Bug 1463494: delete the sensor observerlist array in a deferred manne…

…r r=froyd
EtlerEdelgard · May 24, 2018 · 5cfa62f · 5cfa62f
1 parent 5cf7331
commit 5cfa62f
Showing 1 changed file with 11 additions and 2 deletions.
diff --git a/hal/Hal.cpp b/hal/Hal.cpp
@@ -438,14 +438,23 @@ UnregisterSensorObserver(SensorType aSensor, ISensorObserver *aObserver) {
   }
   DisableSensorNotifications(aSensor);
 
-  // Destroy sSensorObservers only if all observer lists are empty.
   for (int i = 0; i < NUM_SENSOR_TYPE; i++) {
     if (gSensorObservers[i].Length() > 0) {
       return;
     }
   }
-  delete [] gSensorObservers;
+
+  // We want to destroy gSensorObservers if all observer lists are
+  // empty, but we have to defer the deallocation via a runnable to
+  // mainthread (since we may be inside NotifySensorChange()/Broadcast()
+  // when it calls UnregisterSensorObserver()).
+  SensorObserverList* sensorlists = gSensorObservers;
   gSensorObservers = nullptr;
+
+  NS_DispatchToMainThread(NS_NewRunnableFunction("UnregisterSensorObserver",
+                                                 [sensorlists]() -> void {
+    delete [] sensorlists;
+  }));
 }
 
 void