time/sys/time.h

   1 /* Copyright (C) 1991-1994,1996-2003,2005,2006,2009,2012
   2         Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _SYS_TIME_H
  20 #define _SYS_TIME_H     1
  21
  22 #include <features.h>
  23
  24 #include <bits/types.h>
  25 #define __need_time_t
  26 #include <time.h>
  27 #define __need_timeval
  28 #include <bits/time.h>
  29
  30 #include <sys/select.h>
  31
  32 #ifndef __suseconds_t_defined
  33 typedef __suseconds_t suseconds_t;
  34 # define __suseconds_t_defined
  35 #endif
  36
  37
  38 __BEGIN_DECLS
  39
  40 #ifdef __USE_GNU
  41 /* Macros for converting between `struct timeval' and `struct timespec'.  */
  42 # define TIMEVAL_TO_TIMESPEC(tv, ts) {                                   \
  43         (ts)->tv_sec = (tv)->tv_sec;                                    \
  44         (ts)->tv_nsec = (tv)->tv_usec * 1000;                           \
  45 }
  46 # define TIMESPEC_TO_TIMEVAL(tv, ts) {                                   \
  47         (tv)->tv_sec = (ts)->tv_sec;                                    \
  48         (tv)->tv_usec = (ts)->tv_nsec / 1000;                           \
  49 }
  50 #endif
  51
  52
  53 #ifdef __USE_BSD
  54 /* Structure crudely representing a timezone.
  55    This is obsolete and should never be used.  */
  56 struct timezone
  57   {
  58     int tz_minuteswest;         /* Minutes west of GMT.  */
  59     int tz_dsttime;             /* Nonzero if DST is ever in effect.  */
  60   };
  61
  62 typedef struct timezone *__restrict __timezone_ptr_t;
  63 #else
  64 typedef void *__restrict __timezone_ptr_t;
  65 #endif
  66
  67 /* Get the current time of day and timezone information,
  68    putting it into *TV and *TZ.  If TZ is NULL, *TZ is not filled.
  69    Returns 0 on success, -1 on errors.
  70    NOTE: This form of timezone information is obsolete.
  71    Use the functions and variables declared in <time.h> instead.  */
  72 extern int gettimeofday (struct timeval *__restrict __tv,
  73                          __timezone_ptr_t __tz) __THROW __nonnull ((1));
  74
  75 #ifdef __USE_BSD
  76 /* Set the current time of day and timezone information.
  77    This call is restricted to the super-user.  */
  78 extern int settimeofday (const struct timeval *__tv,
  79                          const struct timezone *__tz)
  80      __THROW __nonnull ((1));
  81
  82 /* Adjust the current time of day by the amount in DELTA.
  83    If OLDDELTA is not NULL, it is filled in with the amount
  84    of time adjustment remaining to be done from the last `adjtime' call.
  85    This call is restricted to the super-user.  */
  86 extern int adjtime (const struct timeval *__delta,
  87                     struct timeval *__olddelta) __THROW;
  88 #endif
  89
  90
  91 /* Values for the first argument to `getitimer' and `setitimer'.  */
  92 enum __itimer_which
  93   {
  94     /* Timers run in real time.  */
  95     ITIMER_REAL = 0,
  96 #define ITIMER_REAL ITIMER_REAL
  97     /* Timers run only when the process is executing.  */
  98     ITIMER_VIRTUAL = 1,
  99 #define ITIMER_VIRTUAL ITIMER_VIRTUAL
 100     /* Timers run when the process is executing and when
 101        the system is executing on behalf of the process.  */
 102     ITIMER_PROF = 2
 103 #define ITIMER_PROF ITIMER_PROF
 104   };
 105
 106 /* Type of the second argument to `getitimer' and
 107    the second and third arguments `setitimer'.  */
 108 struct itimerval
 109   {
 110     /* Value to put into `it_value' when the timer expires.  */
 111     struct timeval it_interval;
 112     /* Time to the next timer expiration.  */
 113     struct timeval it_value;
 114   };
 115
 116 #if defined __USE_GNU && !defined __cplusplus
 117 /* Use the nicer parameter type only in GNU mode and not for C++ since the
 118    strict C++ rules prevent the automatic promotion.  */
 119 typedef enum __itimer_which __itimer_which_t;
 120 #else
 121 typedef int __itimer_which_t;
 122 #endif
 123
 124 /* Set *VALUE to the current setting of timer WHICH.
 125    Return 0 on success, -1 on errors.  */
 126 extern int getitimer (__itimer_which_t __which,
 127                       struct itimerval *__value) __THROW;
 128
 129 /* Set the timer WHICH to *NEW.  If OLD is not NULL,
 130    set *OLD to the old value of timer WHICH.
 131    Returns 0 on success, -1 on errors.  */
 132 extern int setitimer (__itimer_which_t __which,
 133                       const struct itimerval *__restrict __new,
 134                       struct itimerval *__restrict __old) __THROW;
 135
 136 /* Change the access time of FILE to TVP[0] and the modification time of
 137    FILE to TVP[1].  If TVP is a null pointer, use the current time instead.
 138    Returns 0 on success, -1 on errors.  */
 139 extern int utimes (const char *__file, const struct timeval __tvp[2])
 140      __THROW __nonnull ((1));
 141
 142 #ifdef __USE_BSD
 143 /* Same as `utimes', but does not follow symbolic links.  */
 144 extern int lutimes (const char *__file, const struct timeval __tvp[2])
 145      __THROW __nonnull ((1));
 146
 147 /* Same as `utimes', but takes an open file descriptor instead of a name.  */
 148 extern int futimes (int __fd, const struct timeval __tvp[2]) __THROW;
 149 #endif
 150
 151 #ifdef __USE_GNU
 152 /* Change the access time of FILE relative to FD to TVP[0] and the
 153    modification time of FILE to TVP[1].  If TVP is a null pointer, use
 154    the current time instead.  Returns 0 on success, -1 on errors.  */
 155 extern int futimesat (int __fd, const char *__file,
 156                       const struct timeval __tvp[2]) __THROW;
 157 #endif
 158
 159
 160 #ifdef __USE_BSD
 161 /* Convenience macros for operations on timevals.
 162    NOTE: `timercmp' does not work for >= or <=.  */
 163 # define timerisset(tvp)        ((tvp)->tv_sec || (tvp)->tv_usec)
 164 # define timerclear(tvp)        ((tvp)->tv_sec = (tvp)->tv_usec = 0)
 165 # define timercmp(a, b, CMP)                                                  \
 166   (((a)->tv_sec == (b)->tv_sec) ?                                             \
 167    ((a)->tv_usec CMP (b)->tv_usec) :                                          \
 168    ((a)->tv_sec CMP (b)->tv_sec))
 169 # define timeradd(a, b, result)                                               \
 170   do {                                                                        \
 171     (result)->tv_sec = (a)->tv_sec + (b)->tv_sec;                             \
 172     (result)->tv_usec = (a)->tv_usec + (b)->tv_usec;                          \
 173     if ((result)->tv_usec >= 1000000)                                         \
 174       {                                                                       \
 175         ++(result)->tv_sec;                                                   \
 176         (result)->tv_usec -= 1000000;                                         \
 177       }                                                                       \
 178   } while (0)
 179 # define timersub(a, b, result)                                               \
 180   do {                                                                        \
 181     (result)->tv_sec = (a)->tv_sec - (b)->tv_sec;                             \
 182     (result)->tv_usec = (a)->tv_usec - (b)->tv_usec;                          \
 183     if ((result)->tv_usec < 0) {                                              \
 184       --(result)->tv_sec;                                                     \
 185       (result)->tv_usec += 1000000;                                           \
 186     }                                                                         \
 187   } while (0)
 188 #endif  /* BSD */
 189
 190 __END_DECLS
 191
 192 #endif /* sys/time.h */