time/sys/time.h

   1 /* Copyright (C) 1991, 92, 93, 94, 96 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 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 #define __need_timeval
  27 #include <timebits.h>
  28
  29
  30 __BEGIN_DECLS
  31
  32 /* Macros for converting between `struct timeval' and `struct timespec'.  */
  33 #define TIMEVAL_TO_TIMESPEC(tv, ts) {                                   \
  34         (ts)->tv_sec = (tv)->tv_sec;                                    \
  35         (ts)->tv_nsec = (tv)->tv_usec * 1000;                           \
  36 }
  37 #define TIMESPEC_TO_TIMEVAL(tv, ts) {                                   \
  38         (tv)->tv_sec = (ts)->tv_sec;                                    \
  39         (tv)->tv_usec = (ts)->tv_nsec / 1000;                           \
  40 }
  41
  42
  43 /* Structure crudely representing a timezone.
  44    This is obsolete and should never be used.  */
  45 struct timezone
  46   {
  47     int tz_minuteswest;         /* Minutes west of GMT.  */
  48     int tz_dsttime;             /* Nonzero if DST is ever in effect.  */
  49   };
  50
  51 /* Get the current time of day and timezone information,
  52    putting it into *TV and *TZ.  If TZ is NULL, *TZ is not filled.
  53    Returns 0 on success, -1 on errors.
  54    NOTE: This form of timezone information is obsolete.
  55    Use the functions and variables declared in <time.h> instead.  */
  56 extern int __gettimeofday __P ((struct timeval *__tv,
  57                                 struct timezone *__tz));
  58 extern int gettimeofday __P ((struct timeval *__tv,
  59                               struct timezone *__tz));
  60
  61 /* Set the current time of day and timezone information.
  62    This call is restricted to the super-user.  */
  63 extern int __settimeofday __P ((__const struct timeval *__tv,
  64                                 __const struct timezone *__tz));
  65 extern int settimeofday __P ((__const struct timeval *__tv,
  66                               __const struct timezone *__tz));
  67
  68 /* Adjust the current time of day by the amount in DELTA.
  69    If OLDDELTA is not NULL, it is filled in with the amount
  70    of time adjustment remaining to be done from the last `adjtime' call.
  71    This call is restricted to the super-user.  */
  72 extern int __adjtime __P ((__const struct timeval *__delta,
  73                            struct timeval *__olddelta));
  74 extern int adjtime __P ((__const struct timeval *__delta,
  75                          struct timeval *__olddelta));
  76
  77
  78 /* Values for the first argument to `getitimer' and `setitimer'.  */
  79 enum __itimer_which
  80   {
  81     /* Timers run in real time.  */
  82     ITIMER_REAL = 0,
  83     /* Timers run only when the process is executing.  */
  84     ITIMER_VIRTUAL = 1,
  85     /* Timers run when the process is executing and when
  86        the system is executing on behalf of the process.  */
  87     ITIMER_PROF = 2
  88   };
  89
  90 /* Type of the second argument to `getitimer' and
  91    the second and third arguments `setitimer'.  */
  92 struct itimerval
  93   {
  94     /* Value to put into `it_value' when the timer expires.  */
  95     struct timeval it_interval;
  96     /* Time to the next timer expiration.  */
  97     struct timeval it_value;
  98   };
  99
 100 /* Set *VALUE to the current setting of timer WHICH.
 101    Return 0 on success, -1 on errors.  */
 102 extern int __getitimer __P ((enum __itimer_which __which,
 103                              struct itimerval *__value));
 104 extern int getitimer __P ((enum __itimer_which __which,
 105                            struct itimerval *__value));
 106
 107 /* Set the timer WHICH to *NEW.  If OLD is not NULL,
 108    set *OLD to the old value of timer WHICH.
 109    Returns 0 on success, -1 on errors.  */
 110 extern int __setitimer __P ((enum __itimer_which __which,
 111                              struct itimerval *__new,
 112                              struct itimerval *__old));
 113 extern int setitimer __P ((enum __itimer_which __which,
 114                            struct itimerval *__new,
 115                            struct itimerval *__old));
 116
 117 /* Change the access time of FILE to TVP[0] and
 118    the modification time of FILE to TVP[1].  */
 119 extern int __utimes __P ((__const char *__file, struct timeval __tvp[2]));
 120 extern int utimes __P ((__const char *__file, struct timeval __tvp[2]));
 121
 122
 123 /* Convenience macros for operations on timevals.
 124    NOTE: `timercmp' does not work for >= or <=.  */
 125 #define timerisset(tvp)         ((tvp)->tv_sec || (tvp)->tv_usec)
 126 #define timerclear(tvp)         ((tvp)->tv_sec = (tvp)->tv_usec = 0)
 127 #define timercmp(a, b, CMP)                                                   \
 128   (((a)->tv_sec == (b)->tv_sec) ?                                             \
 129    ((a)->tv_usec CMP (b)->tv_usec) :                                          \
 130    ((a)->tv_sec CMP (b)->tv_sec))
 131 #define timeradd(a, b, result)                                                \
 132   do {                                                                        \
 133     (result)->tv_sec = (a)->tv_sec + (b)->tv_sec;                             \
 134     (result)->tv_usec = (a)->tv_usec + (b)->tv_usec;                          \
 135     if ((result)->tv_usec >= 1000000)                                         \
 136       {                                                                       \
 137         ++(result)->tv_sec;                                                   \
 138         (result)->tv_usec -= 1000000;                                         \
 139       }                                                                       \
 140   } while (0)
 141 #define timersub(a, b, result)                                                \
 142   do {                                                                        \
 143     (result)->tv_sec = (a)->tv_sec - (b)->tv_sec;                             \
 144     (result)->tv_usec = (a)->tv_usec - (b)->tv_usec;                          \
 145     if ((result)->tv_usec < 0) {                                              \
 146       --(result)->tv_sec;                                                     \
 147       (result)->tv_usec += 1000000;                                           \
 148     }                                                                         \
 149   } while (0)
 150
 151
 152 __END_DECLS
 153
 154 #ifdef __USE_BSD
 155 /* Set an alarm to go off (generating a SIGALRM signal) in VALUE
 156    microseconds.  If INTERVAL is nonzero, when the alarm goes off, the
 157    timer is reset to go off every INTERVAL microseconds thereafter.
 158    Returns the number of microseconds remaining before the alarm.  */
 159 extern unsigned int ualarm __P ((unsigned int __value,
 160                                  unsigned int __interval));
 161 #endif
 162
 163 #endif /* sys/time.h */