sysdeps/generic/hp-timing.h

   1 /* High precision, low overhead timing functions.  Generic version.
   2    Copyright (C) 1998-2019 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef _HP_TIMING_H
  21 #define _HP_TIMING_H    1
  22
  23 #include <time.h>
  24 #include <stdint.h>
  25 #include <hp-timing-common.h>
  26
  27 /* It should not be used for ld.so.  */
  28 #define HP_TIMING_INLINE        (0)
  29
  30 typedef uint64_t hp_timing_t;
  31
  32 /* The clock_gettime (CLOCK_MONOTONIC) has unspecified starting time,
  33    nano-second accuracy, and for some architectues is implemented as
  34    vDSO symbol.  */
  35 #define HP_TIMING_NOW(var) \
  36 ({                                                              \
  37   struct timespec tv;                                           \
  38   __clock_gettime (CLOCK_MONOTONIC, &tv);                       \
  39   (var) = (tv.tv_nsec + UINT64_C(1000000000) * tv.tv_sec);      \
  40 })
  41
  42 #endif  /* hp-timing.h */