isc/unix/stdtime.c

	stdtime.c revision e7fb847ed570dd8c1bcdacabb3d69bd81feb79ae
/*
 * Copyright (C) 2004, 2005  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 1999-2001  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

/* $Id: stdtime.c,v 1.17 2005/06/08 02:07:01 marka Exp $ */

/*! \file */

#include <config.h>

#include <stddef.h> /* NULL */
#include <stdlib.h> /* NULL */
#include <syslog.h>

#include <sys/time.h>

#include <isc/stdtime.h>
#include <isc/util.h>

#ifndef ISC_FIX_TV_USEC
#define ISC_FIX_TV_USEC 1
#endif

#define US_PER_S 1000000

#if ISC_FIX_TV_USEC
static inline void
fix_tv_usec(struct timeval *tv) {
    isc_boolean_t fixed = ISC_FALSE;

    if (tv->tv_usec < 0) {
        fixed = ISC_TRUE;
        do {
            tv->tv_sec -= 1;
            tv->tv_usec += US_PER_S;
        } while (tv->tv_usec < 0);
    } else if (tv->tv_usec >= US_PER_S) {
        fixed = ISC_TRUE;
        do {
            tv->tv_sec += 1;
            tv->tv_usec -= US_PER_S;
        } while (tv->tv_usec >=US_PER_S);
    }
    /*
     * Call syslog directly as we are called from the logging functions.
     */
    if (fixed)
        (void)syslog(LOG_ERR, "gettimeofday returned bad tv_usec: corrected");
}
#endif

void
isc_stdtime_get(isc_stdtime_t *t) {
    struct timeval tv;

    /*
     * Set 't' to the number of seconds since 00:00:00 UTC, January 1,
     * 1970.
     */

    REQUIRE(t != NULL);

    RUNTIME_CHECK(gettimeofday(&tv, NULL) != -1);

#if ISC_FIX_TV_USEC
    fix_tv_usec(&tv);
    INSIST(tv.tv_usec >= 0);
#else
    INSIST(tv.tv_usec >= 0 && tv.tv_usec < US_PER_S);
#endif

    *t = (unsigned int)tv.tv_sec;
}