sleep and Timer

[Rob Hall]

> >def run(self):
> >    while self.quit = false:
> >        DO SOME STUFF
> >        time.sleep(120)
> What if instead of sleeping you had an event object and waited for it with
a timeout of 120, e.g.,
>          evt.wait(120)
>          if evt.isSet(): # means another thread set the event, meaning
kill
>              # die here -- should be immediately after event is set
>          #otherwise just let loop continue around
> >
>

I rather like this approach.  It works well.

The trouble is, once I go above 200 threads, it starts to bog down.

See my other post for an example using sleep(), together with some stats.

With the same problem here, using your solution, I get the following stats:

Time to create 500 threads:  216.85
Time to kill all threads:    34.72

As you can see, when working with a large number of threads, it isn't quite
upt-to-speed (excuse the pun).

But I love the solution for a small number of threads!  In this case it is
comparible in speed.  Thanks!

Here is the ammended program:

import time
import threading
import random

class test(threading.Thread):
    def __init__(self, number):
        threading.Thread.__init__(self)
        self.terminate = 0
        self.number = number
        self.evt = threading.Event()

    def run(self):
        print 'Thread %d launched' % self.number
        sleepTime = random.random() * 10
        while 1:
            self.evt.wait(sleepTime)
            if self.evt.isSet():
                break

        print '>>>> Thread %d terminated.' % self.number


    def quit(self):
        print 'Exiting thread %d.' % self.number
        self.evt.set()


# Create the threads
startCreate = time.time()
threadList = []
for number in range(1,501):
    t = test(number)
    t.start()
    threadList.append(t)
endCreate = time.time()

time.sleep(2)

# Kill the threads
startKill = time.time()
for t in threadList:
    t.quit()
for t in threadList:
    t.join()

endKill = time.time()

# Display results
timeCreate = endCreate - startCreate
timeKill = endKill - startKill
print 'Time taken to create threads is %f.' % timeCreate
print 'Time taken to kill threads is %f.' % timeKill