i8`. +unsafe impl super::AtomicType for bool { + type Repr = i8; +} + // SAFETY: `i8` has the same size and alignment with itself, and is round-trip transmutable to // itself. unsafe impl super::AtomicType for i8 { |