diff --git a/futures-util/src/future/future/shared.rs b/futures-util/src/future/future/shared.rs index d7ba49ec44..cc900ba5b6 100644 --- a/futures-util/src/future/future/shared.rs +++ b/futures-util/src/future/future/shared.rs @@ -262,19 +262,20 @@ where let waker = waker_ref(&inner.notifier); let mut cx = Context::from_waker(&waker); - struct Reset<'a>(&'a AtomicUsize); + struct Reset<'a> { + state: &'a AtomicUsize, + did_not_panic: bool, + } impl Drop for Reset<'_> { fn drop(&mut self) { - use std::thread; - - if thread::panicking() { - self.0.store(POISONED, SeqCst); + if !self.did_not_panic { + self.state.store(POISONED, SeqCst); } } } - let _reset = Reset(&inner.notifier.state); + let mut reset = Reset { state: &inner.notifier.state, did_not_panic: false }; let output = { let future = unsafe { @@ -284,12 +285,15 @@ where } }; - match future.poll(&mut cx) { + let poll_result = future.poll(&mut cx); + reset.did_not_panic = true; + + match poll_result { Poll::Pending => { if inner.notifier.state.compare_exchange(POLLING, IDLE, SeqCst, SeqCst).is_ok() { // Success - drop(_reset); + drop(reset); this.inner = Some(inner); return Poll::Pending; } else { @@ -313,7 +317,7 @@ where waker.wake(); } - drop(_reset); // Make borrow checker happy + drop(reset); // Make borrow checker happy drop(wakers_guard); // Safety: We're in the COMPLETE state diff --git a/futures/tests/future_shared.rs b/futures/tests/future_shared.rs index 3ceaebb5c8..20a021bc35 100644 --- a/futures/tests/future_shared.rs +++ b/futures/tests/future_shared.rs @@ -3,6 +3,7 @@ use futures::executor::{block_on, LocalPool}; use futures::future::{self, FutureExt, LocalFutureObj, TryFutureExt}; use futures::task::LocalSpawn; use std::cell::{Cell, RefCell}; +use std::panic::AssertUnwindSafe; use std::rc::Rc; use std::task::Poll; use std::thread; @@ -194,3 +195,34 @@ fn shared_future_that_wakes_itself_until_pending_is_returned() { // has returned pending assert_eq!(block_on(futures::future::join(fut, async { proceed.set(true) })), ((), ())); } + +#[test] +#[should_panic(expected = "inner future panicked during poll")] +fn panic_while_poll() { + let fut = futures::future::poll_fn::(|_cx| panic!("test")).shared(); + + let fut_captured = fut.clone(); + std::panic::catch_unwind(AssertUnwindSafe(|| { + block_on(fut_captured); + })) + .unwrap_err(); + + block_on(fut); +} + +#[test] +#[should_panic(expected = "test_marker")] +fn poll_while_panic() { + struct S; + + impl Drop for S { + fn drop(&mut self) { + let fut = futures::future::ready(1).shared(); + assert_eq!(block_on(fut.clone()), 1); + assert_eq!(block_on(fut), 1); + } + } + + let _s = S {}; + panic!("test_marker"); +}