#!/usr/bin/python2.2

from Tkinter import *
import os,sys,signal
def abortf():
  print "aborting child "+str(os.getpid())
  os.abort()

def onAlarm(signum,stackframe):
   print "waiting for a child to exit"
   signal.alarm(5)

def onSigchild(signum,stackframe):
   global cnt
   (wpid,exitcode)=os.waitpid(-1,os.WNOHANG)
   if (os.WIFEXITED(exitcode) ):
        print "The child "+str(wpid)+" exited normally\n"
   if (os.WIFSIGNALED(exitcode) ):
        print "The child "+str(wpid)+" exited on a signal\n"   
   cnt=cnt-1
   print "The value of cnt is now "+str(cnt)
   if not cnt:
     print "All children have exited"


def childProg():
  root = Tk()
  root.title('Child Window ')
  Label(root, text="Press Button to Exit").pack(side=TOP,pady=10)
  Label(root, text="My PID is "+str(os.getpid())).pack(side=LEFT,pady=10)
  Button(root, text="Abort", command=abortf).pack(side=RIGHT)
  Button(root, text="Exit", command=root.quit).pack(side=RIGHT)
  root.mainloop()
n=int(sys.argv[1])
print "Forking "+str(n)+" children"
for i in range(1,n+1):
  processid = os.fork()
  if (processid):
    print "spawing child "+str(processid)
  else:
    cnt=1
    childProg()
    break
if not processid:
  pass
else:
  global cnt
  cnt=n
  print "waiting for all children to exit"
  tt=0
  signal.signal(signal.SIGALRM,onAlarm)
  signal.signal(signal.SIGCHLD,onSigchild)
  signal.alarm(5)
  while 1 :
#do some other work
    if not cnt:
      sys.exit()