Struct smol::Executor

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pub struct Executor<'a> { /* private fields */ }

Expand description

An async executor.

Examples

A multi-threaded executor:

use async_channel::unbounded;
use async_executor::Executor;
use easy_parallel::Parallel;
use futures_lite::future;

let ex = Executor::new();
let (signal, shutdown) = unbounded::<()>();

Parallel::new()
    // Run four executor threads.
    .each(0..4, |_| future::block_on(ex.run(shutdown.recv())))
    // Run the main future on the current thread.
    .finish(|| future::block_on(async {
        println!("Hello world!");
        drop(signal);
    }));

Implementations§

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impl<'a> Executor<'a>

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pub const fn new() -> Executor<'a>

Creates a new executor.

Examples

use async_executor::Executor;

let ex = Executor::new();

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pub fn is_empty(&self) -> bool

Returns true if there are no unfinished tasks.

Examples

use async_executor::Executor;

let ex = Executor::new();
assert!(ex.is_empty());

let task = ex.spawn(async {
    println!("Hello world");
});
assert!(!ex.is_empty());

assert!(ex.try_tick());
assert!(ex.is_empty());

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pub fn spawn<T>(&self, future: impl Future<Output = T> + Send + 'a) -> Task<T> ⓘwhere
T: 'a + Send,

Spawns a task onto the executor.

Examples

use async_executor::Executor;

let ex = Executor::new();

let task = ex.spawn(async {
    println!("Hello world");
});

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pub fn try_tick(&self) -> bool

Attempts to run a task if at least one is scheduled.

Running a scheduled task means simply polling its future once.

Examples

use async_executor::Executor;

let ex = Executor::new();
assert!(!ex.try_tick()); // no tasks to run

let task = ex.spawn(async {
    println!("Hello world");
});
assert!(ex.try_tick()); // a task was found

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pub async fn tick(&self) -> impl Future<Output = ()>

Runs a single task.

Running a task means simply polling its future once.

If no tasks are scheduled when this method is called, it will wait until one is scheduled.

Examples

use async_executor::Executor;
use futures_lite::future;

let ex = Executor::new();

let task = ex.spawn(async {
    println!("Hello world");
});
future::block_on(ex.tick()); // runs the task

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pub async fn run<T>(
&self,
future: impl Future<Output = T>
) -> impl Future<Output = T>

Runs the executor until the given future completes.

Examples

use async_executor::Executor;
use futures_lite::future;

let ex = Executor::new();

let task = ex.spawn(async { 1 + 2 });
let res = future::block_on(ex.run(async { task.await * 2 }));

assert_eq!(res, 6);