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XEP-0198: fix race conditions on enable/resume

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This code splits out the `enabled` property into `enabled_in` and
`enabled_out` to reflect that client and server enable 0198
asynchronously.

This also moves the actual enabling code into the stanza processing
logic, because apparently, `enable.send()` was just added into the end
of the send queue, but `enable` got enabled immediately, so that poezio
requested ACKs for whatever happened to be in the queue before.

Async is hard, let's go get fishing.
This commit is contained in:
Georg Lukas 2020-03-28 21:18:13 +01:00
parent deb6d4f176
commit 85c9967b9c
1 changed files with 26 additions and 10 deletions
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36
slixmpp/plugins/xep_0198/stream_management.py
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@ -71,7 +71,8 @@ class XEP_0198(BasePlugin):
self.window_counter = self.window
self.enabled = False
self.enabled_in = False
self.enabled_out = False
self.unacked_queue = collections.deque()
register_stanza_plugin(StreamFeatures, stanza.StreamManagement)
@ -158,11 +159,17 @@ class XEP_0198(BasePlugin):
def disconnected(self, event):
"""Reset enabled state until we can resume/reenable."""
self.enabled = False
log.debug("disconnected, disabling SM")
self.xmpp.event('sm_disabled', event)
self.enabled_in = False
self.enabled_out = False
def session_end(self, event):
"""Reset stream management state."""
self.enabled = False
log.debug("session_end, disabling SM")
self.xmpp.event('sm_disabled', event)
self.enabled_in = False
self.enabled_out = False
self.unacked_queue.clear()
self.sm_id = None
self.handled = 0
@ -177,6 +184,7 @@ class XEP_0198(BasePlugin):
def request_ack(self, e=None):
"""Request an ack from the server."""
log.debug("requesting ack")
req = stanza.RequestAck(self.xmpp)
self.xmpp.send_raw(str(req))
@ -199,9 +207,7 @@ class XEP_0198(BasePlugin):
enable = stanza.Enable(self.xmpp)
enable['resume'] = self.allow_resume
enable.send()
self.enabled = True
self.handled = 0
self.unacked_queue.clear()
log.debug("enabling SM")
waiter = Waiter('enabled_or_failed',
MatchMany([
@ -210,11 +216,11 @@ class XEP_0198(BasePlugin):
self.xmpp.register_handler(waiter)
result = await waiter.wait()
elif self.sm_id and self.allow_resume and 'bind' not in self.xmpp.features:
self.enabled = True
resume = stanza.Resume(self.xmpp)
resume['h'] = self.handled
resume['previd'] = self.sm_id
resume.send()
log.debug("resuming SM")
# Wait for a response before allowing stream feature processing
# to continue. The actual result processing will be done in the
@ -237,6 +243,8 @@ class XEP_0198(BasePlugin):
self.xmpp.features.add('stream_management')
if stanza['id']:
self.sm_id = stanza['id']
self.enabled_in = True
self.handled = 0
self.xmpp.event('sm_enabled', stanza)
def _handle_resumed(self, stanza):
@ -245,6 +253,7 @@ class XEP_0198(BasePlugin):
Raises a :term:`session_resumed` event.
"""
self.xmpp.features.add('stream_management')
self.enabled_in = True
self._handle_ack(stanza)
for id, stanza in self.unacked_queue:
self.xmpp.send(stanza, use_filters=False)
@ -258,7 +267,8 @@ class XEP_0198(BasePlugin):
Raises an :term:`sm_failed` event.
"""
self.enabled = False
self.enabled_in = False
self.enabled_out = False
self.unacked_queue.clear()
self.xmpp.event('sm_failed', stanza)
@ -295,7 +305,7 @@ class XEP_0198(BasePlugin):
def _handle_incoming(self, stanza):
"""Increment the handled counter for each inbound stanza."""
if not self.enabled:
if not self.enabled_in:
return stanza
if isinstance(stanza, (Message, Presence, Iq)):
@ -305,7 +315,13 @@ class XEP_0198(BasePlugin):
def _handle_outgoing(self, stanza):
"""Store outgoing stanzas in a queue to be acked."""
if not self.enabled:
from slixmpp.plugins.xep_0198 import stanza as st
if isinstance(stanza, (st.Enable, st.Resume)):
self.enabled_out = True
self.unacked_queue.clear()
log.debug("enabling outgoing SM: %s" % stanza)
if not self.enabled_out:
return stanza
if isinstance(stanza, (Message, Presence, Iq)):