def test_fork_pid_check():
q = MPQueue()
pid = os.fork()
# Generate random numbers in the parent and child processes after forking.
# The child sends back their numbers to the parent where we check to see
# if we get collisions or not.
if pid > 0:
# parent
rns = {_rand.rand64bits(check_pid=True) for _ in range(100)}
child_rns = q.get()
if PYTHON_VERSION_INFO >= (3, 7):
# Python 3.7+ have fork hooks which should be used
# Hence we should not get any collisions
assert rns & child_rns == set()
else:
# Python < 3.7 we have the pid check so there also
# should not be any collisions.
assert rns & child_rns == set()
else:
# child
try:
rngs = {_rand.rand64bits(check_pid=True) for _ in range(100)}
q.put(rngs)
finally:
# Kill the process so it doesn't continue running the rest of the
# test suite in a separate process. Note we can't use sys.exit()
# as it raises an exception that pytest will detect as an error.
os._exit(0)
def test_multiprocess():
q = MPQueue()
def target(q):
assert sum((_ is _rand.seed for _ in forksafe._registry)) == 1
q.put([_rand.rand64bits() for _ in range(100)])
ps = [mp.Process(target=target, args=(q,)) for _ in range(30)]
for p in ps:
p.start()
for p in ps:
p.join()
assert p.exitcode == 0
ids_list = [_rand.rand64bits() for _ in range(1000)]
ids = set(ids_list)
assert len(ids_list) == len(ids), "Collisions found in ids"
while not q.empty():
child_ids_list = q.get()
child_ids = set(child_ids_list)
assert len(child_ids_list) == len(child_ids), "Collisions found in subprocess ids"
assert ids & child_ids == set()
ids = ids | child_ids # accumulate the ids
def test_random():
m = set()
for i in range(0, 2 ** 16):
n = _rand.rand64bits()
assert 0 <= n <= 2 ** 64 - 1
assert n not in m
m.add(n)
def test_fork_pid_check():
q = MPQueue()
pid = os.fork()
# Generate random numbers in the parent and child processes after forking.
# The child sends back their numbers to the parent where we check to see
# if we get collisions or not.
if pid > 0:
# parent
rns = {_rand.rand64bits() for _ in range(100)}
child_rns = q.get()
assert rns & child_rns == set()
else:
# child
try:
rngs = {_rand.rand64bits() for _ in range(100)}
q.put(rngs)
finally:
# Kill the process so it doesn't continue running the rest of the
# test suite in a separate process. Note we can't use sys.exit()
# as it raises an exception that pytest will detect as an error.
os._exit(0)
def target(q):
assert sum((_ is _rand.seed for _ in forksafe._registry)) == 1
q.put([_rand.rand64bits() for _ in range(100)])
def _target():
# Generate a bunch of numbers to try to maximize the chance that
# two threads will be calling rand64bits at the same time.
rngs = [_rand.rand64bits() for _ in range(200000)]
q.put(rngs)
def target(q):
q.put([_rand.rand64bits() for _ in range(100)])
def f():
_ = _rand.rand64bits()
_ = _rand.rand64bits()
