Make it easier to debug cases where conn.getConnector() returns None.

This happens from time to time in tests, most probably during shutdown as
it doesn't make tests fail. This will help tracking this bug down.

git-svn-id: https://svn.erp5.org/repos/neo/trunk@1666 71dcc9de-d417-0410-9af5-da40c76e7ee4

neo/connection.py

@@ -26,6 +26,8 @@ from neo.connector import ConnectorException, ConnectorTryAgainException, \
 from neo.util import dump
 from neo.logger import PACKET_LOGGER
 
+from neo import attributeTracker
+
 def not_closed(func):
     def decorator(self, *args, **kw):
         if self.connector is None:
@@ -134,6 +136,14 @@ class BaseConnection(object):
     def hasPendingMessages(self):
         return False
 
+    def whoSetConnector(self):
+        """
+          Debugging method: call this method to know who set the current
+          connector value.
+        """
+        return attributeTracker.whoSet(self, 'connector')
+
+attributeTracker.track(BaseConnection)
 
 class ListeningConnection(BaseConnection):
     """A listen connection."""

neo/event.py

@@ -232,25 +232,33 @@ class EpollEventManager(object):
             pass
 
     def addReader(self, conn):
-        fd = conn.getConnector().getDescriptor()
+        connector = conn.getConnector()
+        assert connector is not None, conn.whoSetConnector()
+        fd = connector.getDescriptor()
         if fd not in self.reader_set:
             self.reader_set.add(fd)
             self.epoll.modify(fd, 1, fd in self.writer_set)
 
     def removeReader(self, conn):
-        fd = conn.getConnector().getDescriptor()
+        connector = conn.getConnector()
+        assert connector is not None, conn.whoSetConnector()
+        fd = connector.getDescriptor()
         if fd in self.reader_set:
             self.reader_set.remove(fd)
             self.epoll.modify(fd, 0, fd in self.writer_set)
 
     def addWriter(self, conn):
-        fd = conn.getConnector().getDescriptor()
+        connector = conn.getConnector()
+        assert connector is not None, conn.whoSetConnector()
+        fd = connector.getDescriptor()
         if fd not in self.writer_set:
             self.writer_set.add(fd)
             self.epoll.modify(fd, fd in self.reader_set, 1)
 
     def removeWriter(self, conn):
-        fd = conn.getConnector().getDescriptor()
+        connector = conn.getConnector()
+        assert connector is not None, conn.whoSetConnector()
+        fd = connector.getDescriptor()
         if fd in self.writer_set:
             self.writer_set.remove(fd)
             self.epoll.modify(fd, fd in self.reader_set, 0)