rx/rx_clock.c

   1 /*
   2 ****************************************************************************
   3 *        Copyright IBM Corporation 1988, 1989 - All Rights Reserved        *
   4 *                                                                          *
   5 * Permission to use, copy, modify, and distribute this software and its    *
   6 * documentation for any purpose and without fee is hereby granted,         *
   7 * provided that the above copyright notice appear in all copies and        *
   8 * that both that copyright notice and this permission notice appear in     *
   9 * supporting documentation, and that the name of IBM not be used in        *
  10 * advertising or publicity pertaining to distribution of the software      *
  11 * without specific, written prior permission.                              *
  12 *                                                                          *
  13 * IBM DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL *
  14 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL IBM *
  15 * BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY      *
  16 * DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER  *
  17 * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING   *
  18 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.    *
  19 ****************************************************************************
  20 */
  21
  22 /* Elapsed time package */
  23
  24 #include "rx_locl.h"
  25
  26 RCSID("$Id$");
  27
  28 #ifndef KERNEL
  29
  30 struct clock clock_now;
  31
  32 int clock_haveCurrentTime;
  33
  34 int clock_nUpdates;
  35
  36 /* Magic tdiff that guarantees a monotonically increasing clock value. */
  37 static struct clock tdiff;
  38
  39 void
  40 clock_Init(void)
  41 {
  42     struct timeval tv;
  43
  44     gettimeofday(&tv, 0);
  45     tdiff.sec  = tv.tv_sec;
  46     tdiff.usec = tv.tv_usec;
  47     clock_now.sec = clock_now.usec = 0;
  48     clock_haveCurrentTime = 1;
  49     clock_nUpdates = 0;
  50 }
  51
  52 /* Refresh value of clock_now. */
  53 void
  54 clock_UpdateTime(void)
  55 {
  56     struct timeval tv;
  57     struct clock t;
  58
  59     gettimeofday(&tv, 0);
  60     t.sec  = tv.tv_sec;
  61     t.usec = tv.tv_usec;
  62     clock_Sub(&t, &tdiff);
  63
  64     /* We can't have time running backwards!!! */
  65     if (clock_Le(&t, &clock_now))
  66     {
  67         /* Calculate new tdiff. */
  68         t.sec = tv.tv_sec;
  69         t.usec = tv.tv_usec;
  70         clock_Sub(&t, &clock_now);
  71         tdiff.sec  = t.sec;
  72         tdiff.usec = t.usec;
  73
  74         /* Fake new time. */
  75         t.sec = tv.tv_sec;
  76         t.usec = tv.tv_usec;
  77         clock_Sub(&t, &tdiff);
  78         t.usec++;
  79         if (t.usec >= 1000000)
  80         {
  81             t.sec += 1;
  82             t.usec = 0;
  83         }
  84     }
  85
  86     clock_now = t;
  87     clock_haveCurrentTime = 1;
  88     clock_nUpdates++;
  89 }
  90
  91 void
  92 clock_ReInit(void)
  93 {
  94 }
  95
  96 #endif                                 /* KERNEL */