time/sys/time.h

   1 /* Copyright (C) 1991-1994,1996-2002,2003,2005,2006
   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, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #ifndef _SYS_TIME_H
  21 #define _SYS_TIME_H     1
  22
  23 #include <features.h>
  24
  25 #include <bits/types.h>
  26 #define __need_time_t
  27 #include <time.h>
  28 #define __need_timeval
  29 #include <bits/time.h>
  30
  31 #include <sys/select.h>
  32
  33 #ifndef __suseconds_t_defined
  34 typedef __suseconds_t suseconds_t;
  35 # define __suseconds_t_defined
  36 #endif
  37
  38
  39 __BEGIN_DECLS
  40
  41 #ifdef __USE_GNU
  42 /* Macros for converting between `struct timeval' and `struct timespec'.  */
  43 # define TIMEVAL_TO_TIMESPEC(tv, ts) {                                   \
  44         (ts)->tv_sec = (tv)->tv_sec;                                    \
  45         (ts)->tv_nsec = (tv)->tv_usec * 1000;                           \
  46 }
  47 # define TIMESPEC_TO_TIMEVAL(tv, ts) {                                   \
  48         (tv)->tv_sec = (ts)->tv_sec;                                    \
  49         (tv)->tv_usec = (ts)->tv_nsec / 1000;                           \
  50 }
  51 #endif
  52
  53
  54 #ifdef __USE_BSD
  55 /* Structure crudely representing a timezone.
  56    This is obsolete and should never be used.  */
  57 struct timezone
  58   {
  59     int tz_minuteswest;         /* Minutes west of GMT.  */
  60     int tz_dsttime;             /* Nonzero if DST is ever in effect.  */
  61   };
  62
  63 typedef struct timezone *__restrict __timezone_ptr_t;
  64 #else
  65 typedef void *__restrict __timezone_ptr_t;
  66 #endif
  67
  68 /* Get the current time of day and timezone information,
  69    putting it into *TV and *TZ.  If TZ is NULL, *TZ is not filled.
  70    Returns 0 on success, -1 on errors.
  71    NOTE: This form of timezone information is obsolete.
  72    Use the functions and variables declared in <time.h> instead.  */
  73 extern int gettimeofday (struct timeval *__restrict __tv,
  74                          __timezone_ptr_t __tz) __THROW __nonnull ((1));
  75
  76 #ifdef __USE_BSD
  77 /* Set the current time of day and timezone information.
  78    This call is restricted to the super-user.  */
  79 extern int settimeofday (__const struct timeval *__tv,
  80                          __const struct timezone *__tz)
  81      __THROW __nonnull ((1));
  82
  83 /* Adjust the current time of day by the amount in DELTA.
  84    If OLDDELTA is not NULL, it is filled in with the amount
  85    of time adjustment remaining to be done from the last `adjtime' call.
  86    This call is restricted to the super-user.  */
  87 extern int adjtime (__const struct timeval *__delta,
  88                     struct timeval *__olddelta) __THROW;
  89 #endif
  90
  91
  92 /* Values for the first argument to `getitimer' and `setitimer'.  */
  93 enum __itimer_which
  94   {
  95     /* Timers run in real time.  */
  96     ITIMER_REAL = 0,
  97 #define ITIMER_REAL ITIMER_REAL
  98     /* Timers run only when the process is executing.  */
  99     ITIMER_VIRTUAL = 1,
 100 #define ITIMER_VIRTUAL ITIMER_VIRTUAL
 101     /* Timers run when the process is executing and when
 102        the system is executing on behalf of the process.  */
 103     ITIMER_PROF = 2
 104 #define ITIMER_PROF ITIMER_PROF
 105   };
 106
 107 /* Type of the second argument to `getitimer' and
 108    the second and third arguments `setitimer'.  */
 109 struct itimerval
 110   {
 111     /* Value to put into `it_value' when the timer expires.  */
 112     struct timeval it_interval;
 113     /* Time to the next timer expiration.  */
 114     struct timeval it_value;
 115   };
 116
 117 #if defined __USE_GNU && !defined __cplusplus
 118 /* Use the nicer parameter type only in GNU mode and not for C++ since the
 119    strict C++ rules prevent the automatic promotion.  */
 120 typedef enum __itimer_which __itimer_which_t;
 121 #else
 122 typedef int __itimer_which_t;
 123 #endif
 124
 125 /* Set *VALUE to the current setting of timer WHICH.
 126    Return 0 on success, -1 on errors.  */
 127 extern int getitimer (__itimer_which_t __which,
 128                       struct itimerval *__value) __THROW;
 129
 130 /* Set the timer WHICH to *NEW.  If OLD is not NULL,
 131    set *OLD to the old value of timer WHICH.
 132    Returns 0 on success, -1 on errors.  */
 133 extern int setitimer (__itimer_which_t __which,
 134                       __const struct itimerval *__restrict __new,
 135                       struct itimerval *__restrict __old) __THROW;
 136
 137 /* Change the access time of FILE to TVP[0] and the modification time of
 138    FILE to TVP[1].  If TVP is a null pointer, use the current time instead.
 139    Returns 0 on success, -1 on errors.  */
 140 extern int utimes (__const char *__file, __const struct timeval __tvp[2])
 141      __THROW __nonnull ((1));
 142
 143 #ifdef __USE_BSD
 144 /* Same as `utimes', but does not follow symbolic links.  */
 145 extern int lutimes (__const char *__file, __const struct timeval __tvp[2])
 146      __THROW __nonnull ((1));
 147
 148 /* Same as `utimes', but takes an open file descriptor instead of a name.  */
 149 extern int futimes (int __fd, __const struct timeval __tvp[2]) __THROW;
 150 #endif
 151
 152 #ifdef __USE_ATFILE
 153 /* Change the access time of FILE relative to FD to TVP[0] and the
 154    modification time of FILE to TVP[1].  If TVP is a null pointer, use
 155    the current time instead.  Returns 0 on success, -1 on errors.  */
 156 extern int futimesat (int __fd, __const char *__file,
 157                       __const struct timeval __tvp[2]) __THROW;
 158 #endif
 159
 160
 161 #ifdef __USE_BSD
 162 /* Convenience macros for operations on timevals.
 163    NOTE: `timercmp' does not work for >= or <=.  */
 164 # define timerisset(tvp)        ((tvp)->tv_sec || (tvp)->tv_usec)
 165 # define timerclear(tvp)        ((tvp)->tv_sec = (tvp)->tv_usec = 0)
 166 # define timercmp(a, b, CMP)                                                  \
 167   (((a)->tv_sec == (b)->tv_sec) ?                                             \
 168    ((a)->tv_usec CMP (b)->tv_usec) :                                          \
 169    ((a)->tv_sec CMP (b)->tv_sec))
 170 # define timeradd(a, b, result)                                               \
 171   do {                                                                        \
 172     (result)->tv_sec = (a)->tv_sec + (b)->tv_sec;                             \
 173     (result)->tv_usec = (a)->tv_usec + (b)->tv_usec;                          \
 174     if ((result)->tv_usec >= 1000000)                                         \
 175       {                                                                       \
 176         ++(result)->tv_sec;                                                   \
 177         (result)->tv_usec -= 1000000;                                         \
 178       }                                                                       \
 179   } while (0)
 180 # define timersub(a, b, result)                                               \
 181   do {                                                                        \
 182     (result)->tv_sec = (a)->tv_sec - (b)->tv_sec;                             \
 183     (result)->tv_usec = (a)->tv_usec - (b)->tv_usec;                          \
 184     if ((result)->tv_usec < 0) {                                              \
 185       --(result)->tv_sec;                                                     \
 186       (result)->tv_usec += 1000000;                                           \
 187     }                                                                         \
 188   } while (0)
 189 #endif  /* BSD */
 190
 191 __END_DECLS
 192
 193 #endif /* sys/time.h */