test/hotspot/jtreg/gc/z/TestSmallHeap.java

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

package gc.z;

/*
 * @test TestSmallHeap
 * @requires vm.gc.Z & !vm.graal.enabled & vm.compMode != "Xcomp"
 * @summary Test ZGC with small heaps
 * @library /
 * @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 static gc.testlibrary.Allocation.blackHole;

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 allocation paths (small/medium/large) are tested.
        for (int length = 16; length <= maxCapacity / 16; length *= 2) {
            System.out.println("Allocating " + length + " bytes");
            blackHole(new byte[length]);
        }

        System.out.println("Success");
    }
}