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