Lock timeout and reset in case a plugin takes too long to initialize or the lock is incorrectly marked as locked in multiprocess context

platypush/context/__init__.py

@@ -2,6 +2,7 @@ import importlib
 import logging
 
 from threading import Lock
+from contextlib import contextmanager
 
 from ..config import Config
 
@@ -20,6 +21,13 @@ plugins_init_locks = {}
 # Reference to the main application bus
 main_bus = None
 
+@contextmanager
+def acquire_timeout(lock, timeout):
+    acquired = lock.acquire(timeout=timeout)
+    yield acquired
+    if acquired:
+        lock.release()
+
 def register_backends(bus=None, global_scope=False, **kwargs):
     """ Initialize the backend objects based on the configuration and returns
         a name -> backend_instance map.
@@ -98,7 +106,11 @@ def get_plugin(plugin_name, reload=False):
         logger.warning('No such class in {}: {}'.format(plugin_name, cls_name))
         raise RuntimeError(e)
 
-    with plugins_init_locks[plugin_name]:
+    with acquire_timeout(plugins_init_locks[plugin_name], 5) as acquired:
+        if not acquired:
+            logger.warning('Lock expired on get_plugin({}), resetting it'.format(plugin_name))
+            plugins_init_locks[plugin_name] = Lock()
+
         if plugins.get(plugin_name) and not reload:
             return plugins[plugin_name]
         plugins[plugin_name] = plugin_class(**plugin_conf)