1 /* xtime -- extended-resolution integer time stamps
3 Copyright (C) 2005, 2006 Free Software Foundation, Inc.
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.
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.
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>. */
18 /* Written by Paul Eggert. */
23 /* xtime_t is a signed type used for time stamps. It is an integer
24 type that is a count of nanoseconds -- except for obsolescent hosts
25 without sufficiently-wide integers, where it is a count of
27 # if HAVE_LONG_LONG_INT
28 typedef long long int xtime_t;
29 # define XTIME_PRECISION 1000000000
32 typedef long int xtime_t;
33 # if LONG_MAX >> 31 >> 31 == 0
34 # define XTIME_PRECISION 1
36 # define XTIME_PRECISION 1000000000
40 /* Return an extended time value that contains S seconds and NS
41 nanoseconds, without any overflow checking. */
43 xtime_make (xtime_t s, long int ns)
45 if (XTIME_PRECISION == 1)
48 return XTIME_PRECISION * s + ns;
51 /* Return the number of seconds in T, which must be nonnegative. */
53 xtime_nonnegative_sec (xtime_t t)
55 return t / XTIME_PRECISION;
58 /* Return the number of seconds in T. */
62 return (XTIME_PRECISION == 1
65 ? (t + XTIME_PRECISION - 1) / XTIME_PRECISION - 1
66 : xtime_nonnegative_sec (t));
69 /* Return the number of nanoseconds in T, which must be nonnegative. */
70 static inline long int
71 xtime_nonnegative_nsec (xtime_t t)
73 return t % XTIME_PRECISION;
76 /* Return the number of nanoseconds in T. */
77 static inline long int
78 xtime_nsec (xtime_t t)
80 long int ns = t % XTIME_PRECISION;
82 ns += XTIME_PRECISION;