/*

 * $Id$

 *

 * Copyright (C) 2003-2009 JNode.org

 *

 * This library is free software; you can redistribute it and/or modify it

 * under the terms of the GNU Lesser General Public License as published

 * by the Free Software Foundation; either version 2.1 of the License, or

 * (at your option) any later version.

 *

 * This library 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 Lesser General Public 

 * License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public License

 * along with this library; If not, write to the Free Software Foundation, Inc., 

 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

 */

package org.jnode.vm.memmgr;

import org.jnode.vm.VmSystemObject;

import org.vmmagic.pragma.UninterruptiblePragma;

/**

 * @author Ewout Prangsma (epr@users.sourceforge.net)

 */

public abstract class VmWriteBarrier extends VmSystemObject {

    /**

     * This method is inlined to implement the write barrier for aastores

     *

     * @param ref   The base pointer of the array

     * @param index The array index being stored into.  NOTE: This is the "natural" index; a[3] will pass 3.

     * @param value The value being stored

     */

    public abstract void arrayStoreWriteBarrier(Object ref, int index, Object value)

        throws UninterruptiblePragma;

    /**

     * This method implements the write barrier for putfields of references

     *

     * @param ref    The base pointer of the array

     * @param offset The offset being stored into.  NOTE: This is in bytes.

     * @param value  The value being stored

     */

    public abstract void putfieldWriteBarrier(Object ref, int offset, Object value)

        throws UninterruptiblePragma;

    /**

     * This method is inlined to implement the write barrier for putstatics of references

     *

     * @param shared       Is this a shared static field

     * @param staticsIndex The offset of static field (in VmSharedStatics or VmIsolatedStatics)

     * @param value        The value being stored

     */

    public abstract void putstaticWriteBarrier(boolean shared, int staticsIndex, Object value)

        throws UninterruptiblePragma;

    /**

     * This method generates write barrier entries needed as a consequence of

     * an explicit user array copies.

     *

     * @param array The referring (source) array.

     * @param start The first "natural" index into the array (e.g. for

     *              <code>a[1]</code>, index = 1).

     * @param end   The last "natural" index into the array

     */

    public abstract void arrayCopyWriteBarrier(Object array, int start, int end)

        throws UninterruptiblePragma;

}