diff options
Diffstat (limited to 'blinker/base.py')
| -rw-r--r-- | blinker/base.py | 39 |
1 files changed, 27 insertions, 12 deletions
diff --git a/blinker/base.py b/blinker/base.py index 675c2e0..0577b65 100644 --- a/blinker/base.py +++ b/blinker/base.py @@ -329,21 +329,12 @@ class Signal(object): def _disconnect(self, receiver_id, sender_id): if sender_id == ANY_ID: if self._by_receiver.pop(receiver_id, False): - empty_buckets = [] - for key, bucket in self._by_sender.items(): + for bucket in self._by_sender.values(): bucket.discard(receiver_id) - if not bucket: - empty_buckets.append(key) - for key in empty_buckets: - del self._by_sender[key] self.receivers.pop(receiver_id, None) else: self._by_sender[sender_id].discard(receiver_id) - if not self._by_sender[sender_id]: - del self._by_sender[sender_id] self._by_receiver[receiver_id].discard(sender_id) - if not self._by_receiver[receiver_id]: - del self._by_receiver[receiver_id] def _cleanup_receiver(self, receiver_ref): """Disconnect a receiver from all senders.""" @@ -356,8 +347,32 @@ class Signal(object): self._weak_senders.pop(sender_id, None) for receiver_id in self._by_sender.pop(sender_id, ()): self._by_receiver[receiver_id].discard(sender_id) - if not self._by_receiver[receiver_id]: - del self._by_receiver[receiver_id] + + def _cleanup_bookkeeping(self): + """Prune unused sender/receiver bookeeping. Not threadsafe. + + Connecting & disconnecting leave behind a small amount of bookeeping + for the receiver and sender values. Typical workloads using Blinker, + for example in most web apps, Flask, CLI scripts, etc., are not + adversely affected by this bookkeeping. + + With a long-running Python process performing dynamic signal routing + with high volume- e.g. connecting to function closures, "senders" are + all unique object instances, and doing all of this over and over- you + may see memory usage will grow due to extraneous bookeeping. (Visible + in memory profiing as an increasing number of empty sets.) + + This method will prune that bookeeping away, with the caveat that such + pruning is not threadsafe. The risk is that cleanup of a fully + disconnected receiver/sender pair occurs while another thread is + connecting that same pair. If you are in the highly dynamic, unique + receiver/sender situation that has lead you to this method, that + failure mode is perhaps not a big deal for you. + """ + for mapping in (self._by_sender, self._by_receiver): + for _id, bucket in list(mapping.items()): + if not bucket: + mapping.pop(_id, None) def _clear_state(self): """Throw away all signal state. Useful for unit tests.""" |