1 // Test that values are not leaked in async functions, even in the cases where:
2 // * Dropping one of the values panics while running the future.
3 // * The future is dropped at one of its suspend points.
4 // * Dropping one of the values panics while dropping the future.
8 // ignore-wasm32-bare compiled with panic=abort by default
10 #![allow(unused_assignments)]
11 #![allow(unused_variables)]
12 #![feature(slice_patterns)]
13 #![feature(async_await)]
16 cell::{Cell, RefCell},
23 task::{Context, Poll, RawWaker, RawWakerVTable, Waker},
27 struct InjectedFailure;
34 impl<T: Unpin> Future for Defer<T> {
36 fn poll(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll<Self::Output> {
38 Poll::Ready(self.value.take().unwrap())
46 /// Allocator tracks the creation and destruction of `Ptr`s.
47 /// The `failing_op`-th operation will panic.
49 data: RefCell<Vec<bool>>,
54 impl panic::UnwindSafe for Allocator {}
55 impl panic::RefUnwindSafe for Allocator {}
57 impl Drop for Allocator {
59 let data = self.data.borrow();
60 if data.iter().any(|d| *d) {
61 panic!("missing free: {:?}", data);
67 fn new(failing_op: usize) -> Self {
68 Allocator { failing_op, cur_ops: Cell::new(0), data: RefCell::new(vec![]) }
70 fn alloc(&self) -> impl Future<Output = Ptr<'_>> + '_ {
71 self.fallible_operation();
73 let mut data = self.data.borrow_mut();
75 let addr = data.len();
77 Defer { ready: false, value: Some(Ptr(addr, self)) }
79 fn fallible_operation(&self) {
80 self.cur_ops.set(self.cur_ops.get() + 1);
82 if self.cur_ops.get() == self.failing_op {
83 panic!(InjectedFailure);
88 // Type that tracks whether it was dropped and can panic when it's created or
90 struct Ptr<'a>(usize, &'a Allocator);
91 impl<'a> Drop for Ptr<'a> {
93 match self.1.data.borrow_mut()[self.0] {
94 false => panic!("double free at index {:?}", self.0),
95 ref mut d => *d = false,
98 self.1.fallible_operation();
102 async fn dynamic_init(a: Rc<Allocator>, c: bool) {
105 _x = Some(a.alloc().await);
109 async fn dynamic_drop(a: Rc<Allocator>, c: bool) {
110 let x = a.alloc().await;
118 struct TwoPtrs<'a>(Ptr<'a>, Ptr<'a>);
119 async fn struct_dynamic_drop(a: Rc<Allocator>, c0: bool, c1: bool, c: bool) {
123 if (c0 && i == 0) || (c1 && i == 1) {
124 x = (a.alloc().await, a.alloc().await, a.alloc().await);
125 y = TwoPtrs(a.alloc().await, a.alloc().await);
136 async fn field_assignment(a: Rc<Allocator>, c0: bool) {
137 let mut x = (TwoPtrs(a.alloc().await, a.alloc().await), a.alloc().await);
139 x.1 = a.alloc().await;
140 x.1 = a.alloc().await;
150 async fn assignment(a: Rc<Allocator>, c0: bool, c1: bool) {
151 let mut _v = a.alloc().await;
152 let mut _w = a.alloc().await;
158 _w = a.alloc().await;
162 async fn array_simple(a: Rc<Allocator>) {
163 let _x = [a.alloc().await, a.alloc().await, a.alloc().await, a.alloc().await];
166 async fn vec_simple(a: Rc<Allocator>) {
167 let _x = vec![a.alloc().await, a.alloc().await, a.alloc().await, a.alloc().await];
170 async fn mixed_drop_and_nondrop(a: Rc<Allocator>) {
171 // check that destructor panics handle drop
172 // and non-drop blocks in the same scope correctly.
174 // Surprisingly enough, this used to not work.
181 #[allow(unreachable_code)]
182 async fn vec_unreachable(a: Rc<Allocator>) {
183 let _x = vec![a.alloc().await, a.alloc().await, a.alloc().await, return];
186 async fn slice_pattern_one_of(a: Rc<Allocator>, i: usize) {
187 let array = [a.alloc().await, a.alloc().await, a.alloc().await, a.alloc().await];
194 let [_, a, ..] = array;
198 let [_, _, a, _] = array;
202 let [_, _, _, a] = array;
205 _ => panic!("unmatched"),
210 async fn subslice_pattern_from_end_with_drop(a: Rc<Allocator>, arg: bool, arg2: bool) {
211 let arr = [a.alloc().await, a.alloc().await, a.alloc().await, a.alloc().await, a.alloc().await];
218 let [.., _x, _] = arr;
220 let [_, _y @ ..] = arr;
225 async fn subslice_pattern_reassign(a: Rc<Allocator>) {
226 let mut ar = [a.alloc().await, a.alloc().await, a.alloc().await];
228 ar = [a.alloc().await, a.alloc().await, a.alloc().await];
229 let [_, _y @ ..] = ar;
233 fn run_test<F, G>(cx: &mut Context<'_>, ref f: F)
235 F: Fn(Rc<Allocator>) -> G,
236 G: Future<Output = ()>,
239 // Run without any panics to find which operations happen after the
240 // penultimate `poll`.
241 let first_alloc = Rc::new(Allocator::new(usize::MAX));
242 let mut fut = Box::pin(f(first_alloc.clone()));
243 let mut ops_before_last_poll = 0;
244 let mut completed = false;
246 ops_before_last_poll = first_alloc.cur_ops.get();
247 if let Poll::Ready(()) = fut.as_mut().poll(cx) {
253 // Start at `ops_before_last_poll` so that we will always be able to
254 // `poll` the expected number of times.
255 for failing_op in ops_before_last_poll..first_alloc.cur_ops.get() {
256 let alloc = Rc::new(Allocator::new(failing_op + 1));
259 let result = panic::catch_unwind(panic::AssertUnwindSafe(move || {
260 let mut fut = Box::pin(f(alloc));
262 let _ = fut.as_mut().poll(cx);
267 Ok(..) => panic!("test executed more ops on first call"),
269 if e.downcast_ref::<InjectedFailure>().is_none() {
270 panic::resume_unwind(e);
282 fn clone_waker(data: *const ()) -> RawWaker {
283 RawWaker::new(data, &RawWakerVTable::new(clone_waker, drop, drop, drop))
287 let waker = unsafe { Waker::from_raw(clone_waker(ptr::null())) };
288 let context = &mut Context::from_waker(&waker);
290 run_test(context, |a| dynamic_init(a, false));
291 run_test(context, |a| dynamic_init(a, true));
292 run_test(context, |a| dynamic_drop(a, false));
293 run_test(context, |a| dynamic_drop(a, true));
295 run_test(context, |a| assignment(a, false, false));
296 run_test(context, |a| assignment(a, false, true));
297 run_test(context, |a| assignment(a, true, false));
298 run_test(context, |a| assignment(a, true, true));
300 run_test(context, |a| array_simple(a));
301 run_test(context, |a| vec_simple(a));
302 run_test(context, |a| vec_unreachable(a));
304 run_test(context, |a| struct_dynamic_drop(a, false, false, false));
305 run_test(context, |a| struct_dynamic_drop(a, false, false, true));
306 run_test(context, |a| struct_dynamic_drop(a, false, true, false));
307 run_test(context, |a| struct_dynamic_drop(a, false, true, true));
308 run_test(context, |a| struct_dynamic_drop(a, true, false, false));
309 run_test(context, |a| struct_dynamic_drop(a, true, false, true));
310 run_test(context, |a| struct_dynamic_drop(a, true, true, false));
311 run_test(context, |a| struct_dynamic_drop(a, true, true, true));
313 run_test(context, |a| field_assignment(a, false));
314 run_test(context, |a| field_assignment(a, true));
316 run_test(context, |a| mixed_drop_and_nondrop(a));
318 run_test(context, |a| slice_pattern_one_of(a, 0));
319 run_test(context, |a| slice_pattern_one_of(a, 1));
320 run_test(context, |a| slice_pattern_one_of(a, 2));
321 run_test(context, |a| slice_pattern_one_of(a, 3));
323 run_test(context, |a| subslice_pattern_from_end_with_drop(a, true, true));
324 run_test(context, |a| subslice_pattern_from_end_with_drop(a, true, false));
325 run_test(context, |a| subslice_pattern_from_end_with_drop(a, false, true));
326 run_test(context, |a| subslice_pattern_from_end_with_drop(a, false, false));
327 run_test(context, |a| subslice_pattern_reassign(a));