45 lines
944 B
Python
45 lines
944 B
Python
# test concurrent mutating access to a shared bytearray object
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#
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# MIT license; Copyright (c) 2016 Damien P. George on behalf of Pycom Ltd
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import _thread
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# the shared bytearray
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ba = bytearray()
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# main thread function
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def th(n, lo, hi):
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for repeat in range(n):
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for i in range(lo, hi):
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l = len(ba)
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ba.append(i)
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assert len(ba) >= l + 1
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l = len(ba)
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ba.extend(bytearray([i]))
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assert len(ba) >= l + 1
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with lock:
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global n_finished
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n_finished += 1
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lock = _thread.allocate_lock()
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n_thread = 4
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n_finished = 0
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# spawn threads
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for i in range(n_thread):
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_thread.start_new_thread(th, (40, i * 256 // n_thread, (i + 1) * 256 // n_thread))
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# busy wait for threads to finish
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while n_finished < n_thread:
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pass
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# check bytearray has correct contents
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print(len(ba))
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count = [0 for _ in range(256)]
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for b in ba:
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count[b] += 1
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print(count)
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