1/* System-dependent timing definitions.  Linux version.
 2   Copyright (C) 1996-2025 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_TIME64_REDIRECTS
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 */