1 /* System-dependent timing definitions. Linux version. 2 Copyright (C) 1996-2022 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. */ 40 extern 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. */ 78 extern int clock_adjtime (__clockid_t __clock_id, struct timex *__utx) __THROW __nonnull((2)); 79 80 #ifdef __USE_TIME_BITS64 81 # if defined(__REDIRECT_NTH) 82 extern 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