use a queue to manage received message in order not to lose them

git-svn-id: https://svn.erp5.org/repos/neo/branches/prototype3@83 71dcc9de-d417-0410-9af5-da40c76e7ee4

neo/client/dispatcher.py

 from threading import Thread
-from Queue import Empty
+from Queue import Empty, Queue
 
 from neo.protocol import PING, Packet
 
+import logging
+
 class Dispatcher(Thread):
     """Dispatcher class use to redirect request to thread."""
 
@@ -11,6 +13,8 @@ class Dispatcher(Thread):
         self._message_queue = message_queue
         self._request_queue = request_queue
         self.em = em
+        # Queue of received packet that have to be processed
+        self.message = Queue()
         # This dict is used to associate conn/message id to client thread queue
         # and thus redispatch answer to the original thread
         self.message_table = {}
@@ -18,25 +22,31 @@ class Dispatcher(Thread):
     def run(self):
         while 1:
             # First check if we receive any new message from other node
-            self.message = None
             m = None
+            try:
                 self.em.poll(1)
-            if self.message is not None:
-                conn, packet = self.message
-                # now send message to waiting thread
+            except KeyError:
+                # This happen when there is no connection
+                logging.error('Dispatcher, run, poll returned a KeyError')
+            while 1:
+                try:
+                    conn, packet =  self.message.get_nowait()
+                except Empty:
+                    break
+                # Send message to waiting thread
                 key = "%s-%s" %(conn.getUUID(),packet.getId())
                 if self.message_table.has_key(key):
                     tmp_q = self.message_table.pop(key)
-                    tmp_q.put(self.message, True)
+                    tmp_q.put((conn, packet), True)
                 else:
-                    conn, packet = self.message
+                    #conn, packet = self.message
                     method_type = packet.getType()
                     if method_type == PING:
                         # must answer with no delay
                         conn.addPacket(Packet().pong(packet.getId()))
                     else:
                         # put message in request queue
-                        self._request_queue.put(self.message, True)
+                        self._request_queue.put((conn, packet), True)
 
             # Then check if a client ask me to send a message
             try:
@@ -44,10 +54,11 @@ class Dispatcher(Thread):
                 if m is not None:
                     tmp_q, msg_id, conn, p = m
                     conn.addPacket(p)
-                    conn.expectMessage(msg_id)
                     if tmp_q is not None:
+                        # We expect an answer
                         key = "%s-%s" %(conn.getUUID(),msg_id)
                         self.message_table[key] = tmp_q
+                        conn.expectMessage(msg_id)
             except Empty:
                 continue