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#![warn(rust_2018_idioms)]
use crate::blocking;
use crate::runtime::thread_pool::ThreadPool;
use crate::runtime::{Park, Unpark};
use futures_util::future::poll_fn;
use std::future::Future;
use std::pin::Pin;
use std::sync::atomic::Ordering::Relaxed;
use std::sync::atomic::*;
use std::sync::{mpsc, Arc};
use std::task::{Context, Poll, Waker};
use std::time::Duration;
#[test]
fn eagerly_drops_futures() {
use std::sync::{mpsc, Mutex};
struct MyPark {
rx: mpsc::Receiver<()>,
tx: Mutex<mpsc::Sender<()>>,
#[allow(dead_code)]
park_tx: mpsc::SyncSender<()>,
unpark_tx: mpsc::SyncSender<()>,
}
impl Park for MyPark {
type Unpark = MyUnpark;
type Error = ();
fn unpark(&self) -> Self::Unpark {
MyUnpark {
tx: Mutex::new(self.tx.lock().unwrap().clone()),
unpark_tx: self.unpark_tx.clone(),
}
}
fn park(&mut self) -> Result<(), Self::Error> {
let _ = self.rx.recv();
Ok(())
}
fn park_timeout(&mut self, duration: Duration) -> Result<(), Self::Error> {
let _ = self.rx.recv_timeout(duration);
Ok(())
}
}
struct MyUnpark {
tx: Mutex<mpsc::Sender<()>>,
#[allow(dead_code)]
unpark_tx: mpsc::SyncSender<()>,
}
impl Unpark for MyUnpark {
fn unpark(&self) {
let _ = self.tx.lock().unwrap().send(());
}
}
let (task_tx, task_rx) = mpsc::channel();
let (drop_tx, drop_rx) = mpsc::channel();
let (park_tx, park_rx) = mpsc::sync_channel(0);
let (unpark_tx, unpark_rx) = mpsc::sync_channel(0);
let blocking_pool = blocking::BlockingPool::new("test".into(), None);
let pool = ThreadPool::new(
4,
blocking_pool.spawner().clone(),
Arc::new(Box::new(|_, next| next())),
move |_| {
let (tx, rx) = mpsc::channel();
MyPark {
tx: Mutex::new(tx),
rx,
park_tx: park_tx.clone(),
unpark_tx: unpark_tx.clone(),
}
},
);
struct MyTask {
task_tx: Option<mpsc::Sender<Waker>>,
drop_tx: mpsc::Sender<()>,
}
impl Future for MyTask {
type Output = ();
fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<()> {
if let Some(tx) = self.get_mut().task_tx.take() {
tx.send(cx.waker().clone()).unwrap();
}
Poll::Pending
}
}
impl Drop for MyTask {
fn drop(&mut self) {
self.drop_tx.send(()).unwrap();
}
}
pool.spawn(MyTask {
task_tx: Some(task_tx),
drop_tx,
});
// Wait until we get the task handle.
let task = task_rx.recv().unwrap();
// Drop the pool, this should result in futures being forcefully dropped.
drop(pool);
// Make sure `MyPark` and `MyUnpark` were dropped during shutdown.
assert_eq!(park_rx.try_recv(), Err(mpsc::TryRecvError::Disconnected));
assert_eq!(unpark_rx.try_recv(), Err(mpsc::TryRecvError::Disconnected));
// If the future is forcefully dropped, then we will get a signal here.
drop_rx.recv().unwrap();
// Ensure `task` lives until after the test completes.
drop(task);
}
#[test]
fn park_called_at_interval() {
struct MyPark {
park_light: Arc<AtomicBool>,
}
struct MyUnpark {}
impl Park for MyPark {
type Unpark = MyUnpark;
type Error = ();
fn unpark(&self) -> Self::Unpark {
MyUnpark {}
}
fn park(&mut self) -> Result<(), Self::Error> {
use std::thread;
use std::time::Duration;
thread::sleep(Duration::from_millis(1));
Ok(())
}
fn park_timeout(&mut self, duration: Duration) -> Result<(), Self::Error> {
if duration == Duration::from_millis(0) {
self.park_light.store(true, Relaxed);
Ok(())
} else {
self.park()
}
}
}
impl Unpark for MyUnpark {
fn unpark(&self) {}
}
let park_light_1 = Arc::new(AtomicBool::new(false));
let park_light_2 = park_light_1.clone();
let (done_tx, done_rx) = mpsc::channel();
let blocking_pool = blocking::BlockingPool::new("test".into(), None);
let pool = ThreadPool::new(
1,
blocking_pool.spawner().clone(),
Arc::new(Box::new(|_, next| next())),
move |idx| {
assert_eq!(idx, 0);
MyPark {
park_light: park_light_2.clone(),
}
},
);
let mut cnt = 0;
pool.spawn(poll_fn(move |cx| {
let did_park_light = park_light_1.load(Relaxed);
if did_park_light {
// There is a bit of a race where the worker can tick a few times
// before seeing the task
assert!(cnt > 50);
done_tx.send(()).unwrap();
return Poll::Ready(());
}
cnt += 1;
cx.waker().wake_by_ref();
Poll::Pending
}));
done_rx.recv().unwrap();
}
|
