Why does the status of parallel jobs is never set to "finished" even after job finished?

I use below code as an example to run jobs in parallel. Even though I see from output that the Jobs have finished, the status is still false. Why is that? I would expect that the status of "status_dict" changes to "True" for finished jobs.

But from below output we see that status stays False even when job has finished.

----------123
{'JOB4': False, 'JOB11': False, 'JOB23': False}
----
JOB4 False
Starting job JOB11...
Starting job JOB4...
Starting job JOB23...
----
JOB11 False
----
JOB23 False
----
JOB4 False
Finished job JOB23.
Finished job JOB4.
Finished job JOB11.
----
JOB11 False
----
JOB23 False
----
JOB4 False
----
JOB11 False

Code:

import multiprocessing, time

# run jobs parallel
def run_job(jn, par):
    print(f"Starting job {jn}...")
    time.sleep(3)
    print(f"Finished job {jn}.")


if __name__ == '__main__':    
    list_jobs = ["JOB4", "JOB11", "JOB23"]
    processes = []

    status_dict = multiprocessing.Manager().dict()
    for jn in list_jobs:
        par = {}
        par["sleep"] = 5
        status_dict[jn] = False
        p = multiprocessing.Process(target=run_job, args=(jn, par))
        processes.append(p)
        p.start()

    
    print("------------123")
    print(status_dict)
    while not all(status_dict.values()):
        for job_id, status in status_dict.items():
            print("----")
            print(job_id, status)
            time.sleep(1)


    print("ENDE")

Problem is I was not updating the status. Below code works:

import multiprocessing, time

# run jobs parallel
def run_job(jn, status):
    print(f"Starting job {jn}...")
    time.sleep(3)
    status.value = True
    print(f"Finished job {jn}.")


if __name__ == '__main__':    
    list_jobs = ["JOB4", "JOB11", "JOB23"]
    processes = []

    status_dict = {}
    for jn in list_jobs:
        par = {}
        par["sleep"] = 5
        status_dict[jn] = multiprocessing.Value('b', False)
        p = multiprocessing.Process(target=run_job, args=(jn, status_dict[jn]))
        processes.append(p)
        p.start()

    
    print("------------123")
    for i in range(100):
        print(status_dict)
        for k in status_dict:
            print("----")
            print(k, status_dict[k].value)
            time.sleep(1)


    print("ENDE")

The reason why the status_dict remains False for all jobs is because you're not updating the dictionary within the run_job function.

To update the status of a job, you can pass the status_dict as an argument to the run_job function, and update it within the function whenever a job is finished. Modified code of function:

def run_job(jn, par, status_dict):
    print(f"Starting job {jn}...")
    time.sleep(3)
    print(f"Finished job {jn}.")
    status_dict[jn] = True

Then, when you start the processes, you can pass the status_dict as an argument:

p = multiprocessing.Process(target=run_job, args=(jn, par, status_dict))

After these changes the code should be fine and work as excepted.