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Have the timeout decrement inside the wait() method

Currently it appears the timeout provided to the wait()
method will be reused X number of times (where X may be
indeterminate depending on reconnections, loss of messages
and so-on) so instead of reusing it which can potentially
result in a infinite number of calls have a new object be
used that will cause the subsequent timeouts used elsewhere
in the wait function to actually decay correctly.

Closes-bug: #1379394

Change-Id: I12c4ea1eef6b857d12246db0483adaf7c87e740c
changes/56/137456/4
Joshua Harlow 7 years ago
committed by Joshua Harlow
parent
commit
f1c7e78a56
  1. 37
      oslo/messaging/_drivers/amqpdriver.py

37
oslo/messaging/_drivers/amqpdriver.py

@ -31,6 +31,30 @@ from oslo.messaging._i18n import _LI
LOG = logging.getLogger(__name__)
class _DecayingTimer(object):
def __init__(self, duration=None):
self._duration = duration
self._ends_at = None
def start(self):
if self._duration is not None:
self._ends_at = time.time() + max(0, self._duration)
return self
def check_return(self, msg_id):
if self._duration is None:
return None
if self._ends_at is None:
raise RuntimeError("Can not check/return a timeout from a timer"
" that has not been started")
left = self._ends_at - time.time()
if left <= 0:
raise messaging.MessagingTimeout('Timed out waiting for a '
'reply to message ID %s'
% msg_id)
return left
class AMQPIncomingMessage(base.IncomingMessage):
def __init__(self, listener, ctxt, message, unique_id, msg_id, reply_q):
@ -220,7 +244,7 @@ class ReplyWaiter(object):
result = data['result']
return result, ending
def _poll_connection(self, msg_id, timeout):
def _poll_connection(self, msg_id, timer):
while True:
while self.incoming:
message_data = self.incoming.pop(0)
@ -232,14 +256,14 @@ class ReplyWaiter(object):
self.waiters.put(incoming_msg_id, message_data)
try:
self.conn.consume(limit=1, timeout=timeout)
self.conn.consume(limit=1, timeout=timer.check_return(msg_id))
except rpc_common.Timeout:
raise messaging.MessagingTimeout('Timed out waiting for a '
'reply to message ID %s'
% msg_id)
def _poll_queue(self, msg_id, timeout):
message = self.waiters.get(msg_id, timeout)
def _poll_queue(self, msg_id, timer):
message = self.waiters.get(msg_id, timeout=timer.check_return(msg_id))
if message is self.waiters.WAKE_UP:
return None, None, True # lock was released
@ -268,6 +292,7 @@ class ReplyWaiter(object):
# have the first thread take responsibility for passing replies not
# intended for itself to the appropriate thread.
#
timer = _DecayingTimer(duration=timeout).start()
final_reply = None
while True:
if self.conn_lock.acquire(False):
@ -286,7 +311,7 @@ class ReplyWaiter(object):
# Now actually poll the connection
while True:
reply, ending = self._poll_connection(msg_id, timeout)
reply, ending = self._poll_connection(msg_id, timer)
if not ending:
final_reply = reply
else:
@ -299,7 +324,7 @@ class ReplyWaiter(object):
self.waiters.wake_all(msg_id)
else:
# We're going to wait for the first thread to pass us our reply
reply, ending, trylock = self._poll_queue(msg_id, timeout)
reply, ending, trylock = self._poll_queue(msg_id, timer)
if trylock:
# The first thread got its reply, let's try and take over
# the responsibility for polling

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