/* Copyright (C) 2003, 2004, 2006, 2010, 2012 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.  */

#include <errno.h>
#include <sysdep.h>
#include <time.h>

#include "kernel-posix-cpu-timers.h"
#include <kernel-features.h>

#ifndef HAVE_CLOCK_GETRES_VSYSCALL
# undef INTERNAL_VSYSCALL
# define INTERNAL_VSYSCALL INTERNAL_SYSCALL
# undef INLINE_VSYSCALL
# define INLINE_VSYSCALL INLINE_SYSCALL
#else
# include <bits/libc-vdso.h>
#endif

#if __ASSUME_POSIX_CPU_TIMERS <= 0 && defined __NR_clock_settime
extern int __libc_missing_posix_cpu_timers attribute_hidden;

static int
maybe_syscall_settime_cpu (clockid_t clock_id, const struct timespec *tp)
{
  int e = EINVAL;

  if (!__libc_missing_posix_cpu_timers)
    {
      INTERNAL_SYSCALL_DECL (err);
      int r = INTERNAL_SYSCALL (clock_settime, err, 2, clock_id, tp);
      if (!INTERNAL_SYSCALL_ERROR_P (r, err))
	return 0;

      e = INTERNAL_SYSCALL_ERRNO (r, err);
      if (e == EINVAL)
	{
	  /* Check whether the kernel supports CPU clocks at all.
	     If not, record it for the future.  */
	  r = INTERNAL_VSYSCALL (clock_getres, err, 2,
				 MAKE_PROCESS_CPUCLOCK (0, CPUCLOCK_SCHED),
				 NULL);
	  if (INTERNAL_SYSCALL_ERROR_P (r, err))
	    __libc_missing_posix_cpu_timers = 1;
	}
    }

  return e;
}
#endif


/* The REALTIME clock is definitely supported in the kernel.  */
#define SYSDEP_SETTIME \
  case CLOCK_REALTIME:							      \
    retval = INLINE_SYSCALL (clock_settime, 2, clock_id, tp);		      \
    break

#ifdef __NR_clock_settime
/* We handled the REALTIME clock here.  */
# define HANDLED_REALTIME	1
#endif

#if __ASSUME_POSIX_CPU_TIMERS > 0
# define HANDLED_CPUTIME 1
# define SYSDEP_SETTIME_CPU \
  retval = INLINE_SYSCALL (clock_settime, 2, clock_id, tp)
#elif defined __NR_clock_settime
# define SYSDEP_SETTIME_CPU \
  retval = maybe_syscall_settime_cpu (clock_id, tp);			      \
  if (retval == 0)							      \
    break;								      \
  if (retval != EINVAL || !__libc_missing_posix_cpu_timers)		      \
    {									      \
      __set_errno (retval);						      \
      retval = -1;							      \
      break;								      \
    }									      \
  do { } while (0)
#endif

#include <sysdeps/unix/clock_settime.c>