/rust/registry/src/index.crates.io-6f17d22bba15001f/futures-util-0.3.21/src/task/spawn.rs

Source (jump to first uncovered line)
use futures_task::{LocalSpawn, Spawn};

#[cfg(feature = "compat")]
use crate::compat::Compat;

#[cfg(feature = "channel")]
#[cfg(feature = "std")]
use crate::future::{FutureExt, RemoteHandle};
#[cfg(feature = "alloc")]
use alloc::boxed::Box;
#[cfg(feature = "alloc")]
use futures_core::future::Future;
#[cfg(feature = "alloc")]
use futures_task::{FutureObj, LocalFutureObj, SpawnError};

impl<Sp: ?Sized> SpawnExt for Sp where Sp: Spawn {}
impl<Sp: ?Sized> LocalSpawnExt for Sp where Sp: LocalSpawn {}

/// Extension trait for `Spawn`.
pub trait SpawnExt: Spawn {
    /// Spawns a task that polls the given future with output `()` to
    /// completion.
    ///
    /// This method returns a [`Result`] that contains a [`SpawnError`] if
    /// spawning fails.
    ///
    /// You can use [`spawn_with_handle`](SpawnExt::spawn_with_handle) if
    /// you want to spawn a future with output other than `()` or if you want
    /// to be able to await its completion.
    ///
    /// Note this method will eventually be replaced with the upcoming
    /// `Spawn::spawn` method which will take a `dyn Future` as input.
    /// Technical limitations prevent `Spawn::spawn` from being implemented
    /// today. Feel free to use this method in the meantime.
    ///
    /// ```
    /// # if cfg!(miri) { return; } // https://github.com/rust-lang/miri/issues/1038
    /// use futures::executor::ThreadPool;
    /// use futures::task::SpawnExt;
    ///
    /// let executor = ThreadPool::new().unwrap();
    ///
    /// let future = async { /* ... */ };
    /// executor.spawn(future).unwrap();
    /// ```
    #[cfg(feature = "alloc")]
    fn spawn<Fut>(&self, future: Fut) -> Result<(), SpawnError>
    where
        Fut: Future<Output = ()> + Send + 'static,
    {
        self.spawn_obj(FutureObj::new(Box::new(future)))
    }

    /// Spawns a task that polls the given future to completion and returns a
    /// future that resolves to the spawned future's output.
    ///
    /// This method returns a [`Result`] that contains a [`RemoteHandle`](crate::future::RemoteHandle), or, if
    /// spawning fails, a [`SpawnError`]. [`RemoteHandle`](crate::future::RemoteHandle) is a future that
    /// resolves to the output of the spawned future.
    ///
    /// ```
    /// # if cfg!(miri) { return; } // https://github.com/rust-lang/miri/issues/1038
    /// use futures::executor::{block_on, ThreadPool};
    /// use futures::future;
    /// use futures::task::SpawnExt;
    ///
    /// let executor = ThreadPool::new().unwrap();
    ///
    /// let future = future::ready(1);
    /// let join_handle_fut = executor.spawn_with_handle(future).unwrap();
    /// assert_eq!(block_on(join_handle_fut), 1);
    /// ```
    #[cfg(feature = "channel")]
    #[cfg_attr(docsrs, doc(cfg(feature = "channel")))]
    #[cfg(feature = "std")]
    fn spawn_with_handle<Fut>(&self, future: Fut) -> Result<RemoteHandle<Fut::Output>, SpawnError>
    where
        Fut: Future + Send + 'static,
        Fut::Output: Send,
    {
        let (future, handle) = future.remote_handle();
        self.spawn(future)?;
        Ok(handle)
    }

    /// Wraps a [`Spawn`] and makes it usable as a futures 0.1 `Executor`.
    /// Requires the `compat` feature to enable.
    #[cfg(feature = "compat")]
    #[cfg_attr(docsrs, doc(cfg(feature = "compat")))]
    fn compat(self) -> Compat<Self>
    where
        Self: Sized,
    {
        Compat::new(self)
    }
}

/// Extension trait for `LocalSpawn`.
pub trait LocalSpawnExt: LocalSpawn {
    /// Spawns a task that polls the given future with output `()` to
    /// completion.
    ///
    /// This method returns a [`Result`] that contains a [`SpawnError`] if
    /// spawning fails.
    ///
    /// You can use [`spawn_with_handle`](SpawnExt::spawn_with_handle) if
    /// you want to spawn a future with output other than `()` or if you want
    /// to be able to await its completion.
    ///
    /// Note this method will eventually be replaced with the upcoming
    /// `Spawn::spawn` method which will take a `dyn Future` as input.
    /// Technical limitations prevent `Spawn::spawn` from being implemented
    /// today. Feel free to use this method in the meantime.
    ///
    /// ```
    /// use futures::executor::LocalPool;
    /// use futures::task::LocalSpawnExt;
    ///
    /// let executor = LocalPool::new();
    /// let spawner = executor.spawner();
    ///
    /// let future = async { /* ... */ };
    /// spawner.spawn_local(future).unwrap();
    /// ```
    #[cfg(feature = "alloc")]
    fn spawn_local<Fut>(&self, future: Fut) -> Result<(), SpawnError>
    where
        Fut: Future<Output = ()> + 'static,
    {
        self.spawn_local_obj(LocalFutureObj::new(Box::new(future)))
    }

    /// Spawns a task that polls the given future to completion and returns a
    /// future that resolves to the spawned future's output.
    ///
    /// This method returns a [`Result`] that contains a [`RemoteHandle`](crate::future::RemoteHandle), or, if
    /// spawning fails, a [`SpawnError`]. [`RemoteHandle`](crate::future::RemoteHandle) is a future that
    /// resolves to the output of the spawned future.
    ///
    /// ```
    /// # if cfg!(miri) { return; } // https://github.com/rust-lang/miri/issues/1038
    /// use futures::executor::LocalPool;
    /// use futures::task::LocalSpawnExt;
    ///
    /// let mut executor = LocalPool::new();
    /// let spawner = executor.spawner();
    ///
    /// let future = async { 1 };
    /// let join_handle_fut = spawner.spawn_local_with_handle(future).unwrap();
    /// assert_eq!(executor.run_until(join_handle_fut), 1);
    /// ```
    #[cfg(feature = "channel")]
    #[cfg_attr(docsrs, doc(cfg(feature = "channel")))]
    #[cfg(feature = "std")]
    fn spawn_local_with_handle<Fut>(
        &self,
        future: Fut,
    ) -> Result<RemoteHandle<Fut::Output>, SpawnError>
    where
        Fut: Future + 'static,
    {
        let (future, handle) = future.remote_handle();
        self.spawn_local(future)?;
        Ok(handle)
    }
}

Coverage Report

Created: 2024-09-08 06:35

Line	Count	Source (jump to first uncovered line)
1		use futures_task::{LocalSpawn, Spawn};
2
3		#[cfg(feature = "compat")]
4		use crate::compat::Compat;
5
6		#[cfg(feature = "channel")]
7		#[cfg(feature = "std")]
8		use crate::future::{FutureExt, RemoteHandle};
9		#[cfg(feature = "alloc")]
10		use alloc::boxed::Box;
11		#[cfg(feature = "alloc")]
12		use futures_core::future::Future;
13		#[cfg(feature = "alloc")]
14		use futures_task::{FutureObj, LocalFutureObj, SpawnError};
15
16		impl<Sp: ?Sized> SpawnExt for Sp where Sp: Spawn {}
17		impl<Sp: ?Sized> LocalSpawnExt for Sp where Sp: LocalSpawn {}
18
19		/// Extension trait for `Spawn`.
20		pub trait SpawnExt: Spawn {
21		/// Spawns a task that polls the given future with output `()` to
22		/// completion.
23		///
24		/// This method returns a [`Result`] that contains a [`SpawnError`] if
25		/// spawning fails.
26		///
27		/// You can use [`spawn_with_handle`](SpawnExt::spawn_with_handle) if
28		/// you want to spawn a future with output other than `()` or if you want
29		/// to be able to await its completion.
30		///
31		/// Note this method will eventually be replaced with the upcoming
32		/// `Spawn::spawn` method which will take a `dyn Future` as input.
33		/// Technical limitations prevent `Spawn::spawn` from being implemented
34		/// today. Feel free to use this method in the meantime.
35		///
36		/// ```
37		/// # if cfg!(miri) { return; } // https://github.com/rust-lang/miri/issues/1038
38		/// use futures::executor::ThreadPool;
39		/// use futures::task::SpawnExt;
40		///
41		/// let executor = ThreadPool::new().unwrap();
42		///
43		/// let future = async { /* ... */ };
44		/// executor.spawn(future).unwrap();
45		/// ```
46		#[cfg(feature = "alloc")]
47	0	fn spawn<Fut>(&self, future: Fut) -> Result<(), SpawnError>
48	0	where
49	0	Fut: Future<Output = ()> + Send + 'static,
50	0	{
51	0	self.spawn_obj(FutureObj::new(Box::new(future)))
52	0	}
53
54		/// Spawns a task that polls the given future to completion and returns a
55		/// future that resolves to the spawned future's output.
56		///
57		/// This method returns a [`Result`] that contains a [`RemoteHandle`](crate::future::RemoteHandle), or, if
58		/// spawning fails, a [`SpawnError`]. [`RemoteHandle`](crate::future::RemoteHandle) is a future that
59		/// resolves to the output of the spawned future.
60		///
61		/// ```
62		/// # if cfg!(miri) { return; } // https://github.com/rust-lang/miri/issues/1038
63		/// use futures::executor::{block_on, ThreadPool};
64		/// use futures::future;
65		/// use futures::task::SpawnExt;
66		///
67		/// let executor = ThreadPool::new().unwrap();
68		///
69		/// let future = future::ready(1);
70		/// let join_handle_fut = executor.spawn_with_handle(future).unwrap();
71		/// assert_eq!(block_on(join_handle_fut), 1);
72		/// ```
73		#[cfg(feature = "channel")]
74		#[cfg_attr(docsrs, doc(cfg(feature = "channel")))]
75		#[cfg(feature = "std")]
76	0	fn spawn_with_handle<Fut>(&self, future: Fut) -> Result<RemoteHandle<Fut::Output>, SpawnError>
77	0	where
78	0	Fut: Future + Send + 'static,
79	0	Fut::Output: Send,
80	0	{
81	0	let (future, handle) = future.remote_handle();
82	0	self.spawn(future)?;
83	0	Ok(handle)
84	0	}
85
86		/// Wraps a [`Spawn`] and makes it usable as a futures 0.1 `Executor`.
87		/// Requires the `compat` feature to enable.
88		#[cfg(feature = "compat")]
89		#[cfg_attr(docsrs, doc(cfg(feature = "compat")))]
90		fn compat(self) -> Compat<Self>
91		where
92		Self: Sized,
93		{
94		Compat::new(self)
95		}
96		}
97
98		/// Extension trait for `LocalSpawn`.
99		pub trait LocalSpawnExt: LocalSpawn {
100		/// Spawns a task that polls the given future with output `()` to
101		/// completion.
102		///
103		/// This method returns a [`Result`] that contains a [`SpawnError`] if
104		/// spawning fails.
105		///
106		/// You can use [`spawn_with_handle`](SpawnExt::spawn_with_handle) if
107		/// you want to spawn a future with output other than `()` or if you want
108		/// to be able to await its completion.
109		///
110		/// Note this method will eventually be replaced with the upcoming
111		/// `Spawn::spawn` method which will take a `dyn Future` as input.
112		/// Technical limitations prevent `Spawn::spawn` from being implemented
113		/// today. Feel free to use this method in the meantime.
114		///
115		/// ```
116		/// use futures::executor::LocalPool;
117		/// use futures::task::LocalSpawnExt;
118		///
119		/// let executor = LocalPool::new();
120		/// let spawner = executor.spawner();
121		///
122		/// let future = async { /* ... */ };
123		/// spawner.spawn_local(future).unwrap();
124		/// ```
125		#[cfg(feature = "alloc")]
126	0	fn spawn_local<Fut>(&self, future: Fut) -> Result<(), SpawnError>
127	0	where
128	0	Fut: Future<Output = ()> + 'static,
129	0	{
130	0	self.spawn_local_obj(LocalFutureObj::new(Box::new(future)))
131	0	}
132
133		/// Spawns a task that polls the given future to completion and returns a
134		/// future that resolves to the spawned future's output.
135		///
136		/// This method returns a [`Result`] that contains a [`RemoteHandle`](crate::future::RemoteHandle), or, if
137		/// spawning fails, a [`SpawnError`]. [`RemoteHandle`](crate::future::RemoteHandle) is a future that
138		/// resolves to the output of the spawned future.
139		///
140		/// ```
141		/// # if cfg!(miri) { return; } // https://github.com/rust-lang/miri/issues/1038
142		/// use futures::executor::LocalPool;
143		/// use futures::task::LocalSpawnExt;
144		///
145		/// let mut executor = LocalPool::new();
146		/// let spawner = executor.spawner();
147		///
148		/// let future = async { 1 };
149		/// let join_handle_fut = spawner.spawn_local_with_handle(future).unwrap();
150		/// assert_eq!(executor.run_until(join_handle_fut), 1);
151		/// ```
152		#[cfg(feature = "channel")]
153		#[cfg_attr(docsrs, doc(cfg(feature = "channel")))]
154		#[cfg(feature = "std")]
155	0	fn spawn_local_with_handle<Fut>(
156	0	&self,
157	0	future: Fut,
158	0	) -> Result<RemoteHandle<Fut::Output>, SpawnError>
159	0	where
160	0	Fut: Future + 'static,
161	0	{
162	0	let (future, handle) = future.remote_handle();
163	0	self.spawn_local(future)?;
164	0	Ok(handle)
165	0	}
166		}