bits/time.h

   1 /* System-dependent timing definitions.  Generic version.
   2    Copyright (C) 1996-2015 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 /*
  20  * Never include this file directly; use <time.h> instead.
  21  */
  22
  23 #ifndef __need_timeval
  24 # ifndef _BITS_TIME_H
  25 #  define _BITS_TIME_H  1
  26
  27 /* ISO/IEC 9899:1999 7.23.1: Components of time
  28    The macro `CLOCKS_PER_SEC' is an expression with type `clock_t' that is
  29    the number per second of the value returned by the `clock' function.  */
  30 /* CAE XSH, Issue 4, Version 2: <time.h>
  31    The value of CLOCKS_PER_SEC is required to be 1 million on all
  32    XSI-conformant systems. */
  33 #  define CLOCKS_PER_SEC  ((clock_t) 1000000)
  34
  35 #  if !defined __STRICT_ANSI__ && !defined __USE_XOPEN2K
  36 /* Even though CLOCKS_PER_SEC has such a strange value CLK_TCK
  37    presents the real value for clock ticks per second for the system.  */
  38 #   include <bits/types.h>
  39 extern long int __sysconf (int);
  40 #   define CLK_TCK ((__clock_t) __sysconf (2))  /* 2 is _SC_CLK_TCK */
  41 #  endif
  42
  43 #  ifdef __USE_POSIX199309
  44 /* Identifier for system-wide realtime clock.  */
  45 #   define CLOCK_REALTIME               0
  46 /* Monotonic system-wide clock.  */
  47 #   define CLOCK_MONOTONIC              1
  48 /* High-resolution timer from the CPU.  */
  49 #   define CLOCK_PROCESS_CPUTIME_ID     2
  50 /* Thread-specific CPU-time clock.  */
  51 #   define CLOCK_THREAD_CPUTIME_ID      3
  52 /* Monotonic system-wide clock, not adjusted for frequency scaling.  */
  53 #   define CLOCK_MONOTONIC_RAW          4
  54 /* Identifier for system-wide realtime clock, updated only on ticks.  */
  55 #   define CLOCK_REALTIME_COARSE        5
  56 /* Monotonic system-wide clock, updated only on ticks.  */
  57 #   define CLOCK_MONOTONIC_COARSE       6
  58
  59 /* Flag to indicate time is absolute.  */
  60 #   define TIMER_ABSTIME                1
  61 #  endif
  62
  63 # endif /* bits/time.h */
  64 #endif
  65
  66 #ifdef __need_timeval
  67 # undef __need_timeval
  68 # ifndef _STRUCT_TIMEVAL
  69 #  define _STRUCT_TIMEVAL       1
  70 #  include <bits/types.h>
  71
  72 /* A time value that is accurate to the nearest
  73    microsecond but also has a range of years.  */
  74 struct timeval
  75   {
  76     __time_t tv_sec;            /* Seconds.  */
  77     __suseconds_t tv_usec;      /* Microseconds.  */
  78   };
  79 # endif /* struct timeval */
  80 #endif  /* need timeval */