#!/usr/bin/env python
     # encoding: utf-8
     #
     # Copyright (c) 2008 Doug Hellmann All rights reserved.
     #
     """
     """
     
     __version__ = "$Id$"
     #end_pymotw_header
     
     import signal
     import threading
     import os
     import time
     
     def signal_handler(num, stack):
         print 'Received signal %d in %s' % (num, threading.currentThread())
     
     signal.signal(signal.SIGUSR1, signal_handler)
     
     def wait_for_signal():
         print 'Waiting for signal in', threading.currentThread()
         signal.pause()
         print 'Done waiting'
     
     # Start a thread that will not receive the signal
     receiver = threading.Thread(target=wait_for_signal, name='receiver')
     receiver.start()
     time.sleep(0.1)
     
     def send_signal():
         print 'Sending signal in', threading.currentThread()
         os.kill(os.getpid(), signal.SIGUSR1)
     
     sender = threading.Thread(target=send_signal, name='sender')
     sender.start()
     sender.join()
     
     # Wait for the thread to see the signal (not going to happen!)
     print 'Waiting for', receiver
     signal.alarm(2)
     receiver.join()