/*

 * Copyright (c) 2019, 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.

 */

package gc.z;

/*

 * @test TestSmallHeap

 * @summary Test ZGC with small heaps

 * @run main/othervm -XX:+UnlockExperimentalVMOptions -XX:+UseZGC -Xlog:gc,gc+init,gc+heap -Xmx8M gc.z.TestSmallHeap

 * @run main/othervm -XX:+UnlockExperimentalVMOptions -XX:+UseZGC -Xlog:gc,gc+init,gc+heap -Xmx16M gc.z.TestSmallHeap

 * @run main/othervm -XX:+UnlockExperimentalVMOptions -XX:+UseZGC -Xlog:gc,gc+init,gc+heap -Xmx32M gc.z.TestSmallHeap

 * @run main/othervm -XX:+UnlockExperimentalVMOptions -XX:+UseZGC -Xlog:gc,gc+init,gc+heap -Xmx64M gc.z.TestSmallHeap

 * @run main/othervm -XX:+UnlockExperimentalVMOptions -XX:+UseZGC -Xlog:gc,gc+init,gc+heap -Xmx128M gc.z.TestSmallHeap

 * @run main/othervm -XX:+UnlockExperimentalVMOptions -XX:+UseZGC -Xlog:gc,gc+init,gc+heap -Xmx256M gc.z.TestSmallHeap

 * @run main/othervm -XX:+UnlockExperimentalVMOptions -XX:+UseZGC -Xlog:gc,gc+init,gc+heap -Xmx512M gc.z.TestSmallHeap

 * @run main/othervm -XX:+UnlockExperimentalVMOptions -XX:+UseZGC -Xlog:gc,gc+init,gc+heap -Xmx1024M gc.z.TestSmallHeap

 */

import java.lang.ref.Reference;

public class TestSmallHeap {

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

        final long maxCapacity = Runtime.getRuntime().maxMemory();

        System.out.println("Max Capacity " + maxCapacity + " bytes");

        // Allocate byte arrays of increasing length, so that

        // all allocaion paths (small/medium/large) are tested.

        for (int length = 16; length <= maxCapacity / 16; length *= 2) {

            System.out.println("Allocating " + length + " bytes");

            Reference.reachabilityFence(new byte[length]);

        }

        System.out.println("Success");

    }

}