Multiprocessing example

multiproc.py

from multiprocessing import Pool, JoinableQueue, Manager
# Note that jqueue.task_done() must be called to decrement the count if jqueue.join() is to be used correctly.

import time, os, signal

def handler(signum, frame):
    print "signal caught in %d" % os.getpid()

signal.signal(signal.SIGTERM, handler)

def run_worker(q):
    try:
        print "start with worker %d" % os.getpid()
        t = q.get_nowait()
        time.sleep(t)
        print "done with worker %d" % os.getpid()
    except JoinableQueue.Empty:
        return
    q.task_done()
    print "task done"

p = Pool(3)

m = Manager()
q = m.JoinableQueue()

q.put(8)
q.put(8)
q.put(8)
#q.put(8)
#q.put(8)

for i in range(3):
    p.apply_async(run_worker, (q,))

print os.getpid()
 
p.close()
print "closed"
try:
    p.join()
except IOError:
    print "terminated sending"
    p.terminate()
    print "terminated sent"
    print "joining...."
    p.join()

print "done %d hm" % + os.getpid()