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# test concurrent mutating access to a shared user instance
#
# MIT license; Copyright (c) 2016 Damien P. George on behalf of Pycom Ltd
import _thread
# the shared user class and instance
class User:
def __init__(self):
self.a = "A"
self.b = "B"
self.c = "C"
user = User()
# main thread function
def th(n, lo, hi):
for repeat in range(n):
for i in range(lo, hi):
setattr(user, "attr_%u" % i, repeat + i)
assert getattr(user, "attr_%u" % i) == repeat + i
with lock:
global n_finished
n_finished += 1
lock = _thread.allocate_lock()
n_repeat = 30
n_range = 50 # 300 for stressful test (uses more heap)
n_thread = 4
n_finished = 0
# spawn threads
for i in range(n_thread):
_thread.start_new_thread(th, (n_repeat, i * n_range, (i + 1) * n_range))
# busy wait for threads to finish
while n_finished < n_thread:
pass
# check user instance has correct contents
print(user.a, user.b, user.c)
for i in range(n_thread * n_range):
assert getattr(user, "attr_%u" % i) == n_repeat - 1 + i
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