1 files changed, 72 insertions, 0 deletions
diff --git a/xpcom/rust/gtest/moz_task/test.rs b/xpcom/rust/gtest/moz_task/test.rs
new file mode 100644
index 0000000000..4261030f47
--- /dev/null
+++ b/xpcom/rust/gtest/moz_task/test.rs
@@ -0,0 +1,72 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use moz_task;
+use std::{
+    future::Future,
+    pin::Pin,
+    sync::atomic::{AtomicBool, Ordering::Relaxed},
+    sync::Arc,
+    task::{Context, Poll, Waker},
+};
+
+/// Demo `Future` to demonstrate executing futures to completion via `nsIEventTarget`.
+struct MyFuture {
+    poll_count: u32,
+    waker: Option<Waker>,
+}
+
+impl Default for MyFuture {
+    fn default() -> Self {
+        Self {
+            poll_count: 0,
+            waker: None,
+        }
+    }
+}
+
+impl Future for MyFuture {
+    type Output = ();
+
+    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<()> {
+        self.poll_count += 1;
+
+        if let Some(waker) = &mut self.waker {
+            if !waker.will_wake(cx.waker()) {
+                *waker = cx.waker().clone();
+            }
+        } else {
+            let waker = cx.waker().clone();
+            self.waker = Some(waker);
+        }
+
+        println!("Poll count = {}", self.poll_count);
+        if self.poll_count > 5 {
+                Poll::Ready(())
+        } else {
+            // Just notify the task that we need to re-polled.
+            if let Some(waker) = &self.waker {
+                waker.wake_by_ref();
+            }
+            Poll::Pending
+        }
+    }
+}
+
+#[no_mangle]
+pub extern "C" fn Rust_Future(it_worked: *mut bool) {
+    let done = Arc::new(AtomicBool::new(false));
+    let done2 = done.clone();
+
+    moz_task::spawn_current_thread(async move {
+        MyFuture::default().await;
+        done.store(true, Relaxed);
+    })
+    .unwrap();
+
+    unsafe {
+        moz_task::gtest_only::spin_event_loop_until(move || done2.load(Relaxed)).unwrap();
+        *it_worked = true;
+    };
+}