Ticket #16547: signal.patch

dispatch/dispatcher.py

@@ -33 +33 @@
         self.providing_args = set(providing_args)
         self.lock = threading.Lock()
 
-    def connect(self, receiver, sender=None, weak=True, dispatch_uid=None):
+    def connect(self, receiver, sender=None, weak=True, dispatch_uid=None, weight=0):
         """
         Connect receiver to sender for signal.
     
@@ -67 +67 @@
                 An identifier used to uniquely identify a particular instance of
                 a receiver. This will usually be a string, though it may be
                 anything hashable.
+
+            weight
+                Signal priority. Greater run first.
         """
         from django.conf import settings
         
@@ -101 +104 @@
 
         self.lock.acquire()
         try:
-            for r_key, _ in self.receivers:
+            for r_key, _, w in self.receivers:
                 if r_key == lookup_key:
                     break
             else:
-                self.receivers.append((lookup_key, receiver))
+                self.receivers.append((lookup_key, receiver, weight))
         finally:
             self.lock.release()
 
@@ -139 +142 @@
         self.lock.acquire()
         try:
             for index in xrange(len(self.receivers)):
-                (r_key, _) = self.receivers[index]
+                (r_key, _, weight) = self.receivers[index]
                 if r_key == lookup_key:
                     del self.receivers[index]
                     break
@@ -221 +224 @@
         none_senderkey = _make_id(None)
         receivers = []
 
-        for (receiverkey, r_senderkey), receiver in self.receivers:
+        for (receiverkey, r_senderkey), receiver, weight in sorted(self.receivers, key=lambda x: x[2], reverse=True):
             if r_senderkey == none_senderkey or r_senderkey == senderkey:
                 if isinstance(receiver, WEAKREF_TYPES):
                     # Dereference the weak reference.
@@ -240 +243 @@
         self.lock.acquire()
         try:
             to_remove = []
-            for key, connected_receiver in self.receivers:
+            for key, connected_receiver, weight in self.receivers:
                 if connected_receiver == receiver:
                     to_remove.append(key)
             for key in to_remove:
                 last_idx = len(self.receivers) - 1
                 # enumerate in reverse order so that indexes are valid even
                 # after we delete some items
-                for idx, (r_key, _) in enumerate(reversed(self.receivers)):
+                for idx, (r_key, _, weight) in enumerate(reversed(self.receivers)):
                     if r_key == key:
                         del self.receivers[last_idx-idx]
         finally: