time/sys/time.h

   1 /* Copyright (C) 1991, 1992, 1993, 1994 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
  16 not, write to the, 1992 Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 #ifndef _SYS_TIME_H
  20
  21 #define _SYS_TIME_H     1
  22 #include <features.h>
  23
  24 #include <time.h>
  25
  26 __BEGIN_DECLS
  27
  28 /* A time value that is accurate to the nearest
  29    microsecond but also has a range of years.  */
  30 struct timeval
  31   {
  32     int tv_sec;                 /* Seconds.  */
  33     int tv_usec;                /* Microseconds.  */
  34   };
  35
  36 /* POSIX.4 structure for a time value.  This is like a `struct timeval' but
  37    has nanoseconds instead of microseconds.  */
  38 struct timespec
  39   {
  40     long int ts_sec;            /* Seconds.  */
  41     long int ts_nsec;           /* Nanoseconds.  */
  42   };
  43
  44 /* Macros for converting between `struct timeval' and `struct timespec'.  */
  45 #define TIMEVAL_TO_TIMESPEC(tv, ts) {                                   \
  46         (ts)->ts_sec = (tv)->tv_sec;                                    \
  47         (ts)->ts_nsec = (tv)->tv_usec * 1000;                           \
  48 }
  49 #define TIMESPEC_TO_TIMEVAL(tv, ts) {                                   \
  50         (tv)->tv_sec = (ts)->ts_sec;                                    \
  51         (tv)->tv_usec = (ts)->ts_nsec / 1000;                           \
  52 }
  53
  54
  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  56    This is obsolete and should never be used.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 /* Get the current time of day and timezone information,
  64    putting it into *TV and *TZ.  If TZ is NULL, *TZ is not filled.
  65    Returns 0 on success, -1 on errors.
  66    NOTE: This form of timezone information is obsolete.
  67    Use the functions and variables declared in <time.h> instead.  */
  68 extern int __gettimeofday __P ((struct timeval *__tv,
  69                                 struct timezone *__tz));
  70 extern int gettimeofday __P ((struct timeval *__tv,
  71                               struct timezone *__tz));
  72
  73 /* Set the current time of day and timezone information.
  74    This call is restricted to the super-user.  */
  75 extern int __settimeofday __P ((__const struct timeval *__tv,
  76                                 __const struct timezone *__tz));
  77 extern int settimeofday __P ((__const struct timeval *__tv,
  78                               __const struct timezone *__tz));
  79
  80 /* Adjust the current time of day by the amount in DELTA.
  81    If OLDDELTA is not NULL, it is filled in with the amount
  82    of time adjustment remaining to be done from the last `adjtime' call.
  83    This call is restricted to the super-user.  */
  84 extern int __adjtime __P ((__const struct timeval *__delta,
  85                            struct timeval *__olddelta));
  86 extern int adjtime __P ((__const struct timeval *__delta,
  87                          struct timeval *__olddelta));
  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     /* Timers run only when the process is executing.  */
  96     ITIMER_VIRTUAL = 1,
  97     /* Timers run when the process is executing and when
  98        the system is executing on behalf of the process.  */
  99     ITIMER_PROF = 2
 100   };
 101
 102 /* Type of the second argument to `getitimer' and
 103    the second and third arguments `setitimer'.  */
 104 struct itimerval
 105   {
 106     /* Value to put into `it_value' when the timer expires.  */
 107     struct timeval it_interval;
 108     /* Time to the next timer expiration.  */
 109     struct timeval it_value;
 110   };
 111
 112 /* Set *VALUE to the current setting of timer WHICH.
 113    Return 0 on success, -1 on errors.  */
 114 extern int __getitimer __P ((enum __itimer_which __which,
 115                              struct itimerval *__value));
 116 extern int getitimer __P ((enum __itimer_which __which,
 117                            struct itimerval *__value));
 118
 119 /* Set the timer WHICH to *NEW.  If OLD is not NULL,
 120    set *OLD to the old value of timer WHICH.
 121    Returns 0 on success, -1 on errors.  */
 122 extern int __setitimer __P ((enum __itimer_which __which,
 123                              struct itimerval *__new,
 124                              struct itimerval *__old));
 125 extern int setitimer __P ((enum __itimer_which __which,
 126                            struct itimerval *__new,
 127                            struct itimerval *__old));
 128
 129 /* Change the access time of FILE to TVP[0] and
 130    the modification time of FILE to TVP[1].  */
 131 extern int __utimes __P ((__const char *__file, struct timeval __tvp[2]));
 132 extern int utimes __P ((__const char *__file, struct timeval __tvp[2]));
 133
 134
 135 /* Convenience macros for operations on timevals.
 136    NOTE: `timercmp' does not work for >= or <=.  */
 137 #define timerisset(tvp)         ((tvp)->tv_sec || (tvp)->tv_usec)
 138 #define timercmp(tvp, uvp, CMP) \
 139   ((tvp)->tv_sec CMP (uvp)->tv_sec || \
 140    (tvp)->tv_sec == (uvp)->tv_sec && (tvp)->tv_usec CMP (uvp)->tv_usec)
 141 #define timerclear(tvp)         ((tvp)->tv_sec = (tvp)->tv_usec = 0)
 142
 143
 144
 145 __END_DECLS
 146
 147 #endif /* sys/time.h */