pub struct OnSignals<'a> { /* private fields */ }
Expand description

A future that completes when some set of signals become available on a Handle.

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impl<'a> OnSignals<'a>

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pub fn new<T: AsHandleRef>(handle: &'a T, signals: Signals) -> Self

Creates a new OnSignals object which will receive notifications when any signals in signals occur on handle.

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pub fn from_ref(handle: HandleRef<'a>, signals: Signals) -> Self

Creates a new OnSignals using a HandleRef instead of an AsHandleRef.

Passing a HandleRef to OnSignals::new is likely to lead to borrow check errors, since the resulting OnSignals is tied to the lifetime of the HandleRef itself and not the handle it refers to. Use this instead when you need to pass a HandleRef.

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pub fn extend_lifetime(self) -> OnSignals<'static>

This function allows the OnSignals object to live for the 'static lifetime, at the cost of disabling automatic cleanup of the port wait.

WARNING: Do not use unless you can guarantee that either:

  • The future is not dropped before it completes, or
  • The handle is dropped without creating additional OnSignals futures for it.

Creating an OnSignals calls zx_object_wait_async, which consumes a small amount of kernel resources. Dropping the OnSignals calls zx_port_cancel to clean up. But calling extend_lifetime disables this cleanup, since the zx_port_wait call requires a reference to the handle. The port registration can also be cleaned up by closing the handle or by waiting for the signal to be triggered. But if neither of these happens, the registration is leaked. This wastes kernel memory and the kernel will eventually kill your process to force a cleanup.

Note that OnSignals will not fire if the handle that was used to create it is dropped or transferred to another process.

Trait Implementations§

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impl Debug for OnSignals<'_>

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

Formats the value using the given formatter. Read more
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impl Drop for OnSignals<'_>

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fn drop(&mut self)

Executes the destructor for this type. Read more
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impl Future for OnSignals<'_>

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type Output = Result<Signals, Status>

The type of value produced on completion.
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fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output>

Attempt to resolve the future to a final value, registering the current task for wakeup if the value is not yet available. Read more
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impl Unpin for OnSignals<'_>

Auto Trait Implementations§

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impl<'a> !RefUnwindSafe for OnSignals<'a>

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impl<'a> Send for OnSignals<'a>

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impl<'a> Sync for OnSignals<'a>

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impl<'a> !UnwindSafe for OnSignals<'a>

Blanket Implementations§

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impl<T> Any for Twhere T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for Twhere T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for Twhere T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T> FutureExt for Twhere T: Future + ?Sized,

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fn map<U, F>(self, f: F) -> Map<Self, F>where F: FnOnce(Self::Output) -> U, Self: Sized,

Map this future’s output to a different type, returning a new future of the resulting type. Read more
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fn map_into<U>(self) -> MapInto<Self, U>where Self::Output: Into<U>, Self: Sized,

Map this future’s output to a different type, returning a new future of the resulting type. Read more
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fn then<Fut, F>(self, f: F) -> Then<Self, Fut, F>where F: FnOnce(Self::Output) -> Fut, Fut: Future, Self: Sized,

Chain on a computation for when a future finished, passing the result of the future to the provided closure f. Read more
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fn left_future<B>(self) -> Either<Self, B>where B: Future<Output = Self::Output>, Self: Sized,

Wrap this future in an Either future, making it the left-hand variant of that Either. Read more
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fn right_future<A>(self) -> Either<A, Self>where A: Future<Output = Self::Output>, Self: Sized,

Wrap this future in an Either future, making it the right-hand variant of that Either. Read more
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fn into_stream(self) -> IntoStream<Self>where Self: Sized,

Convert this future into a single element stream. Read more
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fn flatten(self) -> Flatten<Self>where Self::Output: Future, Self: Sized,

Flatten the execution of this future when the output of this future is itself another future. Read more
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fn flatten_stream(self) -> FlattenStream<Self>where Self::Output: Stream, Self: Sized,

Flatten the execution of this future when the successful result of this future is a stream. Read more
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fn fuse(self) -> Fuse<Self>where Self: Sized,

Fuse a future such that poll will never again be called once it has completed. This method can be used to turn any Future into a FusedFuture. Read more
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fn inspect<F>(self, f: F) -> Inspect<Self, F>where F: FnOnce(&Self::Output), Self: Sized,

Do something with the output of a future before passing it on. Read more
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fn catch_unwind(self) -> CatchUnwind<Self>where Self: Sized + UnwindSafe,

Catches unwinding panics while polling the future. Read more
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fn shared(self) -> Shared<Self>where Self: Sized, Self::Output: Clone,

Create a cloneable handle to this future where all handles will resolve to the same result. Read more
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fn remote_handle(self) -> (Remote<Self>, RemoteHandle<Self::Output>)where Self: Sized,

Turn this future into a future that yields () on completion and sends its output to another future on a separate task. Read more
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fn boxed<'a>(self) -> Pin<Box<dyn Future<Output = Self::Output> + Send + 'a>>where Self: Sized + Send + 'a,

Wrap the future in a Box, pinning it. Read more
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fn boxed_local<'a>(self) -> Pin<Box<dyn Future<Output = Self::Output> + 'a>>where Self: Sized + 'a,

Wrap the future in a Box, pinning it. Read more
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fn unit_error(self) -> UnitError<Self>where Self: Sized,

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fn never_error(self) -> NeverError<Self>where Self: Sized,

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fn poll_unpin(&mut self, cx: &mut Context<'_>) -> Poll<Self::Output>where Self: Unpin,

A convenience for calling Future::poll on Unpin future types.
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fn now_or_never(self) -> Option<Self::Output>where Self: Sized,

Evaluates and consumes the future, returning the resulting output if the future is ready after the first call to Future::poll. Read more
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impl<T> Instrument for T

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fn instrument(self, span: Span) -> Instrumented<Self>

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more
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fn in_current_span(self) -> Instrumented<Self>

Instruments this type with the current Span, returning an Instrumented wrapper. Read more
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impl<T, U> Into<U> for Twhere U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<F> IntoFuture for Fwhere F: Future,

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type Output = <F as Future>::Output

The output that the future will produce on completion.
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type IntoFuture = F

Which kind of future are we turning this into?
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fn into_future(self) -> <F as IntoFuture>::IntoFuture

Creates a future from a value. Read more
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impl<T> Pointable for T

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const ALIGN: usize = _

The alignment of pointer.
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type Init = T

The type for initializers.
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unsafe fn init(init: <T as Pointable>::Init) -> usize

Initializes a with the given initializer. Read more
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unsafe fn deref<'a>(ptr: usize) -> &'a T

Dereferences the given pointer. Read more
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unsafe fn deref_mut<'a>(ptr: usize) -> &'a mut T

Mutably dereferences the given pointer. Read more
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unsafe fn drop(ptr: usize)

Drops the object pointed to by the given pointer. Read more
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impl<F> TimeoutExt for Fwhere F: Future,

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fn on_timeout<WT, OT>(self, time: WT, on_timeout: OT) -> OnTimeout<Self, OT> where WT: WakeupTime, OT: FnOnce() -> Self::Output,

Wraps the future in a timeout, calling on_timeout to produce a result when the timeout occurs.
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fn on_stalled<OS>( self, timeout: Duration, on_stalled: OS ) -> OnStalled<Self, OS> where OS: FnOnce() -> Self::Output,

Wraps the future in a stall-guard, calling on_stalled to produce a result when the future hasn’t been otherwise polled within the timeout. This is a heuristic - spurious wakeups will keep the detection from triggering, and moving all work to external tasks or threads with force the triggering early.
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impl<T, U> TryFrom<U> for Twhere U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<F, T, E> TryFuture for Fwhere F: Future<Output = Result<T, E>> + ?Sized,

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type Ok = T

The type of successful values yielded by this future
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type Error = E

The type of failures yielded by this future
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fn try_poll( self: Pin<&mut F>, cx: &mut Context<'_> ) -> Poll<<F as Future>::Output>

Poll this TryFuture as if it were a Future. Read more
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impl<Fut> TryFutureExt for Futwhere Fut: TryFuture + ?Sized,

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fn flatten_sink<Item>(self) -> FlattenSink<Self, Self::Ok>where Self::Ok: Sink<Item, Error = Self::Error>, Self: Sized,

Flattens the execution of this future when the successful result of this future is a [Sink]. Read more
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fn map_ok<T, F>(self, f: F) -> MapOk<Self, F>where F: FnOnce(Self::Ok) -> T, Self: Sized,

Maps this future’s success value to a different value. Read more
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fn map_ok_or_else<T, E, F>(self, e: E, f: F) -> MapOkOrElse<Self, F, E>where F: FnOnce(Self::Ok) -> T, E: FnOnce(Self::Error) -> T, Self: Sized,

Maps this future’s success value to a different value, and permits for error handling resulting in the same type. Read more
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fn map_err<E, F>(self, f: F) -> MapErr<Self, F>where F: FnOnce(Self::Error) -> E, Self: Sized,

Maps this future’s error value to a different value. Read more
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fn err_into<E>(self) -> ErrInto<Self, E>where Self: Sized, Self::Error: Into<E>,

Maps this future’s Error to a new error type using the Into trait. Read more
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fn ok_into<U>(self) -> OkInto<Self, U>where Self: Sized, Self::Ok: Into<U>,

Maps this future’s Ok to a new type using the Into trait.
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fn and_then<Fut, F>(self, f: F) -> AndThen<Self, Fut, F>where F: FnOnce(Self::Ok) -> Fut, Fut: TryFuture<Error = Self::Error>, Self: Sized,

Executes another future after this one resolves successfully. The success value is passed to a closure to create this subsequent future. Read more
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fn or_else<Fut, F>(self, f: F) -> OrElse<Self, Fut, F>where F: FnOnce(Self::Error) -> Fut, Fut: TryFuture<Ok = Self::Ok>, Self: Sized,

Executes another future if this one resolves to an error. The error value is passed to a closure to create this subsequent future. Read more
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fn inspect_ok<F>(self, f: F) -> InspectOk<Self, F>where F: FnOnce(&Self::Ok), Self: Sized,

Do something with the success value of a future before passing it on. Read more
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fn inspect_err<F>(self, f: F) -> InspectErr<Self, F>where F: FnOnce(&Self::Error), Self: Sized,

Do something with the error value of a future before passing it on. Read more
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fn try_flatten(self) -> TryFlatten<Self, Self::Ok>where Self::Ok: TryFuture<Error = Self::Error>, Self: Sized,

Flatten the execution of this future when the successful result of this future is another future. Read more
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fn try_flatten_stream(self) -> TryFlattenStream<Self>where Self::Ok: TryStream<Error = Self::Error>, Self: Sized,

Flatten the execution of this future when the successful result of this future is a stream. Read more
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fn unwrap_or_else<F>(self, f: F) -> UnwrapOrElse<Self, F>where Self: Sized, F: FnOnce(Self::Error) -> Self::Ok,

Unwraps this future’s output, producing a future with this future’s Ok type as its Output type. Read more
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fn into_future(self) -> IntoFuture<Self>where Self: Sized,

Wraps a [TryFuture] into a type that implements Future. Read more
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fn try_poll_unpin( &mut self, cx: &mut Context<'_> ) -> Poll<Result<Self::Ok, Self::Error>>where Self: Unpin,

A convenience method for calling [TryFuture::try_poll] on Unpin future types.
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impl<T, U> TryInto<U> for Twhere U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
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impl<T> WithSubscriber for T

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fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>where S: Into<Dispatch>,

Attaches the provided Subscriber to this type, returning a WithDispatch wrapper. Read more
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fn with_current_subscriber(self) -> WithDispatch<Self>

Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more