openstack/deb-python-taskflow
Code Issues Proposed changes

Avoid holding the state lock while notifying

Browse Source 
To avoid dead lock where a notifier will callback
into the engine to perform a further state transition
make sure we activate the state change notifiation
after locking and not during it.

Fixes bug 1301091

Change-Id: Ic81e15150e44d36489757372db32adfb5440feb4
This commit is contained in:
Joshua Harlow
2014-04-01 13:57:04 -07:00
committed by Thomas Goirand
parent 456cd32b8c
commit 7f7c9285d1
1 changed files with 8 additions and 7 deletions
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15
taskflow/engines/action_engine/engine.py
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@@ -110,17 +110,18 @@ class ActionEngine(base.EngineBase):
failures = self.storage.get_failures()
misc.Failure.reraise_if_any(failures.values())
@lock_utils.locked(lock='_state_lock')
def _change_state(self, state):
old_state = self.storage.get_flow_state()
if not states.check_flow_transition(old_state, state):
return
self.storage.set_flow_state(state)
with self._state_lock:
old_state = self.storage.get_flow_state()
if not states.check_flow_transition(old_state, state):
return
self.storage.set_flow_state(state)
try:
flow_uuid = self._flow.uuid
except AttributeError:
# NOTE(harlowja): if the flow was just a single task, then it will
# not itself have a uuid, but the constructed flow_detail will.
# NOTE(harlowja): if the flow was just a single task, then it
# will not itself have a uuid, but the constructed flow_detail
# will.
if self._flow_detail is not None:
flow_uuid = self._flow_detail.uuid
else: