library/std/src/sys_common/condvar.rs

   1 use crate::sys::locks as imp;
   2 use crate::sys_common::mutex::MovableMutex;
   3 use crate::time::Duration;
   4
   5 mod check;
   6
   7 type CondvarCheck = <imp::MovableMutex as check::CondvarCheck>::Check;
   8
   9 /// An OS-based condition variable.
  10 pub struct Condvar {
  11     inner: imp::MovableCondvar,
  12     check: CondvarCheck,
  13 }
  14
  15 impl Condvar {
  16     /// Creates a new condition variable for use.
  17     #[inline]
  18     #[rustc_const_stable(feature = "const_locks", since = "1.63.0")]
  19     pub const fn new() -> Self {
  20         Self { inner: imp::MovableCondvar::new(), check: CondvarCheck::new() }
  21     }
  22
  23     /// Signals one waiter on this condition variable to wake up.
  24     #[inline]
  25     pub fn notify_one(&self) {
  26         unsafe { self.inner.notify_one() };
  27     }
  28
  29     /// Awakens all current waiters on this condition variable.
  30     #[inline]
  31     pub fn notify_all(&self) {
  32         unsafe { self.inner.notify_all() };
  33     }
  34
  35     /// Waits for a signal on the specified mutex.
  36     ///
  37     /// Behavior is undefined if the mutex is not locked by the current thread.
  38     ///
  39     /// May panic if used with more than one mutex.
  40     #[inline]
  41     pub unsafe fn wait(&self, mutex: &MovableMutex) {
  42         self.check.verify(mutex);
  43         self.inner.wait(mutex.raw())
  44     }
  45
  46     /// Waits for a signal on the specified mutex with a timeout duration
  47     /// specified by `dur` (a relative time into the future).
  48     ///
  49     /// Behavior is undefined if the mutex is not locked by the current thread.
  50     ///
  51     /// May panic if used with more than one mutex.
  52     #[inline]
  53     pub unsafe fn wait_timeout(&self, mutex: &MovableMutex, dur: Duration) -> bool {
  54         self.check.verify(mutex);
  55         self.inner.wait_timeout(mutex.raw(), dur)
  56     }
  57 }