memory.m

## Copyright (C) 2012 - 2019 Markus Bergholz <markuman@gmail.com>
## Copyright (C) 2015 JuanPi Carbajal <ajuanpi+dev@gmail.com>
## Copyright (C) 2019 Philip Nienhuis

## This program is free software; you can redistribute it and/or modify it under
## the terms of the GNU General Public License as published by the Free Software
## Foundation; either version 3 of the License, or (at your option) any later
## version.
##
## This program is distributed in the hope that it will be useful, but WITHOUT
## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
## FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
## details.
##
## You should have received a copy of the GNU General Public License along with
## this program; if not, see <http://www.gnu.org/licenses/>.

## -*- texinfo -*-
##
##
## memory returns information about how much physical
## memory is available and how much is currently being
## used by Octave

function m = memory()

    if (isunix && ~ismac)

      # open /proc/meminfo
      meminfo = fopen ("/proc/meminfo", "r");
      PID     = getpid;
      total   = str2double ( ...
                cell2mat (cell2mat ( ...
                regexp( ...
                fread(meminfo, "char=>char").', ...
                "MemTotal:(.*?) kB\n", "tokens"))));
      fclose (meminfo);

      # open /proc/<pid>/statm
      statm = fopen (sprintf ("/proc/%d/statm", PID), "r");
      # statm is measured in pages. the pagesize is 4096 bytes
      mem   = sscanf ( ...
              fread (statm, "char=>char").', ...
               "%d ").'([1 2 3 6]) * 4 / 1024;
      fclose (statm);

      if (nargout < 1)
        # print verbose output
        fprintf (["\n Total memory usage by GNU Octave (VmSize): \t %g MB"], mem(1));
        fprintf ("\n RSS Size: \t\t\t\t\t %g MB", mem(2));
        fprintf ("\n shared pages: \t\t\t\t\t %g MB", mem(3));
        fprintf ("\n data + stack size: \t\t\t\t %g MB", mem(4));
        fprintf ("\n Physical Memory (RAM): \t\t\t %g MB\n\n", total/1024);
        fflush (stdout);
      endif

      m = struct ("total",mem(1),"rss",mem(2), ...
                  "shared",mem(3),"data",mem(4), ...
                  "physical", total/1024);
    else
      process = "octave";
      [~, d] = system ("tasklist");
      d = strsplit (d, "\n")';
      try
	d = d(strncmpi (d, process, length (process)));
	m = cellfun (@(x) sscanf (strrep (x(65:end), " ", ""), "%d"), d, "uni", 1);
      end_try_catch
    endif

endfunction