You can use the Timer in threading. Look at what is done in the attached
script. You can basically use three functions to start the timer, stop
the timer and do what ever it is to be done upon expiring.
There maybe easier ways, but this will work. You can call the
start_timer with a time in seconds and then it will terminate and there
you can call a different function that does the rest of your stuff.
Johan.
Raduz wrote:
Hi all
Simple question: Is it possible to stop a running function after certain
predefined time?
Right now I have some home-made bash scripts for recording shows from net
broadcasted ogg stream, that use wget for stream downloading, and two "at"
jobs - one for first script (which prepares directory it's going to save to,
dumps info about it's own PID, and execs wget for actual download), second for
another script (which reads PID info dumped by the first script, uses it to
kill wget and performs some clean-up tasks).
I would like to convert this routine to Python using pycurl module, or maybe
even standard urllib.urlretrieve. Problem is, downloaded file is a stream
without end, so I have to stop the downloader manually, and I would prefer to
drop the "two scripts" approach - no more PID saving and process killing. I
want one clean package, which will start the download, let it run for some
time, and then stop it correctly. I just don't know how to time the download.
Can anybody give some sugestions, please? Is the threading way to go? Thanks.
"""
This module is helpful when something must be done on a timer.
It is for testing purposes but the main class can be used in other applications
with modifications to the timerExpired function. You can put your own stuff in there
that must happen when the timer has expired.
It is used by executing it from the shell with arguments -t, -s and optional -x.
argument -t: timer duration in seconds.
argument -s: choice to stop the timer after a default 5 seconds,
optional -x: if -s was 'y' and an delay in seconds before the timer must be stopped.
Author: J Geldenhuys
AccessTel
Date : 2005-08-11
"""
# The threading module is used that has the code to start
# and stop the timer instance, so, why not use it?
from threading import Timer
# time module is imported to sleep a while after timer is started
# before stopping it.
import time
# Main class to get timer instance going
class timer:
# start timer with n seconds and go to self.timerExpired
def startTimer(self, n):
self.t = Timer(n, self.timerExpired)
print 'Timer started for %d seconds'% n
#start the timer instance
self.t.start()
# Called if argument is true to stop it.
def stopTimer(self):
# First look if the timer is active
if self.t.isAlive():
print 'Timer found active'
#Stop the timer instance
self.t.cancel()
print 'Timer stopped'
# If not active, do nothing
else:
print 'Timer inactive'
# Put code in here to execute after timer has expired.
def timerExpired(self):
print 'Timer expired, go to do what you want'
# Help the user understand how to use this module
def printUsageAndExit():
print
print "Usage: %s -t[time-out] "\
"-s[sleep before stopping, 'y' or 'n'] \r\noptional -x[seconds to wait before stopping]\r\n\r\n"\
"Example: timertest.py -t 10 -s y -x 6\r\n" % sys.argv[0]
print
sys.exit(1)
if __name__ == '__main__':
import sys, getopt, string
l = (len(sys.argv))
if l <= 4:
printUsageAndExit()
arg3 = int('5')
optlist, args = getopt.getopt(sys.argv[1:], "t:s:x:")
for opt in optlist:
if opt[0] == '-t':
if not (opt[1].isdigit()):
printUsageAndExit()
arg1 = int(opt[1])
elif opt[0] == '-s':
arg2 = (opt[1])
#printUsageAndExit()
elif opt[0] == '-x':
if not (opt[1].isdigit()):
printUsageAndExit()
arg3 = int(opt[1])
x = timer()
if arg2 == 'y':
x.startTimer(arg1)
time.sleep(arg3)
print 'You chose to stop the timer after %s with option %s'%(str(arg3), arg2)
x.stopTimer()
if arg2 == 'n':
x.startTimer(arg1)
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