libchill/remaintime.c

   1 /* Implement timing-related runtime actions for CHILL.
   2    Copyright (C) 1992,1993 Free Software Foundation, Inc.
   3    Author: Wilfried Moser
   4
   5    This file is part of GNU CC.
   6
   7    GNU CC is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2, or (at your option)
  10    any later version.
  11
  12    GNU CC is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with GNU CC; see the file COPYING.  If not, write to
  19    the Free Software Foundation, 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, USA.  */
  21
  22 /* As a special exception, if you link this library with other files,
  23    some of which are compiled with GCC, to produce an executable,
  24    this library does not by itself cause the resulting executable
  25    to be covered by the GNU General Public License.
  26    This exception does not however invalidate any other reasons why
  27    the executable file might be covered by the GNU General Public License.  */
  28
  29 #include "rts.h"
  30
  31 /*
  32  * function __remaintime
  33  *
  34  * parameters:
  35  *      since   pointer to the  initial RtsTime
  36  *      dur     the duration value
  37  *      t       pointer to the remaining RtsTime
  38  *
  39  * returns:
  40  *      int     0 .. there is a remaining time
  41  *              1 .. there is no remaining time
  42  *
  43  * exceptions:
  44  *      none
  45  *
  46  * abstract:
  47  *      This function writes to t the remaining duration value in RtsTime format
  48  *      from a given start (since) and the current RtsTime.
  49  *
  50  */
  51
  52 extern void __convert_duration_rtstime (unsigned long dur, RtsTime *t);
  53
  54 int
  55   __remaintime (since, dur, t)
  56 RtsTime       *since;
  57 unsigned long  dur;
  58 RtsTime       *t;
  59 {
  60   RtsTime now, dur_in_rtstime, tmp, diff;
  61
  62   __rtstime (&now);
  63   __convert_duration_rtstime (dur, &dur_in_rtstime);
  64
  65   tmp.secs = since->secs;
  66   tmp.nanosecs = since->nanosecs;
  67
  68   /* calculate the difference of absolute times */
  69   if (tmp.nanosecs > now.nanosecs)
  70     {
  71       tmp.secs--;
  72       tmp.nanosecs += 1000000000;
  73     }
  74   diff.secs = now.secs - tmp.secs;
  75   diff.nanosecs = now.nanosecs - tmp.nanosecs;
  76
  77   /* substract diff from duration */
  78   if (diff.nanosecs > dur_in_rtstime.nanosecs)
  79     {
  80       dur_in_rtstime.secs--;
  81       dur_in_rtstime.nanosecs += 1000000000;
  82     }
  83
  84   t->secs = dur_in_rtstime.secs - diff.secs;
  85   t->nanosecs = dur_in_rtstime.nanosecs - diff.nanosecs;
  86
  87   if (t->secs > dur_in_rtstime.secs)
  88     return 1;
  89   else
  90     return 0;
  91 }