[−][src]Struct async_scoped::Scope
A scope to allow controlled spawning of non 'static
futures. Futures can be spawned using spawn or
spawn_cancellable methods.
Safety
This type uses Drop implementation to guarantee
safety. It is not safe to forget this object unless it
is driven to completion.
Implementations
impl<'a, T: Send + 'static, Sp: Spawner<T> + Blocker> Scope<'a, T, Sp>[src]
pub unsafe fn create() -> Self[src]
Create a Scope object.
This function is unsafe as futs may hold futures
which have to be manually driven to completion.
pub fn spawn<F: Future<Output = T> + Send + 'a>(&mut self, f: F)[src]
Spawn a future with async_std::task::spawn. The
future is expected to be driven to completion before
'a expires.
impl<'a, T, Sp: Spawner<T> + Blocker> Scope<'a, T, Sp>[src]
pub fn len(&self) -> usize[src]
Total number of futures spawned in this scope.
pub fn remaining(&self) -> usize[src]
Number of futures remaining in this scope.
pub async fn collect<'_>(&'_ mut self) -> Vec<T>[src]
A slighly optimized collect on the stream. Also
useful when we can not move out of self.
impl<'a, T, Sp: Spawner<T> + Blocker> Scope<'a, T, Sp>[src]
pub unsafe fn scope<R, F>(f: F) -> (Self, R) where
T: Send + 'static,
Sp: Spawner<T> + Blocker,
F: FnOnce(&mut Scope<'a, T, Sp>) -> R, [src]
T: Send + 'static,
Sp: Spawner<T> + Blocker,
F: FnOnce(&mut Scope<'a, T, Sp>) -> R,
Creates a Scope to spawn non-'static futures. The
function is called with a block which takes an &mut Scope. The spawn method on this arg. can be used to
spawn "local" futures.
Returns
The function returns the created Scope, and the return
value of the block passed to it. The returned stream and
is expected to be driven completely before being
forgotten. Dropping this stream causes the stream to be
driven while blocking the current thread. The values
returned from the stream are the output of the futures
spawned.
Safety
The returned stream is expected to be run to completion before being forgotten. Dropping it is okay, but blocks the current thread until all spawned futures complete.
pub fn scope_and_block<R, F>(f: F) -> (R, Vec<T>) where
T: Send + 'static,
Sp: Spawner<T> + Blocker,
F: FnOnce(&mut Scope<'a, T, Sp>) -> R, [src]
T: Send + 'static,
Sp: Spawner<T> + Blocker,
F: FnOnce(&mut Scope<'a, T, Sp>) -> R,
A function that creates a scope and immediately awaits,
blocking the current thread for spawned futures to
complete. The outputs of the futures are collected as a
Vec and returned along with the output of the block.
Safety
This function is safe to the best of our understanding as it blocks the current thread until the stream is driven to completion, implying that all the spawned futures have completed too. However, care must be taken to ensure a recursive usage of this function doesn't lead to deadlocks.
When scope is used recursively, you may also use the
unsafe scope_and_* functions as long as this function
is used at the top level. In this case, either the
recursively spawned should have the same lifetime as the
top-level scope, or there should not be any spurious
future cancellations within the top level scope.
pub async unsafe fn scope_and_collect<R, F>(f: F) -> (R, Vec<T>) where
T: Send + 'static,
F: FnOnce(&mut Scope<'a, T, Sp>) -> R, [src]
T: Send + 'static,
F: FnOnce(&mut Scope<'a, T, Sp>) -> R,
An asynchronous function that creates a scope and
immediately awaits the stream. The outputs of the
futures are collected as a Vec and returned along with
the output of the block.
Safety
This function is not completely safe: please see
cancellation_soundness in tests.rs for a
test-case that suggests how this can lead to invalid
memory access if not dealt with care.
The caller must ensure that the lifetime 'a is valid until the returned future is fully driven. Dropping the future is okay, but blocks the current thread until all spawned futures complete.
Trait Implementations
impl<'a, T, Sp: Spawner<T> + Blocker> Drop for Scope<'a, T, Sp>[src]
impl<'a, T, Sp: Spawner<T> + Blocker> PinnedDrop for Scope<'a, T, Sp>[src]
impl<'a, T, Sp: Spawner<T> + Blocker> Stream for Scope<'a, T, Sp>[src]
type Item = T
Values yielded by the stream.
fn poll_next(
self: Pin<&mut Self>,
cx: &mut Context<'_>
) -> Poll<Option<Self::Item>>[src]
self: Pin<&mut Self>,
cx: &mut Context<'_>
) -> Poll<Option<Self::Item>>
fn size_hint(&self) -> (usize, Option<usize>)[src]
impl<'pin, 'a, T, Sp: Spawner<T> + Blocker> Unpin for Scope<'a, T, Sp> where
__Scope<'pin, 'a, T, Sp>: Unpin, [src]
__Scope<'pin, 'a, T, Sp>: Unpin,
impl<'a, T, Sp: Spawner<T> + Blocker> UnsafeUnpin for Scope<'a, T, Sp>[src]
Auto Trait Implementations
impl<'a, T, Sp> !RefUnwindSafe for Scope<'a, T, Sp>
impl<'a, T, Sp> Send for Scope<'a, T, Sp> where
Sp: Send,
<Sp as Spawner<T>>::SpawnHandle: Send,
Sp: Send,
<Sp as Spawner<T>>::SpawnHandle: Send,
impl<'a, T, Sp> Sync for Scope<'a, T, Sp> where
Sp: Sync,
<Sp as Spawner<T>>::SpawnHandle: Sync,
Sp: Sync,
<Sp as Spawner<T>>::SpawnHandle: Sync,
impl<'a, T, Sp> !UnwindSafe for Scope<'a, T, Sp>
Blanket Implementations
impl<T> Any for T where
T: 'static + ?Sized, [src]
T: 'static + ?Sized,
impl<T> Borrow<T> for T where
T: ?Sized, [src]
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized, [src]
T: ?Sized,
pub fn borrow_mut(&mut self) -> &mut T[src]
impl<T> From<T> for T[src]
impl<T, U> Into<U> for T where
U: From<T>, [src]
U: From<T>,
impl<T> StreamExt for T where
T: Stream + ?Sized, [src]
T: Stream + ?Sized,
fn next(&mut self) -> Next<'_, Self> where
Self: Unpin, [src]
Self: Unpin,
fn into_future(self) -> StreamFuture<Self> where
Self: Unpin, [src]
Self: Unpin,
fn map<T, F>(self, f: F) -> Map<Self, F> where
F: FnMut(Self::Item) -> T, [src]
F: FnMut(Self::Item) -> T,
fn enumerate(self) -> Enumerate<Self>[src]
fn filter<Fut, F>(self, f: F) -> Filter<Self, Fut, F> where
F: FnMut(&Self::Item) -> Fut,
Fut: Future<Output = bool>, [src]
F: FnMut(&Self::Item) -> Fut,
Fut: Future<Output = bool>,
fn filter_map<Fut, T, F>(self, f: F) -> FilterMap<Self, Fut, F> where
F: FnMut(Self::Item) -> Fut,
Fut: Future<Output = Option<T>>, [src]
F: FnMut(Self::Item) -> Fut,
Fut: Future<Output = Option<T>>,
fn then<Fut, F>(self, f: F) -> Then<Self, Fut, F> where
F: FnMut(Self::Item) -> Fut,
Fut: Future, [src]
F: FnMut(Self::Item) -> Fut,
Fut: Future,
fn collect<C>(self) -> Collect<Self, C> where
C: Default + Extend<Self::Item>, [src]
C: Default + Extend<Self::Item>,
fn concat(self) -> Concat<Self> where
Self::Item: Extend<<Self::Item as IntoIterator>::Item>,
Self::Item: IntoIterator,
Self::Item: Default, [src]
Self::Item: Extend<<Self::Item as IntoIterator>::Item>,
Self::Item: IntoIterator,
Self::Item: Default,
fn cycle(self) -> Cycle<Self> where
Self: Clone, [src]
Self: Clone,
fn fold<T, Fut, F>(self, init: T, f: F) -> Fold<Self, Fut, T, F> where
F: FnMut(T, Self::Item) -> Fut,
Fut: Future<Output = T>, [src]
F: FnMut(T, Self::Item) -> Fut,
Fut: Future<Output = T>,
fn flatten(self) -> Flatten<Self> where
Self::Item: Stream, [src]
Self::Item: Stream,
fn flat_map<U, F>(self, f: F) -> FlatMap<Self, U, F> where
F: FnMut(Self::Item) -> U,
U: Stream, [src]
F: FnMut(Self::Item) -> U,
U: Stream,
fn scan<S, B, Fut, F>(self, initial_state: S, f: F) -> Scan<Self, S, Fut, F> where
F: FnMut(&mut S, Self::Item) -> Fut,
Fut: Future<Output = Option<B>>, [src]
F: FnMut(&mut S, Self::Item) -> Fut,
Fut: Future<Output = Option<B>>,
fn skip_while<Fut, F>(self, f: F) -> SkipWhile<Self, Fut, F> where
F: FnMut(&Self::Item) -> Fut,
Fut: Future<Output = bool>, [src]
F: FnMut(&Self::Item) -> Fut,
Fut: Future<Output = bool>,
fn take_while<Fut, F>(self, f: F) -> TakeWhile<Self, Fut, F> where
F: FnMut(&Self::Item) -> Fut,
Fut: Future<Output = bool>, [src]
F: FnMut(&Self::Item) -> Fut,
Fut: Future<Output = bool>,
fn take_until<Fut>(self, fut: Fut) -> TakeUntil<Self, Fut> where
Fut: Future, [src]
Fut: Future,
fn for_each<Fut, F>(self, f: F) -> ForEach<Self, Fut, F> where
F: FnMut(Self::Item) -> Fut,
Fut: Future<Output = ()>, [src]
F: FnMut(Self::Item) -> Fut,
Fut: Future<Output = ()>,
fn for_each_concurrent<Fut, F>(
self,
limit: impl Into<Option<usize>>,
f: F
) -> ForEachConcurrent<Self, Fut, F> where
F: FnMut(Self::Item) -> Fut,
Fut: Future<Output = ()>, [src]
self,
limit: impl Into<Option<usize>>,
f: F
) -> ForEachConcurrent<Self, Fut, F> where
F: FnMut(Self::Item) -> Fut,
Fut: Future<Output = ()>,
fn take(self, n: usize) -> Take<Self>[src]
fn skip(self, n: usize) -> Skip<Self>[src]
fn fuse(self) -> Fuse<Self>[src]
fn by_ref(&mut self) -> &mut Self[src]
fn catch_unwind(self) -> CatchUnwind<Self> where
Self: UnwindSafe, [src]
Self: UnwindSafe,
fn boxed<'a>(
self
) -> Pin<Box<dyn Stream<Item = Self::Item> + 'a + Send, Global>> where
Self: Send + 'a, [src]
self
) -> Pin<Box<dyn Stream<Item = Self::Item> + 'a + Send, Global>> where
Self: Send + 'a,
fn boxed_local<'a>(self) -> Pin<Box<dyn Stream<Item = Self::Item> + 'a, Global>> where
Self: 'a, [src]
Self: 'a,
fn buffered(self, n: usize) -> Buffered<Self> where
Self::Item: Future, [src]
Self::Item: Future,
fn buffer_unordered(self, n: usize) -> BufferUnordered<Self> where
Self::Item: Future, [src]
Self::Item: Future,
fn zip<St>(self, other: St) -> Zip<Self, St> where
St: Stream, [src]
St: Stream,
fn chain<St>(self, other: St) -> Chain<Self, St> where
St: Stream<Item = Self::Item>, [src]
St: Stream<Item = Self::Item>,
fn peekable(self) -> Peekable<Self>[src]
fn chunks(self, capacity: usize) -> Chunks<Self>[src]
fn ready_chunks(self, capacity: usize) -> ReadyChunks<Self>[src]
fn forward<S>(self, sink: S) -> Forward<Self, S> where
S: Sink<Self::Ok, Error = Self::Error>,
Self: TryStream, [src]
S: Sink<Self::Ok, Error = Self::Error>,
Self: TryStream,
fn split<Item>(self) -> (SplitSink<Self, Item>, SplitStream<Self>) where
Self: Sink<Item>, [src]
Self: Sink<Item>,
fn inspect<F>(self, f: F) -> Inspect<Self, F> where
F: FnMut(&Self::Item), [src]
F: FnMut(&Self::Item),
fn left_stream<B>(self) -> Either<Self, B> where
B: Stream<Item = Self::Item>, [src]
B: Stream<Item = Self::Item>,
fn right_stream<B>(self) -> Either<B, Self> where
B: Stream<Item = Self::Item>, [src]
B: Stream<Item = Self::Item>,
fn poll_next_unpin(&mut self, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> where
Self: Unpin, [src]
Self: Unpin,
fn select_next_some(&mut self) -> SelectNextSome<'_, Self> where
Self: Unpin + FusedStream, [src]
Self: Unpin + FusedStream,
impl<T, U> TryFrom<U> for T where
U: Into<T>, [src]
U: Into<T>,
type Error = Infallible
The type returned in the event of a conversion error.
pub fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>[src]
impl<T, U> TryInto<U> for T where
U: TryFrom<T>, [src]
U: TryFrom<T>,
type Error = <U as TryFrom<T>>::Error
The type returned in the event of a conversion error.
pub fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>[src]
impl<S, T, E> TryStream for S where
S: Stream<Item = Result<T, E>> + ?Sized, [src]
S: Stream<Item = Result<T, E>> + ?Sized,
type Ok = T
The type of successful values yielded by this future
type Error = E
The type of failures yielded by this future
pub fn try_poll_next(
self: Pin<&mut S>,
cx: &mut Context<'_>
) -> Poll<Option<Result<<S as TryStream>::Ok, <S as TryStream>::Error>>>[src]
self: Pin<&mut S>,
cx: &mut Context<'_>
) -> Poll<Option<Result<<S as TryStream>::Ok, <S as TryStream>::Error>>>
impl<S> TryStreamExt for S where
S: TryStream + ?Sized, [src]
S: TryStream + ?Sized,
fn err_into<E>(self) -> ErrInto<Self, E> where
Self::Error: Into<E>, [src]
Self::Error: Into<E>,
fn map_ok<T, F>(self, f: F) -> MapOk<Self, F> where
F: FnMut(Self::Ok) -> T, [src]
F: FnMut(Self::Ok) -> T,
fn map_err<E, F>(self, f: F) -> MapErr<Self, F> where
F: FnMut(Self::Error) -> E, [src]
F: FnMut(Self::Error) -> E,
fn and_then<Fut, F>(self, f: F) -> AndThen<Self, Fut, F> where
F: FnMut(Self::Ok) -> Fut,
Fut: TryFuture<Error = Self::Error>, [src]
F: FnMut(Self::Ok) -> Fut,
Fut: TryFuture<Error = Self::Error>,
fn or_else<Fut, F>(self, f: F) -> OrElse<Self, Fut, F> where
F: FnMut(Self::Error) -> Fut,
Fut: TryFuture<Ok = Self::Ok>, [src]
F: FnMut(Self::Error) -> Fut,
Fut: TryFuture<Ok = Self::Ok>,
fn inspect_ok<F>(self, f: F) -> InspectOk<Self, F> where
F: FnMut(&Self::Ok), [src]
F: FnMut(&Self::Ok),
fn inspect_err<F>(self, f: F) -> InspectErr<Self, F> where
F: FnMut(&Self::Error), [src]
F: FnMut(&Self::Error),
fn into_stream(self) -> IntoStream<Self>[src]
fn try_next(&mut self) -> TryNext<'_, Self> where
Self: Unpin, [src]
Self: Unpin,
fn try_for_each<Fut, F>(self, f: F) -> TryForEach<Self, Fut, F> where
F: FnMut(Self::Ok) -> Fut,
Fut: TryFuture<Ok = (), Error = Self::Error>, [src]
F: FnMut(Self::Ok) -> Fut,
Fut: TryFuture<Ok = (), Error = Self::Error>,
fn try_skip_while<Fut, F>(self, f: F) -> TrySkipWhile<Self, Fut, F> where
F: FnMut(&Self::Ok) -> Fut,
Fut: TryFuture<Ok = bool, Error = Self::Error>, [src]
F: FnMut(&Self::Ok) -> Fut,
Fut: TryFuture<Ok = bool, Error = Self::Error>,
fn try_take_while<Fut, F>(self, f: F) -> TryTakeWhile<Self, Fut, F> where
F: FnMut(&Self::Ok) -> Fut,
Fut: TryFuture<Ok = bool, Error = Self::Error>, [src]
F: FnMut(&Self::Ok) -> Fut,
Fut: TryFuture<Ok = bool, Error = Self::Error>,
fn try_for_each_concurrent<Fut, F>(
self,
limit: impl Into<Option<usize>>,
f: F
) -> TryForEachConcurrent<Self, Fut, F> where
F: FnMut(Self::Ok) -> Fut,
Fut: Future<Output = Result<(), Self::Error>>, [src]
self,
limit: impl Into<Option<usize>>,
f: F
) -> TryForEachConcurrent<Self, Fut, F> where
F: FnMut(Self::Ok) -> Fut,
Fut: Future<Output = Result<(), Self::Error>>,
fn try_collect<C>(self) -> TryCollect<Self, C> where
C: Default + Extend<Self::Ok>, [src]
C: Default + Extend<Self::Ok>,
fn try_filter<Fut, F>(self, f: F) -> TryFilter<Self, Fut, F> where
F: FnMut(&Self::Ok) -> Fut,
Fut: Future<Output = bool>, [src]
F: FnMut(&Self::Ok) -> Fut,
Fut: Future<Output = bool>,
fn try_filter_map<Fut, F, T>(self, f: F) -> TryFilterMap<Self, Fut, F> where
F: FnMut(Self::Ok) -> Fut,
Fut: TryFuture<Ok = Option<T>, Error = Self::Error>, [src]
F: FnMut(Self::Ok) -> Fut,
Fut: TryFuture<Ok = Option<T>, Error = Self::Error>,
fn try_flatten(self) -> TryFlatten<Self> where
Self::Ok: TryStream,
<Self::Ok as TryStream>::Error: From<Self::Error>, [src]
Self::Ok: TryStream,
<Self::Ok as TryStream>::Error: From<Self::Error>,
fn try_fold<T, Fut, F>(self, init: T, f: F) -> TryFold<Self, Fut, T, F> where
F: FnMut(T, Self::Ok) -> Fut,
Fut: TryFuture<Ok = T, Error = Self::Error>, [src]
F: FnMut(T, Self::Ok) -> Fut,
Fut: TryFuture<Ok = T, Error = Self::Error>,
fn try_concat(self) -> TryConcat<Self> where
Self::Ok: Extend<<Self::Ok as IntoIterator>::Item>,
Self::Ok: IntoIterator,
Self::Ok: Default, [src]
Self::Ok: Extend<<Self::Ok as IntoIterator>::Item>,
Self::Ok: IntoIterator,
Self::Ok: Default,
fn try_buffer_unordered(self, n: usize) -> TryBufferUnordered<Self> where
Self::Ok: TryFuture,
<Self::Ok as TryFuture>::Error == Self::Error, [src]
Self::Ok: TryFuture,
<Self::Ok as TryFuture>::Error == Self::Error,
fn try_buffered(self, n: usize) -> TryBuffered<Self> where
Self::Ok: TryFuture,
<Self::Ok as TryFuture>::Error == Self::Error, [src]
Self::Ok: TryFuture,
<Self::Ok as TryFuture>::Error == Self::Error,
fn try_poll_next_unpin(
&mut self,
cx: &mut Context<'_>
) -> Poll<Option<Result<Self::Ok, Self::Error>>> where
Self: Unpin, [src]
&mut self,
cx: &mut Context<'_>
) -> Poll<Option<Result<Self::Ok, Self::Error>>> where
Self: Unpin,
fn into_async_read(self) -> IntoAsyncRead<Self> where
Self: TryStreamExt<Error = Error> + Unpin,
Self::Ok: AsRef<[u8]>, [src]
Self: TryStreamExt<Error = Error> + Unpin,
Self::Ok: AsRef<[u8]>,