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# test using lock to coordinate access to global mutable objects
#
# MIT license; Copyright (c) 2016 Damien P. George on behalf of Pycom Ltd
import time
import _thread
def fac(n):
x = 1
for i in range(1, n + 1):
x *= i
return x
def thread_entry():
while True:
with jobs_lock:
try:
f, arg = jobs.pop(0)
except IndexError:
return
ans = f(arg)
with output_lock:
output.append((arg, ans))
# create a list of jobs
jobs = [(fac, i) for i in range(20, 80)]
jobs_lock = _thread.allocate_lock()
n_jobs = len(jobs)
# create a list to store the results
output = []
output_lock = _thread.allocate_lock()
# spawn threads to do the jobs
for i in range(4):
try:
_thread.start_new_thread(thread_entry, ())
except OSError:
# System cannot create a new thead, so stop trying to create them.
break
# wait for the jobs to complete
while True:
with jobs_lock:
if len(output) == n_jobs:
break
time.sleep(0)
# sort and print the results
output.sort(key=lambda x: x[0])
for arg, ans in output:
print(arg, ans)
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