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

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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package gc.x;

/*
 * @test TestSmallHeap
 * @requires vm.gc.ZSinglegen
 * @summary Test ZGC with small heaps
 * @library / /test/lib
 * @run driver gc.x.TestSmallHeap 8M 16M 32M 64M 128M 256M 512M 1024M
 */

import jdk.test.lib.process.ProcessTools;
import static gc.testlibrary.Allocation.blackHole;

public class TestSmallHeap {
    public static class Test {
        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");
        }
    }

    public static void main(String[] args) throws Exception {
        for (var maxCapacity: args) {
            ProcessTools.executeLimitedTestJava(
                "-XX:+UseZGC",
                "-XX:-ZGenerational",
                "-Xlog:gc,gc+init,gc+reloc,gc+heap",
                "-Xmx" + maxCapacity,
                Test.class.getName())
                    .outputTo(System.out)
                    .errorTo(System.out)
                    .shouldContain("Success")
                    .shouldHaveExitValue(0);
        }
    }
}