libiberty/physmem.c

   1 /* Calculate the size of physical memory.
   2    Copyright 2000, 2001 Free Software Foundation, Inc.
   3
   4    This program is free software; you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 2, or (at your option)
   7    any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; if not, write to the Free Software Foundation,
  16    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  17
  18 /* Written by Paul Eggert.  */
  19
  20 #if HAVE_CONFIG_H
  21 # include <config.h>
  22 #endif
  23
  24 #if HAVE_UNISTD_H
  25 # include <unistd.h>
  26 #endif
  27
  28 #if HAVE_SYS_PSTAT_H
  29 # include <sys/pstat.h>
  30 #endif
  31
  32 /* Return the total amount of physical memory.  */
  33 double
  34 physmem_total ()
  35 {
  36 #if defined _SC_PHYS_PAGES && defined _SC_PAGESIZE
  37   {
  38     double pages = sysconf (_SC_PHYS_PAGES);
  39     double pagesize = sysconf (_SC_PAGESIZE);
  40     if (0 <= pages && 0 <= pagesize)
  41       return pages * pagesize;
  42   }
  43 #endif
  44
  45 #if HAVE_PSTAT_GETSTATIC
  46   {
  47     struct pst_static pss;
  48     if (0 <= pstat_getstatic (&pss, sizeof pss, 1, 0))
  49       {
  50         double pages = pss.physical_memory;
  51         double pagesize = pss.page_size;
  52         if (0 <= pages && 0 <= pagesize)
  53           return pages * pagesize;
  54       }
  55   }
  56 #endif
  57
  58   /* Return 0 if we can't determine the value.  */
  59   return 0;
  60 }
  61
  62 /* Return the amount of physical memory available.  */
  63 double
  64 physmem_available ()
  65 {
  66 #if defined _SC_AVPHYS_PAGES && defined _SC_PAGESIZE
  67   {
  68     double pages = sysconf (_SC_AVPHYS_PAGES);
  69     double pagesize = sysconf (_SC_PAGESIZE);
  70     if (0 <= pages && 0 <= pagesize)
  71       return pages * pagesize;
  72   }
  73 #endif
  74
  75 #if HAVE_PSTAT_GETSTATIC && HAVE_PSTAT_GETDYNAMIC
  76   {
  77     struct pst_static pss;
  78     struct pst_dynamic psd;
  79     if (0 <= pstat_getstatic (&pss, sizeof pss, 1, 0)
  80         && 0 <= pstat_getdynamic (&psd, sizeof psd, 1, 0))
  81       {
  82         double pages = psd.psd_free;
  83         double pagesize = pss.page_size;
  84         if (0 <= pages && 0 <= pagesize)
  85           return pages * pagesize;
  86       }
  87   }
  88 #endif
  89
  90   /* Guess 25% of physical memory.  */
  91   return physmem_total () / 4;
  92 }