usr/iscsi_timer.c

   1 /*
   2  * iSCSI timer
   3  *
   4  * Copyright (C) 2002 Cisco Systems, Inc.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published
   8  * by the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14  * General Public License for more details.
  15  *
  16  * See the file COPYING included with this distribution for more details.
  17  */
  18 #include <string.h>
  19 #include <sys/time.h>
  20
  21 void iscsi_timer_clear(struct timeval *timer)
  22 {
  23         memset(timer, 0, sizeof (*timer));
  24 }
  25
  26 /* set timer to now + seconds */
  27 void iscsi_timer_set(struct timeval *timer, int seconds)
  28 {
  29         if (timer) {
  30                 memset(timer, 0, sizeof (*timer));
  31                 gettimeofday(timer, NULL);
  32
  33                 timer->tv_sec += seconds;
  34         }
  35 }
  36
  37 int iscsi_timer_expired(struct timeval *timer)
  38 {
  39         struct timeval now;
  40
  41         /* no timer, can't have expired */
  42         if ((timer == NULL) || ((timer->tv_sec == 0) && (timer->tv_usec == 0)))
  43                 return 0;
  44
  45         memset(&now, 0, sizeof (now));
  46         gettimeofday(&now, NULL);
  47
  48         if (now.tv_sec > timer->tv_sec)
  49                 return 1;
  50         if ((now.tv_sec == timer->tv_sec) && (now.tv_usec >= timer->tv_usec))
  51                 return 1;
  52         return 0;
  53 }
  54
  55 int iscsi_timer_msecs_until(struct timeval *timer)
  56 {
  57         struct timeval now;
  58         int msecs;
  59         long partial;
  60
  61         /* no timer, can't have expired, infinite time til it expires */
  62         if ((timer == NULL) || ((timer->tv_sec == 0) && (timer->tv_usec == 0)))
  63                 return -1;
  64
  65         memset(&now, 0, sizeof (now));
  66         gettimeofday(&now, NULL);
  67
  68         /* already expired? */
  69         if (now.tv_sec > timer->tv_sec)
  70                 return 0;
  71         if ((now.tv_sec == timer->tv_sec) && (now.tv_usec >= timer->tv_usec))
  72                 return 0;
  73
  74         /* not expired yet, do the math */
  75         partial = timer->tv_usec - now.tv_usec;
  76         if (partial < 0) {
  77                 partial += 1000 * 1000;
  78                 msecs = (partial + 500) / 1000;
  79                 msecs += (timer->tv_sec - now.tv_sec - 1) * 1000;
  80         } else {
  81                 msecs = (partial + 500) / 1000;
  82                 msecs += (timer->tv_sec - now.tv_sec) * 1000;
  83         }
  84
  85         return msecs;
  86 }