--- a/channels.py	Sun Apr 19 22:16:11 2009 -0700
+++ b/channels.py	Sun Apr 19 23:06:30 2009 -0700
@@ -1,4 +1,4 @@
-import weakref
+import cosocket
 
 _channels = {}
 
@@ -9,19 +9,33 @@
 
     def execute(self, dispatcher):
         if self.channel_name in _channels:
-            for weakling in _channels[self.channel_name].itervaluerefs():
-                receiver = weakling()
-                if receiver:
-                    receiver.continue_from_yield(self.message)
+            receivers = _channels[self.channel_name].values()
             del _channels[self.channel_name]
+            for receiver in receivers:
+                receiver.continue_from_yield(self.message)
         dispatcher.continue_from_yield()
 
-class until_message_received(object):
+class _until_message_received(object):
     def __init__(self, channel_name):
         self.channel_name = channel_name
+        self._fd = None
 
     def execute(self, dispatcher):
         if self.channel_name not in _channels:
-            _channels[self.channel_name] = weakref.WeakValueDictionary()
-        fd = dispatcher.socket.fileno()
-        _channels[self.channel_name][fd] = dispatcher
+            _channels[self.channel_name] = {}
+        self._fd = dispatcher.socket.fileno()
+        _channels[self.channel_name][self._fd] = dispatcher
+
+    def abort(self):
+        if (self.channel_name in _channels and
+            self._fd in _channels[self.channel_name]):
+            del _channels[self.channel_name][self._fd]
+
+def until_message_received(channel_name):
+    instruction = _until_message_received(channel_name)
+    try:
+        message = yield instruction
+        yield cosocket.return_value(message)
+    except GeneratorExit:
+        instruction.abort()
+        raise

--- a/cosocket.py	Sun Apr 19 22:16:11 2009 -0700
+++ b/cosocket.py	Sun Apr 19 23:06:30 2009 -0700
@@ -14,6 +14,14 @@
         if conn:
             self.continue_from_yield()
 
+    def close_coroutine_and_return_to_caller(self, message):
+        self.__close_coroutine(self.__coroutine)
+        if self.__coroutine_stack:
+            self.__coroutine = self.__coroutine_stack.pop()
+            self.continue_from_yield(message)
+        else:
+            self.__coroutine = None
+
     def continue_from_yield(self, message = None, exception = None):
         try:
             if exception:
@@ -131,3 +139,10 @@
 
     def execute(self, dispatcher):
         dispatcher.push(self.content)
+
+class return_value(object):
+    def __init__(self, value):
+        self.value = value
+
+    def execute(self, dispatcher):
+        dispatcher.close_coroutine_and_return_to_caller(self.value)