From: jeff AT dtv DOT net (Jeff Smart)
Subject: gethostby... broken when forked
3 Dec 1997 23:48:35 -0800
Message-ID: <34862B09.3FFE.cygnus.gnu-win32@dtv.net>
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To: gnu-win32 AT cygnus DOT com

I have found the BSD calls gethostbyname and gethostbyaddr break when
they are used in a child process that was forked.

I compiled this snippet on Win95 using gnu-win32 b18 with the latest
coolview dll and lib dated 26Nov97.

The code will always return an exception violation:
STATUS_ACCESS_VIOLATION once gethostbyname is called.
If fork() is removed, then gethostbyname works..
It appears fork() is screwing these address lookup calls.
I do not have the latest sources to find this bug.  Has anyone else
found this nasty ?

Cheers,
Jeff


[----------------- begin -----------------------]
#include <stdio.h>
#include <netdb.h>
#include <sys/socket.h>
#include <netinet/in.h>

int main(argc, argv)
int argc;
char *argv[];
{
  struct hostent *hostptr; /* Internet host struct from netdb.h	*/
  char hostname[256];
  int childpid;

  strcpy(hostname, argv[1]);
  printf("PARENT STARTED PID=%d\n", getpid());

  if ((childpid = fork()) < 0) {
    printf("fork failed\n");
    exit(0);

  } else if (childpid == 0) {		/* start child process */
    printf("CHILD STARTED PID=%d\n", getpid());
    hostptr = gethostbyname(hostname);	/* BOMBS HERE */
    printf("hostptr = %p\n", hostptr);
    exit(0);

  }
}
[--------------------- end --------------------]
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