TestPinnedGarbage.java

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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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/* @test TestPinnedGarbage
 * @summary Test that garbage in the pinned region does not crash VM
 * @key randomness
 * @requires vm.gc.Shenandoah
 * @library /test/lib
 *
 * @run main/othervm/native -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xmx128m
 *      -XX:+UseShenandoahGC -XX:ShenandoahGCMode=passive
 *      -XX:+ShenandoahVerify -XX:+ShenandoahDegeneratedGC
 *      TestPinnedGarbage
 *
 * @run main/othervm/native -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xmx128m
 *      -XX:+UseShenandoahGC -XX:ShenandoahGCMode=passive
 *      -XX:+ShenandoahVerify -XX:-ShenandoahDegeneratedGC
 *      TestPinnedGarbage
 */

/* @test TestPinnedGarbage
 * @summary Test that garbage in the pinned region does not crash VM
 * @key randomness
 * @requires vm.gc.Shenandoah
 * @library /test/lib
 *
 * @run main/othervm/native -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xmx128m
 *      -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=aggressive
 *      TestPinnedGarbage
 *
 * @run main/othervm/native -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xmx128m
 *      -XX:+UseShenandoahGC
 *      -XX:+ShenandoahVerify
 *      TestPinnedGarbage
 */

import java.util.Arrays;
import java.util.Random;
import jdk.test.lib.Utils;

public class TestPinnedGarbage {
    static {
        System.loadLibrary("TestPinnedGarbage");
    }

    private static final int NUM_RUNS      = 1_000;
    private static final int OBJS_COUNT    = 1 << 10;
    private static final int GARBAGE_COUNT = 1 << 18;

    private static native void pin(int[] a);
    private static native void unpin(int[] a);

    public static void main(String[] args) {
        Random rng = Utils.getRandomInstance();
        for (int i = 0; i < NUM_RUNS; i++) {
            test(rng);
        }
    }

    private static void test(Random rng) {
        Object[] objs = new Object[OBJS_COUNT];
        for (int i = 0; i < OBJS_COUNT; i++) {
            objs[i] = new MyClass();
        }

        int[] cog = new int[10];
        int cogIdx = rng.nextInt(OBJS_COUNT);
        objs[cogIdx] = cog;
        pin(cog);

        for (int i = 0; i < GARBAGE_COUNT; i++) {
            int rIdx = rng.nextInt(OBJS_COUNT);
            if (rIdx != cogIdx) {
                objs[rIdx] = new MyClass();
            }
        }

        unpin(cog);
    }

    public static class MyClass {
        public Object ref = new Object();
    }

}