[Tutor] question about number of threads

[Kent Johnson]

shawn bright wrote:
> Hey there,
> i have an app that runs several processes as threads.
> using the threading.Thread()
> 
> now, i have another app that does the same thing. Now, pretty soon, we 
> will be combining all the features of the two packages together into one 
> app.
> 
> My question is, is there a limit on how many threads one GUI application 
> can have running in the background ?
> Most of them are sleeping most of the time. They wake up and do 
> something every 10 seconds, 20 minutes, etc...

IIRC the number of threads is limited by memory - each thread requires 
some heap space for its stack, etc. I don't think you will have trouble 
until you have hundreds or thousands of threads.

For example on my computer this program prints 1031 before it exits with 
thread.error: can't start new thread:

import time
from threading import Thread, activeCount

def run():
     while 1:
         time.sleep(1)

while 1:
     print activeCount()
     t=Thread(target=run)
     t.setDaemon(1)
     t.start()

(The setDaemon() call lets the application exit normally when it gets an 
exception; otherwise it hangs with all the threads running.)

Kent