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emacs/lib/timespec.h
2022-02-23 11:41:02 -08:00

103 lines
2.8 KiB
C

/* timespec -- System time interface
Copyright (C) 2000, 2002, 2004-2005, 2007, 2009-2022 Free Software
Foundation, Inc.
This file is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation, either version 3 of the
License, or (at your option) any later version.
This file 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 Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>. */
#if ! defined TIMESPEC_H
#define TIMESPEC_H
#include <time.h>
#ifndef _GL_INLINE_HEADER_BEGIN
#error "Please include config.h first."
#endif
_GL_INLINE_HEADER_BEGIN
#ifndef _GL_TIMESPEC_INLINE
# define _GL_TIMESPEC_INLINE _GL_INLINE
#endif
#ifdef __cplusplus
extern "C" {
#endif
#include "arg-nonnull.h"
/* Inverse resolution of timespec timestamps (in units per second),
and log base 10 of the inverse resolution. */
enum { TIMESPEC_HZ = 1000000000 };
enum { LOG10_TIMESPEC_HZ = 9 };
/* Obsolescent names for backward compatibility.
They are misnomers, because TIMESPEC_RESOLUTION is not a resolution. */
enum { TIMESPEC_RESOLUTION = TIMESPEC_HZ };
enum { LOG10_TIMESPEC_RESOLUTION = LOG10_TIMESPEC_HZ };
/* Return a timespec with seconds S and nanoseconds NS. */
_GL_TIMESPEC_INLINE struct timespec
make_timespec (time_t s, long int ns)
{
struct timespec r;
r.tv_sec = s;
r.tv_nsec = ns;
return r;
}
/* Return negative, zero, positive if A < B, A == B, A > B, respectively. */
_GL_TIMESPEC_INLINE int _GL_ATTRIBUTE_PURE
timespec_cmp (struct timespec a, struct timespec b)
{
return 2 * _GL_CMP (a.tv_sec, b.tv_sec) + _GL_CMP (a.tv_nsec, b.tv_nsec);
}
/* Return -1, 0, 1, depending on the sign of A. A.tv_nsec must be
nonnegative. */
_GL_TIMESPEC_INLINE int _GL_ATTRIBUTE_PURE
timespec_sign (struct timespec a)
{
return _GL_CMP (a.tv_sec, 0) + (!a.tv_sec & !!a.tv_nsec);
}
struct timespec timespec_add (struct timespec, struct timespec)
_GL_ATTRIBUTE_CONST;
struct timespec timespec_sub (struct timespec, struct timespec)
_GL_ATTRIBUTE_CONST;
struct timespec dtotimespec (double)
_GL_ATTRIBUTE_CONST;
/* Return an approximation to A, of type 'double'. */
_GL_TIMESPEC_INLINE double
timespectod (struct timespec a)
{
return a.tv_sec + a.tv_nsec / 1e9;
}
long int gettime_res (void);
struct timespec current_timespec (void);
void gettime (struct timespec *) _GL_ARG_NONNULL ((1));
int settime (struct timespec const *) _GL_ARG_NONNULL ((1));
#ifdef __cplusplus
}
#endif
_GL_INLINE_HEADER_END
#endif