sysdeps/unix/sysv/linux/bits/time.h

   1 /* System-dependent timing definitions.  Linux version.
   2    Copyright (C) 1996-2016 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 #if defined __need_timeval || defined __USE_GNU
  24 # ifndef _STRUCT_TIMEVAL
  25 #  define _STRUCT_TIMEVAL       1
  26 #  include <bits/types.h>
  27
  28 /* A time value that is accurate to the nearest
  29    microsecond but also has a range of years.  */
  30 struct timeval
  31   {
  32     __time_t tv_sec;            /* Seconds.  */
  33     __suseconds_t tv_usec;      /* Microseconds.  */
  34   };
  35 # endif /* struct timeval */
  36 #endif
  37
  38 #ifndef __need_timeval
  39 # ifndef _BITS_TIME_H
  40 #  define _BITS_TIME_H  1
  41
  42 /* ISO/IEC 9899:1999 7.23.1: Components of time
  43    The macro `CLOCKS_PER_SEC' is an expression with type `clock_t' that is
  44    the number per second of the value returned by the `clock' function.  */
  45 /* CAE XSH, Issue 4, Version 2: <time.h>
  46    The value of CLOCKS_PER_SEC is required to be 1 million on all
  47    XSI-conformant systems. */
  48 #  define CLOCKS_PER_SEC  ((clock_t) 1000000)
  49
  50 #  if (!defined __STRICT_ANSI__ || defined __USE_POSIX) \
  51    && !defined __USE_XOPEN2K
  52 /* Even though CLOCKS_PER_SEC has such a strange value CLK_TCK
  53    presents the real value for clock ticks per second for the system.  */
  54 #   include <bits/types.h>
  55 extern long int __sysconf (int);
  56 #   define CLK_TCK ((__clock_t) __sysconf (2))  /* 2 is _SC_CLK_TCK */
  57 #  endif
  58
  59 #  ifdef __USE_POSIX199309
  60 /* Identifier for system-wide realtime clock.  */
  61 #   define CLOCK_REALTIME               0
  62 /* Monotonic system-wide clock.  */
  63 #   define CLOCK_MONOTONIC              1
  64 /* High-resolution timer from the CPU.  */
  65 #   define CLOCK_PROCESS_CPUTIME_ID     2
  66 /* Thread-specific CPU-time clock.  */
  67 #   define CLOCK_THREAD_CPUTIME_ID      3
  68 /* Monotonic system-wide clock, not adjusted for frequency scaling.  */
  69 #   define CLOCK_MONOTONIC_RAW          4
  70 /* Identifier for system-wide realtime clock, updated only on ticks.  */
  71 #   define CLOCK_REALTIME_COARSE        5
  72 /* Monotonic system-wide clock, updated only on ticks.  */
  73 #   define CLOCK_MONOTONIC_COARSE       6
  74 /* Monotonic system-wide clock that includes time spent in suspension.  */
  75 #   define CLOCK_BOOTTIME               7
  76 /* Like CLOCK_REALTIME but also wakes suspended system.  */
  77 #   define CLOCK_REALTIME_ALARM         8
  78 /* Like CLOCK_BOOTTIME but also wakes suspended system.  */
  79 #   define CLOCK_BOOTTIME_ALARM         9
  80 /* Like CLOCK_REALTIME but in International Atomic Time.  */
  81 #   define CLOCK_TAI                    11
  82
  83 /* Flag to indicate time is absolute.  */
  84 #   define TIMER_ABSTIME                1
  85 #  endif
  86
  87 #  ifdef __USE_GNU
  88 #   include <bits/timex.h>
  89
  90 __BEGIN_DECLS
  91
  92 /* Tune a POSIX clock.  */
  93 extern int clock_adjtime (__clockid_t __clock_id, struct timex *__utx) __THROW;
  94
  95 __END_DECLS
  96 #  endif /* use GNU */
  97
  98 # endif /* bits/time.h */
  99 #endif
 100
 101 #undef __need_timeval