def test_or_with_nocancel():
calls = set()
def delayed_call(delay):
time.sleep(delay)
calls.add(delay)
return delay
executor = Executors.thread_pool(max_workers=2)
futures = [
executor.submit(delayed_call, x) for x in (0.5, 0.1, 0.2, 1.0, 1.1)
]
futures = [f_nocancel(f) for f in futures]
future = f_or(*futures)
result = future.result()
# Result comes from the future which completed first
assert result == 0.1
# Only this calls should have completed so far
assert calls == set([0.1])
# But if we wait on this...
assert futures[-1].result() == 1.1
# Then they've all completed now, thanks to nocancel
assert calls == set([0.1, 0.2, 0.5, 1.0, 1.1])
def test_timeout():
def sleep_then_return(x):
time.sleep(x)
return x
with Executors.thread_pool(max_workers=2) as executor:
futures = [
executor.submit(sleep_then_return, x)
for x in [0.5, 0.5, 0.5, 0.5, 0.5]
]
futures[3] = f_nocancel(futures[3])
futures = [f_timeout(f, 0.02) for f in futures]
try:
futures[-1].result()
raise AssertionError("Should have failed")
except CancelledError:
# expected
pass
assert futures[0].result() == 0.5
assert futures[1].result() == 0.5
assert futures[2].cancelled()
assert futures[3].result() == 0.5
assert futures[4].cancelled()
def test_and_with_nocancel():
calls = set()
error = RuntimeError("simulated error")
def delayed_call(delay):
if delay is error:
raise error
time.sleep(delay)
calls.add(delay)
return delay
executor = Executors.thread_pool(max_workers=2)
futures = [
executor.submit(delayed_call, x) for x in (0.5, error, 0.2, 1.1, 1.2)
]
futures = [f_nocancel(f) for f in futures]
future = f_and(*futures)
exception = future.exception()
# error should have been propagated
assert exception is error
# nothing else has been called yet
assert not calls
# but if we wait on the last future...
assert futures[-1].result() == 1.2
# then all calls were made thanks to nocancel
assert calls == set([0.5, 0.2, 1.1, 1.2])
def test_nocancel():
executor = Executors.thread_pool(max_workers=2)
futures = [f_nocancel(executor.submit(delay_then, x)) for x in [1, 2, 3, 4, 5]]
for f in futures:
# Should not be able to cancel it even though most
# are not started yet
assert not f.cancel()
assert [f.result() for f in futures] == [1, 2, 3, 4, 5]
def test_nocancel():
with pytest.raises(TypeError):
f_nocancel("a")
with pytest.raises(TypeError):
f_nocancel(future="a")