root/lib/timespec.h

INCLUDED FROM

DEFINITIONS

1. make_timespec
2. timespec_cmp
3. timespec_sign
4. timespec_add

     1 /* timespec -- System time interface
     2 
     3    Copyright (C) 2000, 2002, 2004-2005, 2007, 2009-2023 Free Software
     4    Foundation, Inc.
     5 
     6    This file is free software: you can redistribute it and/or modify
     7    it under the terms of the GNU Lesser General Public License as
     8    published by the Free Software Foundation, either version 3 of the
     9    License, or (at your option) any later version.
    10 
    11    This file is distributed in the hope that it will be useful,
    12    but WITHOUT ANY WARRANTY; without even the implied warranty of
    13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    14    GNU Lesser General Public License for more details.
    15 
    16    You should have received a copy of the GNU Lesser General Public License
    17    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
    18 
    19 #if ! defined TIMESPEC_H
    20 #define TIMESPEC_H
    21 
    22 /* This file uses _GL_INLINE_HEADER_BEGIN, _GL_INLINE, _GL_ATTRIBUTE_CONST,
    23    _GL_ATTRIBUTE_PURE, _GL_CMP.  */
    24 #if !_GL_CONFIG_H_INCLUDED
    25  #error "Please include config.h first."
    26 #endif
    27 
    28 #include <time.h>
    29 
    30 _GL_INLINE_HEADER_BEGIN
    31 #ifndef _GL_TIMESPEC_INLINE
    32 # define _GL_TIMESPEC_INLINE _GL_INLINE
    33 #endif
    34 
    35 #ifdef __cplusplus
    36 extern "C" {
    37 #endif
    38 
    39 #include "arg-nonnull.h"
    40 
    41 /* Inverse resolution of timespec timestamps (in units per second),
    42    and log base 10 of the inverse resolution.  */
    43 
    44 enum { TIMESPEC_HZ = 1000000000 };
    45 enum { LOG10_TIMESPEC_HZ = 9 };
    46 
    47 /* Obsolescent names for backward compatibility.
    48    They are misnomers, because TIMESPEC_RESOLUTION is not a resolution.  */
    49 
    50 enum { TIMESPEC_RESOLUTION = TIMESPEC_HZ };
    51 enum { LOG10_TIMESPEC_RESOLUTION = LOG10_TIMESPEC_HZ };
    52 
    53 /* Return a timespec with seconds S and nanoseconds NS.  */
    54 
    55 _GL_TIMESPEC_INLINE struct timespec
    56 make_timespec (time_t s, long int ns)
    57 {
    58   return (struct timespec) { .tv_sec = s, .tv_nsec = ns };
    59 }
    60 
    61 /* Return negative, zero, positive if A < B, A == B, A > B, respectively.  */
    62 
    63 _GL_TIMESPEC_INLINE int _GL_ATTRIBUTE_PURE
    64 timespec_cmp (struct timespec a, struct timespec b)
    65 {
    66   return 2 * _GL_CMP (a.tv_sec, b.tv_sec) + _GL_CMP (a.tv_nsec, b.tv_nsec);
    67 }
    68 
    69 /* Return -1, 0, 1, depending on the sign of A.  A.tv_nsec must be
    70    nonnegative.  */
    71 _GL_TIMESPEC_INLINE int _GL_ATTRIBUTE_PURE
    72 timespec_sign (struct timespec a)
    73 {
    74   return _GL_CMP (a.tv_sec, 0) + (!a.tv_sec & !!a.tv_nsec);
    75 }
    76 
    77 struct timespec timespec_add (struct timespec, struct timespec)
    78   _GL_ATTRIBUTE_CONST;
    79 struct timespec timespec_sub (struct timespec, struct timespec)
    80   _GL_ATTRIBUTE_CONST;
    81 struct timespec dtotimespec (double)
    82   _GL_ATTRIBUTE_CONST;
    83 
    84 /* Return an approximation to A, of type 'double'.  */
    85 _GL_TIMESPEC_INLINE double
    86 timespectod (struct timespec a)
    87 {
    88   return a.tv_sec + a.tv_nsec / 1e9;
    89 }
    90 
    91 long int gettime_res (void);
    92 struct timespec current_timespec (void);
    93 void gettime (struct timespec *) _GL_ARG_NONNULL ((1));
    94 int settime (struct timespec const *) _GL_ARG_NONNULL ((1));
    95 
    96 #ifdef __cplusplus
    97 }
    98 #endif
    99 
   100 _GL_INLINE_HEADER_END
   101 
   102 #endif