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glibc  2.9
tst-sem7.c
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00001 /* Copyright (C) 2003 Free Software Foundation, Inc.
00002    This file is part of the GNU C Library.
00003    Contributed by Ulrich Drepper <drepper@redhat.com>, 2003.
00004 
00005    The GNU C Library is free software; you can redistribute it and/or
00006    modify it under the terms of the GNU Lesser General Public
00007    License as published by the Free Software Foundation; either
00008    version 2.1 of the License, or (at your option) any later version.
00009 
00010    The GNU C Library is distributed in the hope that it will be useful,
00011    but WITHOUT ANY WARRANTY; without even the implied warranty of
00012    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00013    Lesser General Public License for more details.
00014 
00015    You should have received a copy of the GNU Lesser General Public
00016    License along with the GNU C Library; if not, write to the Free
00017    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00018    02111-1307 USA.  */
00019 
00020 #include <errno.h>
00021 #include <fcntl.h>
00022 #include <semaphore.h>
00023 #include <stdio.h>
00024 #include <stdlib.h>
00025 #include <unistd.h>
00026 
00027 
00028 static void
00029 remove_sem (int status, void *arg)
00030 {
00031   sem_unlink (arg);
00032 }
00033 
00034 
00035 int
00036 main (void)
00037 {
00038   sem_t *s;
00039   sem_t *s2;
00040   sem_t *s3;
00041 
00042   s = sem_open ("/glibc-tst-sem7", O_CREAT, 0600, 1);
00043   if (s == SEM_FAILED)
00044     {
00045       if (errno == ENOSYS)
00046        {
00047          puts ("sem_open not supported.  Oh well.");
00048          return 0;
00049        }
00050 
00051       /* Maybe the shm filesystem has strict permissions.  */
00052       if (errno == EACCES)
00053        {
00054          puts ("sem_open not allowed.  Oh well.");
00055          return 0;
00056        }
00057 
00058       printf ("sem_open: %m\n");
00059       return 1;
00060     }
00061 
00062   on_exit (remove_sem, (void *) "/glibc-tst-sem7");
00063 
00064   /* We have the semaphore object.  Now try again.  We should get the
00065      same address.  */
00066   s2 = sem_open ("/glibc-tst-sem7", O_CREAT, 0600, 1);
00067   if (s2 == SEM_FAILED)
00068     {
00069       puts ("2nd sem_open failed");
00070       return 1;
00071     }
00072   if (s != s2)
00073     {
00074       puts ("2nd sem_open didn't return the same address");
00075       return 1;
00076     }
00077 
00078   /* And again, this time without O_CREAT.  */
00079   s3 = sem_open ("/glibc-tst-sem7", 0);
00080   if (s3 == SEM_FAILED)
00081     {
00082       puts ("3rd sem_open failed");
00083       return 1;
00084     }
00085   if (s != s3)
00086     {
00087       puts ("3rd sem_open didn't return the same address");
00088       return 1;
00089     }
00090 
00091   /* Now close the handle.  Three times.  */
00092   if (sem_close (s2) != 0)
00093     {
00094       puts ("1st sem_close failed");
00095       return 1;
00096     }
00097   if (sem_close (s) != 0)
00098     {
00099       puts ("2nd sem_close failed");
00100       return 1;
00101     }
00102   if (sem_close (s3) != 0)
00103     {
00104       puts ("3rd sem_close failed");
00105       return 1;
00106     }
00107 
00108   return 0;
00109 }