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# test capability for threads to access a shared immutable data structure
#
# MIT license; Copyright (c) 2016 Damien P. George on behalf of Pycom Ltd
import _thread
def foo(i):
pass
def thread_entry(n, tup):
for i in tup:
foo(i)
with lock:
global n_finished
n_finished += 1
lock = _thread.allocate_lock()
n_thread = 0
n_thread_max = 2
n_finished = 0
# the shared data structure
tup = (1, 2, 3, 4)
# spawn threads
for _ in range(n_thread_max):
try:
_thread.start_new_thread(thread_entry, (100, tup))
n_thread += 1
except OSError:
# System cannot create a new thead, so stop trying to create them.
break
# also run the function on this main thread
thread_entry(100, tup)
n_thread += 1
# busy wait for threads to finish
while n_finished < n_thread:
pass
print(tup)
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