smol-rs
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atomic-waker
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Replace deprecated compare_and_swap with compare_exchange

This commit is contained in:
Taiki Endo 2020-12-24 21:20:33 +09:00
parent 5d18d15e1d
commit e039c44a53
1 changed files with 12 additions and 10 deletions
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22
src/lib.rs
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@ -3,7 +3,7 @@
use std::cell::UnsafeCell;
use std::fmt;
use std::sync::atomic::AtomicUsize;
use std::sync::atomic::Ordering::{Acquire, Release, AcqRel};
use std::sync::atomic::Ordering::{AcqRel, Acquire, Release};
use std::task::Waker;
/// A synchronization primitive for task wakeup.
@ -261,7 +261,11 @@ impl AtomicWaker {
/// }
/// ```
pub fn register(&self, waker: &Waker) {
match self.state.compare_and_swap(WAITING, REGISTERING, Acquire) {
match self
.state
.compare_exchange(WAITING, REGISTERING, Acquire, Acquire)
.unwrap_or_else(|x| x)
{
WAITING => {
unsafe {
// Locked acquired, update the waker cell
@ -277,8 +281,9 @@ impl AtomicWaker {
// nothing to acquire, only release. In case of concurrent
// wakers, we need to acquire their releases, so success needs
// to do both.
let res = self.state.compare_exchange(
REGISTERING, WAITING, AcqRel, Acquire);
let res = self
.state
.compare_exchange(REGISTERING, WAITING, AcqRel, Acquire);
match res {
Ok(_) => {
@ -342,9 +347,7 @@ impl AtomicWaker {
//
// We just want to maintain memory safety. It is ok to drop the
// call to `register`.
debug_assert!(
state == REGISTERING ||
state == REGISTERING | WAKING);
debug_assert!(state == REGISTERING || state == REGISTERING | WAKING);
}
}
}
@ -389,9 +392,8 @@ impl AtomicWaker {
// not.
//
debug_assert!(
state == REGISTERING ||
state == REGISTERING | WAKING ||
state == WAKING);
state == REGISTERING || state == REGISTERING | WAKING || state == WAKING
);
None
}
}