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# Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.
from twisted.internet import _threadedselect
_threadedselect.install()
from twisted.internet.defer import Deferred
from twisted.python.failure import Failure
from twisted.internet import reactor
from twisted.python.runtime import seconds
from itertools import count
from Queue import Queue, Empty
class TwistedManager(object):
def __init__(self):
self.twistedQueue = Queue()
self.key = count()
self.results = {}
def getKey(self):
# get a unique identifier
return self.key.next()
def start(self):
# start the reactor
reactor.interleave(self.twistedQueue.put)
def _stopIterating(self, value, key):
self.results[key] = value
def stop(self):
# stop the reactor
key = self.getKey()
reactor.addSystemEventTrigger('after', 'shutdown',
self._stopIterating, True, key)
reactor.stop()
self.iterate(key)
def getDeferred(self, d):
# get the result of a deferred or raise if it failed
key = self.getKey()
d.addBoth(self._stopIterating, key)
res = self.iterate(key)
if isinstance(res, Failure):
res.raiseException()
return res
def poll(self, noLongerThan=1.0):
# poll the reactor for up to noLongerThan seconds
base = seconds()
try:
while (seconds() - base) <= noLongerThan:
callback = self.twistedQueue.get_nowait()
callback()
except Empty:
pass
def iterate(self, key=None):
# iterate the reactor until it has the result we're looking for
while key not in self.results:
callback = self.twistedQueue.get()
callback()
return self.results.pop(key)
def fakeDeferred(msg):
d = Deferred()
def cb():
print "deferred called back"
d.callback(msg)
reactor.callLater(2, cb)
return d
def fakeCallback():
print "twisted is still running"
def main():
m = TwistedManager()
print "starting"
m.start()
print "setting up a 1sec callback"
reactor.callLater(1, fakeCallback)
print "getting a deferred"
res = m.getDeferred(fakeDeferred("got it!"))
print "got the deferred:", res
print "stopping"
m.stop()
print "stopped"
if __name__ == '__main__':
main()
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