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

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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

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 *

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 * 2 along with this work; if not, write to the Free Software Foundation,

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package gc.g1;

/*

 * @test TestHumongousRemSetsMatch

 * @bug 8205426

 * @summary Test to make sure that humongous object remset states are in sync

 * @key gc

 * @requires vm.gc.G1

 * @library /test/lib

 * @build sun.hotspot.WhiteBox

 * @run driver ClassFileInstaller sun.hotspot.WhiteBox

 * @run main/othervm -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -Xmx512M -Xms512M -Xmn10M -XX:ParallelGCThreads=2 -XX:-UseDynamicNumberOfGCThreads -XX:+UseG1GC -XX:+WhiteBoxAPI -XX:G1HeapRegionSize=1M -XX:+VerifyAfterGC -Xlog:gc,gc+remset+tracking=trace gc.g1.TestHumongousRemsetsMatch

 */

import sun.hotspot.WhiteBox;

public class TestHumongousRemsetsMatch {

    // G1 at the moment uses one thread every this amount of regions.

    private static final int WorkerThreadBoundary = 384;

    private static final int ObjSizeInRegions = 17;

    private static final int M = 1024 * 1024;

    private static final int TypeArrayObjSize = ObjSizeInRegions * M / 4 /* sizeof(int) */ - 1024 /* > header size */;

    public static void main(String[] args) throws Exception {

        WhiteBox wb = WhiteBox.getWhiteBox();

        for (int j = 0; j < 3; j++) {

            wb.fullGC(); // Start with a clean slate

            // It may happen that our 7-region sized humongous objects may just be "misaligned"

            // so that they do not cross the region 384 boundary. Try to counter this by offsetting

            // the humongous objects just a little.

            Object alignmentFudge = new int[(j + 1) * M / 4 /* sizeof(int) */ - 1024];

            // Fill the heap so that more than WorkerThreadBoundary regions are occupied with humongous objects

            // and hopefully one of these objects crosses the region WorkerThreadBoundary boundary.

            Object[] lotsOfHumongousObjects = new Object[(WorkerThreadBoundary / ObjSizeInRegions) + 3];

            for (int i = 0; i < lotsOfHumongousObjects.length; i++) {

                lotsOfHumongousObjects[i] = new int[TypeArrayObjSize];

            }

            wb.fullGC();

            // Trigger a concurrent cycle and wait until the Remark pause

            wb.g1StartConcMarkCycle();

            while (wb.g1InConcurrentMark()) {

                Thread.sleep(200);

            }

            wb.youngGC(); // Trigger verification error.

            System.out.println(lotsOfHumongousObjects + " " + alignmentFudge);

        }

    }

}