Oct 18, 2019 · Oct 18, 2019 · Oct 18, 2019 · Oct 18, 2019 · Oct 19, 2019 · Oct 19, 2019
diff --git a/src/sync/mutex.rs b/src/sync/mutex.rs
        } else {
            let mut blocked = self.mutex.blocked.lock();

            // Try locking again because it's possible the mutex got unlocked before
            // we acquire the lock of `blocked`.
            let state = self.mutex.state.fetch_or(LOCK | BLOCKED, Ordering::Relaxed);
            if state & LOCK == 0 {
                std::mem::drop(blocked);
                self.deregister_waker(true);
                return Poll::Ready(())
            }

            // Register the current task.
            match self.opt_key {
                None => {
                    if blocked.is_empty() {
                        self.mutex.state.fetch_or(BLOCKED, Ordering::Relaxed);
                    }

                    // Insert a new entry into the list of blocked tasks.
                    let w = cx.waker().clone();
                    let key = blocked.insert(Some(w));
                }
            }

            // Try locking again because it's possible the mutex got unlocked just
            // before the current task was registered as a blocked task.
            if self.mutex.try_lock() {
                std::mem::drop(blocked);
                self.deregister_waker(true);
                Poll::Ready(())
            } else {
                Poll::Pending
            }
            Poll::Pending
        }
    }
 }
Original file line number	Diff line number	Diff line change
Expand Up		@@ -111,13 +111,18 @@ impl<'a> Future for RawLockFuture<'a> {
		} else {
		let mut blocked = self.mutex.blocked.lock();

		// Try locking again because it's possible the mutex got unlocked before
		// we acquire the lock of `blocked`.
		let state = self.mutex.state.fetch_or(LOCK \| BLOCKED, Ordering::Relaxed);
		if state & LOCK == 0 {
		std::mem::drop(blocked);
		self.deregister_waker(true);
		return Poll::Ready(())
		}

		// Register the current task.
		match self.opt_key {
		None => {
		if blocked.is_empty() {
		self.mutex.state.fetch_or(BLOCKED, Ordering::Relaxed);
		}

		// Insert a new entry into the list of blocked tasks.
		let w = cx.waker().clone();
		let key = blocked.insert(Some(w));
Expand All		@@ -134,15 +139,7 @@ impl<'a> Future for RawLockFuture<'a> {
		}
		}

		// Try locking again because it's possible the mutex got unlocked just
		// before the current task was registered as a blocked task.
		if self.mutex.try_lock() {
		std::mem::drop(blocked);
		self.deregister_waker(true);
		Poll::Ready(())
		} else {
		Poll::Pending
		}
		Poll::Pending
		}
		}
		}
Expand Down