libchill/waituntil.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, 675 Mass Ave, Cambridge, MA 02139, USA.  */
  20
  21 /* As a special exception, if you link this library with other files,
  22    some of which are compiled with GCC, to produce an executable,
  23    this library does not by itself cause the resulting executable
  24    to be covered by the GNU General Public License.
  25    This exception does not however invalidate any other reasons why
  26    the executable file might be covered by the GNU General Public License.  */
  27
  28 #include "rtltypes.h"
  29 #include "rts.h"
  30
  31 EXCEPTION (timerfail);
  32
  33 /*
  34  * function __wait_until
  35  *
  36  * parameters:
  37  *     abstime   absolute time value
  38  *     filename
  39  *     linenumber
  40  *
  41  * returns:
  42  *     int   0 on success, 1 on failure
  43  *
  44  * exceptions:
  45  *     timerfail
  46  *
  47  * abstract:
  48  *     check for given argument is valid, calculate how long to wait in
  49  *     seconds and call os to do it.
  50  *
  51  */
  52
  53 int
  54 __wait_until (abstime, filename, linenumber)
  55      unsigned long  abstime;
  56      char          *filename;
  57      int            linenumber;
  58 {
  59   RtsTime       now, delta, abs_rtstime;
  60
  61   /* get current time */
  62   __rtstime (&now);
  63
  64   abs_rtstime.secs = abstime;
  65   abs_rtstime.nanosecs = 0;
  66
  67   if (abs_rtstime.nanosecs < now.nanosecs)
  68     {
  69       abs_rtstime.secs--;
  70       abs_rtstime.nanosecs += 1000000000;
  71     }
  72
  73   delta.secs = abs_rtstime.secs - now.secs;
  74   delta.nanosecs = abs_rtstime.nanosecs - now.nanosecs;
  75
  76   if (delta.secs > abs_rtstime.secs)
  77     /* cannot wait into past */
  78     return 1;
  79
  80   return __delay_this (wait_wait, &delta, filename, linenumber) == 1 ? 0 : 1;
  81 }