/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at
http://mozilla.org/MPL/2.0/. */
use std::{
future::Future,
pin::Pin,
task::{Context, Poll, Waker},
};
/// Demo `Future` to demonstrate executing futures to completion via `nsIEventTarget`.
struct MyFuture {
poll_count: u32,
waker: Option<Waker>,
expect_main_thread: bool,
}
impl MyFuture {
fn new(expect_main_thread: bool) -> Self {
Self {
poll_count: 0,
waker: None,
expect_main_thread,
}
}
}
impl Future for MyFuture {
type Output = u32;
fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<u32> {
assert_eq!(moz_task::is_main_thread(), self.expect_main_thread);
self.poll_count += 1;
if let Some(waker) = &mut self.waker {
if !waker.will_wake(cx.waker()) {
*waker = cx.waker().clone();
}
} else {
let waker = cx.waker().clone();
self.waker = Some(waker);
}
println!("Poll count = {}", self.poll_count);
if self.poll_count > 5 {
Poll::Ready(self.poll_count)
} else {
// Just notify the task that we need to re-polled.
if let Some(waker) = &self.waker {
waker.wake_by_ref();
}
Poll::Pending
}
}
}
#[no_mangle]
pub extern "C" fn Rust_Future(it_worked: *mut bool) {
let future = async move {
assert_eq!(MyFuture::new(true).await, 6);
assert_eq!(
moz_task::spawn_local("Rust_Future inner spawn_local", MyFuture::new(true)).await,
6
);
assert_eq!(
moz_task::spawn("Rust_Future inner spawn", MyFuture::new(false)).await,
6
);
unsafe {
*it_worked = true;
}
};
unsafe {
moz_task::gtest_only::spin_event_loop_until("Rust_Future", future).unwrap();
};
}
