weak007.java

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
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 *
 * 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).
 *
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 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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/*
 * @test
 * @key stress randomness
 *
 * @summary converted from VM Testbase gc/gctests/WeakReference/weak007.
 * VM Testbase keywords: [gc, stress, stressopt, nonconcurrent]
 *
 * @library /vmTestbase
 *          /test/lib
 * @run main/othervm -XX:-UseGCOverheadLimit gc.gctests.WeakReference.weak007.weak007 -t 1
 */

package gc.gctests.WeakReference.weak007;

import nsk.share.TestFailure;
import nsk.share.gc.*;
import java.lang.ref.WeakReference;
import java.lang.ref.Reference;

/**
 * Test that GC correctly clears weak references.
 *
 * This test creates a number of weak references,
 * each of which points to the next, then provokes
 * GC with Algorithms.eatMemory(). The test succeeds
 * if last reference has been cleared and the object
 * has been finalized.
 */
public class weak007 extends ThreadedGCTest {

    class Worker implements Runnable {

        private int length = 10000;
        private int objectSize = 10000;
        private Reference[] references;

        private void makeReferences() {
            references[length - 1] = null;
            FinMemoryObject obj = new FinMemoryObject(objectSize);
            references[0] = new WeakReference(obj);
            for (int i = 1; i < length; ++i) {
                references[i] = new WeakReference(references[i - 1]);
            }
            for (int i = 0; i < length - 1; ++i) {
                references[i] = null;
            }
        }

        public void run() {
            makeReferences();
            Algorithms.eatMemory(getExecutionController());
            if (getExecutionController().continueExecution()) {
                if (references[length - 1].get() != null) {
                    throw new TestFailure("Last weak reference has not been cleared");
                }
            } else {
                log.info("Completed iterations: " + getExecutionController().getIteration());
            }
        }

        public Worker() {
            log.info("Array size: " + length);
            log.info("Object size: " + objectSize);
            references = new WeakReference[length];
        }
    }

    @Override
    protected Runnable createRunnable(int i) {
        return new Worker();
    }

    public static void main(String[] args) {
        GC.runTest(new weak007(), args);
    }
}