1. Eliminate putrequest(): only used in asynccall(), merge it there.

2. Add additional debugging statements and enhance others.
3. Clarify comments.
4. Move SocketIO.nextseq class attribute to beginning of class.

Lib/idlelib/rpc.py

@@ -90,6 +90,8 @@ objecttable = {}
 
 class SocketIO:
 
+    nextseq = 0
+
     def __init__(self, sock, objtable=None, debugging=None):
         self.mainthread = threading.currentThread()
         if debugging is not None:
@@ -174,19 +176,21 @@ class SocketIO:
             return ("EXCEPTION", (mod, name, args, tb))
 
     def remotecall(self, oid, methodname, args, kwargs):
-        self.debug("remotecall:")
+        self.debug("calling asynccall via remotecall")
         seq = self.asynccall(oid, methodname, args, kwargs)
         return self.asyncreturn(seq)
 
     def asynccall(self, oid, methodname, args, kwargs):
         request = ("call", (oid, methodname, args, kwargs))
-        seq = self.putrequest(request)
-        self.debug(("asyncall:%d:" % seq), oid, methodname, args, kwargs)
+        seq = self.newseq()
+        self.debug(("asynccall:%d:" % seq), oid, methodname, args, kwargs)
+        self.putmessage((seq, request))
         return seq
 
     def asyncreturn(self, seq):
+        self.debug("asyncreturn:%d:call getresponse(): " % seq)
         response = self.getresponse(seq)
-        self.debug(("asyncreturn:%d:" % seq), response)
+        self.debug(("asyncreturn:%d:response: " % seq), response)
         return self.decoderesponse(response)
 
     def decoderesponse(self, response):
@@ -194,7 +198,7 @@ class SocketIO:
         if how == "OK":
             return what
         if how == "EXCEPTION":
-            self.debug("decoderesponse: Internal EXCEPTION:", what)
+            self.debug("decoderesponse: EXCEPTION:", what)
             mod, name, args, tb = what
             self.traceback = tb
             if mod: # not string exception
@@ -220,6 +224,12 @@ class SocketIO:
         raise SystemError, (how, what)
 
     def mainloop(self):
+        """Listen on socket until I/O not ready or EOF
+
+        pollpacket() will loop looking for seq number None, which never
+        comes.  The loop will exit when self.ioready() returns 0.
+
+        """
         try:
             self.getresponse(None)
         except EOFError:
@@ -242,8 +252,10 @@ class SocketIO:
         return obj
 
     def _getresponse(self, myseq):
+        self.debug("_getresponse:myseq:", myseq)
         if threading.currentThread() is self.mainthread:
-            # Main thread: does all reading of requests and responses
+            # Main thread: does all reading of requests or responses
+            # Loop here until there is message traffic on the socket
             while 1:
                 response = self.pollresponse(myseq, None)
                 if response is not None:
@@ -259,21 +271,14 @@ class SocketIO:
             del self.responses[myseq]
             del self.cvars[myseq]
             self.statelock.release()
-            return response
-
-    def putrequest(self, request):
-        seq = self.newseq()
-        self.putmessage((seq, request))
-        return seq
-
-    nextseq = 0
+            return response  # might be None
 
     def newseq(self):
         self.nextseq = seq = self.nextseq + 2
         return seq
 
     def putmessage(self, message):
-        ##self.debug("putmessage: ", message)
+        self.debug("putmessage:%d:" % message[0])
         try:
             s = pickle.dumps(message)
         except:
@@ -337,16 +342,28 @@ class SocketIO:
         return message
 
     def pollresponse(self, myseq, wait=0.0):
-        # Loop while there's no more buffered input or until specific response
+        """Handle messages received on the socket.
+
+        Some messages received may be asynchronous 'call' commands, and
+        some may be responses intended for other threads.
+
+        Loop until message with myseq sequence number is received.  Save others
+        in self.responses and notify the owning thread, except that 'call'
+        commands are handed off to localcall() and the response sent back
+        across the link with the appropriate sequence number.
+
+        """
         while 1:
             message = self.pollmessage(wait)
-            if message is None:
+            if message is None:  # socket not ready
                 return None
             wait = 0.0
             seq, resq = message
+            self.debug("pollresponse:%d:myseq:%s" % (seq, myseq))
             if resq[0] == "call":
-                self.debug("call_localcall:%d:" % seq)
+                self.debug("pollresponse:%d:call_localcall" % seq)
                 response = self.localcall(resq)
+                self.debug("pollresponse:%d:response:%s" % (seq, response))
                 self.putmessage((seq, response))
                 continue
             elif seq == myseq:
@@ -410,7 +427,7 @@ class RPCClient(SocketIO):
     def accept(self):
         working_sock, address = self.listening_sock.accept()
         if self.debugging:
-            print>>sys.__stderr__, "** Connection request from ", address
+            print>>sys.__stderr__, "****** Connection request from ", address
         if address[0] == '127.0.0.1':
             SocketIO.__init__(self, working_sock)
         else: