def test_submit(self):
e = LocalDaskExecutor()
with e.start():
assert e.submit(lambda: 1).compute() == 1
assert e.submit(lambda x: x, 1).compute() == 1
assert e.submit(lambda x: x, x=1).compute() == 1
assert e.submit(lambda: prefect).compute() is prefect
def test_wait(self):
e = LocalDaskExecutor()
with e.start():
assert e.wait(1) == 1
assert e.wait(prefect) is prefect
assert e.wait(e.submit(lambda: 1)) == 1
assert e.wait(e.submit(lambda x: x, 1)) == 1
assert e.wait(e.submit(lambda x: x, x=1)) == 1
assert e.wait(e.submit(lambda: prefect)) is prefect
def test_configurable_scheduler(self):
e = LocalDaskExecutor(scheduler="synchronous")
assert e.scheduler == "synchronous"
def check_scheduler(val):
assert dask.config.get("scheduler") == val
with dask.config.set(scheduler="threads"):
check_scheduler("threads")
with e.start():
e.submit(check_scheduler, "synchronous")
def test_submit_sets_task_name(self):
e = LocalDaskExecutor()
with e.start():
f = e.submit(lambda x: x + 1, 1, extra_context={"task_name": "inc"})
(res,) = e.wait([f])
assert f.key.startswith("inc-")
assert res == 2
f = e.submit(
lambda x: x + 1, 1, extra_context={"task_name": "inc", "task_index": 1}
)
(res,) = e.wait([f])
assert f.key.startswith("inc-1-")
assert res == 2
def test_interrupt_stops_running_tasks_quickly(self, scheduler):
# Windows implements `queue.get` using polling,
# which means we can set an exception to interrupt the call to `get`.
# Python 3 on other platforms requires sending SIGINT to the main thread.
if os.name == "nt":
from _thread import interrupt_main
else:
main_thread = threading.get_ident()
def interrupt_main():
import signal
signal.pthread_kill(main_thread, signal.SIGINT)
def long_task():
for i in range(50):
time.sleep(0.1)
e = LocalDaskExecutor(scheduler)
try:
interrupter = threading.Timer(0.5, interrupt_main)
interrupter.start()
start = time.time()
with e.start():
e.wait(e.submit(long_task))
except KeyboardInterrupt:
pass
except Exception:
assert False, "Failed to interrupt"
stop = time.time()
if stop - start > 4:
assert False, "Failed to interrupt"
def test_only_compute_once(self, scheduler, tmpdir):
e = LocalDaskExecutor(scheduler)
def inc(x, path):
if os.path.exists(path):
raise ValueError("Should only run once!")
with open(path, "wb"):
pass
return x + 1
with e.start():
f1 = e.submit(inc, 0, str(tmpdir.join("f1")))
f2 = e.submit(inc, f1, str(tmpdir.join("f2")))
f3 = e.submit(inc, f2, str(tmpdir.join("f3")))
assert e.wait([f1]) == [1]
assert e.wait([f2]) == [2]
assert e.wait([f3]) == [3]
assert e.wait([f1, f2, f3]) == [1, 2, 3]
def test_only_compute_once(self):
e = LocalDaskExecutor()
count = 0
def inc(x):
nonlocal count
count += 1
return x + 1
with e.start():
f1 = e.submit(inc, 0)
f2 = e.submit(inc, f1)
f3 = e.submit(inc, f2)
assert e.wait([f1]) == [1]
assert count == 1
assert e.wait([f2]) == [2]
assert count == 2
assert e.wait([f3]) == [3]
assert count == 3
assert e.wait([f1, f2, f3]) == [1, 2, 3]
assert count == 3
