util/timeval.c

   1 /*
   2  * Copyright (c) 1999 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 /*
  35  * Timeval stuff
  36  */
  37
  38 #ifdef HAVE_CONFIG_H
  39 #include <config.h>
  40 RCSID("$Id$");
  41 #endif
  42
  43 #include "roken.h"
  44
  45 /*
  46  * Make `t1' consistent.
  47  */
  48
  49 void
  50 timevalfix(struct timeval *t1)
  51 {
  52     if (t1->tv_usec < 0) {
  53         t1->tv_sec--;
  54         t1->tv_usec += 1000000;
  55     }
  56     if (t1->tv_usec >= 1000000) {
  57         t1->tv_sec++;
  58         t1->tv_usec -= 1000000;
  59     }
  60 }
  61
  62 /*
  63  * t1 += t2
  64  */
  65
  66 void
  67 timevaladd(struct timeval *t1, const struct timeval *t2)
  68 {
  69     t1->tv_sec  += t2->tv_sec;
  70     t1->tv_usec += t2->tv_usec;
  71     timevalfix(t1);
  72 }
  73
  74 /*
  75  * t1 -= t2
  76  */
  77
  78 void
  79 timevalsub(struct timeval *t1, const struct timeval *t2)
  80 {
  81     t1->tv_sec  -= t2->tv_sec;
  82     t1->tv_usec -= t2->tv_usec;
  83     timevalfix(t1);
  84 }