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Struct std::task::RawWakerVTable
pub struct RawWakerVTable { /* private fields */ }
A virtual function pointer table (vtable) that specifies the behavior of a RawWaker
.
The pointer passed to all functions inside the vtable is the data
pointer from the enclosing RawWaker
object.
The functions inside this struct are only intended to be called on the data
pointer of a properly constructed RawWaker
object from inside the RawWaker
implementation. Calling one of the contained functions using any other data
pointer will cause undefined behavior.
These functions must all be thread-safe (even though RawWaker
is !Send + !Sync
) because Waker
is Send + Sync
, and thus wakers may be moved to arbitrary threads or invoked by &
reference. For example, this means that if the clone
and drop
functions manage a reference count, they must do so atomically.
Implementations
impl RawWakerVTable
pub const fn new(
clone: unsafe fn(_: *const ()) -> RawWaker,
wake: unsafe fn(_: *const ()),
wake_by_ref: unsafe fn(_: *const ()),
drop: unsafe fn(_: *const ())
) -> RawWakerVTable
Creates a new RawWakerVTable
from the provided clone
, wake
, wake_by_ref
, and drop
functions.
These functions must all be thread-safe (even though RawWaker
is !Send + !Sync
) because Waker
is Send + Sync
, and thus wakers may be moved to arbitrary threads or invoked by &
reference. For example, this means that if the clone
and drop
functions manage a reference count, they must do so atomically.
clone
This function will be called when the RawWaker
gets cloned, e.g. when the Waker
in which the RawWaker
is stored gets cloned.
The implementation of this function must retain all resources that are required for this additional instance of a RawWaker
and associated task. Calling wake
on the resulting RawWaker
should result in a wakeup of the same task that would have been awoken by the original RawWaker
.
wake
This function will be called when wake
is called on the Waker
. It must wake up the task associated with this RawWaker
.
The implementation of this function must make sure to release any resources that are associated with this instance of a RawWaker
and associated task.
wake_by_ref
This function will be called when wake_by_ref
is called on the Waker
. It must wake up the task associated with this RawWaker
.
This function is similar to wake
, but must not consume the provided data pointer.
drop
This function gets called when a Waker
gets dropped.
The implementation of this function must make sure to release any resources that are associated with this instance of a RawWaker
and associated task.
Trait Implementations
impl Clone for RawWakerVTable
fn clone(&self) -> RawWakerVTable
fn clone_from(&mut self, source: &Self)
source
. Read more
impl Debug for RawWakerVTable
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>
impl PartialEq for RawWakerVTable
fn eq(&self, other: &RawWakerVTable) -> bool
self
and other
values to be equal, and is used by ==
.
fn ne(&self, other: &Rhs) -> bool
!=
. The default implementation is almost always sufficient, and should not be overridden without very good reason.
impl Copy for RawWakerVTable
impl StructuralPartialEq for RawWakerVTable
Auto Trait Implementations
impl RefUnwindSafe for RawWakerVTable
impl Send for RawWakerVTable
impl Sync for RawWakerVTable
impl Unpin for RawWakerVTable
impl UnwindSafe for RawWakerVTable
Blanket Implementations
impl<T> Any for T
where
T: 'static + ?Sized,
impl<T> Borrow<T> for T
where
T: ?Sized,
impl<T> BorrowMut<T> for T
where
T: ?Sized,
impl<T> From<T> for T
fn from(t: T) -> T
Returns the argument unchanged.
impl<T, U> Into<U> for T
where
U: From<T>,
fn into(self) -> U
Calls U::from(self)
.
That is, this conversion is whatever the implementation of From<T> for U
chooses to do.
impl<T> ToOwned for T
where
T: Clone,
type Owned = T
fn to_owned(&self) -> T
fn clone_into(&self, target: &mut T)
impl<T, U> TryFrom<U> for T
where
U: Into<T>,
type Error = Infallible
fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>
impl<T, U> TryInto<U> for T
where
U: TryFrom<T>,
type Error = <U as TryFrom<T>>::Error
fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>
© 2010 The Rust Project Developers
Licensed under the Apache License, Version 2.0 or the MIT license, at your option.
https://doc.rust-lang.org/std/task/struct.RawWakerVTable.html