jdk/test/java/rmi/reliability/benchmark/bench/serial/ReplaceTrees.java

/* 
 * Copyright 1999 Sun Microsystems, Inc.  All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code 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
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 */

/*
 *
 */

package bench.serial;

import bench.Benchmark;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;

/**
 * Benchmark for testing speed of writes and reads of a tree of replaceable
 * objects.
 */
public class ReplaceTrees implements Benchmark {
    
    static class Node implements Serializable {
        Object parent, left, right;
        
	Node(Object parent, Object left, Object right) {
	    this.parent = parent;
	    this.left = left;
	    this.right = right;
	}

        Node(Object parent, int depth) {
            this.parent = parent;
            if (depth > 0) {
                left = new Node(this, depth - 1);
                right = new Node(this, depth - 1);
            }
        }
	
	Object writeReplace() {
	    return new RepNode(parent, left, right);
	}
    }
    
    static class RepNode implements Serializable {
	Object parent, left, right;
	
	RepNode(Object parent, Object left, Object right) {
	    this.parent = parent;
	    this.left = left;
	    this.right = right;
	}
	
	Object readResolve() {
	    return new Node(parent, left, right);
	}
    }
    
    /**
     * Write and read a tree of replaceable objects from a stream.  The
     * benchmark is run in batches: each "batch" consists of a fixed number of
     * read/write cycles, and the stream is flushed (and underlying stream
     * buffer cleared) in between each batch.
     * Arguments: <tree depth> <# batches> <# cycles per batch>
     */
    public long run(String[] args) throws Exception {
	int depth = Integer.parseInt(args[0]);
	int nbatches = Integer.parseInt(args[1]);
	int ncycles = Integer.parseInt(args[2]);
	Node[] trees = genTrees(depth, ncycles);
	StreamBuffer sbuf = new StreamBuffer();
	ObjectOutputStream oout = 
	    new ObjectOutputStream(sbuf.getOutputStream());
	ObjectInputStream oin = 
	    new ObjectInputStream(sbuf.getInputStream());
	
	doReps(oout, oin, sbuf, trees, 1);	// warmup

	long start = System.currentTimeMillis();
	doReps(oout, oin, sbuf, trees, nbatches);
        return System.currentTimeMillis() - start;
    }

    /**
     * Generate object trees.
     */
    Node[] genTrees(int depth, int ntrees) {
	Node[] trees = new Node[ntrees];
	for (int i = 0; i < ntrees; i++) {
	    trees[i] = new Node(null, depth);
	}
	return trees;
    }

    /**
     * Run benchmark for given number of batches, with each batch containing
     * the given number of cycles.
     */
    void doReps(ObjectOutputStream oout, ObjectInputStream oin,
	        StreamBuffer sbuf, Node[] trees, int nbatches)
	throws Exception
    {
	int ncycles = trees.length;
	for (int i = 0; i < nbatches; i++) {
	    sbuf.reset();
	    oout.reset();
	    for (int j = 0; j < ncycles; j++) {
		oout.writeObject(trees[j]);
	    }
	    oout.flush();
	    for (int j = 0; j < ncycles; j++) {
		oin.readObject();
	    }
	}
    }
}