async drop tests for box

1 files changed, 109 insertions, 0 deletions

diff --git a/tests/ui/async-await/async-drop/async-drop-box.rs b/tests/ui/async-await/async-drop/async-drop-box.rs
new file mode 100644
index 00000000000..0a6ed412863
--- /dev/null
+++ b/tests/ui/async-await/async-drop/async-drop-box.rs
@@ -0,0 +1,109 @@
+//@ run-pass
+//@ check-run-results
+// struct `Foo` has both sync and async drop.
+// `Foo` is always inside `Box`
+// Sync version is called in sync context, async version is called in async function.
+
+//@ known-bug: #143658
+// async version is never actually called
+
+#![feature(async_drop)]
+#![allow(incomplete_features)]
+
+use std::mem::ManuallyDrop;
+
+//@ edition: 2021
+
+#[inline(never)]
+fn myprintln(msg: &str, my_resource_handle: usize) {
+    println!("{} : {}", msg, my_resource_handle);
+}
+
+use std::{
+    future::{Future, async_drop_in_place, AsyncDrop},
+    pin::{pin, Pin},
+    sync::{mpsc, Arc},
+    task::{Context, Poll, Wake, Waker},
+};
+
+struct Foo {
+    my_resource_handle: usize,
+}
+
+impl Foo {
+    fn new(my_resource_handle: usize) -> Self {
+        let out = Foo {
+            my_resource_handle,
+        };
+        myprintln("Foo::new()", my_resource_handle);
+        out
+    }
+}
+
+impl Drop for Foo {
+    fn drop(&mut self) {
+        myprintln("Foo::drop()", self.my_resource_handle);
+    }
+}
+
+impl AsyncDrop for Foo {
+    async fn drop(self: Pin<&mut Self>) {
+        myprintln("Foo::async drop()", self.my_resource_handle);
+    }
+}
+
+fn main() {
+    {
+        let _ = Box::new(Foo::new(7));
+    }
+    println!("Middle");
+    block_on(bar(10));
+    println!("Done")
+}
+
+async fn bar(ident_base: usize) {
+    let _first = Box::new(Foo::new(ident_base));
+}
+
+fn block_on<F>(fut_unpin: F) -> F::Output
+where
+    F: Future,
+{
+    let mut fut_pin = pin!(ManuallyDrop::new(fut_unpin));
+    let mut fut: Pin<&mut F> = unsafe {
+        Pin::map_unchecked_mut(fut_pin.as_mut(), |x| &mut **x)
+    };
+    let (waker, rx) = simple_waker();
+    let mut context = Context::from_waker(&waker);
+    let rv = loop {
+        match fut.as_mut().poll(&mut context) {
+            Poll::Ready(out) => break out,
+            // expect wake in polls
+            Poll::Pending => rx.try_recv().unwrap(),
+        }
+    };
+    let drop_fut_unpin = unsafe { async_drop_in_place(fut.get_unchecked_mut()) };
+    let mut drop_fut: Pin<&mut _> = pin!(drop_fut_unpin);
+    loop {
+        match drop_fut.as_mut().poll(&mut context) {
+            Poll::Ready(()) => break,
+            Poll::Pending => rx.try_recv().unwrap(),
+        }
+    }
+    rv
+}
+
+fn simple_waker() -> (Waker, mpsc::Receiver<()>) {
+    struct SimpleWaker {
+        tx: std::sync::mpsc::Sender<()>,
+    }
+
+    impl Wake for SimpleWaker {
+        fn wake(self: Arc<Self>) {
+            self.tx.send(()).unwrap();
+        }
+    }
+
+    let (tx, rx) = mpsc::channel();
+    (Waker::from(Arc::new(SimpleWaker { tx })), rx)
+}