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relaxed orderings in thread::park example

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This commit is contained in:
Ibraheem Ahmed 2023-06-20 20:05:31 -04:00
parent e9868ef8df
commit bf27f12d94
1 changed files with 4 additions and 3 deletions
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7
library/std/src/thread/mod.rs
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@ -893,7 +893,8 @@ pub fn sleep(dur: Duration) {
/// ///
/// Note that being unblocked does not imply a call was made to `unpark`, because /// Note that being unblocked does not imply a call was made to `unpark`, because
/// wakeups can also be spurious. For example, a valid, but inefficient, /// wakeups can also be spurious. For example, a valid, but inefficient,
/// implementation could have `park` and `unpark` return immediately without doing anything. /// implementation could have `park` and `unpark` return immediately without doing anything,
/// making *all* wakeups spurious.
/// ///
/// # Examples /// # Examples
/// ///
@ -908,7 +909,7 @@ pub fn sleep(dur: Duration) {
/// let parked_thread = thread::spawn(move || { /// let parked_thread = thread::spawn(move || {
/// // We want to wait until the flag is set. We *could* just spin, but using /// // We want to wait until the flag is set. We *could* just spin, but using
/// // park/unpark is more efficient. /// // park/unpark is more efficient.
/// while !flag2.load(Ordering::Acquire) { /// while !flag2.load(Ordering::Relaxed) {
/// println!("Parking thread"); /// println!("Parking thread");
/// thread::park(); /// thread::park();
/// // We *could* get here spuriously, i.e., way before the 10ms below are over! /// // We *could* get here spuriously, i.e., way before the 10ms below are over!
@ -925,7 +926,7 @@ pub fn sleep(dur: Duration) {
/// // There is no race condition here, if `unpark` /// // There is no race condition here, if `unpark`
/// // happens first, `park` will return immediately. /// // happens first, `park` will return immediately.
/// // Hence there is no risk of a deadlock. /// // Hence there is no risk of a deadlock.
/// flag.store(true, Ordering::Release); /// flag.store(true, Ordering::Relaxed);
/// println!("Unpark the thread"); /// println!("Unpark the thread");
/// parked_thread.thread().unpark(); /// parked_thread.thread().unpark();
/// ///