time/sys/time.h

   1 /* Copyright (C) 1991, 92, 93, 94, 96, 97 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 Library General Public License as
   6    published by the Free Software Foundation; either version 2 of the
   7    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    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 #ifndef _SYS_TIME_H
  20 #define _SYS_TIME_H     1
  21
  22 #include <features.h>
  23
  24 #include <time.h>
  25 #include <sys/select.h>
  26
  27 #define __need_timeval
  28 #include <bits/time.h>
  29
  30
  31 __BEGIN_DECLS
  32
  33 /* Macros for converting between `struct timeval' and `struct timespec'.  */
  34 #define TIMEVAL_TO_TIMESPEC(tv, ts) {                                   \
  35         (ts)->tv_sec = (tv)->tv_sec;                                    \
  36         (ts)->tv_nsec = (tv)->tv_usec * 1000;                           \
  37 }
  38 #define TIMESPEC_TO_TIMEVAL(tv, ts) {                                   \
  39         (tv)->tv_sec = (ts)->tv_sec;                                    \
  40         (tv)->tv_usec = (ts)->tv_nsec / 1000;                           \
  41 }
  42
  43
  44 /* Structure crudely representing a timezone.
  45    This is obsolete and should never be used.  */
  46 struct timezone
  47   {
  48     int tz_minuteswest;         /* Minutes west of GMT.  */
  49     int tz_dsttime;             /* Nonzero if DST is ever in effect.  */
  50   };
  51
  52 /* Get the current time of day and timezone information,
  53    putting it into *TV and *TZ.  If TZ is NULL, *TZ is not filled.
  54    Returns 0 on success, -1 on errors.
  55    NOTE: This form of timezone information is obsolete.
  56    Use the functions and variables declared in <time.h> instead.  */
  57 extern int __gettimeofday __P ((struct timeval *__tv,
  58                                 struct timezone *__tz));
  59 extern int gettimeofday __P ((struct timeval *__tv,
  60                               struct timezone *__tz));
  61
  62 /* Set the current time of day and timezone information.
  63    This call is restricted to the super-user.  */
  64 extern int __settimeofday __P ((__const struct timeval *__tv,
  65                                 __const struct timezone *__tz));
  66 extern int settimeofday __P ((__const struct timeval *__tv,
  67                               __const struct timezone *__tz));
  68
  69 /* Adjust the current time of day by the amount in DELTA.
  70    If OLDDELTA is not NULL, it is filled in with the amount
  71    of time adjustment remaining to be done from the last `adjtime' call.
  72    This call is restricted to the super-user.  */
  73 extern int __adjtime __P ((__const struct timeval *__delta,
  74                            struct timeval *__olddelta));
  75 extern int adjtime __P ((__const struct timeval *__delta,
  76                          struct timeval *__olddelta));
  77
  78
  79 /* Values for the first argument to `getitimer' and `setitimer'.  */
  80 enum __itimer_which
  81   {
  82     /* Timers run in real time.  */
  83     ITIMER_REAL = 0,
  84 #define ITIMER_REAL ITIMER_REAL
  85     /* Timers run only when the process is executing.  */
  86     ITIMER_VIRTUAL = 1,
  87 #define ITIMER_VIRTUAL ITIMER_VIRTUAL
  88     /* Timers run when the process is executing and when
  89        the system is executing on behalf of the process.  */
  90     ITIMER_PROF = 2
  91 #define ITIMER_PROF ITIMER_PROF
  92   };
  93
  94 /* Type of the second argument to `getitimer' and
  95    the second and third arguments `setitimer'.  */
  96 struct itimerval
  97   {
  98     /* Value to put into `it_value' when the timer expires.  */
  99     struct timeval it_interval;
 100     /* Time to the next timer expiration.  */
 101     struct timeval it_value;
 102   };
 103
 104 /* Set *VALUE to the current setting of timer WHICH.
 105    Return 0 on success, -1 on errors.  */
 106 extern int __getitimer __P ((enum __itimer_which __which,
 107                              struct itimerval *__value));
 108 extern int getitimer __P ((enum __itimer_which __which,
 109                            struct itimerval *__value));
 110
 111 /* Set the timer WHICH to *NEW.  If OLD is not NULL,
 112    set *OLD to the old value of timer WHICH.
 113    Returns 0 on success, -1 on errors.  */
 114 extern int __setitimer __P ((enum __itimer_which __which,
 115                              __const struct itimerval *__new,
 116                              struct itimerval *__old));
 117 extern int setitimer __P ((enum __itimer_which __which,
 118                            __const struct itimerval *__new,
 119                            struct itimerval *__old));
 120
 121 /* Change the access time of FILE to TVP[0] and
 122    the modification time of FILE to TVP[1].  */
 123 extern int __utimes __P ((__const char *__file, struct timeval __tvp[2]));
 124 extern int utimes __P ((__const char *__file, struct timeval __tvp[2]));
 125
 126
 127 /* Convenience macros for operations on timevals.
 128    NOTE: `timercmp' does not work for >= or <=.  */
 129 #define timerisset(tvp)         ((tvp)->tv_sec || (tvp)->tv_usec)
 130 #define timerclear(tvp)         ((tvp)->tv_sec = (tvp)->tv_usec = 0)
 131 #define timercmp(a, b, CMP)                                                   \
 132   (((a)->tv_sec == (b)->tv_sec) ?                                             \
 133    ((a)->tv_usec CMP (b)->tv_usec) :                                          \
 134    ((a)->tv_sec CMP (b)->tv_sec))
 135 #define timeradd(a, b, result)                                                \
 136   do {                                                                        \
 137     (result)->tv_sec = (a)->tv_sec + (b)->tv_sec;                             \
 138     (result)->tv_usec = (a)->tv_usec + (b)->tv_usec;                          \
 139     if ((result)->tv_usec >= 1000000)                                         \
 140       {                                                                       \
 141         ++(result)->tv_sec;                                                   \
 142         (result)->tv_usec -= 1000000;                                         \
 143       }                                                                       \
 144   } while (0)
 145 #define timersub(a, b, result)                                                \
 146   do {                                                                        \
 147     (result)->tv_sec = (a)->tv_sec - (b)->tv_sec;                             \
 148     (result)->tv_usec = (a)->tv_usec - (b)->tv_usec;                          \
 149     if ((result)->tv_usec < 0) {                                              \
 150       --(result)->tv_sec;                                                     \
 151       (result)->tv_usec += 1000000;                                           \
 152     }                                                                         \
 153   } while (0)
 154
 155 __END_DECLS
 156
 157 #endif /* sys/time.h */