test_threading.py

import threading
import time

working_flag = False
pending_flag = False

def run_test():
    global working_flag, pending_flag

    if working_flag:
        # request triggered when the job is running, so set pending
        pending_flag = True
        print("bounced")
        return
    
    # run task in background
    threading.Thread(target = test).start()

def test():
    global working_flag, pending_flag

    working_flag = True
    print("starting")
    time.sleep(2)
    print("done")
    working_flag = False

    if pending_flag:
        # we got another request, so run once more
        pending_flag = False
        run_test()

if __name__ == "__main__":
    run_test()
    run_test()
    run_test()
    run_test()
    time.sleep(2)
    run_test()
    run_test()
    run_test()
    
# output
"""
> python3 test_thread.py
starting
bounced
bounced
bounced
bounced
bounced
bounced
done
starting
done
"""