Struct WaitQueue

pub struct WaitQueue {
    num_wakers: AtomicU32,
    wakers: SpinLock<VecDeque<Arc<Waker>>, LocalIrqDisabled>,
}

A wait queue.

One may wait on a wait queue to put its executing thread to sleep. Multiple threads may be the waiters of a wait queue. Other threads may invoke the wake-family methods of a wait queue to wake up one or many waiting threads.

Fields

num_wakers: AtomicU32

wakers: SpinLock<VecDeque<Arc<Waker>>, LocalIrqDisabled>

Implementations

impl WaitQueue

pub const fn new() -> Self

Creates a new, empty wait queue.

pub fn wait_until<F, R>(&self, cond: F) -> R

where F: FnMut() -> Option<R>,

Waits until some condition is met.

This method takes a closure that tests a user-given condition. The method only returns if the condition returns Some(_). A waker thread should first make the condition Some(_), then invoke the wake-family method. This ordering is important to ensure that waiter threads do not lose any wakeup notifications.

By taking a condition closure, this wait-wakeup mechanism becomes more efficient and robust.

pub fn wake_one(&self) -> bool

Wakes up one waiting thread, if there is one at the point of time when this method is called, returning whether such a thread was woken up.

pub fn wake_all(&self) -> usize

Wakes up all waiting threads, returning the number of threads that were woken up.

fn is_empty(&self) -> bool

Trait Implementations

impl Default for WaitQueue

fn default() -> Self

Returns the “default value” for a type.