how to kill a thread in python?

[shanenin]

I have a very simple plugin I wrote for freevo. below is the plugin. it will shutdown your computer after your avi file has finished playing, kind of like a sleep timer.

#!/usr/bin/env python

import os
import time
import commands
import thread

import plugin

from gui.PopupBox import PopupBox
from gui.ConfirmBox import ConfirmBox

class PluginInterface(plugin.ItemPlugin):
    """
    this plugin will power down your system using the command
    "shutdown -h now" after your avi file has finished.
    you can enable it by adding this to your local conf file
    plugin.activate('video.autoshutdown')
    """
    def __init__(self):
        plugin.ItemPlugin.__init__(self)

    def actions(self, item):
        self.item = item
        if item.type == 'video':
                    return [ (self.confirm_start_timer, 'engage autoshutoff') ]
        else:
            return []

    def confirm_start_timer(self, arg=None, menuw=None):
        ConfirmBox(text=_('engage autoshutoff for the following avi file\n\
                                         "%s"') % self.item.name,
                   handler=self.start_timer, default_choice=1).show()

    def start_timer(self, arg=None, menuw=None):
        box = PopupBox(text=_('you must start your avi file within ' \
                                               'one minute to prevent the shutdown' \
                                               ' to begin' ))
        box.show()
        time.sleep(6)
        box.destroy()
        thread.start_new_thread(self.run_timer,())

    def run_timer(self):
        while True:
            time.sleep(60)
            if commands.getoutput('ps -ewf').__contains__(self.item.filename)== False:
                os.system('shutdown -h now')
                break

the run_timer method is started as a new thread using this line of code

thread.start_new_thread(self.run_timer,())

the run timer_method checks at an interval of every minute to see if an avi file is playing, if the avi is no longer playing, it will send the computer the shutdown command. I would like to be able to abort the shutdown if possible. Is their a way to kill the thread that I started, maybe some sort of kill method?

[G-Do]

Hi shanenin,

Here's one way of doing it:

import sys, os, time, thread
# Keep track of thread PIDs
t1, t2 = 0, 0
# The major thread function
def f(timeslice):
    # Set t2 to the PID for this thread
    global t2
    t2 = os.getpid()
    # Loop, do something after every timeslice
    while True:
        # You would do something intelligent here
        time.sleep(timeslice)
# Set t1 to the PID for the parent thread
t1 = os.getpid()
# Start a new thread
thread.start_new_thread(f, (10,))
# Wait a bit and print the two PIDs
time.sleep(1)
print "PIDs:", t1, t2
# Give the user an option to stop the thread and the program
while True:
    answer = raw_input("Stop thread now? Y/N: ")
    if answer in [ "Y", "y" ]:
        os.popen("kill -9 "+str(t2))
        break
# Do something here - maybe cleanup?
# Terminate gracefully
sys.exit(0)

You can keep doing stuff in the parent thread after you have killed the spawned thread. Alternatively, you could spawn two threads, one which queries the user for input and the other which plays the AVI/shuts down. The first could write to some global flag, which the second would check every timeslice - if the flag goes up, the second thread self-terminates.

An alternative to calling "kill" explicitly is to subclass the Thread class and call the join() method on your thread instance. See here for details.

[shanenin]

thanks. I appreciate the nice example :-)