signal.alarm replacement in Windows [Python]

Question

I have a function that occasionally hangs.

Normally I would set an alarm, but I'm in Windows and it's unavailable.

Is there a simple way around this, or should I just create a thread that calls time.sleep()?

Answer 1

The most robust solution is to use a subprocess, then kill that subprocess. Python2.6 adds .kill() to subprocess.Popen().

I don't think your threading approach works as you expect. Deleting your reference to the Thread object won't kill the thread. Instead, you'd need to set an attribute that the thread checks once it wakes up.

Answer 2

Here's how the original poster solved his own problem:

Ended up going with a thread. Only trick was using os._exit instead of sys.exit

import os
import time
import threading

class Alarm (threading.Thread):
    def __init__ (self, timeout):
        threading.Thread.__init__ (self)
        self.timeout = timeout
        self.setDaemon (True)
    def run (self):
        time.sleep (self.timeout)
        os._exit (1)

alarm = Alarm (4)
alarm.start ()
time.sleep (2)
del alarm
print 'yup'

alarm = Alarm (4)
alarm.start ()
time.sleep (8)
del alarm
print 'nope'  # we don't make it this far