1/* xtime -- extended-resolution integer timestamps
2
3 Copyright (C) 2005-2006, 2009-2019 Free Software Foundation, Inc.
4
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 3 of the License, or
8 (at your option) any later version.
9
10 This program 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
13 GNU General Public License for more details.
14
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <https://www.gnu.org/licenses/>. */
17
18/* Written by Paul Eggert. */
19
20#ifndef XTIME_H_
21#define XTIME_H_ 1
22
23#ifndef _GL_INLINE_HEADER_BEGIN
24 #error "Please include config.h first."
25#endif
26_GL_INLINE_HEADER_BEGIN
27#ifndef XTIME_INLINE
28# define XTIME_INLINE _GL_INLINE
29#endif
30
31/* xtime_t is a signed type used for timestamps. It is an integer
32 type that is a count of nanoseconds -- except for obsolescent hosts
33 without sufficiently-wide integers, where it is a count of
34 seconds. */
35#if HAVE_LONG_LONG_INT
36typedef long long int xtime_t;
37# define XTIME_PRECISION 1000000000
38#else
39# include <limits.h>
40typedef long int xtime_t;
41# if LONG_MAX >> 31 >> 31 == 0
42# define XTIME_PRECISION 1
43# else
44# define XTIME_PRECISION 1000000000
45# endif
46#endif
47
48#ifdef __cplusplus
49extern "C" {
50#endif
51
52/* Return an extended time value that contains S seconds and NS
53 nanoseconds. */
54XTIME_INLINE xtime_t
55xtime_make (xtime_t s, long int ns)
56{
57 const long int giga = 1000 * 1000 * 1000;
58 s += ns / giga;
59 ns %= giga;
60 if (XTIME_PRECISION == 1)
61 return s;
62 else
63 return XTIME_PRECISION * s + ns;
64}
65
66/* Return the number of seconds in T, which must be nonnegative. */
67XTIME_INLINE xtime_t
68xtime_nonnegative_sec (xtime_t t)
69{
70 return t / XTIME_PRECISION;
71}
72
73/* Return the number of seconds in T. */
74XTIME_INLINE xtime_t
75xtime_sec (xtime_t t)
76{
77 return (XTIME_PRECISION == 1
78 ? t
79 : t < 0
80 ? (t + XTIME_PRECISION - 1) / XTIME_PRECISION - 1
81 : xtime_nonnegative_sec (t));
82}
83
84/* Return the number of nanoseconds in T, which must be nonnegative. */
85XTIME_INLINE long int
86xtime_nonnegative_nsec (xtime_t t)
87{
88 return t % XTIME_PRECISION;
89}
90
91/* Return the number of nanoseconds in T. */
92XTIME_INLINE long int
93xtime_nsec (xtime_t t)
94{
95 long int ns = t % XTIME_PRECISION;
96 if (ns < 0)
97 ns += XTIME_PRECISION;
98 return ns;
99}
100
101#ifdef __cplusplus
102}
103#endif
104
105#endif
106