rust/src/test/run-pass/futures-api.rs
2018-08-06 12:18:47 +02:00

96 lines
2.8 KiB
Rust

// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
#![feature(arbitrary_self_types, futures_api, pin)]
#![allow(unused)]
use std::boxed::PinBox;
use std::future::Future;
use std::mem::PinMut;
use std::rc::Rc;
use std::sync::{
Arc,
atomic::{self, AtomicUsize},
};
use std::future::FutureObj;
use std::task::{
Context, Poll,
Wake, Waker, LocalWaker,
Spawn, SpawnObjError,
local_waker, local_waker_from_nonlocal,
};
struct Counter {
local_wakes: AtomicUsize,
nonlocal_wakes: AtomicUsize,
}
impl Wake for Counter {
fn wake(this: &Arc<Self>) {
this.nonlocal_wakes.fetch_add(1, atomic::Ordering::SeqCst);
}
unsafe fn wake_local(this: &Arc<Self>) {
this.local_wakes.fetch_add(1, atomic::Ordering::SeqCst);
}
}
struct NoopSpawner;
impl Spawn for NoopSpawner {
fn spawn_obj(&mut self, _: FutureObj<'static, ()>) -> Result<(), SpawnObjError> {
Ok(())
}
}
struct MyFuture;
impl Future for MyFuture {
type Output = ();
fn poll(self: PinMut<Self>, cx: &mut Context) -> Poll<Self::Output> {
// Ensure all the methods work appropriately
cx.waker().wake();
cx.waker().wake();
cx.local_waker().wake();
cx.spawner().spawn_obj(PinBox::new(MyFuture).into()).unwrap();
Poll::Ready(())
}
}
fn test_local_waker() {
let counter = Arc::new(Counter {
local_wakes: AtomicUsize::new(0),
nonlocal_wakes: AtomicUsize::new(0),
});
let waker = unsafe { local_waker(counter.clone()) };
let spawner = &mut NoopSpawner;
let cx = &mut Context::new(&waker, spawner);
assert_eq!(Poll::Ready(()), PinMut::new(&mut MyFuture).poll(cx));
assert_eq!(1, counter.local_wakes.load(atomic::Ordering::SeqCst));
assert_eq!(2, counter.nonlocal_wakes.load(atomic::Ordering::SeqCst));
}
fn test_local_as_nonlocal_waker() {
let counter = Arc::new(Counter {
local_wakes: AtomicUsize::new(0),
nonlocal_wakes: AtomicUsize::new(0),
});
let waker: LocalWaker = local_waker_from_nonlocal(counter.clone());
let spawner = &mut NoopSpawner;
let cx = &mut Context::new(&waker, spawner);
assert_eq!(Poll::Ready(()), PinMut::new(&mut MyFuture).poll(cx));
assert_eq!(0, counter.local_wakes.load(atomic::Ordering::SeqCst));
assert_eq!(3, counter.nonlocal_wakes.load(atomic::Ordering::SeqCst));
}
fn main() {
test_local_waker();
test_local_as_nonlocal_waker();
}