sysdeps/unix/sysv/linux/clock_settime.c

   1 /* Copyright (C) 2003, 2004 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, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <sysdep.h>
  20
  21 #include "kernel-features.h"
  22
  23
  24 #ifdef __ASSUME_POSIX_TIMERS
  25 /* This means the REALTIME clock is definitely supported in the
  26    kernel.  */
  27 # define SYSDEP_SETTIME \
  28   case CLOCK_REALTIME:                                                        \
  29     retval = INLINE_SYSCALL (clock_settime, 2, clock_id, tp);                 \
  30     break
  31 #elif defined __NR_clock_settime
  32 /* Is the syscall known to exist?  */
  33 extern int __libc_missing_posix_timers attribute_hidden;
  34
  35 /* The REALTIME clock might be available.  Try the syscall first.  */
  36 # define SYSDEP_SETTIME \
  37   case CLOCK_REALTIME:                                                        \
  38     {                                                                         \
  39       int e = EINVAL;                                                         \
  40                                                                               \
  41       if (!__libc_missing_posix_timers)                                       \
  42         {                                                                     \
  43           INTERNAL_SYSCALL_DECL (err);                                        \
  44           int r = INTERNAL_SYSCALL (clock_settime, err, 2, clock_id, tp);     \
  45           if (!INTERNAL_SYSCALL_ERROR_P (r, err))                             \
  46             {                                                                 \
  47               retval = 0;                                                     \
  48               break;                                                          \
  49             }                                                                 \
  50                                                                               \
  51           e = INTERNAL_SYSCALL_ERRNO (r, err);                                \
  52           if (e == ENOSYS)                                                    \
  53             {                                                                 \
  54               __libc_missing_posix_timers = 1;                                \
  55               e = EINVAL;                                                     \
  56             }                                                                 \
  57         }                                                                     \
  58                                                                               \
  59       /* Fallback code.  */                                                   \
  60       if (e == EINVAL && clock_id == CLOCK_REALTIME)                          \
  61         HANDLE_REALTIME;                                                      \
  62       else                                                                    \
  63         {                                                                     \
  64           __set_errno (e);                                                    \
  65           retval = -1;                                                        \
  66         }                                                                     \
  67     }                                                                         \
  68     break
  69 #endif
  70
  71 #ifdef __NR_clock_settime
  72 /* We handled the REALTIME clock here.  */
  73 # define HANDLED_REALTIME       1
  74 #endif
  75
  76 #include <sysdeps/unix/clock_settime.c>