class TestCancellationToken(unittest.TestCase):
def setUp(self):
self.ct = CancellationToken()
self.sleep_time = 0.2
self.count = 15
def test_token(self):
self.assertFalse(self.ct.is_cancellation_requested())
self.ct.request_cancellation()
self.assertTrue(self.ct.is_cancellation_requested())
self.assertRaises(SystemExit, lambda: self.ct.raise_if_cancelled())
def test_cancelling_threads(self):
# Create a bunch of threads and start a timer
threads = [
threading.Thread(target=sleeper, args=(self.sleep_time, self.ct))
for _ in range(self.count)
]
start = timer()
for t in threads:
t.start()
# Request cancellation and wait for threads to end
self.ct.request_cancellation()
for t in threads:
t.join()
# Assert that threads finished faster than 1.5x the sleep time
stop = timer()
self.assertLess(stop - start, 1.5 * self.sleep_time)
def test_process_is_not_killed_immediately_after_cancellation(self):
ct = CancellationToken()
with subprocess.Popen(["sleep", "1"]) as proc:
res = mcerd.MCERD.cancellation_check(proc, 0.05, ct)
obs = MockObserver()
res.subscribe(obs)
ct.request_cancellation()
self.assertIsNone(proc.poll(), msg=FAILURE_MSG)
self.assertEqual([], obs.nexts, msg=FAILURE_MSG)
def test_cancellation_check_returns_one_item_at_maximum(self):
ct = CancellationToken()
with subprocess.Popen(["sleep", "1"]) as proc:
res = mcerd.MCERD.cancellation_check(proc, 0.01, ct)
obs = MockObserver()
res.subscribe(obs)
time.sleep(0.25)
ct.request_cancellation()
time.sleep(0.25)
self.assertEqual(1, len(obs.nexts), msg=FAILURE_MSG)
def test_requesting_cancellation_kills_the_process(self):
ct = CancellationToken()
with subprocess.Popen(["sleep", "1"]) as proc:
res = mcerd.MCERD.cancellation_check(proc, 0.01, ct)
obs = MockObserver()
res.subscribe(obs)
ct.request_cancellation()
time.sleep(DEFAULT_SLEEP_TIME)
self.assertNotEqual(0, int(proc.poll()), msg=FAILURE_MSG)
self.assertEqual([{
"is_running": False,
"msg": "Simulation was stopped"
}],
obs.nexts,
msg=FAILURE_MSG)
def test_cancelling_after_process_ends_does_not_change_observed_values(
self):
ct = CancellationToken()
with subprocess.Popen(["echo", "hello"], stdout=subprocess.DEVNULL) as \
proc:
res = mcerd.MCERD.cancellation_check(proc, 0.01, ct)
obs = MockObserver()
res.subscribe(obs)
ct.request_cancellation()
time.sleep(DEFAULT_SLEEP_TIME)
self.assertEqual(0, proc.poll(), msg=FAILURE_MSG)
self.assertEqual([{
"is_running": False,
"msg": "Simulation was stopped"
}],
obs.nexts,
msg=FAILURE_MSG)