nptl/tst-barrier2.c

   1 /* Tests process-shared barriers.
   2    Copyright (C) 2002-2017 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <errno.h>
  21 #include <pthread.h>
  22 #include <stdint.h>
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <unistd.h>
  27 #include <sys/mman.h>
  28 #include <sys/wait.h>
  29
  30
  31 static int
  32 do_test (void)
  33 {
  34   size_t ps = sysconf (_SC_PAGESIZE);
  35   char tmpfname[] = "/tmp/tst-barrier2.XXXXXX";
  36   char data[ps];
  37   void *mem;
  38   int fd;
  39   pthread_barrier_t *b;
  40   pthread_barrierattr_t a;
  41   pid_t pid;
  42   int serials = 0;
  43   int cnt;
  44   int status;
  45   int p;
  46
  47   fd = mkstemp (tmpfname);
  48   if (fd == -1)
  49     {
  50       printf ("cannot open temporary file: %m\n");
  51       return 1;
  52     }
  53
  54   /* Make sure it is always removed.  */
  55   unlink (tmpfname);
  56
  57   /* Create one page of data.  */
  58   memset (data, '\0', ps);
  59
  60   /* Write the data to the file.  */
  61   if (write (fd, data, ps) != (ssize_t) ps)
  62     {
  63       puts ("short write");
  64       return 1;
  65     }
  66
  67   mem = mmap (NULL, ps, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
  68   if (mem == MAP_FAILED)
  69     {
  70       printf ("mmap failed: %m\n");
  71       return 1;
  72     }
  73
  74   b = (pthread_barrier_t *) (((uintptr_t) mem + __alignof (pthread_barrier_t))
  75                              & ~(__alignof (pthread_barrier_t) - 1));
  76
  77   if (pthread_barrierattr_init (&a) != 0)
  78     {
  79       puts ("barrierattr_init failed");
  80       return 1;
  81     }
  82
  83   if (pthread_barrierattr_getpshared (&a, &p) != 0)
  84     {
  85       puts ("1st barrierattr_getpshared failed");
  86       return 1;
  87     }
  88
  89   if (p != PTHREAD_PROCESS_PRIVATE)
  90     {
  91       puts ("default pshared value wrong");
  92       return 1;
  93     }
  94
  95   if (pthread_barrierattr_setpshared (&a, PTHREAD_PROCESS_SHARED) != 0)
  96     {
  97       puts ("barrierattr_setpshared failed");
  98       return 1;
  99     }
 100
 101   if (pthread_barrierattr_getpshared (&a, &p) != 0)
 102     {
 103       puts ("2nd barrierattr_getpshared failed");
 104       return 1;
 105     }
 106
 107   if (p != PTHREAD_PROCESS_SHARED)
 108     {
 109       puts ("pshared value after setpshared call wrong");
 110       return 1;
 111     }
 112
 113   if (pthread_barrier_init (b, &a, 2) != 0)
 114     {
 115       puts ("barrier_init failed");
 116       return 1;
 117     }
 118
 119   if (pthread_barrierattr_destroy (&a) != 0)
 120     {
 121       puts ("barrierattr_destroy failed");
 122       return 1;
 123     }
 124
 125   puts ("going to fork now");
 126   pid = fork ();
 127   if (pid == -1)
 128     {
 129       puts ("fork failed");
 130       return 1;
 131     }
 132
 133   /* Just to be sure we don't hang forever.  */
 134   alarm (4);
 135
 136 #define N 30
 137   for (cnt = 0; cnt < N; ++cnt)
 138     {
 139       int e;
 140
 141       e = pthread_barrier_wait (b);
 142       if (e == PTHREAD_BARRIER_SERIAL_THREAD)
 143         ++serials;
 144       else if (e != 0)
 145         {
 146           printf ("%s: barrier_wait returned value %d != 0 and PTHREAD_BARRIER_SERIAL_THREAD\n",
 147                   pid == 0 ? "child" : "parent", e);
 148           return 1;
 149         }
 150     }
 151
 152   alarm (0);
 153
 154   printf ("%s: was %d times the serial thread\n",
 155           pid == 0 ? "child" : "parent", serials);
 156
 157   if (pid == 0)
 158     /* The child.  Pass the number of times we had the serializing
 159        thread back to the parent.  */
 160     exit (serials);
 161
 162   if (waitpid (pid, &status, 0) != pid)
 163     {
 164       puts ("waitpid failed");
 165       return 1;
 166     }
 167
 168   if (!WIFEXITED (status))
 169     {
 170       puts ("child exited abnormally");
 171       return 1;
 172     }
 173
 174   if (WEXITSTATUS (status) + serials != N)
 175     {
 176       printf ("total number of serials is %d, expected %d\n",
 177               WEXITSTATUS (status) + serials, N);
 178       return 1;
 179     }
 180
 181   return 0;
 182 }
 183
 184 #define TEST_FUNCTION do_test ()
 185 #include "../test-skeleton.c"