nptl/pthread_clock_gettime.c

   1 /* Copyright (C) 2001, 2002 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 License as
   6    published by the Free Software Foundation; either version 2.1 of the
   7    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; see the file COPYING.LIB.  If not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 #include <stdlib.h>
  20 #include <time.h>
  21 #include <libc-internal.h>
  22 #include "pthreadP.h"
  23
  24
  25 #if HP_TIMING_AVAIL
  26 int
  27 __pthread_clock_gettime (hp_timing_t freq, struct timespec *tp)
  28 {
  29   hp_timing_t tsc;
  30
  31   /* Get the current counter.  */
  32   HP_TIMING_NOW (tsc);
  33
  34   /* Compute the offset since the start time of the process.  */
  35   tsc -= THREAD_GETMEM (THREAD_SELF, cpuclock_offset);
  36
  37   /* Compute the seconds.  */
  38   tp->tv_sec = tsc / freq;
  39
  40   /* And the nanoseconds.  This computation should be stable until
  41      we get machines with about 16GHz frequency.  */
  42   tp->tv_nsec = ((tsc % freq) * 1000000000ull) / freq;
  43
  44   return 0;
  45 }
  46 #endif