matthauck · November 6, 2017 07:13 · Nov 6, 2017
diff --git a/async_poller.rs b/async_poller.rs
@@ -0,0 +1,47 @@
+use std::sync::Arc;
+use std::sync::mpsc::{SyncSender, sync_channel};
+use std::thread;
+
+use futures::{self, Async, Future};
+use futures::executor::{Notify, Spawn};
+
+pub type VoidFuture = Box<Future<Item = (), Error = ()>>;
+
+pub fn consume(mut fut: VoidFuture) {
+    let (tx, rx) = sync_channel(1);
+    let mut spawned = futures::executor::spawn(fut);
+    let notifier = Arc::new(AsyncNotifier { sender: Arc::new(tx) });
+
+    loop {
+        match spawned.poll_future_notify(&notifier, 0) {
+            Ok(Async::Ready(_)) => {
+                debug!("Async future finished");
+                break;
+            }
+            Ok(Async::NotReady) => {
+                debug!("Async future not ready");
+                if let Err(_) = rx.recv() {
+                    error!("Error waiting for future. Aborting");
+                    break;
+                }
+                debug!("Async future woke up");
+            }
+            Err(_) => {
+                error!("Error polling async future.");
+                break;
+            }
+        }
+    }
+}
+
+#[derive(Clone)]
+struct AsyncNotifier {
+    sender: Arc<SyncSender<()>>,
+}
+
+impl Notify for AsyncNotifier {
+    fn notify(&self, id: usize) {
+        debug!("AsyncNotifier received notification");
+        let _ = self.sender.send(());
+    }
+}