improve reliability of hang monitor tests

components/background_hang_monitor/background_hang_monitor.rs

@@ -33,17 +33,19 @@ impl HangMonitorRegister {
         monitoring_enabled: bool,
     ) -> Box<dyn BackgroundHangMonitorRegister> {
         let (sender, port) = unbounded();
-        let _ = thread::Builder::new().spawn(move || {
+        let _ = thread::Builder::new()
-            let mut monitor = BackgroundHangMonitorWorker::new(
+            .spawn(move || {
-                constellation_chan,
+                let mut monitor = BackgroundHangMonitorWorker::new(
-                control_port,
+                    constellation_chan,
-                port,
+                    control_port,
-                monitoring_enabled,
+                    port,
-            );
+                    monitoring_enabled,
-            while monitor.run() {
+                );
-                // Monitoring until all senders have been dropped...
+                while monitor.run() {
-            }
+                    // Monitoring until all senders have been dropped...
-        });
+                }
+            })
+            .expect("Couldn't start BHM worker.");
         Box::new(HangMonitorRegister {
             sender,
             monitoring_enabled,

components/background_hang_monitor/tests/hang_monitor_tests.rs

@@ -197,12 +197,18 @@ fn test_hang_monitoring_exit_signal() {
     );
 
     let (exit_sender, exit_receiver) = ipc::channel().expect("Failed to create IPC channel!");
+
     // Send the exit message.
-    let _ = control_sender.send(BackgroundHangMonitorControlMsg::Exit(exit_sender));
+    if control_sender
+        .send(BackgroundHangMonitorControlMsg::Exit(exit_sender))
+        .is_ok()
+    {
+        // Assert we receive a confirmation back.
+        assert!(exit_receiver.recv().is_ok());
 
-    // Assert we receive a confirmation back.
+        // Assert we get the exit signal.
-    assert!(exit_receiver.recv().is_ok());
+        while !closing.load(Ordering::SeqCst) {
-
+            thread::sleep(Duration::from_millis(10));
-    // Assert we get the exit signal.
+        }
-    while !closing.load(Ordering::SeqCst) {}
+    }
 }