Merge pull request #232 from mahkoh/jorth/fix-hc-tick

metal: prevent infinite loop in hardware-cursor update

src/tasks/hardware_cursor.rs

@@ -24,6 +24,10 @@ pub async fn handle_hardware_cursor_tick(state: Rc<State>) {
                     log::error!("Could not wait for cursor tick: {}", ErrorFmt(e));
                     break;
                 }
+            } else {
+                if state.hardware_tick_cursor.is_not_empty() {
+                    break;
+                }
             }
             state.refresh_hardware_cursors();
         }

src/utils/queue.rs

@@ -50,6 +50,14 @@ impl<T> AsyncQueue<T> {
         AsyncQueueNonEmpty { queue: self }
     }
 
+    pub fn is_empty(&self) -> bool {
+        unsafe { self.data.get().deref().is_empty() }
+    }
+
+    pub fn is_not_empty(&self) -> bool {
+        !self.is_empty()
+    }
+
     pub fn clear(&self) {
         unsafe {
             mem::take(self.data.get().deref_mut());