pub struct Parker { /* private fields */ }
Expand description
A thread parking primitive.
Conceptually, each Parker
has an associated token which is initially not present:
-
The
park
method blocks the current thread unless or until the token is available, at which point it automatically consumes the token. -
The
park_timeout
andpark_deadline
methods work the same aspark
, but block for a specified maximum time. -
The
unpark
method atomically makes the token available if it wasn’t already. Because the token is initially absent,unpark
followed bypark
will result in the second call returning immediately.
In other words, each Parker
acts a bit like a spinlock that can be locked and unlocked using
park
and unpark
.
Examples
use std::thread;
use std::time::Duration;
use crossbeam_utils::sync::Parker;
let p = Parker::new();
let u = p.unparker().clone();
// Make the token available.
u.unpark();
// Wakes up immediately and consumes the token.
p.park();
thread::spawn(move || {
thread::sleep(Duration::from_millis(500));
u.unpark();
});
// Wakes up when `u.unpark()` provides the token.
p.park();
Implementations
impl Parker
impl Parker
pub fn park(&self)
pub fn park(&self)
Blocks the current thread until the token is made available.
Examples
use crossbeam_utils::sync::Parker;
let p = Parker::new();
let u = p.unparker().clone();
// Make the token available.
u.unpark();
// Wakes up immediately and consumes the token.
p.park();
pub fn park_timeout(&self, timeout: Duration)
pub fn park_timeout(&self, timeout: Duration)
Blocks the current thread until the token is made available, but only for a limited time.
Examples
use std::time::Duration;
use crossbeam_utils::sync::Parker;
let p = Parker::new();
// Waits for the token to become available, but will not wait longer than 500 ms.
p.park_timeout(Duration::from_millis(500));
pub fn park_deadline(&self, deadline: Instant)
pub fn park_deadline(&self, deadline: Instant)
Blocks the current thread until the token is made available, or until a certain deadline.
Examples
use std::time::{Duration, Instant};
use crossbeam_utils::sync::Parker;
let p = Parker::new();
let deadline = Instant::now() + Duration::from_millis(500);
// Waits for the token to become available, but will not wait longer than 500 ms.
p.park_deadline(deadline);
pub fn unparker(&self) -> &Unparker
pub fn unparker(&self) -> &Unparker
Returns a reference to an associated Unparker
.
The returned Unparker
doesn’t have to be used by reference - it can also be cloned.
Examples
use crossbeam_utils::sync::Parker;
let p = Parker::new();
let u = p.unparker().clone();
// Make the token available.
u.unpark();
// Wakes up immediately and consumes the token.
p.park();
pub fn into_raw(this: Parker) -> *const ()
pub fn into_raw(this: Parker) -> *const ()
Converts a Parker
into a raw pointer.
Examples
use crossbeam_utils::sync::Parker;
let p = Parker::new();
let raw = Parker::into_raw(p);
pub unsafe fn from_raw(ptr: *const ()) -> Parker
pub unsafe fn from_raw(ptr: *const ()) -> Parker
Converts a raw pointer into a Parker
.
Safety
This method is safe to use only with pointers returned by Parker::into_raw
.
Examples
use crossbeam_utils::sync::Parker;
let p = Parker::new();
let raw = Parker::into_raw(p);
let p = unsafe { Parker::from_raw(raw) };
Trait Implementations
Auto Trait Implementations
Blanket Implementations
impl<T, U> AsBindGroupShaderType<U> for Twhere
U: ShaderType,
&'a T: for<'a> Into<U>,
impl<T, U> AsBindGroupShaderType<U> for Twhere
U: ShaderType,
&'a T: for<'a> Into<U>,
fn as_bind_group_shader_type(
&self,
_images: &HashMap<Handle<Image>, <Image as RenderAsset>::PreparedAsset, RandomState, Global>
) -> U
fn as_bind_group_shader_type(
&self,
_images: &HashMap<Handle<Image>, <Image as RenderAsset>::PreparedAsset, RandomState, Global>
) -> U
T
[ShaderType
] for self
. When used in [AsBindGroup
]
derives, it is safe to assume that all images in self
exist. Read moresourceimpl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
impl<T> Downcast for Twhere
T: Any,
impl<T> Downcast for Twhere
T: Any,
fn into_any(self: Box<T, Global>) -> Box<dyn Any + 'static, Global>
fn into_any(self: Box<T, Global>) -> Box<dyn Any + 'static, Global>
Box<dyn Trait>
(where Trait: Downcast
) to Box<dyn Any>
. Box<dyn Any>
can
then be further downcast
into Box<ConcreteType>
where ConcreteType
implements Trait
. Read morefn into_any_rc(self: Rc<T>) -> Rc<dyn Any + 'static>
fn into_any_rc(self: Rc<T>) -> Rc<dyn Any + 'static>
Rc<Trait>
(where Trait: Downcast
) to Rc<Any>
. Rc<Any>
can then be
further downcast
into Rc<ConcreteType>
where ConcreteType
implements Trait
. Read morefn as_any(&self) -> &(dyn Any + 'static)
fn as_any(&self) -> &(dyn Any + 'static)
&Trait
(where Trait: Downcast
) to &Any
. This is needed since Rust cannot
generate &Any
’s vtable from &Trait
’s. Read morefn as_any_mut(&mut self) -> &mut (dyn Any + 'static)
fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)
&mut Trait
(where Trait: Downcast
) to &Any
. This is needed since Rust cannot
generate &mut Any
’s vtable from &mut Trait
’s. Read moreimpl<T> FromWorld for Twhere
T: Default,
impl<T> FromWorld for Twhere
T: Default,
fn from_world(_world: &mut World) -> T
fn from_world(_world: &mut World) -> T
Self
using data from the given [World]sourceimpl<T> Instrument for T
impl<T> Instrument for T
sourcefn instrument(self, span: Span) -> Instrumented<Self>
fn instrument(self, span: Span) -> Instrumented<Self>
sourcefn in_current_span(self) -> Instrumented<Self>
fn in_current_span(self) -> Instrumented<Self>
impl<T> Pointable for T
impl<T> Pointable for T
impl<SS, SP> SupersetOf<SS> for SPwhere
SS: SubsetOf<SP>,
impl<SS, SP> SupersetOf<SS> for SPwhere
SS: SubsetOf<SP>,
fn to_subset(&self) -> Option<SS>
fn to_subset(&self) -> Option<SS>
self
from the equivalent element of its
superset. Read morefn is_in_subset(&self) -> bool
fn is_in_subset(&self) -> bool
self
is actually part of its subset T
(and can be converted to it).fn to_subset_unchecked(&self) -> SS
fn to_subset_unchecked(&self) -> SS
self.to_subset
but without any property checks. Always succeeds.fn from_subset(element: &SS) -> SP
fn from_subset(element: &SS) -> SP
self
to the equivalent element of its superset.