A Python script with threads in a duplicated process on Linux

Question

I am running a Python script (version 3.6.8) on AWS t2.micro instance with Amazon Linux AMI 2018.03. The script runs two long-running threads as shown below.

I monitor CPU and memory usage with htop, which shows 2 processes for my script both taking resources. Based on the output it doesn't seem like two processes are actually running. On macOS, where I developed the script, htop shows only 1 process for my script. The first image below shows collapsed processes on Linux and the second one shows them in a tree view.

Am I using Python threads the wrong way? Or do macOS and Linux show processes for python script differently?

from threading import Thread
from time import sleep


def thread(sec_sleep):
    while 1:
        print('sleep', sec_sleep)
        sleep(sec_sleep)


def init_services():
    t = Thread(target=thread, args=(1, ))
    t.daemon = True
    t.start()


def main():
    init_services()
    thread(2)


if __name__ == "__main__":
    main()

output looks fine to me ... what do you mean when you say the output makes it look like they are not both running ... — Joran Beasley
– Joran Beasley, Commented Jan 9, 2020 at 5:29

Berkay · Accepted Answer · 2020-01-09 06:07:29Z

3

First of all there is nothing wrong with that. htop shows individual threads as separate processes by default. If you are press capital H it will show only main process(press again to switch back).

answered Jan 9, 2020 at 6:07

Berkay

917 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

A Python script with threads in a duplicated process on Linux

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related