include/sys/time.h

   1 /* Copyright (C) 1991-1994,1996-2003,2005,2006,2009
   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  55    This is obsolete and should never be used.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 libc_hidden_proto(gettimeofday)
  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;
  82 libc_hidden_proto(settimeofday)
  83
  84 /* Adjust the current time of day by the amount in DELTA.
  85    If OLDDELTA is not NULL, it is filled in with the amount
  86    of time adjustment remaining to be done from the last `adjtime' call.
  87    This call is restricted to the super-user.  */
  88 extern int adjtime (const struct timeval *__delta,
  89                     struct timeval *__olddelta) __THROW;
  90 #endif
  91
  92
  93 /* Values for the first argument to `getitimer' and `setitimer'.  */
  94 enum __itimer_which
  95   {
  96     /* Timers run in real time.  */
  97     ITIMER_REAL = 0,
  98 #define ITIMER_REAL ITIMER_REAL
  99     /* Timers run only when the process is executing.  */
 100     ITIMER_VIRTUAL = 1,
 101 #define ITIMER_VIRTUAL ITIMER_VIRTUAL
 102     /* Timers run when the process is executing and when
 103        the system is executing on behalf of the process.  */
 104     ITIMER_PROF = 2
 105 #define ITIMER_PROF ITIMER_PROF
 106   };
 107
 108 /* Type of the second argument to `getitimer' and
 109    the second and third arguments `setitimer'.  */
 110 struct itimerval
 111   {
 112     /* Value to put into `it_value' when the timer expires.  */
 113     struct timeval it_interval;
 114     /* Time to the next timer expiration.  */
 115     struct timeval it_value;
 116   };
 117
 118 #if defined __USE_GNU && !defined __cplusplus
 119 /* Use the nicer parameter type only in GNU mode and not for C++ since the
 120    strict C++ rules prevent the automatic promotion.  */
 121 typedef enum __itimer_which __itimer_which_t;
 122 #else
 123 typedef int __itimer_which_t;
 124 #endif
 125
 126 /* Set *VALUE to the current setting of timer WHICH.
 127    Return 0 on success, -1 on errors.  */
 128 extern int getitimer (__itimer_which_t __which,
 129                       struct itimerval *__value) __THROW;
 130
 131 /* Set the timer WHICH to *NEW.  If OLD is not NULL,
 132    set *OLD to the old value of timer WHICH.
 133    Returns 0 on success, -1 on errors.  */
 134 extern int setitimer (__itimer_which_t __which,
 135                       const struct itimerval *__restrict __new,
 136                       struct itimerval *__restrict __old) __THROW;
 137 libc_hidden_proto(setitimer)
 138
 139 /* Change the access time of FILE to TVP[0] and the modification time of
 140    FILE to TVP[1].  If TVP is a null pointer, use the current time instead.
 141    Returns 0 on success, -1 on errors.  */
 142 extern int utimes (const char *__file, const struct timeval __tvp[2])
 143      __THROW __nonnull ((1));
 144 libc_hidden_proto(utimes)
 145
 146 #ifdef __USE_BSD
 147 /* Same as `utimes', but does not follow symbolic links.  */
 148 extern int lutimes (const char *__file, const struct timeval __tvp[2])
 149      __THROW __nonnull ((1));
 150
 151 #if 0
 152 /* Same as `utimes', but takes an open file descriptor instead of a name.  */
 153 extern int futimes (int __fd, const struct timeval __tvp[2]) __THROW;
 154 #endif
 155 #endif
 156
 157 #ifdef __USE_GNU
 158 /* Change the access time of FILE relative to FD to TVP[0] and the
 159    modification time of FILE to TVP[1].  If TVP is a null pointer, use
 160    the current time instead.  Returns 0 on success, -1 on errors.  */
 161 extern int futimesat (int __fd, const char *__file,
 162                       const struct timeval __tvp[2]) __THROW;
 163 #endif
 164
 165
 166 #ifdef __USE_BSD
 167 /* Convenience macros for operations on timevals.
 168    NOTE: `timercmp' does not work for >= or <=.  */
 169 # define timerisset(tvp)        ((tvp)->tv_sec || (tvp)->tv_usec)
 170 # define timerclear(tvp)        ((tvp)->tv_sec = (tvp)->tv_usec = 0)
 171 # define timercmp(a, b, CMP)                                                  \
 172   (((a)->tv_sec == (b)->tv_sec) ?                                             \
 173    ((a)->tv_usec CMP (b)->tv_usec) :                                          \
 174    ((a)->tv_sec CMP (b)->tv_sec))
 175 # define timeradd(a, b, result)                                               \
 176   do {                                                                        \
 177     (result)->tv_sec = (a)->tv_sec + (b)->tv_sec;                             \
 178     (result)->tv_usec = (a)->tv_usec + (b)->tv_usec;                          \
 179     if ((result)->tv_usec >= 1000000)                                         \
 180       {                                                                       \
 181         ++(result)->tv_sec;                                                   \
 182         (result)->tv_usec -= 1000000;                                         \
 183       }                                                                       \
 184   } while (0)
 185 # define timersub(a, b, result)                                               \
 186   do {                                                                        \
 187     (result)->tv_sec = (a)->tv_sec - (b)->tv_sec;                             \
 188     (result)->tv_usec = (a)->tv_usec - (b)->tv_usec;                          \
 189     if ((result)->tv_usec < 0) {                                              \
 190       --(result)->tv_sec;                                                     \
 191       (result)->tv_usec += 1000000;                                           \
 192     }                                                                         \
 193   } while (0)
 194 #endif  /* BSD */
 195
 196 __END_DECLS
 197
 198 #endif /* sys/time.h */