Checking on a thread / remove from list

Question

I have a thread which extends Thread. The code looks a little like this;

class MyThread(Thread):     def run(self):         # Do stuff  my_threads = [] while has_jobs() and len(my_threads) < 5:     new_thread = MyThread(next_job_details())     new_thread.run()     my_threads.append(new_thread)  for my_thread in my_threads     my_thread.join()     # Do stuff 

So here in my pseudo code I check to see if there is any jobs (like a db etc) and if there is some jobs, and if there is less than 5 threads running, create new threads.

So from here, I then check over my threads and this is where I get stuck, I can use .join() but my understanding is that - this then waits until it's finished so if the first thread it checks is still in progress, it then waits till it's done - even if the other threads are finished....

so is there a way to check if a thread is done, then remove it if so?

eg

for my_thread in my_threads:     if my_thread.done():         # process results         del (my_threads[my_thread]) ?? will that work... 

Answer 1

As TokenMacGuy says, you should use thread.is_alive() to check if a thread is still running. To remove no longer running threads from your list you can use a list comprehension:

for t in my_threads:     if not t.is_alive():         # get results from thread         t.handled = True my_threads = [t for t in my_threads if not t.handled] 

This avoids the problem of removing items from a list while iterating over it.

Answer 2

you need to call thread.isAlive()to find out if the thread is still running