45 lines
944 B
Python
45 lines
944 B
Python
|
# test concurrent mutating access to a shared bytearray object
|
||
|
|
#
|
||
|
|
# MIT license; Copyright (c) 2016 Damien P. George on behalf of Pycom Ltd
|
||
|
|
|
||
|
|
import _thread
|
||
|
|
|
||
|
|
# the shared bytearray
|
||
|
|
ba = bytearray()
|
||
|
|
|
||
|
|
# main thread function
|
||
|
|
def th(n, lo, hi):
|
||
|
|
for repeat in range(n):
|
||
|
|
for i in range(lo, hi):
|
||
|
|
l = len(ba)
|
||
|
|
ba.append(i)
|
||
|
|
assert len(ba) >= l + 1
|
||
|
|
|
||
|
|
l = len(ba)
|
||
|
|
ba.extend(bytearray([i]))
|
||
|
|
assert len(ba) >= l + 1
|
||
|
|
|
||
|
|
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, (40, i * 256 // n_thread, (i + 1) * 256 // n_thread))
|
||
|
|
|
||
|
|
# busy wait for threads to finish
|
||
|
|
while n_finished < n_thread:
|
||
|
|
pass
|
||
|
|
|
||
|
|
# check bytearray has correct contents
|
||
|
|
print(len(ba))
|
||
|
|
count = [0 for _ in range(256)]
|
||
|
|
for b in ba:
|
||
|
|
count[b] += 1
|
||
|
|
print(count)
|
||
|
|
|