1/* System-dependent timing definitions. Linux version.
2 Copyright (C) 1996-2024 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 <https://www.gnu.org/licenses/>. */
18
19/*
20 * Never include this file directly; use <time.h> instead.
21 */
22
23#ifndef _BITS_TIME_H
24#define _BITS_TIME_H 1
25
26#include <bits/types.h>
27
28/* ISO/IEC 9899:1999 7.23.1: Components of time
29 The macro `CLOCKS_PER_SEC' is an expression with type `clock_t' that is
30 the number per second of the value returned by the `clock' function. */
31/* CAE XSH, Issue 4, Version 2: <time.h>
32 The value of CLOCKS_PER_SEC is required to be 1 million on all
33 XSI-conformant systems. */
34#define CLOCKS_PER_SEC ((__clock_t) 1000000)
35
36#if (!defined __STRICT_ANSI__ || defined __USE_POSIX) \
37 && !defined __USE_XOPEN2K
38/* Even though CLOCKS_PER_SEC has such a strange value CLK_TCK
39 presents the real value for clock ticks per second for the system. */
40extern long int __sysconf (int);
41# define CLK_TCK ((__clock_t) __sysconf (2)) /* 2 is _SC_CLK_TCK */
42#endif
43
44#ifdef __USE_POSIX199309
45/* Identifier for system-wide realtime clock. */
46# define CLOCK_REALTIME 0
47/* Monotonic system-wide clock. */
48# define CLOCK_MONOTONIC 1
49/* High-resolution timer from the CPU. */
50# define CLOCK_PROCESS_CPUTIME_ID 2
51/* Thread-specific CPU-time clock. */
52# define CLOCK_THREAD_CPUTIME_ID 3
53/* Monotonic system-wide clock, not adjusted for frequency scaling. */
54# define CLOCK_MONOTONIC_RAW 4
55/* Identifier for system-wide realtime clock, updated only on ticks. */
56# define CLOCK_REALTIME_COARSE 5
57/* Monotonic system-wide clock, updated only on ticks. */
58# define CLOCK_MONOTONIC_COARSE 6
59/* Monotonic system-wide clock that includes time spent in suspension. */
60# define CLOCK_BOOTTIME 7
61/* Like CLOCK_REALTIME but also wakes suspended system. */
62# define CLOCK_REALTIME_ALARM 8
63/* Like CLOCK_BOOTTIME but also wakes suspended system. */
64# define CLOCK_BOOTTIME_ALARM 9
65/* Like CLOCK_REALTIME but in International Atomic Time. */
66# define CLOCK_TAI 11
67
68/* Flag to indicate time is absolute. */
69# define TIMER_ABSTIME 1
70#endif
71
72#ifdef __USE_GNU
73# include <bits/timex.h>
74
75__BEGIN_DECLS
76
77/* Tune a POSIX clock. */
78extern int clock_adjtime (__clockid_t __clock_id, struct timex *__utx) __THROW __nonnull((2));
79
80#ifdef __USE_TIME_BITS64
81# if defined(__REDIRECT_NTH)
82extern int __REDIRECT_NTH (clock_adjtime, (__clockid_t __clock_id,
83 struct timex *__utx),
84 __clock_adjtime64) __nonnull((2));
85# else
86# define clock_adjtime __clock_adjtime64
87# endif
88#endif
89
90__END_DECLS
91#endif /* use GNU */
92
93#endif /* bits/time.h */
94