Struct alloc::task::Waker

#[repr(transparent)]
pub struct Waker { /* fields omitted */ }

🔬 This is a nightly-only experimental API. (futures_api)

futures in libcore are unstable

A Waker is a handle for waking up a task by notifying its executor that it is ready to be run.

This handle contains a trait object pointing to an instance of the UnsafeWake trait, allowing notifications to get routed through it.

Methods

impl Waker

pub unsafe fn new(inner: NonNull<dyn UnsafeWake + 'static>) -> Waker

🔬 This is a nightly-only experimental API. (futures_api)

futures in libcore are unstable

Constructs a new Waker directly.

Note that most code will not need to call this. Implementers of the UnsafeWake trait will typically provide a wrapper that calls this but you otherwise shouldn't call it directly.

If you're working with the standard library then it's recommended to use the Waker::from function instead which works with the safe Arc type and the safe Wake trait.

pub fn wake(&self)

🔬 This is a nightly-only experimental API. (futures_api)

futures in libcore are unstable

Wake up the task associated with this Waker.

pub fn will_wake(&self, other: &Waker) -> bool

🔬 This is a nightly-only experimental API. (futures_api)

futures in libcore are unstable

Returns whether or not this Waker and other awaken the same task.

This function works on a best-effort basis, and may return false even when the Wakers would awaken the same task. However, if this function returns true, it is guaranteed that the Wakers will awaken the same task.

This function is primarily used for optimization purposes.

pub fn will_wake_local(&self, other: &LocalWaker) -> bool

🔬 This is a nightly-only experimental API. (futures_api)

futures in libcore are unstable

Returns whether or not this Waker and other LocalWaker awaken the same task.

This function works on a best-effort basis, and may return false even when the Wakers would awaken the same task. However, if this function returns true, it is guaranteed that the Wakers will awaken the same task.

This function is primarily used for optimization purposes.

Trait Implementations

impl Clone for Waker

fn clone(&self) -> Waker

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl From<LocalWaker> for Waker

fn from(local_waker: LocalWaker) -> Waker

Converts a LocalWaker into a Waker.

This conversion turns a !Sync LocalWaker into a Sync Waker, allowing a wakeup object to be sent to another thread, but giving up its ability to do specialized thread-local wakeup behavior.

impl Drop for Waker

fn drop(&mut self)

Executes the destructor for this type.

impl Debug for Waker

fn fmt(&self, f: &mut Formatter) -> Result<(), Error>

Formats the value using the given formatter.

impl Unpin for Waker

impl Sync for Waker

impl Send for Waker

impl<T> From<Arc<T>> for Waker where     T: Wake + 'static,

fn from(rc: Arc<T>) -> Waker

Performs the conversion.