def __init__(self, listener, ctxt, message, unique_id, msg_id, reply_q,
obsolete_reply_queues):
"""
message is Intance of
simpleservice.rpc.driver.message.RabbitMessage
AMQPIncomingMessage for dispather
"""
self.ctxt = ctxt
self.message = message
self.listener = listener
self.unique_id = unique_id
self.msg_id = msg_id
self.reply_q = reply_q
self._obsolete_reply_queues = obsolete_reply_queues
self.stopwatch = timeutils.StopWatch()
self.stopwatch.start()
def wait(self, timeout=None):
"""Waits until the latch is released.
:param timeout: wait until the timeout expires
:type timeout: number
:returns: true if the latch has been released before the
timeout expires otherwise false
:rtype: boolean
"""
watch = timeutils.StopWatch(duration=timeout)
watch.start()
with self._cond:
while self._count > 0:
if watch.expired():
return False
else:
self._cond.wait(watch.leftover(return_none=True))
return True
def _run_loop(self,
idle_for_func,
initial_delay=None,
stop_on_exception=True):
kind = self._KIND
func_name = reflection.get_callable_name(self.f)
func = self.f if stop_on_exception else _safe_wrapper(
self.f, kind, func_name)
if initial_delay:
greenthread.sleep(initial_delay)
try:
watch = timeutils.StopWatch()
while self._running:
watch.restart()
result = func(*self.args, **self.kw)
watch.stop()
if not self._running:
break
idle = idle_for_func(result, watch.elapsed())
LOG.trace(
'%(kind)s %(func_name)r sleeping '
'for %(idle).02f seconds', {
'func_name': func_name,
'idle': idle,
'kind': kind
})
greenthread.sleep(idle)
except LoopingCallDone as e:
self.done.send(e.retvalue)
except Exception:
exc_info = sys.exc_info()
try:
LOG.error('%(kind)s %(func_name)r failed', {
'kind': kind,
'func_name': func_name
},
exc_info=exc_info)
self.done.send_exception(*exc_info)
finally:
del exc_info
return
else:
self.done.send(True)
def build(self, statistics, timeout=None, gather_statistics=True):
"""Builds a state-machine (that is used during running)."""
if gather_statistics:
watches = {}
state_statistics = {}
statistics['seconds_per_state'] = state_statistics
# watches = {}
for timed_state in TIMED_STATES:
state_statistics[timed_state.lower()] = 0.0
watches[timed_state] = timeutils.StopWatch()
statistics['discarded_failures'] = 0
statistics['awaiting'] = 0
statistics['completed'] = 0
statistics['incomplete'] = 0
memory = MachineMemory()
if timeout is None:
timeout = WAITING_TIMEOUT
# Cache some local functions/methods...
do_complete = self._completer.complete
do_complete_failure = self._completer.complete_failure
get_atom_intention = self._storage.get_atom_intention
def do_schedule(next_nodes):
with self._storage.lock.write_lock():
return self._scheduler.schedule(
sorted(next_nodes,
key=lambda node: getattr(node, 'priority', 0),
reverse=True))
def iter_next_atoms(atom=None, apply_deciders=True):
# Yields and filters and tweaks the next atoms to run...
maybe_atoms_it = self._selector.iter_next_atoms(atom=atom)
for atom, late_decider in maybe_atoms_it:
if apply_deciders:
proceed = late_decider.check_and_affect(self._runtime)
if proceed:
yield atom
else:
yield atom
def resume(old_state, new_state, event):
# This reaction function just updates the state machines memory
# to include any nodes that need to be executed (from a previous
# attempt, which may be empty if never ran before) and any nodes
# that are now ready to be ran.
with self._storage.lock.write_lock():
memory.next_up.update(
iter_utils.unique_seen(
(self._completer.resume(), iter_next_atoms())))
return SCHEDULE
def game_over(old_state, new_state, event):
# This reaction function is mainly a intermediary delegation
# function that analyzes the current memory and transitions to
# the appropriate handler that will deal with the memory values,
# it is *always* called before the final state is entered.
if memory.failures:
return FAILED
with self._storage.lock.read_lock():
leftover_atoms = iter_utils.count(
# Avoid activating the deciders, since at this point
# the engine is finishing and there will be no more further
# work done anyway...
iter_next_atoms(apply_deciders=False))
if leftover_atoms:
# Ok we didn't finish (either reverting or executing...) so
# that means we must of been stopped at some point...
LOG.trace(
"Suspension determined to have been reacted to"
" since (at least) %s atoms have been left in an"
" unfinished state", leftover_atoms)
return SUSPENDED
elif self._runtime.is_success():
return SUCCESS
else:
return REVERTED
def schedule(old_state, new_state, event):
# This reaction function starts to schedule the memory's next
# nodes (iff the engine is still runnable, which it may not be
# if the user of this engine has requested the engine/storage
# that holds this information to stop or suspend); handles failures
# that occur during this process safely...
with self._storage.lock.write_lock():
current_flow_state = self._storage.get_flow_state()
if current_flow_state == st.RUNNING and memory.next_up:
not_done, failures = do_schedule(memory.next_up)
if not_done:
memory.not_done.update(not_done)
if failures:
memory.failures.extend(failures)
memory.next_up.intersection_update(not_done)
elif current_flow_state == st.SUSPENDING and memory.not_done:
# Try to force anything not cancelled to now be cancelled
# so that the executor that gets it does not continue to
# try to work on it (if the future execution is still in
# its backlog, if it's already being executed, this will
# do nothing).
memory.cancel_futures()
return WAIT
def complete_an_atom(fut):
# This completes a single atom saving its result in
# storage and preparing whatever predecessors or successors will
# now be ready to execute (or revert or retry...); it also
# handles failures that occur during this process safely...
atom = fut.atom
try:
outcome, result = fut.result()
do_complete(atom, outcome, result)
if isinstance(result, failure.Failure):
retain = do_complete_failure(atom, outcome, result)
if retain:
memory.failures.append(result)
else:
# NOTE(harlowja): avoid making any intention request
# to storage unless we are sure we are in DEBUG
# enabled logging (otherwise we will call this all
# the time even when DEBUG is not enabled, which
# would suck...)
if LOG.isEnabledFor(logging.DEBUG):
intention = get_atom_intention(atom.name)
LOG.debug(
"Discarding failure '%s' (in response"
" to outcome '%s') under completion"
" units request during completion of"
" atom '%s' (intention is to %s)", result,
outcome, atom, intention)
if gather_statistics:
statistics['discarded_failures'] += 1
if gather_statistics:
statistics['completed'] += 1
# except futures.CancelledError:
except futurist.CancelledError:
# Well it got cancelled, skip doing anything
# and move on; at a further time it will be resumed
# and something should be done with it to get it
# going again.
return WAS_CANCELLED
except Exception:
memory.failures.append(failure.Failure())
LOG.exception("Engine '%s' atom post-completion"
" failed", atom)
return FAILED_COMPLETING
else:
return SUCCESSFULLY_COMPLETED
def wait(old_state, new_state, event):
# call sometime in the future, or equivalent that will work in
# py2 and py3.
if memory.not_done:
done, not_done = self._waiter(memory.not_done, timeout=timeout)
memory.done.update(done)
memory.not_done = not_done
return ANALYZE
def analyze(old_state, new_state, event):
# This reaction function is responsible for analyzing all nodes
# that have finished executing/reverting and figuring
# out what nodes are now ready to be ran (and then triggering those
# nodes to be scheduled in the future); handles failures that
# occur during this process safely...
next_up = set()
with self._storage.lock.write_lock():
while memory.done:
fut = memory.done.pop()
# Force it to be completed so that we can ensure that
# before we iterate over any successors or predecessors
# that we know it has been completed and saved and so on...
completion_status = complete_an_atom(fut)
if (not memory.failures
and completion_status != WAS_CANCELLED):
atom = fut.atom
try:
more_work = set(iter_next_atoms(atom=atom))
except Exception:
memory.failures.append(failure.Failure())
LOG.exception(
"Engine '%s' atom post-completion"
" next atom searching failed", atom)
else:
next_up.update(more_work)
current_flow_state = self._storage.get_flow_state()
if (current_flow_state == st.RUNNING and next_up
and not memory.failures):
memory.next_up.update(next_up)
return SCHEDULE
elif memory.not_done:
if current_flow_state == st.SUSPENDING:
memory.cancel_futures()
return WAIT
else:
return FINISH
def on_exit(old_state, event):
LOG.trace("Exiting old state '%s' in response to event '%s'",
old_state, event)
if gather_statistics:
if old_state in watches:
w = watches[old_state]
w.stop()
state_statistics[old_state.lower()] += w.elapsed()
if old_state in (st.SCHEDULING, st.WAITING):
statistics['incomplete'] = len(memory.not_done)
if old_state in (st.ANALYZING, st.SCHEDULING):
statistics['awaiting'] = len(memory.next_up)
def on_enter(new_state, event):
LOG.trace("Entering new state '%s' in response to event '%s'",
new_state, event)
if gather_statistics and new_state in watches:
watches[new_state].restart()
state_kwargs = {
'on_exit': on_exit,
'on_enter': on_enter,
}
m = machines.FiniteMachine()
m.add_state(GAME_OVER, **state_kwargs)
m.add_state(UNDEFINED, **state_kwargs)
m.add_state(st.ANALYZING, **state_kwargs)
m.add_state(st.RESUMING, **state_kwargs)
m.add_state(st.REVERTED, terminal=True, **state_kwargs)
m.add_state(st.SCHEDULING, **state_kwargs)
m.add_state(st.SUCCESS, terminal=True, **state_kwargs)
m.add_state(st.SUSPENDED, terminal=True, **state_kwargs)
m.add_state(st.WAITING, **state_kwargs)
m.add_state(st.FAILURE, terminal=True, **state_kwargs)
m.default_start_state = UNDEFINED
m.add_transition(GAME_OVER, st.REVERTED, REVERTED)
m.add_transition(GAME_OVER, st.SUCCESS, SUCCESS)
m.add_transition(GAME_OVER, st.SUSPENDED, SUSPENDED)
m.add_transition(GAME_OVER, st.FAILURE, FAILED)
m.add_transition(UNDEFINED, st.RESUMING, START)
m.add_transition(st.ANALYZING, GAME_OVER, FINISH)
m.add_transition(st.ANALYZING, st.SCHEDULING, SCHEDULE)
m.add_transition(st.ANALYZING, st.WAITING, WAIT)
m.add_transition(st.RESUMING, st.SCHEDULING, SCHEDULE)
m.add_transition(st.SCHEDULING, st.WAITING, WAIT)
m.add_transition(st.WAITING, st.ANALYZING, ANALYZE)
m.add_reaction(GAME_OVER, FINISH, game_over)
m.add_reaction(st.ANALYZING, ANALYZE, analyze)
m.add_reaction(st.RESUMING, START, resume)
m.add_reaction(st.SCHEDULING, SCHEDULE, schedule)
m.add_reaction(st.WAITING, WAIT, wait)
m.freeze()
return (m, memory)
def run_iter(self, timeout=None):
"""Runs the engine using iteration (or die trying).
:param timeout: timeout to wait for any atoms to complete (this timeout
will be used during the waiting period that occurs after the
waiting state is yielded when unfinished atoms are being waited
on).
Instead of running to completion in a blocking manner, this will
return a generator which will yield back the various states that the
engine is going through (and can be used to run multiple engines at
once using a generator per engine). The iterator returned also
responds to the ``send()`` method from :pep:`0342` and will attempt to
suspend itself if a truthy value is sent in (the suspend may be
delayed until all active atoms have finished).
NOTE(harlowja): using the ``run_iter`` method will **not** retain the
engine lock while executing so the user should ensure that there is
only one entity using a returned engine iterator (one per engine) at a
given time.
"""
self.compile()
self.prepare()
self.validate()
# Keep track of the last X state changes, which if a failure happens
# are quite useful to log (and the performance of tracking this
# should be negligible).
last_transitions = collections.deque(
maxlen=max(1, self.MAX_MACHINE_STATES_RETAINED))
with _start_stop(self._task_executor, self._retry_executor):
self._change_state(states.RUNNING)
if self._gather_statistics:
self._statistics.clear()
w = timeutils.StopWatch()
w.start()
else:
w = None
try:
closed = False
machine, memory = self._runtime.builder.build(
self._statistics,
timeout=timeout,
gather_statistics=self._gather_statistics)
r = runners.FiniteRunner(machine)
for transition in r.run_iter(builder.START):
last_transitions.append(transition)
_prior_state, new_state = transition
# NOTE(harlowja): skip over meta-states
if new_state in builder.META_STATES:
continue
if new_state == states.FAILURE:
failure.Failure.reraise_if_any(memory.failures)
if closed:
continue
try:
try_suspend = yield new_state
except GeneratorExit:
# The generator was closed, attempt to suspend and
# continue looping until we have cleanly closed up
# shop...
closed = True
self.suspend()
except Exception:
# Capture the failure, and ensure that the
# machine will notice that something externally
# has sent an exception in and that it should
# finish up and reraise.
memory.failures.append(failure.Failure())
closed = True
else:
if try_suspend:
self.suspend()
except Exception:
with excutils.save_and_reraise_exception():
if not hasattr(last_transitions, 'maxlen'):
maxlen = int(
re.match("^.*?maxlen=([0-9]+)\)$",
str(last_transitions)).group(1))
else:
maxlen = last_transitions.maxlen
LOG.error(
"Engine execution has failed, something"
" bad must of happened (last"
" %s machine transitions were %s)", maxlen,
list(last_transitions))
self._change_state(states.FAILURE)
else:
if last_transitions:
_prior_state, new_state = last_transitions[-1]
if new_state not in self.IGNORABLE_STATES:
self._change_state(new_state)
if new_state not in self.NO_RERAISING_STATES:
e_failures = self.storage.get_execute_failures()
r_failures = self.storage.get_revert_failures()
er_failures = itertools.chain(
six.itervalues(e_failures),
six.itervalues(r_failures))
failure.Failure.reraise_if_any(er_failures)
finally:
if w is not None:
w.stop()
self._statistics['active_for'] = w.elapsed()
def __init__(self, duration=None):
self._watch = timeutils.StopWatch(duration=duration)