Trait web_thread::web::ScopeExt

pub trait ScopeExt<'scope> {
    // Required methods
    fn spawn_async<F1, F2, T>(
        &'scope self,
        f: F1,
    ) -> ScopedJoinHandle<'scope, T>
       where F1: 'scope + FnOnce() -> F2 + Send,
             F2: 'scope + Future<Output = T>,
             T: 'scope + Send;
    fn spawn_with_message<F1, F2, T, M>(
        &'scope self,
        f: F1,
        message: M,
    ) -> ScopedJoinHandle<'scope, T>
       where F1: 'scope + FnOnce(M) -> F2 + Send,
             F2: 'scope + Future<Output = T>,
             T: 'scope + Send,
             M: 'scope + MessageSend;
}

Available on Web only.

Web-specific extension for web_thread::Scope.

Required Methods

fn spawn_async<F1, F2, T>(&'scope self, f: F1) -> ScopedJoinHandle<'scope, T>

where F1: 'scope + FnOnce() -> F2 + Send, F2: 'scope + Future<Output = T>, T: 'scope + Send,

Async version of Scope::spawn().

Notes

Commonly a long-running thread is used by sending messages or tasks to it and blocking it when there is no work. Unfortunately this is often undesirable on the Web platform as it prevents yielding to the event loop.

Therefor being able to await the next task instead of blocking the thread is essential to build long-running threads on the Web platform.

Panics

If the main thread does not support spawning threads, see has_spawn_support().

Example

use web_thread::web::{self, ScopeExt};

let (sender, receiver) = async_channel::unbounded::<usize>();

web::scope_async(move |scope| async move {
	scope.spawn_async(move || async move {
		while let Ok(message) = receiver.recv().await {
			web_sys::console::log_1(&message.into());
		}
	});
});

for message in 0..10 {
	sender.try_send(message).unwrap();
}

fn spawn_with_message<F1, F2, T, M>( &'scope self, f: F1, message: M, ) -> ScopedJoinHandle<'scope, T>

where F1: 'scope + FnOnce(M) -> F2 + Send, F2: 'scope + Future<Output = T>, T: 'scope + Send, M: 'scope + MessageSend,

Available on crate feature message only.

ScopeExt::spawn_async() with message.

For a more complete documentation see ScopeExt::spawn_async() and spawn_with_message().

Panics

• If the main thread does not support spawning threads, see has_spawn_support().
• If message was unable to be cloned.

Object Safety

This trait is not object safe.

Implementors

impl<'scope> ScopeExt<'scope> for Scope<'scope, '_>