SIGCHLD, SIG_IGN and zombie processes

From: Grzegorz Jablonski (gwj_at_mangled_w-s.pl)
Date: 09/27/03 

Date: Sat, 27 Sep 2003 22:51:49 +0200

Hello all,

I have the following program:

#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <unistd.h>

int main ()
{
 int i, j;

 signal (SIGCHLD, SIG_IGN);
 printf ("server waiting\n");
 if (fork () == 0)
 {
  printf ("hello from child\n");
  sleep (1);
  printf ("goodbye from child\n");
  exit (0);
 }
 for (i = 0; i < 10000000; i++) j += i;
 sleep (300);
 exit (0);
}

I ignore SIGCHLD to prevent creation of the zombie processes.
This program works as intended, no zombie is created.
If I remove the dummy for loop, the zombie process appears.
Am I mising something, or is it a bug?
I use kernel 2.4.21 with glibc-2.3.1

Regards,
GWJ

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