def largeFibonnaciNumber():
"""
Represent a long running blocking function by calculating
the TARGETth Fibonnaci number
"""
TARGET = 10000
first = 0
second = 1
for i in xrange(TARGET - 1):
new = first + second
first = second
second = new
return second
from twisted.internet import threads, reactor
def fibonacciCallback(result):
"""
Callback which manages the largeFibonnaciNumber result by
printing it out
"""
print "largeFibonnaciNumber result =", result
# make sure the reactor stops after the callback chain finishes,
# just so that this example terminates
reactor.stop()
def run():
"""
Run a series of operations, deferring the largeFibonnaciNumber
operation to a thread and performing some other operations after
adding the callback
"""
# get our Deferred which will be called with the largeFibonnaciNumber result
d = threads.deferToThread(largeFibonnaciNumber)
# add our callback to print it out
d.addCallback(fibonacciCallback)
print "1st line after the addition of the callback"
print "2nd line after the addition of the callback"
if __name__ == '__main__':
run()
reactor.run()
