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      1 /*	$NetBSD: vm-limit.c,v 1.1.1.1 2016/01/13 21:42:18 christos Exp $	*/
      2 
      3 /* Functions for memory limit warnings.
      4    Copyright (C) 1990, 1992 Free Software Foundation, Inc.
      5 
      6 
      7 This file is part of the GNU C Library.  Its master source is NOT part of
      8 the C library, however.  The master source lives in /gd/gnu/lib.
      9 
     10 The GNU C Library is free software; you can redistribute it and/or
     11 modify it under the terms of the GNU Library General Public License as
     12 published by the Free Software Foundation; either version 2 of the
     13 License, or (at your option) any later version.
     14 
     15 The GNU C Library is distributed in the hope that it will be useful,
     16 but WITHOUT ANY WARRANTY; without even the implied warranty of
     17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     18 Library General Public License for more details.
     19 
     20 You should have received a copy of the GNU Library General Public
     21 License along with the GNU C Library; see the file COPYING.LIB.  If
     22 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
     23 Cambridge, MA 02139, USA.  */
     24 
     25 #ifdef emacs
     26 #include <config.h>
     27 #include "lisp.h"
     28 #endif
     29 
     30 #ifndef emacs
     31 #include <stddef.h>
     32 typedef size_t SIZE;
     33 typedef void *POINTER;
     34 #define EXCEEDS_LISP_PTR(x) 0
     35 #endif
     36 
     37 #include "mem-limits.h"
     38 
     39 /*
     40   Level number of warnings already issued.
     41   0 -- no warnings issued.
     42   1 -- 75% warning already issued.
     43   2 -- 85% warning already issued.
     44   3 -- 95% warning issued; keep warning frequently.
     45 */
     46 static int warnlevel;
     47 
     48 /* Function to call to issue a warning;
     49    0 means don't issue them.  */
     50 static void (*warn_function) ();
     51 
     52 /* Get more memory space, complaining if we're near the end. */
     53 
     54 static void
     55 check_memory_limits ()
     56 {
     57   extern POINTER (*__morecore) ();
     58 
     59   register POINTER cp;
     60   unsigned long five_percent;
     61   unsigned long data_size;
     62 
     63   if (lim_data == 0)
     64     get_lim_data ();
     65   five_percent = lim_data / 20;
     66 
     67   /* Find current end of memory and issue warning if getting near max */
     68   cp = (char *) (*__morecore) (0);
     69   data_size = (char *) cp - (char *) data_space_start;
     70 
     71   if (warn_function)
     72     switch (warnlevel)
     73       {
     74       case 0:
     75 	if (data_size > five_percent * 15)
     76 	  {
     77 	    warnlevel++;
     78 	    (*warn_function) ("Warning: past 75% of memory limit");
     79 	  }
     80 	break;
     81 
     82       case 1:
     83 	if (data_size > five_percent * 17)
     84 	  {
     85 	    warnlevel++;
     86 	    (*warn_function) ("Warning: past 85% of memory limit");
     87 	  }
     88 	break;
     89 
     90       case 2:
     91 	if (data_size > five_percent * 19)
     92 	  {
     93 	    warnlevel++;
     94 	    (*warn_function) ("Warning: past 95% of memory limit");
     95 	  }
     96 	break;
     97 
     98       default:
     99 	(*warn_function) ("Warning: past acceptable memory limits");
    100 	break;
    101       }
    102 
    103   /* If we go down below 70% full, issue another 75% warning
    104      when we go up again.  */
    105   if (data_size < five_percent * 14)
    106     warnlevel = 0;
    107   /* If we go down below 80% full, issue another 85% warning
    108      when we go up again.  */
    109   else if (warnlevel > 1 && data_size < five_percent * 16)
    110     warnlevel = 1;
    111   /* If we go down below 90% full, issue another 95% warning
    112      when we go up again.  */
    113   else if (warnlevel > 2 && data_size < five_percent * 18)
    114     warnlevel = 2;
    115 
    116   if (EXCEEDS_LISP_PTR (cp))
    117     (*warn_function) ("Warning: memory in use exceeds lisp pointer size");
    118 }
    119 
    120 /* Cause reinitialization based on job parameters;
    121    also declare where the end of pure storage is. */
    122 
    123 void
    124 memory_warnings (start, warnfun)
    125      POINTER start;
    126      void (*warnfun) ();
    127 {
    128   extern void (* __after_morecore_hook) ();     /* From gmalloc.c */
    129 
    130   if (start)
    131     data_space_start = start;
    132   else
    133     data_space_start = start_of_data ();
    134 
    135   warn_function = warnfun;
    136   __after_morecore_hook = check_memory_limits;
    137 }
    138