time.h

Go to the documentation of this file.

/*
 * Copyright (c) 1982, 1986, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)time.h      8.5 (Berkeley) 5/4/95
 */
#ifndef __SYSINTERF_TIME_H__
#define __SYSINTERF_TIME_H__

/*
 * Structure returned by gettimeofday(2) system call,
 * and used in other calls.
 */
struct timeval {
        long    tv_sec;         /* seconds */
        long    tv_usec;        /* and microseconds */
};

/*
 * Structure defined by POSIX.1b to be like a timeval.
 */
struct timespec {
        time_t  tv_sec;         /* seconds */
        long    tv_nsec;        /* and nanoseconds */
};

#define TIMEVAL_TO_TIMESPEC(tv, ts) {                                   \
        (ts)->tv_sec = (tv)->tv_sec;                                    \
        (ts)->tv_nsec = (tv)->tv_usec * 1000;                           \
}
#define TIMESPEC_TO_TIMEVAL(tv, ts) {                                   \
        (tv)->tv_sec = (ts)->tv_sec;                                    \
        (tv)->tv_usec = (ts)->tv_nsec / 1000;                           \
}

/*
 * Note: timezone is obsolete. All timezone handling is now in
 * userland. Its just here for back compatibility.
 */
struct timezone {
        int     tz_minuteswest; /* minutes west of Greenwich */
        int     tz_dsttime;     /* type of dst correction */
};

/* Operations on timevals. */
#define timerclear(tvp)         (tvp)->tv_sec = (tvp)->tv_usec = 0
#define timerisset(tvp)         ((tvp)->tv_sec || (tvp)->tv_usec)
#define timercmp(tvp, uvp, cmp)                                         \
        (((tvp)->tv_sec == (uvp)->tv_sec) ?                             \
            ((tvp)->tv_usec cmp (uvp)->tv_usec) :                       \
            ((tvp)->tv_sec cmp (uvp)->tv_sec))
#define timeradd(tvp, uvp, vvp)                                         \
        do {                                                            \
                (vvp)->tv_sec = (tvp)->tv_sec + (uvp)->tv_sec;          \
                (vvp)->tv_usec = (tvp)->tv_usec + (uvp)->tv_usec;       \
                if ((vvp)->tv_usec >= 1000000) {                        \
                        (vvp)->tv_sec++;                                \
                        (vvp)->tv_usec -= 1000000;                      \
                }                                                       \
        } while (/* CONSTCOND */ 0)
#define timersub(tvp, uvp, vvp)                                         \
        do {                                                            \
                (vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec;          \
                (vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec;       \
                if ((vvp)->tv_usec < 0) {                               \
                        (vvp)->tv_sec--;                                \
                        (vvp)->tv_usec += 1000000;                      \
                }                                                       \
        } while (/* CONSTCOND */ 0)

/* Operations on timespecs. */
#define timespecclear(tsp)              (tsp)->tv_sec = (tsp)->tv_nsec = 0
#define timespecisset(tsp)              ((tsp)->tv_sec || (tsp)->tv_nsec)
#define timespeccmp(tsp, usp, cmp)                                      \
        (((tsp)->tv_sec == (usp)->tv_sec) ?                             \
            ((tsp)->tv_nsec cmp (usp)->tv_nsec) :                       \
            ((tsp)->tv_sec cmp (usp)->tv_sec))
#define timespecadd(tsp, usp, vsp)                                      \
        do {                                                            \
                (vsp)->tv_sec = (tsp)->tv_sec + (usp)->tv_sec;          \
                (vsp)->tv_nsec = (tsp)->tv_nsec + (usp)->tv_nsec;       \
                if ((vsp)->tv_nsec >= 1000000000L) {                    \
                        (vsp)->tv_sec++;                                \
                        (vsp)->tv_nsec -= 1000000000L;                  \
                }                                                       \
        } while (/* CONSTCOND */ 0)
#define timespecsub(tsp, usp, vsp)                                      \
        do {                                                            \
                (vsp)->tv_sec = (tsp)->tv_sec - (usp)->tv_sec;          \
                (vsp)->tv_nsec = (tsp)->tv_nsec - (usp)->tv_nsec;       \
                if ((vsp)->tv_nsec < 0) {                               \
                        (vsp)->tv_sec--;                                \
                        (vsp)->tv_nsec += 1000000000L;                  \
                }                                                       \
        } while (/* CONSTCOND */ 0)

/*
 * Names of the interval timers, and structure
 * defining a timer setting.
 */
#define ITIMER_REAL     0
#define ITIMER_VIRTUAL  1
#define ITIMER_PROF     2

struct  itimerval {
        struct  timeval it_interval;    /* timer interval */
        struct  timeval it_value;       /* current value */
};

/*
 * Getkerninfo clock information structure
 */
struct clockinfo {
        int     hz;             /* clock frequency */
        int     tick;           /* micro-seconds per hz tick */
        int     tickadj;        /* clock skew rate for adjtime() */
        int     stathz;         /* statistics clock frequency */
        int     profhz;         /* profiling clock frequency */
};

#define CLOCK_REALTIME  0
#define CLOCK_VIRTUAL   1
#define CLOCK_PROF      2
#define CLOCK_MONOTONIC 3

#define TIMER_RELTIME   0x0     /* relative timer */
#define TIMER_ABSTIME   0x1     /* absolute timer */

#endif

---