Fixed #14533 -- Make django signals more thread-safe. Thanks milosu for the patch! (f27e6f0d) · Commits · Dom Sekotill / django

django/dispatch/dispatcher.py

+35 −18

Original line number	Diff line number	Diff line
		import weakref
		import threading

		from django.dispatch import saferef

		@@ -30,6 +31,7 @@ class Signal(object):
		if providing_args is None:
		providing_args = []
		self.providing_args = set(providing_args)
		self.lock = threading.Lock()

		def connect(self, receiver, sender=None, weak=True, dispatch_uid=None):
		"""
		@@ -97,11 +99,15 @@ class Signal(object):
		if weak:
		receiver = saferef.safeRef(receiver, onDelete=self._remove_receiver)

		try:
		self.lock.acquire()
		for r_key, _ in self.receivers:
		if r_key == lookup_key:
		break
		else:
		self.receivers.append((lookup_key, receiver))
		finally:
		self.lock.release()

		def disconnect(self, receiver=None, sender=None, weak=True, dispatch_uid=None):
		"""
		@@ -130,11 +136,15 @@ class Signal(object):
		else:
		lookup_key = (_make_id(receiver), _make_id(sender))

		try:
		self.lock.acquire()
		for index in xrange(len(self.receivers)):
		(r_key, _) = self.receivers[index]
		if r_key == lookup_key:
		del self.receivers[index]
		break
		finally:
		self.lock.release()

		def send(self, sender, **named):
		"""
		@@ -227,14 +237,21 @@ class Signal(object):
		Remove dead receivers from connections.
		"""

		try:
		self.lock.acquire()
		to_remove = []
		for key, connected_receiver in self.receivers:
		if connected_receiver == receiver:
		to_remove.append(key)
		for key in to_remove:
		for idx, (r_key, _) in enumerate(self.receivers):
		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)):
		if r_key == key:
		del self.receivers[idx]
		del self.receivers[last_idx-idx]
		finally:
		self.lock.release()


		def receiver(signal, **kwargs):