time/sys/time.h

   1 /* Copyright (C) 1991,92,93,94,96,97,98,99,2000 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 #ifndef __suseconds_t_defined
  31 typedef __suseconds_t suseconds_t;
  32 # define __suseconds_t_defined
  33 #endif
  34
  35
  36 __BEGIN_DECLS
  37
  38 /* Macros for converting between `struct timeval' and `struct timespec'.  */
  39 #define TIMEVAL_TO_TIMESPEC(tv, ts) {                                   \
  40         (ts)->tv_sec = (tv)->tv_sec;                                    \
  41         (ts)->tv_nsec = (tv)->tv_usec * 1000;                           \
  42 }
  43 #define TIMESPEC_TO_TIMEVAL(tv, ts) {                                   \
  44         (tv)->tv_sec = (ts)->tv_sec;                                    \
  45         (tv)->tv_usec = (ts)->tv_nsec / 1000;                           \
  46 }
  47
  48
  49 /* Structure crudely representing a timezone.
  50    This is obsolete and should never be used.  */
  51 struct timezone
  52   {
  53     int tz_minuteswest;         /* Minutes west of GMT.  */
  54     int tz_dsttime;             /* Nonzero if DST is ever in effect.  */
  55   };
  56
  57 #if defined __USE_GNU || defined __USE_BSD
  58 typedef struct timezone *__timezone_ptr_t;
  59 #else
  60 typedef void *__timezone_ptr_t;
  61 #endif
  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 (struct timeval *__tv, __timezone_ptr_t __tz) __THROW;
  69
  70 /* Set the current time of day and timezone information.
  71    This call is restricted to the super-user.  */
  72 extern int settimeofday (__const struct timeval *__tv,
  73                          __const struct timezone *__tz) __THROW;
  74
  75 /* Adjust the current time of day by the amount in DELTA.
  76    If OLDDELTA is not NULL, it is filled in with the amount
  77    of time adjustment remaining to be done from the last `adjtime' call.
  78    This call is restricted to the super-user.  */
  79 extern int adjtime (__const struct timeval *__delta,
  80                     struct timeval *__olddelta) __THROW;
  81
  82
  83 /* Values for the first argument to `getitimer' and `setitimer'.  */
  84 enum __itimer_which
  85   {
  86     /* Timers run in real time.  */
  87     ITIMER_REAL = 0,
  88 #define ITIMER_REAL ITIMER_REAL
  89     /* Timers run only when the process is executing.  */
  90     ITIMER_VIRTUAL = 1,
  91 #define ITIMER_VIRTUAL ITIMER_VIRTUAL
  92     /* Timers run when the process is executing and when
  93        the system is executing on behalf of the process.  */
  94     ITIMER_PROF = 2
  95 #define ITIMER_PROF ITIMER_PROF
  96   };
  97
  98 /* Type of the second argument to `getitimer' and
  99    the second and third arguments `setitimer'.  */
 100 struct itimerval
 101   {
 102     /* Value to put into `it_value' when the timer expires.  */
 103     struct timeval it_interval;
 104     /* Time to the next timer expiration.  */
 105     struct timeval it_value;
 106   };
 107
 108 #ifdef __USE_GNU
 109 typedef enum __itimer_which __itimer_which_t;
 110 #else
 111 typedef int __itimer_which_t;
 112 #endif
 113
 114 /* Set *VALUE to the current setting of timer WHICH.
 115    Return 0 on success, -1 on errors.  */
 116 extern int getitimer (__itimer_which_t __which,
 117                       struct itimerval *__value) __THROW;
 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 (__itimer_which_t __which,
 123                       __const struct itimerval *__new,
 124                       struct itimerval *__old) __THROW;
 125
 126 /* Change the access time of FILE to TVP[0] and
 127    the modification time of FILE to TVP[1].  */
 128 extern int utimes (__const char *__file, __const struct timeval __tvp[2])
 129      __THROW;
 130
 131
 132 /* Convenience macros for operations on timevals.
 133    NOTE: `timercmp' does not work for >= or <=.  */
 134 #define timerisset(tvp)         ((tvp)->tv_sec || (tvp)->tv_usec)
 135 #define timerclear(tvp)         ((tvp)->tv_sec = (tvp)->tv_usec = 0)
 136 #define timercmp(a, b, CMP)                                                   \
 137   (((a)->tv_sec == (b)->tv_sec) ?                                             \
 138    ((a)->tv_usec CMP (b)->tv_usec) :                                          \
 139    ((a)->tv_sec CMP (b)->tv_sec))
 140 #define timeradd(a, b, result)                                                \
 141   do {                                                                        \
 142     (result)->tv_sec = (a)->tv_sec + (b)->tv_sec;                             \
 143     (result)->tv_usec = (a)->tv_usec + (b)->tv_usec;                          \
 144     if ((result)->tv_usec >= 1000000)                                         \
 145       {                                                                       \
 146         ++(result)->tv_sec;                                                   \
 147         (result)->tv_usec -= 1000000;                                         \
 148       }                                                                       \
 149   } while (0)
 150 #define timersub(a, b, result)                                                \
 151   do {                                                                        \
 152     (result)->tv_sec = (a)->tv_sec - (b)->tv_sec;                             \
 153     (result)->tv_usec = (a)->tv_usec - (b)->tv_usec;                          \
 154     if ((result)->tv_usec < 0) {                                              \
 155       --(result)->tv_sec;                                                     \
 156       (result)->tv_usec += 1000000;                                           \
 157     }                                                                         \
 158   } while (0)
 159
 160 __END_DECLS
 161
 162 #endif /* sys/time.h */