Struct core::task::RawWakerVTable
1.36.0 · source · pub struct RawWakerVTable { /* private fields */ }
Expand description
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§
source§impl RawWakerVTable
impl RawWakerVTable
const: 1.36.0 · sourcepub const fn new(
clone: unsafe fn(_: *const ()) -> RawWaker,
wake: unsafe fn(_: *const ()),
wake_by_ref: unsafe fn(_: *const ()),
drop: unsafe fn(_: *const ())
) -> Self
pub const fn new( clone: unsafe fn(_: *const ()) -> RawWaker, wake: unsafe fn(_: *const ()), wake_by_ref: unsafe fn(_: *const ()), drop: unsafe fn(_: *const ()) ) -> Self
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§
source§impl Clone for RawWakerVTable
impl Clone for RawWakerVTable
source§fn clone(&self) -> RawWakerVTable
fn clone(&self) -> RawWakerVTable
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for RawWakerVTable
impl Debug for RawWakerVTable
source§impl PartialEq for RawWakerVTable
impl PartialEq for RawWakerVTable
source§fn eq(&self, other: &RawWakerVTable) -> bool
fn eq(&self, other: &RawWakerVTable) -> bool
self
and other
values to be equal, and is used
by ==
.