Fix issue with asyncio.Queue which is not thread safe.

gns3server/compute/notification_manager.py

@@ -15,7 +15,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-
+import asyncio
 from contextlib import contextmanager
 from gns3server.utils.notification_queue import NotificationQueue
 
@@ -28,6 +28,7 @@ class NotificationManager:
 
     def __init__(self):
         self._listeners = set()
+        self._loop = asyncio.get_event_loop()
 
     @contextmanager
     def queue(self):
@@ -54,7 +55,7 @@ class NotificationManager:
         """
 
         for listener in self._listeners:
-            listener.put_nowait((action, event, kwargs))
+            self._loop.call_soon_threadsafe(listener.put_nowait, (action, event, kwargs))
 
     @staticmethod
     def reset():