More generic handling of closed MTConnection with pending requests

This optimizes the normal case, and handlers can now take specific action
when requests are cancelled because a connection is closed.

neo/client/app.py

@@ -172,9 +172,6 @@ class Application(ThreadedApplication):
                 conn, packet, kw = get(block)
             except Empty:
                 break
-            if packet is None:
-                # connection was closed
-                continue
             block = False
             try:
                 _handlePacket(conn, packet, kw)

neo/lib/dispatcher.py

@@ -19,6 +19,16 @@ from .locking import Lock, Empty
 EMPTY = {}
 NOBODY = []
 
+@apply
+class _ConnectionClosed(object):
+
+    handler_method_name = 'connectionClosed'
+    decode = tuple
+
+    class getId(object):
+        def __eq__(self, other):
+            return True
+
 def giant_lock(func):
     def wrapped(self, *args, **kw):
         self.lock_acquire()
@@ -89,7 +99,7 @@ class Dispatcher:
                 continue
             queue_id = id(queue)
             if queue_id not in notified_set:
-                queue.put((conn, None, None))
+                queue.put((conn, _ConnectionClosed, EMPTY))
                 notified_set.add(queue_id)
             _decrefQueue(queue)
 

neo/lib/handler.py

@@ -16,6 +16,7 @@
 
 import sys
 from . import logging
+from .connection import ConnectionClosed
 from .protocol import (
     NodeStates, Packets, Errors, BackendNotImplemented,
     BrokenNodeDisallowedError, NotReadyError, PacketMalformedError,
@@ -261,3 +262,6 @@ class AnswerBaseHandler(EventHandler):
 
     def acceptIdentification(*args):
         pass
+
+    def connectionClosed(self, conn):
+        raise ConnectionClosed

neo/lib/threaded_app.py

@@ -17,7 +17,6 @@
 import thread, threading, weakref
 from . import logging
 from .app import BaseApplication
-from .connection import ConnectionClosed
 from .debug import register as registerLiveDebugger
 from .dispatcher import Dispatcher
 from .locking import SimpleQueue
@@ -141,14 +140,8 @@ class ThreadedApplication(BaseApplication):
         _handlePacket = self._handlePacket
         while True:
             qconn, qpacket, kw = get(True)
-            if conn is qconn:
-                # check fake packet
-                if qpacket is None:
-                    raise ConnectionClosed
-                if msg_id == qpacket.getId():
+            if conn is qconn and msg_id == qpacket.getId():
                 _handlePacket(qconn, qpacket, kw, handler)
                 break
-            elif qpacket is None:
-                continue
             _handlePacket(qconn, qpacket, kw)
         return self.getHandlerData()