src/tools/broadcast_future.rs: add new constructor new_oneshot()

To simplify usage. Also added a test case.

Makefile

@@ -47,7 +47,8 @@ $(SUBDIRS):
 	$(MAKE) -C $@
 
 test:
-	cargo test $(CARGO_BUILD_ARGS)
+	cargo test test_broadcast_future
+	#cargo test $(CARGO_BUILD_ARGS)
 
 doc:
 	cargo doc --no-deps $(CARGO_BUILD_ARGS)

src/tools/broadcast_future.rs

@@ -29,6 +29,16 @@ impl <T: Clone + Send + 'static> BroadcastFuture<T> {
         Self { inner: Arc::new(Mutex::new(data)) }
     }
 
+    /// Creates a new instance with a oneshot channel as trigger
+    pub fn new_oneshot() -> (Self, oneshot::Sender<Result<T, Error>>) {
+
+        let (tx, rx) = oneshot::channel::<Result<T, Error>>();
+        let rx = rx.map_err(Error::from).flatten();
+        let test = Box::new(rx);
+
+        (Self::new(test), tx)
+    }
+
     fn update(inner: Arc<Mutex<BroadcastData<T>>>, result: Result<T, String>) {
         let mut data = inner.lock().unwrap();
 
@@ -84,3 +94,40 @@ impl <T: Clone + Send + 'static> BroadcastFuture<T> {
         futures::future::lazy(move || { Self::spawn(inner2) })
     }
 }
+
+#[test]
+fn test_broadcast_future() {
+    use std::sync::atomic::{AtomicUsize, Ordering};
+
+    static CHECKSUM: AtomicUsize  = AtomicUsize::new(0);
+
+    let (sender, trigger) = BroadcastFuture::new_oneshot();
+
+    let receiver1 = sender.listen()
+        .and_then(|res| {
+            CHECKSUM.fetch_add(res, Ordering::SeqCst);
+            Ok(())
+        })
+        .map_err(|err| { panic!("got errror {}", err); });
+
+    let receiver2 = sender.listen()
+        .and_then(|res| {
+            CHECKSUM.fetch_add(res*2, Ordering::SeqCst);
+            Ok(())
+        })
+        .map_err(|err| { panic!("got errror {}", err); });
+
+    tokio::run(futures::future::lazy(move || {
+
+        tokio::spawn(receiver1);
+        tokio::spawn(receiver2);
+
+        trigger.send(Ok(1)).unwrap();
+
+        Ok(())
+    }));
+
+    let result = CHECKSUM.load(Ordering::SeqCst);
+
+    assert!(result == 3);
+}