TestCSLocker.java

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 *
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 * 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,
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 */

package gc.cslocker;

import static gc.testlibrary.Allocation.blackHole;

/*
 * @test TestCSLocker
 * @bug 6186200
 * @library /
 * @summary This short test check RFE 6186200 changes. One thread locked
 * @summary completely in JNI CS, while other is trying to allocate memory
 * @summary provoking GC. OOM means FAIL, deadlock means PASS.
 * @run main/native/othervm -Xmx256m gc.cslocker.TestCSLocker
 */

public class TestCSLocker extends Thread
{
    static int timeout = 5000;
    public static void main(String args[]) throws Exception {
        long startTime = System.currentTimeMillis();

        // start garbage producer thread
        GarbageProducer garbageProducer = new GarbageProducer(1000000, 10);
        garbageProducer.start();

        // start CS locker thread
        CSLocker csLocker = new CSLocker();
        csLocker.start();

        // check timeout to success deadlocking
        while(System.currentTimeMillis() < startTime + timeout) {
            System.out.println("sleeping...");
            sleep(1000);
        }

        csLocker.unlock();
        garbageProducer.interrupt();
    }
}

class GarbageProducer extends Thread
{
    private int size;
    private int sleepTime;

    GarbageProducer(int size, int sleepTime) {
        this.size = size;
        this.sleepTime = sleepTime;
    }

    public void run() {
        boolean isRunning = true;

        while (isRunning) {
            try {
                blackHole(new int[size]);
                sleep(sleepTime);
            } catch (InterruptedException e) {
                isRunning = false;
            }
        }
    }
}

class CSLocker extends Thread
{
    static { System.loadLibrary("TestCSLocker"); }

    public void run() {
        int[] a = new int[10];
        a[0] = 1;
        if (!lock(a)) {
            throw new RuntimeException("failed to acquire CSLock");
        }
    }

    native boolean lock(int[] array);
    native void unlock();
}