stdlib/tst-setcontext.c

   1 /* Copyright (C) 2001 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 Library General Public License as
   6    published by the Free Software Foundation; either version 2 of the
   7    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    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 #include <errno.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <ucontext.h>
  23
  24 static ucontext_t ctx[3];
  25
  26 static int was_in_f1;
  27 static int was_in_f2;
  28
  29 static void
  30 f1 (long a0, long a1, long a2, long a3)
  31 {
  32   printf ("start f1(a0=%lx,a1=%lx,a2=%lx,a3=%lx)\n", a0, a1, a2, a3);
  33
  34   if (a0 != 1 || a1 != 2 || a2 != 3 || a3 != -4)
  35     {
  36       puts ("arg mismatch");
  37       exit (-1);
  38     }
  39
  40   if (swapcontext (&ctx[1], &ctx[2]) != 0)
  41     {
  42       printf ("%s: swapcontext: %m\n", __FUNCTION__);
  43       exit (1);
  44     }
  45   puts ("finish f1");
  46   was_in_f1 = 1;
  47 }
  48
  49 static void
  50 f2 (void)
  51 {
  52   puts ("start f2");
  53   if (swapcontext (&ctx[2], &ctx[1]) != 0)
  54     {
  55       printf ("%s: swapcontext: %m\n", __FUNCTION__);
  56       exit (1);
  57     }
  58   puts ("finish f2");
  59   was_in_f2 = 1;
  60 }
  61
  62 int
  63 main (void)
  64 {
  65   char st1[8192];
  66   char st2[8192];
  67
  68   puts ("making contexts");
  69   if (getcontext (&ctx[1]) != 0)
  70     {
  71       if (errno == ENOSYS)
  72         exit (0);
  73
  74       printf ("%s: getcontext: %m\n", __FUNCTION__);
  75       exit (1);
  76     }
  77   ctx[1].uc_stack.ss_sp = st1;
  78   ctx[1].uc_stack.ss_size = sizeof st1;
  79   ctx[1].uc_link = &ctx[0];
  80   makecontext (&ctx[1], (void (*) (void)) f1, 4, 1, 2, 3, -4);
  81
  82   if (getcontext (&ctx[2]) != 0)
  83     {
  84       printf ("%s: second getcontext: %m\n", __FUNCTION__);
  85       exit (1);
  86     }
  87   ctx[2].uc_stack.ss_sp = st2;
  88   ctx[2].uc_stack.ss_size = sizeof st2;
  89   ctx[2].uc_link = &ctx[1];
  90   makecontext (&ctx[2], f2, 0);
  91
  92   puts ("swapping contexts");
  93   if (swapcontext (&ctx[0], &ctx[2]) != 0)
  94     {
  95       printf ("%s: swapcontext: %m\n", __FUNCTION__);
  96       exit (1);
  97     }
  98   puts ("back at main program");
  99
 100   if (was_in_f1 == 0)
 101     {
 102       puts ("didn't reach f1");
 103       exit (1);
 104     }
 105   if (was_in_f2 == 0)
 106     {
 107       puts ("didn't reach f2");
 108       exit (1);
 109     }
 110
 111   puts ("test succeeded");
 112   return 0;
 113 }