Java example source code file (InfiniteValidationLoopTest.java)

This example Java source code file (InfiniteValidationLoopTest.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

awt, countdownlatch, failed, frame, graphics, graphicsconfiguration, image, image_incompatible, image_ok, image_restored, infinitevalidationlooptest, interruptedexception, loop_threshold, override, runtimeexception, threading, threads, volatileimage

The InfiniteValidationLoopTest.java Java example source code

/*
 * Copyright (c) 2007, 2008, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

/*
 * @test
 * @bug 6648018
 * @summary Tests that we don't run into infinite validation loop when copying
            a VolatileImage to the screen
 * @author Dmitri.Trembovetski@sun.com: area=Graphics
 * @run main/othervm InfiniteValidationLoopTest
 * @run main/othervm -Dsun.java2d.d3d=false InfiniteValidationLoopTest
 */
import java.awt.Color;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.GraphicsConfiguration;
import static java.awt.image.VolatileImage.*;
import java.awt.image.VolatileImage;
import java.util.concurrent.CountDownLatch;

public class InfiniteValidationLoopTest extends Frame {
    private static volatile boolean failed = false;
    private static final int LOOP_THRESHOLD = 50;
    private static volatile CountDownLatch latch;
    private VolatileImage vi;

    public InfiniteValidationLoopTest() {
        super("InfiniteValidationLoopTest");
    }

    @Override
    public void paint(Graphics g) {
        try {
            runTest(g);
        } finally {
            latch.countDown();
        }
    }

    private void runTest(Graphics g) {
        int status = IMAGE_OK;
        int count1 = 0;
        do {
            GraphicsConfiguration gc = getGraphicsConfiguration();
            int count2 = 0;
            while (vi == null || (status = vi.validate(gc)) != IMAGE_OK) {
                if (++count2 > LOOP_THRESHOLD) {
                    System.err.println("Infinite loop detected: count2="+count2);
                    failed = true;
                    return;
                }
                if (vi == null || status == IMAGE_INCOMPATIBLE) {
                    if (vi != null) { vi.flush(); vi = null; }
                    vi = gc.createCompatibleVolatileImage(100, 100);
                    continue;
                }
                if (status == IMAGE_RESTORED) {
                    Graphics gg = vi.getGraphics();
                    gg.setColor(Color.green);
                    gg.fillRect(0, 0, vi.getWidth(), vi.getHeight());
                    break;
                }
            }
            g.drawImage(vi, getInsets().left, getInsets().top, null);
            if (++count1 > LOOP_THRESHOLD) {
                System.err.println("Infinite loop detected: count1="+count1);
                failed = true;
                return;
            }
        } while (vi.contentsLost());
    }

    public static void main(String[] args) {
        latch = new CountDownLatch(1);
        InfiniteValidationLoopTest t1 = new InfiniteValidationLoopTest();
        t1.pack();
        t1.setSize(200, 200);
        t1.setVisible(true);
        try { latch.await(); } catch (InterruptedException ex) {}
        t1.dispose();

        latch = new CountDownLatch(1);
        t1 = new InfiniteValidationLoopTest();
        t1.pack();
        t1.setSize(50, 50);
        t1.setVisible(true);
        try { latch.await(); } catch (InterruptedException ex) {}
        t1.dispose();

        if (failed) {
            throw new
                RuntimeException("Failed: infinite validattion loop detected");
        }
        System.out.println("Test PASSED");
    }
}