time/sys/time.h

   1 /* Copyright (C) 1991-2024 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #ifndef _SYS_TIME_H
  19 #define _SYS_TIME_H     1
  20
  21 #include <features.h>
  22
  23 #include <bits/types.h>
  24 #include <bits/types/time_t.h>
  25 #include <bits/types/struct_timeval.h>
  26
  27 #ifndef __suseconds_t_defined
  28 typedef __suseconds_t suseconds_t;
  29 # define __suseconds_t_defined
  30 #endif
  31
  32 #include <sys/select.h>
  33
  34 __BEGIN_DECLS
  35
  36 #ifdef __USE_GNU
  37 /* Macros for converting between `struct timeval' and `struct timespec'.  */
  38 # define TIMEVAL_TO_TIMESPEC(tv, ts) {                                   \
  39         (ts)->tv_sec = (tv)->tv_sec;                                    \
  40         (ts)->tv_nsec = (tv)->tv_usec * 1000;                           \
  41 }
  42 # define TIMESPEC_TO_TIMEVAL(tv, ts) {                                   \
  43         (tv)->tv_sec = (ts)->tv_sec;                                    \
  44         (tv)->tv_usec = (ts)->tv_nsec / 1000;                           \
  45 }
  46 #endif
  47
  48
  49 #ifdef __USE_MISC
  50 /* Structure crudely representing a timezone.
  51    This is obsolete and should never be used.  */
  52 struct timezone
  53   {
  54     int tz_minuteswest;         /* Minutes west of GMT.  */
  55     int tz_dsttime;             /* Nonzero if DST is ever in effect.  */
  56   };
  57 #endif
  58
  59 /* Get the current time of day, putting it into *TV.
  60    If TZ is not null, *TZ must be a struct timezone, and both fields
  61    will be set to zero.
  62    Calling this function with a non-null TZ is obsolete;
  63    use localtime etc. instead.
  64    This function itself is semi-obsolete;
  65    most callers should use time or clock_gettime instead. */
  66 #ifndef __USE_TIME64_REDIRECTS
  67 extern int gettimeofday (struct timeval *__restrict __tv,
  68                          void *__restrict __tz) __THROW __nonnull ((1));
  69 #else
  70 # ifdef __REDIRECT_NTH
  71 extern int __REDIRECT_NTH (gettimeofday, (struct timeval *__restrict __tv,
  72                                           void *__restrict __tz),
  73                            __gettimeofday64) __nonnull ((1));
  74 # else
  75 #  define gettimeofday __gettimeofday64
  76 # endif
  77 #endif
  78
  79 #ifdef __USE_MISC
  80 # ifndef __USE_TIME64_REDIRECTS
  81 /* Set the current time of day and timezone information.
  82    This call is restricted to the super-user.
  83    Setting the timezone in this way is obsolete, but we don't yet
  84    warn about it because it still has some uses for which there is
  85    no alternative.  */
  86 extern int settimeofday (const struct timeval *__tv,
  87                          const struct timezone *__tz)
  88      __THROW;
  89
  90 /* Adjust the current time of day by the amount in DELTA.
  91    If OLDDELTA is not NULL, it is filled in with the amount
  92    of time adjustment remaining to be done from the last `adjtime' call.
  93    This call is restricted to the super-user.  */
  94 extern int adjtime (const struct timeval *__delta,
  95                     struct timeval *__olddelta) __THROW;
  96 # else
  97 #  ifdef __REDIRECT_NTH
  98 extern int __REDIRECT_NTH (settimeofday, (const struct timeval *__tv,
  99                                           const struct timezone *__tz),
 100                            __settimeofday64);
 101
 102 extern int __REDIRECT_NTH (adjtime, (const struct timeval *__delta,
 103                                      struct timeval *__olddelta),
 104                            __adjtime64);
 105 #  else
 106 #   define settimeofday __settimeofday64
 107 #   define adjtime __adjtime64
 108 #  endif
 109 # endif
 110 #endif
 111
 112
 113 /* Values for the first argument to `getitimer' and `setitimer'.  */
 114 enum __itimer_which
 115   {
 116     /* Timers run in real time.  */
 117     ITIMER_REAL = 0,
 118 #define ITIMER_REAL ITIMER_REAL
 119     /* Timers run only when the process is executing.  */
 120     ITIMER_VIRTUAL = 1,
 121 #define ITIMER_VIRTUAL ITIMER_VIRTUAL
 122     /* Timers run when the process is executing and when
 123        the system is executing on behalf of the process.  */
 124     ITIMER_PROF = 2
 125 #define ITIMER_PROF ITIMER_PROF
 126   };
 127
 128 /* Type of the second argument to `getitimer' and
 129    the second and third arguments `setitimer'.  */
 130 struct itimerval
 131   {
 132     /* Value to put into `it_value' when the timer expires.  */
 133     struct timeval it_interval;
 134     /* Time to the next timer expiration.  */
 135     struct timeval it_value;
 136   };
 137
 138 #if defined __USE_GNU && !defined __cplusplus
 139 /* Use the nicer parameter type only in GNU mode and not for C++ since the
 140    strict C++ rules prevent the automatic promotion.  */
 141 typedef enum __itimer_which __itimer_which_t;
 142 #else
 143 typedef int __itimer_which_t;
 144 #endif
 145
 146 #ifndef __USE_TIME64_REDIRECTS
 147 /* Set *VALUE to the current setting of timer WHICH.
 148    Return 0 on success, -1 on errors.  */
 149 extern int getitimer (__itimer_which_t __which,
 150                       struct itimerval *__value) __THROW;
 151
 152 /* Set the timer WHICH to *NEW.  If OLD is not NULL,
 153    set *OLD to the old value of timer WHICH.
 154    Returns 0 on success, -1 on errors.  */
 155 extern int setitimer (__itimer_which_t __which,
 156                       const struct itimerval *__restrict __new,
 157                       struct itimerval *__restrict __old) __THROW;
 158
 159 /* Change the access time of FILE to TVP[0] and the modification time of
 160    FILE to TVP[1].  If TVP is a null pointer, use the current time instead.
 161    Returns 0 on success, -1 on errors.  */
 162 extern int utimes (const char *__file, const struct timeval __tvp[2])
 163      __THROW __nonnull ((1));
 164
 165 #else
 166 # ifdef __REDIRECT_NTH
 167 extern int __REDIRECT_NTH (getitimer, (__itimer_which_t __which,
 168                                        struct itimerval *__value),
 169                            __getitimer64);
 170
 171 extern int __REDIRECT_NTH (setitimer, (__itimer_which_t __which,
 172                                        const struct itimerval *__restrict __new,
 173                                        struct itimerval *__restrict __old),
 174                            __setitimer64);
 175
 176 extern int __REDIRECT_NTH (utimes, (const char *__file,
 177                                     const struct timeval __tvp[2]),
 178                            __utimes64) __nonnull ((1));
 179 # else
 180 #  define getitimer __getitimer64
 181 #  define setitimer __setitimer64
 182 #  define utimes __utimes64
 183 # endif
 184 #endif
 185
 186 #ifdef __USE_MISC
 187 # ifndef __USE_TIME64_REDIRECTS
 188 /* Same as `utimes', but does not follow symbolic links.  */
 189 extern int lutimes (const char *__file, const struct timeval __tvp[2])
 190      __THROW __nonnull ((1));
 191
 192 /* Same as `utimes', but takes an open file descriptor instead of a name.  */
 193 extern int futimes (int __fd, const struct timeval __tvp[2]) __THROW;
 194 # else
 195 #  ifdef __REDIRECT_NTH
 196 extern int __REDIRECT_NTH (lutimes, (const char *__file,
 197                                      const struct timeval __tvp[2]),
 198                            __lutimes64) __nonnull ((1));
 199
 200 extern int __REDIRECT_NTH (futimes, (int __fd, const struct timeval __tvp[2]),
 201                            __futimes64);
 202 #  else
 203 #   define lutimes __lutimes64
 204 #   define futimes __futimes64
 205 #  endif
 206 # endif
 207 #endif
 208
 209 #ifdef __USE_GNU
 210 # ifndef __USE_TIME64_REDIRECTS
 211 /* Change the access time of FILE relative to FD to TVP[0] and the
 212    modification time of FILE to TVP[1].  If TVP is a null pointer, use
 213    the current time instead.  Returns 0 on success, -1 on errors.  */
 214 extern int futimesat (int __fd, const char *__file,
 215                       const struct timeval __tvp[2]) __THROW;
 216 # else
 217 #  ifdef __REDIRECT_NTH
 218 extern int __REDIRECT_NTH (futimesat, (int __fd, const char *__file,
 219                                        const struct timeval __tvp[2]),
 220                            __futimesat64);
 221 #  else
 222 #   define futimesat __futimesat64
 223 #  endif
 224 # endif
 225 #endif
 226
 227
 228 #ifdef __USE_MISC
 229 /* Convenience macros for operations on timevals.
 230    NOTE: `timercmp' does not work for >= or <=.  */
 231 # define timerisset(tvp)        ((tvp)->tv_sec || (tvp)->tv_usec)
 232 # define timerclear(tvp)        ((tvp)->tv_sec = (tvp)->tv_usec = 0)
 233 # define timercmp(a, b, CMP)                                                  \
 234   (((a)->tv_sec == (b)->tv_sec)                                               \
 235    ? ((a)->tv_usec CMP (b)->tv_usec)                                          \
 236    : ((a)->tv_sec CMP (b)->tv_sec))
 237 # define timeradd(a, b, result)                                               \
 238   do {                                                                        \
 239     (result)->tv_sec = (a)->tv_sec + (b)->tv_sec;                             \
 240     (result)->tv_usec = (a)->tv_usec + (b)->tv_usec;                          \
 241     if ((result)->tv_usec >= 1000000)                                         \
 242       {                                                                       \
 243         ++(result)->tv_sec;                                                   \
 244         (result)->tv_usec -= 1000000;                                         \
 245       }                                                                       \
 246   } while (0)
 247 # define timersub(a, b, result)                                               \
 248   do {                                                                        \
 249     (result)->tv_sec = (a)->tv_sec - (b)->tv_sec;                             \
 250     (result)->tv_usec = (a)->tv_usec - (b)->tv_usec;                          \
 251     if ((result)->tv_usec < 0) {                                              \
 252       --(result)->tv_sec;                                                     \
 253       (result)->tv_usec += 1000000;                                           \
 254     }                                                                         \
 255   } while (0)
 256 #endif  /* Misc.  */
 257
 258 __END_DECLS
 259
 260 #endif /* sys/time.h */