Python thread Never Stops?-CodePudding

I wrote the following simple program in python:

import sys
from multiprocessing.pool import ThreadPool


def handle_ip(ip_address):
    print('Child Thread')
    # Visit Web Page etc...
    sys.exit()


print('HI')
ip_addresses = ['1234']
pool = ThreadPool(processes=6)
p_results = [pool.apply_async(handle_ip, (ip,)) for ip in ip_addresses]
for result in p_results:
    result.get()
# Wait for ALL threads to finish
print('BYE')

For some reason it never stops running (BYE is never being printed), what's the problem?

I have 6 threads but only 1 is running as there is only one ip address in input, plus sys.exit() terminates current thread only so after it's terminated main thread should continue and end the program.

Please Note, I want to exit only the current thread, that's why I used sys.exit().

My code is much more complex and this is only a simple example to show the problem (even though it doesn't make much of a sense to immediately kill the thread)

CodePudding user response：

Try calling pool.close() before your loop.

CodePudding user response：

Why you don't use concurrent?

from concurrent.futures import ThreadPoolExecutor


def handle_ip(ip_address):
    print('Child Thread')


print('HI')
ip_addresses = ['1234']

with ThreadPoolExecutor(max_workers=6) as executor:
    results = executor.map(handle_ip, ip_addresses)

print('BYE')