BoxesToCommit.java

/*
 * JVSTM: a Java library for Software Transactional Memory
 * Copyright (C) 2005 INESC-ID Software Engineering Group
 * http://www.esw.inesc-id.pt
 *
 * 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 St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Author's contact:
 * INESC-ID Software Engineering Group
 * Rua Alves Redol 9
 * 1000 - 029 Lisboa
 * Portugal
 */
package jvstm;

import java.util.concurrent.atomic.AtomicBoolean;

import jvstm.util.Cons;

public class BoxesToCommit {

    public static final BoxesToCommit EMPTY_BOXES = new BoxesToCommit();

    /*
     * There are nBlocks of VBoxes ranged from 0 to nBlocks-1. Any i-th block
     * (except the last one) manages VBoxes from i*blockSize (including) to
     * i*blockSize+blockSize (excluding). The last block manages the range from
     * i*blockSize (including) to writeSetLength (excluding).
     */
    protected final int nBlocks;
    /* The number of VBoxes per block */
    protected final int blockSize;
    /* All the VBoxes lined-up in a fixed array for direct access */
    protected final VBox[] allWrittenVBoxes;
    protected final Object[] allWrittenValues;
    // the previous arrays may be allocated in a larger size than required.
    // This happens when the same box is first written to the standard
    // write-set and later re-written in-place. For this reason we should
    // never use the arrays 'length' attribute; use instead writeSetLength.
    protected final int writeSetLength;
    /* The VBoxBodies created when writing-back each block of VBoxes */
    protected final Cons<GarbageCollectable>[] bodiesPerBlock;
    /* A write-back status for each bucket */
    protected final AtomicBoolean[] blocksDone;

    private BoxesToCommit() {
        this.nBlocks = 0;
        this.blockSize = 0;
        this.allWrittenVBoxes = new VBox[0];
        this.allWrittenValues = new Object[0];
        this.writeSetLength = 0;
        this.bodiesPerBlock = new Cons[0];
        this.blocksDone = new AtomicBoolean[0];
    }

    public BoxesToCommit(int nBlocks, int blockSize, VBox[] allWrittenVBoxes, Object[] allWrittenValues, int writeSetLength,
            Cons<GarbageCollectable>[] bodiesPerBlock, AtomicBoolean[] blocksDone) {
        this.nBlocks = nBlocks;
        this.blockSize = blockSize;
        this.allWrittenVBoxes = allWrittenVBoxes;
        this.allWrittenValues = allWrittenValues;
        this.writeSetLength = writeSetLength;
        this.bodiesPerBlock = bodiesPerBlock;
        this.blocksDone = blocksDone;
    }

}