Island: Add LockingIslandEventQueueDecorator

monkey/monkey_island/cc/event_queue/__init__.py

@@ -1,3 +1,4 @@
 from .types import IslandEventSubscriber
 from .i_island_event_queue import IIslandEventQueue, IslandEventTopic
 from .pypubsub_island_event_queue import PyPubSubIslandEventQueue
+from .locking_island_event_queue_decorator import LockingIslandEventQueueDecorator

monkey/monkey_island/cc/event_queue/locking_island_event_queue_decorator.py

@@ -0,0 +1,20 @@
+from threading import Lock
+
+from . import IIslandEventQueue, IslandEventSubscriber, IslandEventTopic
+
+
+class LockingIslandEventQueueDecorator(IIslandEventQueue):
+    """
+    Makes an IIslandEventQueue thread-safe by locking publish()
+    """
+
+    def __init__(self, island_event_queue: IIslandEventQueue):
+        self._lock = Lock()
+        self._island_event_queue = island_event_queue
+
+    def subscribe(self, topic: IslandEventTopic, subscriber: IslandEventSubscriber):
+        self._island_event_queue.subscribe(topic, subscriber)
+
+    def publish(self, topic: IslandEventTopic, **kwargs):
+        with self._lock:
+            self._island_event_queue.publish(topic, **kwargs)