Add _handle_keepalive_exception plugin hook (fix #49)

Author: vmalloc

backslash/contrib/keepalive_thread.py

@@ -1,17 +1,19 @@
-import threading
 import logbook
+import sys
+import threading
 
 _logger = logbook.Logger(__name__)
 
 
 class KeepaliveThread(threading.Thread):
 
-    def __init__(self, client, session, interval):
+    def __init__(self, client, session, interval, error_callback=None):
         super(KeepaliveThread, self).__init__()
         self._client = client
         self._session = session
         self._interval = interval / 2.0
         self._stopped_event = threading.Event()
+        self._error_callback = error_callback
         self.daemon = True
 
     def run(self):
@@ -22,6 +24,8 @@ def run(self):
                 self._session.send_keepalive()
         except Exception: #pylint: disable=broad-except
             _logger.error('Quitting keepalive thread due to exception', exc_info=True)
+            if self._error_callback is not None:
+                self._error_callback(sys.exc_info())
             raise
         finally:
             _logger.debug('Backslash keepalive thread terminated')

backslash/contrib/slash_plugin.py

@@ -88,6 +88,9 @@ def webapp_url(self):
     def _handle_exception(self, exc_info):
         pass
 
+    def _handle_keepalive_exception(self, exc_info):
+        pass
+
     def _get_backslash_url(self):
         return self._url
 
@@ -145,7 +148,7 @@ def session_start(self):
             self.client.api.call.add_label(session_id=self.session.id, label=label)
 
         if self._keepalive_interval is not None:
-            self._keepalive_thread = KeepaliveThread(self.client, self.session, self._keepalive_interval)
+            self._keepalive_thread = KeepaliveThread(self.client, self.session, self._keepalive_interval, error_callback=self._handle_keepalive_exception)
             self._keepalive_thread.start()
 
     def _get_initial_session_metadata(self):