/* Copyright (C) 1999-2018 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 <time.h>

#include <sys/time.h>

#include <ldsodefs.h>

#if HP_TIMING_AVAIL

/* Clock frequency of the processor.  We make it a 64-bit variable

   because some jokers are already playing with processors with more

   than 4GHz.  */

static hp_timing_t freq;

/* This function is defined in the thread library.  */

extern void __pthread_clock_settime (clockid_t clock_id, hp_timing_t offset)

     __attribute__ ((__weak__));

static int

hp_timing_settime (clockid_t clock_id, const struct timespec *tp)

{

  hp_timing_t tsc;

  hp_timing_t usertime;

  /* First thing is to get the current time.  */

  HP_TIMING_NOW (tsc);

  if (__glibc_unlikely (freq == 0))

    {

      /* This can only happen if we haven't initialized the `freq'

	 variable yet.  Do this now. We don't have to protect this

	 code against multiple execution since all of them should lead

	 to the same result.  */

      freq = __get_clockfreq ();

      if (__glibc_unlikely (freq == 0))

	/* Something went wrong.  */

	return -1;

    }

  /* Convert the user-provided time into CPU ticks.  */

  usertime = tp->tv_sec * freq + (tp->tv_nsec * freq) / 1000000000ull;

  /* Determine the offset and use it as the new base value.  */

  if (clock_id == CLOCK_PROCESS_CPUTIME_ID

      || __pthread_clock_settime == NULL)

    GL(dl_cpuclock_offset) = tsc - usertime;

  else

    __pthread_clock_settime (clock_id, tsc - usertime);

  return 0;

}

#endif

/* Set CLOCK to value TP.  */

int

__clock_settime (clockid_t clock_id, const struct timespec *tp)

{

  int retval;

  /* Make sure the time cvalue is OK.  */

  if (tp->tv_nsec < 0 || tp->tv_nsec >= 1000000000)

    {

      __set_errno (EINVAL);

      return -1;

    }

  switch (clock_id)

    {

    case CLOCK_REALTIME:

      {

	struct timeval tv;

	TIMESPEC_TO_TIMEVAL (&tv, tp);

	retval = __settimeofday (&tv, NULL);

      }

      break;

    default:

# if HP_TIMING_AVAIL

      if (CPUCLOCK_WHICH (clock_id) == CLOCK_PROCESS_CPUTIME_ID

	  || CPUCLOCK_WHICH (clock_id) == CLOCK_THREAD_CPUTIME_ID)

	retval = hp_timing_settime (clock_id, tp);

      else

# endif

	{

	  __set_errno (EINVAL);

	  retval = -1;

	}

      break;

    }

  return retval;

}

weak_alias (__clock_settime, clock_settime)