rm_/lib/xtime.h

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/* xtime -- extended-resolution integer timestamps
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Copyright (C) 2005-2006, 2009-2022 Free Software Foundation, Inc.
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This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>. */
/* Written by Paul Eggert. */
#ifndef XTIME_H_
#define XTIME_H_ 1
#ifndef _GL_INLINE_HEADER_BEGIN
#error "Please include config.h first."
#endif
_GL_INLINE_HEADER_BEGIN
#ifndef XTIME_INLINE
# define XTIME_INLINE _GL_INLINE
#endif
/* xtime_t is a signed type used for timestamps. It is an integer
type that is a count of nanoseconds. */
typedef long long int xtime_t;
#define XTIME_PRECISION 1000000000
#ifdef __cplusplus
extern "C" {
#endif
/* Return an extended time value that contains S seconds and NS
nanoseconds. S and NS should be nonnegative; otherwise, integer
overflow can occur even if the result is in range. */
XTIME_INLINE xtime_t
xtime_make (xtime_t s, long int ns)
{
return XTIME_PRECISION * s + ns;
}
/* The following functions split an extended time value:
T = XTIME_PRECISION * xtime_sec (T) + xtime_nsec (T)
with 0 <= xtime_nsec (T) < XTIME_PRECISION. */
/* Return the number of seconds in T, which must be nonnegative. */
XTIME_INLINE xtime_t
xtime_nonnegative_sec (xtime_t t)
{
return t / XTIME_PRECISION;
}
/* Return the number of seconds in T. */
XTIME_INLINE xtime_t
xtime_sec (xtime_t t)
{
return (t + (t < 0)) / XTIME_PRECISION - (t < 0);
}
/* Return the number of nanoseconds in T, which must be nonnegative. */
XTIME_INLINE long int
xtime_nonnegative_nsec (xtime_t t)
{
return t % XTIME_PRECISION;
}
/* Return the number of nanoseconds in T. */
XTIME_INLINE long int
xtime_nsec (xtime_t t)
{
long int ns = t % XTIME_PRECISION;
if (ns < 0)
ns += XTIME_PRECISION;
return ns;
}
#ifdef __cplusplus
}
#endif
#endif