source: branches/0.17.x/abcl/src/org/armedbear/lisp/gc.java

/*
 * gc.java
 *
 * Copyright (C) 2003-2005 Peter Graves
 * $Id: gc.java 11488 2008-12-27 10:50:33Z ehuelsmann $
 *
 * 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 2
 * 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * As a special exception, the copyright holders of this library give you
 * permission to link this library with independent modules to produce an
 * executable, regardless of the license terms of these independent
 * modules, and to copy and distribute the resulting executable under
 * terms of your choice, provided that you also meet, for each linked
 * independent module, the terms and conditions of the license of that
 * module.  An independent module is a module which is not derived from
 * or based on this library.  If you modify this library, you may extend
 * this exception to your version of the library, but you are not
 * obligated to do so.  If you do not wish to do so, delete this
 * exception statement from your version.
 */

package org.armedbear.lisp;

// ### gc
public final class gc extends Primitive
{
    private gc()
    {
        super("gc", PACKAGE_EXT);
    }

    @Override
    public LispObject execute()
    {
        Runtime runtime = Runtime.getRuntime();
        long free = 0;
        long maxFree = 0;
        while (true) {
            try {
                runtime.gc();
                Thread.sleep(100);
                runtime.runFinalization();
                Thread.sleep(100);
                runtime.gc();
                Thread.sleep(100);
            }
            catch (InterruptedException e) {}
            free = runtime.freeMemory();
            if (free > maxFree)
                maxFree = free;
            else
                break;
        }
        return number(free);
    }

    private static final Primitive GC = new gc();
}