nptl/tst-context1.c

   1 /* Copyright (C) 2003 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@redhat.com>, 2003.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <errno.h>
  21 #include <error.h>
  22 #include <limits.h>
  23 #include <pthread.h>
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <ucontext.h>
  27
  28
  29 #define N       4
  30
  31 static char stacks[N][PTHREAD_STACK_MIN];
  32 static ucontext_t ctx[N][2];
  33 static volatile int failures;
  34
  35
  36 static void
  37 fct (long int n)
  38 {
  39   /* Just to use the thread local descriptor.  */
  40   printf ("%ld: in %s now\n", n, __FUNCTION__);
  41   errno = 0;
  42 }
  43
  44
  45 static void *
  46 tf (void *arg)
  47 {
  48   int n = (int) (long int) arg;
  49
  50   if (getcontext (&ctx[n][1]) != 0)
  51     {
  52       printf ("%d: cannot get context: %m\n", n);
  53       exit (1);
  54     }
  55
  56   printf ("%d: %s: before makecontext\n", n, __FUNCTION__);
  57
  58   ctx[n][1].uc_stack.ss_sp = stacks[n];
  59   ctx[n][1].uc_stack.ss_size = PTHREAD_STACK_MIN;
  60   ctx[n][1].uc_link = &ctx[n][0];
  61   makecontext (&ctx[n][1], (void (*) (void)) fct, 1, (long int) n);
  62
  63   printf ("%d: %s: before swapcontext\n", n, __FUNCTION__);
  64
  65   if (swapcontext (&ctx[n][0], &ctx[n][1]) != 0)
  66     {
  67       ++failures;
  68       printf ("%d: %s: swapcontext failed\n", n, __FUNCTION__);
  69     }
  70   else
  71     printf ("%d: back in %s\n", n, __FUNCTION__);
  72
  73   return NULL;
  74 }
  75
  76
  77 static volatile int global;
  78
  79
  80 static int
  81 do_test (void)
  82 {
  83   int n;
  84   pthread_t th[N];
  85   ucontext_t mctx;
  86
  87   puts ("making contexts");
  88   if (getcontext (&mctx) != 0)
  89     {
  90       if (errno == ENOSYS)
  91         {
  92           puts ("context handling not supported");
  93           exit (0);
  94         }
  95
  96       printf ("%s: getcontext: %m\n", __FUNCTION__);
  97       exit (1);
  98     }
  99
 100   /* Play some tricks with this context.  */
 101   if (++global == 1)
 102     if (setcontext (&mctx) != 0)
 103       {
 104         puts ("setcontext failed");
 105         exit (1);
 106       }
 107   if (global != 2)
 108     {
 109       puts ("global not incremented twice");
 110       exit (1);
 111     }
 112   puts ("global OK");
 113
 114   for (n = 0; n < N; ++n)
 115     if (pthread_create (&th[n], NULL, tf, (void *) (long int) n) != 0)
 116       {
 117         puts ("create failed");
 118         exit (1);
 119       }
 120
 121   for (n = 0; n < N; ++n)
 122     if (pthread_join (th[n], NULL) != 0)
 123       {
 124         puts ("join failed");
 125         exit (1);
 126       }
 127
 128   return failures;
 129 }
 130
 131 #define TEST_FUNCTION do_test ()
 132 #include "../test-skeleton.c"