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# test concurrent mutating access to a shared set object
#
# MIT license; Copyright (c) 2016 Damien P. George on behalf of Pycom Ltd
import _thread
# the shared set
se = set([-1, -2, -3, -4])
# main thread function
def th(n, lo, hi):
for repeat in range(n):
for i in range(lo, hi):
se.add(i)
assert i in se
se.remove(i)
assert i not in se
with lock:
global n_finished
n_finished += 1
lock = _thread.allocate_lock()
n_thread = 4
n_finished = 0
# spawn threads
for i in range(n_thread):
_thread.start_new_thread(th, (50, i * 500, (i + 1) * 500))
# busy wait for threads to finish
while n_finished < n_thread:
pass
# check set has correct contents
print(sorted(se))
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