blob: b85abd8c2acdc9db9dbea97481e67f3f5e5fd1ee [file] [log] [blame]
#![cfg(feature = "full")]
use tokio::net::TcpListener;
use tokio::runtime;
use tokio_test::{assert_ok, assert_pending};
use futures::task::{waker_ref, ArcWake};
use std::future::Future;
use std::net::TcpStream;
use std::pin::Pin;
use std::sync::{mpsc, Arc, Mutex};
use std::task::Context;
struct Task<T> {
future: Mutex<Pin<Box<T>>>,
impl<T: Send> ArcWake for Task<T> {
fn wake_by_ref(_: &Arc<Self>) {
// Do nothing...
impl<T> Task<T> {
fn new(future: T) -> Task<T> {
Task {
future: Mutex::new(Box::pin(future)),
fn test_drop_on_notify() {
// When the reactor receives a kernel notification, it notifies the
// task that holds the associated socket. If this notification results in
// the task being dropped, the socket will also be dropped.
// Previously, there was a deadlock scenario where the reactor, while
// notifying, held a lock and the task being dropped attempted to acquire
// that same lock in order to clean up state.
// To simulate this case, we create a fake executor that does nothing when
// the task is notified. This simulates an executor in the process of
// shutting down. Then, when the task handle is dropped, the task itself is
// dropped.
let mut rt = runtime::Builder::new()
let (addr_tx, addr_rx) = mpsc::channel();
// Define a task that just drains the listener
let task = Arc::new(Task::new(async move {
// Create a listener
let mut listener = assert_ok!(TcpListener::bind("").await);
// Send the address
let addr = listener.local_addr().unwrap();
loop {
let _ = listener.accept().await;
rt.enter(|| {
let waker = waker_ref(&task);
let mut cx = Context::from_waker(&waker);
assert_pending!(task.future.lock().unwrap().as_mut().poll(&mut cx));
// Get the address
let addr = addr_rx.recv().unwrap();
// Establish a connection to the acceptor
let _s = TcpStream::connect(&addr).unwrap();
// Force the reactor to turn
rt.block_on(async {});