I have a script which must execute some shell commands. However if command takes too long to complete it must be forcibly killed. Consider the following code snippet:
import asyncio, random q = asyncio.Queue() MAX_WAIT = 5 @asyncio.coroutine def blocking_task(sec): print('This task will sleep {} sec.'.format(sec)) create = asyncio.create_subprocess_shell( 'sleep {s}; echo "Woke up after {s} sec." >> ./tst.log'.format(s=sec), stdout=asyncio.subprocess.PIPE) proc = yield from create yield from proc.wait() @asyncio.coroutine def produce(): while True: q.put_nowait(random.randint(3,8)) yield from asyncio.sleep(0.5 + random.random()) @asyncio.coroutine def consume(): while True: value = yield from q.get() try: yield from asyncio.wait_for(blocking_task(value), MAX_WAIT) except asyncio.TimeoutError: print('~/~ Job has been cancelled !!') else: print('=/= Job has been done :]') loop = asyncio.get_event_loop() asyncio.ensure_future(produce()) asyncio.ensure_future(consume()) loop.run_forever() This code produce the following output:
This task will sleep 4 sec. =/= Job has been done :] This task will sleep 8 sec. ~/~ Job has been cancelled !! This task will sleep 5 sec. ~/~ Job has been cancelled !! So it seems that it's working as expected, jobs are stopped if they take too long to finish. But if I check the log I can confirm that however time consuming tasks continued running and were not actually stopped / killed / aborted:
Woke up after 4 sec. Woke up after 8 sec. Woke up after 5 sec. I would expect there should be just one line in the log, as other processes must have been aborted before they had a chance to finish:
Woke up after 4 sec. Is there a way to achieve what I want?
I'm not even sure if I need asyncio here, perhaps concurrent.futures could be used too. Either way task is the same - terminate tasks, which are taking too much time to finish.
