# 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 = 2
n_finished = 0

# the shared data structure
tup = (1, 2, 3, 4)

# spawn threads
for i in range(n_thread):
 _thread.start_new_thread(thread_entry, (100, tup))

# busy wait for threads to finish
while n_finished < n_thread:
 pass
print(tup)