time/sys/time.h

   1 /* Copyright (C) 1991-2014 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    <http://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 #define __need_time_t
  25 #include <time.h>
  26 #define __need_timeval
  27 #include <bits/time.h>
  28
  29 #include <sys/select.h>
  30
  31 #ifndef __suseconds_t_defined
  32 typedef __suseconds_t suseconds_t;
  33 # define __suseconds_t_defined
  34 #endif
  35
  36
  37 __BEGIN_DECLS
  38
  39 #ifdef __USE_GNU
  40 /* Macros for converting between `struct timeval' and `struct timespec'.  */
  41 # define TIMEVAL_TO_TIMESPEC(tv, ts) {                                   \
  42         (ts)->tv_sec = (tv)->tv_sec;                                    \
  43         (ts)->tv_nsec = (tv)->tv_usec * 1000;                           \
  44 }
  45 # define TIMESPEC_TO_TIMEVAL(tv, ts) {                                   \
  46         (tv)->tv_sec = (ts)->tv_sec;                                    \
  47         (tv)->tv_usec = (ts)->tv_nsec / 1000;                           \
  48 }
  49 #endif
  50
  51
  52 #ifdef __USE_MISC
  53 /* Structure crudely representing a timezone.
  54    This is obsolete and should never be used.  */
  55 struct timezone
  56   {
  57     int tz_minuteswest;         /* Minutes west of GMT.  */
  58     int tz_dsttime;             /* Nonzero if DST is ever in effect.  */
  59   };
  60
  61 typedef struct timezone *__restrict __timezone_ptr_t;
  62 #else
  63 typedef void *__restrict __timezone_ptr_t;
  64 #endif
  65
  66 /* Get the current time of day and timezone information,
  67    putting it into *TV and *TZ.  If TZ is NULL, *TZ is not filled.
  68    Returns 0 on success, -1 on errors.
  69    NOTE: This form of timezone information is obsolete.
  70    Use the functions and variables declared in <time.h> instead.  */
  71 extern int gettimeofday (struct timeval *__restrict __tv,
  72                          __timezone_ptr_t __tz) __THROW __nonnull ((1));
  73
  74 #ifdef __USE_MISC
  75 /* Set the current time of day and timezone information.
  76    This call is restricted to the super-user.  */
  77 extern int settimeofday (const struct timeval *__tv,
  78                          const struct timezone *__tz)
  79      __THROW;
  80
  81 /* Adjust the current time of day by the amount in DELTA.
  82    If OLDDELTA is not NULL, it is filled in with the amount
  83    of time adjustment remaining to be done from the last `adjtime' call.
  84    This call is restricted to the super-user.  */
  85 extern int adjtime (const struct timeval *__delta,
  86                     struct timeval *__olddelta) __THROW;
  87 #endif
  88
  89
  90 /* Values for the first argument to `getitimer' and `setitimer'.  */
  91 enum __itimer_which
  92   {
  93     /* Timers run in real time.  */
  94     ITIMER_REAL = 0,
  95 #define ITIMER_REAL ITIMER_REAL
  96     /* Timers run only when the process is executing.  */
  97     ITIMER_VIRTUAL = 1,
  98 #define ITIMER_VIRTUAL ITIMER_VIRTUAL
  99     /* Timers run when the process is executing and when
 100        the system is executing on behalf of the process.  */
 101     ITIMER_PROF = 2
 102 #define ITIMER_PROF ITIMER_PROF
 103   };
 104
 105 /* Type of the second argument to `getitimer' and
 106    the second and third arguments `setitimer'.  */
 107 struct itimerval
 108   {
 109     /* Value to put into `it_value' when the timer expires.  */
 110     struct timeval it_interval;
 111     /* Time to the next timer expiration.  */
 112     struct timeval it_value;
 113   };
 114
 115 #if defined __USE_GNU && !defined __cplusplus
 116 /* Use the nicer parameter type only in GNU mode and not for C++ since the
 117    strict C++ rules prevent the automatic promotion.  */
 118 typedef enum __itimer_which __itimer_which_t;
 119 #else
 120 typedef int __itimer_which_t;
 121 #endif
 122
 123 /* Set *VALUE to the current setting of timer WHICH.
 124    Return 0 on success, -1 on errors.  */
 125 extern int getitimer (__itimer_which_t __which,
 126                       struct itimerval *__value) __THROW;
 127
 128 /* Set the timer WHICH to *NEW.  If OLD is not NULL,
 129    set *OLD to the old value of timer WHICH.
 130    Returns 0 on success, -1 on errors.  */
 131 extern int setitimer (__itimer_which_t __which,
 132                       const struct itimerval *__restrict __new,
 133                       struct itimerval *__restrict __old) __THROW;
 134
 135 /* Change the access time of FILE to TVP[0] and the modification time of
 136    FILE to TVP[1].  If TVP is a null pointer, use the current time instead.
 137    Returns 0 on success, -1 on errors.  */
 138 extern int utimes (const char *__file, const struct timeval __tvp[2])
 139      __THROW __nonnull ((1));
 140
 141 #ifdef __USE_MISC
 142 /* Same as `utimes', but does not follow symbolic links.  */
 143 extern int lutimes (const char *__file, const struct timeval __tvp[2])
 144      __THROW __nonnull ((1));
 145
 146 /* Same as `utimes', but takes an open file descriptor instead of a name.  */
 147 extern int futimes (int __fd, const struct timeval __tvp[2]) __THROW;
 148 #endif
 149
 150 #ifdef __USE_GNU
 151 /* Change the access time of FILE relative to FD to TVP[0] and the
 152    modification time of FILE to TVP[1].  If TVP is a null pointer, use
 153    the current time instead.  Returns 0 on success, -1 on errors.  */
 154 extern int futimesat (int __fd, const char *__file,
 155                       const struct timeval __tvp[2]) __THROW;
 156 #endif
 157
 158
 159 #ifdef __USE_MISC
 160 /* Convenience macros for operations on timevals.
 161    NOTE: `timercmp' does not work for >= or <=.  */
 162 # define timerisset(tvp)        ((tvp)->tv_sec || (tvp)->tv_usec)
 163 # define timerclear(tvp)        ((tvp)->tv_sec = (tvp)->tv_usec = 0)
 164 # define timercmp(a, b, CMP)                                                  \
 165   (((a)->tv_sec == (b)->tv_sec) ?                                             \
 166    ((a)->tv_usec CMP (b)->tv_usec) :                                          \
 167    ((a)->tv_sec CMP (b)->tv_sec))
 168 # define timeradd(a, b, result)                                               \
 169   do {                                                                        \
 170     (result)->tv_sec = (a)->tv_sec + (b)->tv_sec;                             \
 171     (result)->tv_usec = (a)->tv_usec + (b)->tv_usec;                          \
 172     if ((result)->tv_usec >= 1000000)                                         \
 173       {                                                                       \
 174         ++(result)->tv_sec;                                                   \
 175         (result)->tv_usec -= 1000000;                                         \
 176       }                                                                       \
 177   } while (0)
 178 # define timersub(a, b, result)                                               \
 179   do {                                                                        \
 180     (result)->tv_sec = (a)->tv_sec - (b)->tv_sec;                             \
 181     (result)->tv_usec = (a)->tv_usec - (b)->tv_usec;                          \
 182     if ((result)->tv_usec < 0) {                                              \
 183       --(result)->tv_sec;                                                     \
 184       (result)->tv_usec += 1000000;                                           \
 185     }                                                                         \
 186   } while (0)
 187 #endif  /* Misc.  */
 188
 189 __END_DECLS
 190
 191 #endif /* sys/time.h */