Merge pull request #116 from simonklb/listener-thread-exception-handler

Add listener thread exception handler

matrix_client/client.py

@@ -321,12 +321,15 @@ def listen_for_events(self, timeout_ms=30000):
         """
         self._sync(timeout_ms)
 
-    def listen_forever(self, timeout_ms=30000):
+    def listen_forever(self, timeout_ms=30000, exception_handler=None):
         """ Keep listening for events forever.
 
         Args:
             timeout_ms (int): How long to poll the Home Server for before
                retrying.
+            exception_handler (func(exception)): Optional exception handler
+               function which can be used to handle exceptions in the caller
+               thread.
         """
         bad_sync_timeout = 5000
         self.should_listen = True
@@ -346,16 +349,24 @@ def listen_forever(self, timeout_ms=30000):
                     raise e
             except Exception as e:
                 logger.exception("Exception thrown during sync")
+                if exception_handler is not None:
+                    exception_handler(e)
+                else:
+                    raise
 
-    def start_listener_thread(self, timeout_ms=30000):
+    def start_listener_thread(self, timeout_ms=30000, exception_handler=None):
         """ Start a listener thread to listen for events in the background.
 
         Args:
             timeout (int): How long to poll the Home Server for before
                retrying.
+            exception_handler (func(exception)): Optional exception handler
+               function which can be used to handle exceptions in the caller
+               thread.
         """
         try:
-            thread = Thread(target=self.listen_forever, args=(timeout_ms, ))
+            thread = Thread(target=self.listen_forever,
+                            args=(timeout_ms, exception_handler))
             thread.daemon = True
             self.sync_thread = thread
             self.should_listen = True