/* clock_getcpuclockid -- Get a clockid_t for process CPU time.  Linux version.

   Copyright (C) 2004-2018 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 <unistd.h>

#include "kernel-posix-cpu-timers.h"

int

__clock_getcpuclockid (pid_t pid, clockid_t *clock_id)

{

  /* The clockid_t value is a simple computation from the PID.

     But we do a clock_getres call to validate it.  */

  const clockid_t pidclock = MAKE_PROCESS_CPUCLOCK (pid, CPUCLOCK_SCHED);

  INTERNAL_SYSCALL_DECL (err);

  int r = INTERNAL_SYSCALL (clock_getres, err, 2, pidclock, NULL);

  if (!INTERNAL_SYSCALL_ERROR_P (r, err))

    {

      *clock_id = pidclock;

      return 0;

    }

  if (INTERNAL_SYSCALL_ERRNO (r, err) == EINVAL)

    {

      /* The clock_getres system call checked the PID for us.  */

      return ESRCH;

    }

  else

    return INTERNAL_SYSCALL_ERRNO (r, err);

}

weak_alias (__clock_getcpuclockid, clock_getcpuclockid)