sysdeps/pthread/tst-_res1.c

   1 /* Copyright (C) 2003-2024 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 /* Test whether _res in glibc 2.1.x and earlier (before __res_state()
  19    was introduced) works.  Portable programs should never do the
  20    dirty things below.  */
  21
  22 #include <pthread.h>
  23 #include <resolv.h>
  24 #include <stdlib.h>
  25 #include <stdio.h>
  26
  27 void *tf (void *resp)
  28 {
  29   if (resp == &_res || resp == __res_state ())
  30     abort ();
  31   _res.retry = 24;
  32   return NULL;
  33 }
  34
  35 void do_test (struct __res_state *resp)
  36 {
  37   if (resp != &_res || resp != __res_state ())
  38     abort ();
  39   if (_res.retry != 12)
  40     abort ();
  41 }
  42
  43 int main (void)
  44 {
  45 #undef _res
  46   extern struct __res_state _res;
  47   pthread_t th;
  48
  49   _res.retry = 12;
  50   if (pthread_create (&th, NULL, tf, &_res) != 0)
  51     {
  52       puts ("create failed");
  53       exit (1);
  54     }
  55
  56   do_test (&_res);
  57
  58   if (pthread_join (th, NULL) != 0)
  59     {
  60       puts ("join failed");
  61       exit (1);
  62     }
  63
  64   do_test (&_res);
  65
  66   exit (0);
  67 }