| // aux-build:arc_wake.rs |
| // edition:2018 |
| // run-pass |
| |
| #![allow(unused_variables)] |
| |
| // Test that the drop order for parameters in a fn and async fn matches up. Also test that |
| // parameters (used or unused) are not dropped until the async fn completes execution. |
| // See also #54716. |
| |
| extern crate arc_wake; |
| |
| use arc_wake::ArcWake; |
| use std::cell::RefCell; |
| use std::future::Future; |
| use std::sync::Arc; |
| use std::rc::Rc; |
| use std::task::Context; |
| |
| struct EmptyWaker; |
| |
| impl ArcWake for EmptyWaker { |
| fn wake(self: Arc<Self>) {} |
| } |
| |
| #[derive(Debug, Eq, PartialEq)] |
| enum DropOrder { |
| Function, |
| Val(&'static str), |
| } |
| |
| type DropOrderListPtr = Rc<RefCell<Vec<DropOrder>>>; |
| |
| struct D(&'static str, DropOrderListPtr); |
| |
| impl Drop for D { |
| fn drop(&mut self) { |
| self.1.borrow_mut().push(DropOrder::Val(self.0)); |
| } |
| } |
| |
| /// Check drop order of temporary "temp" as compared to x, y, and z. |
| /// |
| /// Expected order: |
| /// - z |
| /// - temp |
| /// - y |
| /// - x |
| async fn foo_async(x: D, _y: D) { |
| let l = x.1.clone(); |
| let z = D("z", l.clone()); |
| l.borrow_mut().push(DropOrder::Function); |
| helper_async(&D("temp", l)).await |
| } |
| |
| async fn helper_async(v: &D) { } |
| |
| fn foo_sync(x: D, _y: D) { |
| let l = x.1.clone(); |
| let z = D("z", l.clone()); |
| l.borrow_mut().push(DropOrder::Function); |
| helper_sync(&D("temp", l)) |
| } |
| |
| fn helper_sync(v: &D) { } |
| |
| fn assert_drop_order_after_poll<Fut: Future<Output = ()>>( |
| f: impl FnOnce(DropOrderListPtr) -> Fut, |
| g: impl FnOnce(DropOrderListPtr), |
| ) { |
| let empty = Arc::new(EmptyWaker); |
| let waker = ArcWake::into_waker(empty); |
| let mut cx = Context::from_waker(&waker); |
| |
| let actual_order = Rc::new(RefCell::new(Vec::new())); |
| let mut fut = Box::pin(f(actual_order.clone())); |
| let r = fut.as_mut().poll(&mut cx); |
| |
| assert!(match r { |
| std::task::Poll::Ready(()) => true, |
| _ => false, |
| }); |
| |
| let expected_order = Rc::new(RefCell::new(Vec::new())); |
| g(expected_order.clone()); |
| |
| assert_eq!(*actual_order.borrow(), *expected_order.borrow()); |
| } |
| |
| fn main() { |
| // Free functions (see doc comment on function for what it tests). |
| assert_drop_order_after_poll(|l| foo_async(D("x", l.clone()), D("_y", l.clone())), |
| |l| foo_sync(D("x", l.clone()), D("_y", l.clone()))); |
| } |