processpool_threadpool.py

import time
import random
import signal
from concurrent.futures import ProcessPoolExecutor, ThreadPoolExecutor


TIMEOUT = 3


def timeout_signal_handler(signum, frame):
    raise TimeoutError()


def main():
    signal.signal(signal.SIGALRM, timeout_signal_handler)
    signal.signal(signal.SIGINT, timeout_signal_handler)
    signal.alarm(TIMEOUT)

    futures = []
    try:
        with ProcessPoolExecutor(max_workers=2) as executor:
            for i in range(10):
                futures.append(executor.submit(do, i))
    except TimeoutError as reason:
        print("Canceling tasks...")
        for e, f in enumerate(futures):
            f.cancel()
            print("     Task [{}] {}".format(e, f))

    signal.alarm(0)


def do(task_name):
    ttime = random.randint(1, 5)
    print("Running task [{}] - Time: {}...".format(task_name, ttime))
    time.sleep(ttime)
    print("Finished task [{}]".format(task_name))


if __name__ == "__main__":
    main()

ThreadPoolExecutor:

Running task [0] - Time: 1...
Running task [1] - Time: 5...
Finished task [0]
Running task [2] - Time: 3...
Canceling tasks...
     Task [0] <Future at 0x7fa6eca02d30 state=finished returned NoneType>
     Task [1] <Future at 0x7fa6ec9bdd30 state=running>
     Task [2] <Future at 0x7fa6ebe33f28 state=running>
     Task [3] <Future at 0x7fa6ebe3b2e8 state=cancelled>
     Task [4] <Future at 0x7fa6ebe3b470 state=cancelled>
     Task [5] <Future at 0x7fa6ebe3b550 state=cancelled>
     Task [6] <Future at 0x7fa6ebe3b630 state=cancelled>
     Task [7] <Future at 0x7fa6ebe3b710 state=cancelled>
     Task [8] <Future at 0x7fa6ebe3b7f0 state=cancelled>
     Task [9] <Future at 0x7fa6ebe3b8d0 state=cancelled>
Finished task [2]
Finished task [1]

ProcessPoolExecutor:

Running task [1] - Time: 4...
Running task [0] - Time: 3...
Canceling tasks...
     Task [0] <Future at 0x7f0c01576e10 state=running>
     Task [1] <Future at 0x7f0c015835c0 state=running>
     Task [2] <Future at 0x7f0c01583668 state=running>
     Task [3] <Future at 0x7f0c01583710 state=running>
     Task [4] <Future at 0x7f0c015837f0 state=running>
     Task [5] <Future at 0x7f0c015838d0 state=cancelled>
     Task [6] <Future at 0x7f0c015839b0 state=cancelled>
     Task [7] <Future at 0x7f0c01583a90 state=cancelled>
     Task [8] <Future at 0x7f0c01583b70 state=cancelled>
     Task [9] <Future at 0x7f0c01583c50 state=cancelled>
Finished task [0]
Running task [2] - Time: 1...
Finished task [1]
Running task [3] - Time: 4...
Finished task [2]
Running task [4] - Time: 4...
Finished task [3]
Finished task [4]