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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

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 * 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).

 *

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

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import java.lang.management.GarbageCollectorMXBean;

import java.util.List;

import java.util.ArrayList;

import jdk.test.lib.ByteCodeLoader;

import jdk.test.lib.compiler.InMemoryJavaCompiler;

import jdk.test.lib.Platform;

import sun.management.ManagementFactoryHelper;

import static jdk.test.lib.Asserts.*;

/* @test TestMetaspacePerfCounters

 * @bug 8014659

 * @requires vm.gc=="null"

 * @summary Tests that performance counters for metaspace and compressed class

 *          space exists and works.

 * @modules java.base/jdk.internal.misc

 *          java.compiler

 *          java.management/sun.management

 *          jdk.internal.jvmstat/sun.jvmstat.monitor

 * @run main/othervm -XX:+IgnoreUnrecognizedVMOptions -XX:-UseCompressedOops -XX:-UseCompressedClassPointers -XX:+UsePerfData -XX:+UseSerialGC TestMetaspacePerfCounters

 * @run main/othervm -XX:+IgnoreUnrecognizedVMOptions -XX:-UseCompressedOops -XX:-UseCompressedClassPointers -XX:+UsePerfData -XX:+UseParallelGC -XX:+UseParallelOldGC TestMetaspacePerfCounters

 * @run main/othervm -XX:+IgnoreUnrecognizedVMOptions -XX:-UseCompressedOops -XX:-UseCompressedClassPointers -XX:+UsePerfData -XX:+UseG1GC TestMetaspacePerfCounters

 *

 * @run main/othervm -XX:+IgnoreUnrecognizedVMOptions -XX:+UseCompressedOops -XX:+UseCompressedClassPointers -XX:+UsePerfData -XX:+UseSerialGC TestMetaspacePerfCounters

 * @run main/othervm -XX:+IgnoreUnrecognizedVMOptions -XX:+UseCompressedOops -XX:+UseCompressedClassPointers -XX:+UsePerfData -XX:+UseParallelGC -XX:+UseParallelOldGC TestMetaspacePerfCounters

 * @run main/othervm -XX:+IgnoreUnrecognizedVMOptions -XX:+UseCompressedOops -XX:+UseCompressedClassPointers -XX:+UsePerfData -XX:+UseG1GC TestMetaspacePerfCounters

 */

public class TestMetaspacePerfCounters {

    public static Class fooClass = null;

    private static final String[] counterNames = {"minCapacity", "maxCapacity", "capacity", "used"};

    private static final List<GarbageCollectorMXBean> gcBeans = ManagementFactoryHelper.getGarbageCollectorMXBeans();

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

        String metaspace = "sun.gc.metaspace";

        String ccs = "sun.gc.compressedclassspace";

        checkPerfCounters(metaspace);

        if (isUsingCompressedClassPointers()) {

            checkPerfCounters(ccs);

            checkUsedIncreasesWhenLoadingClass(ccs);

        } else {

            checkEmptyPerfCounters(ccs);

            checkUsedIncreasesWhenLoadingClass(metaspace);

        }

    }

    private static void checkPerfCounters(String ns) throws Exception {

        long gcCountBefore;

        long gcCountAfter;

        long minCapacity;

        long maxCapacity;

        long capacity;

        long used;

        // The perf counter values are updated during GC and to be able to

        // do the assertions below we need to ensure that the values are from

        // the same GC cycle.

        do {

            gcCountBefore = currentGCCount();

            minCapacity = getMinCapacity(ns);

            maxCapacity = getMaxCapacity(ns);

            capacity = getCapacity(ns);

            used = getUsed(ns);

            gcCountAfter = currentGCCount();

            assertGTE(gcCountAfter, gcCountBefore);

        } while(gcCountAfter > gcCountBefore);

        assertGTE(minCapacity, 0L);

        assertGTE(used, minCapacity);

        assertGTE(capacity, used);

        assertGTE(maxCapacity, capacity);

    }

    private static void checkEmptyPerfCounters(String ns) throws Exception {

        for (PerfCounter counter : countersInNamespace(ns)) {

            String msg = "Expected " + counter.getName() + " to equal 0";

            assertEQ(counter.longValue(), 0L, msg);

        }

    }

    private static void checkUsedIncreasesWhenLoadingClass(String ns) throws Exception {

        // Need to ensure that used is up to date and that all unreachable

        // classes are unloaded before doing this check.

        System.gc();

        long before = getUsed(ns);

        fooClass = compileAndLoad("Foo", "public class Foo { }");

        System.gc();

        long after = getUsed(ns);

        assertGT(after, before);

    }

    private static List<PerfCounter> countersInNamespace(String ns) throws Exception {

        List<PerfCounter> counters = new ArrayList<>();

        for (String name : counterNames) {

            counters.add(PerfCounters.findByName(ns + "." + name));

        }

        return counters;

    }

    private static Class<?> compileAndLoad(String name, String source) throws Exception {

        byte[] byteCode = InMemoryJavaCompiler.compile(name, source);

        return ByteCodeLoader.load(name, byteCode);

    }

    private static boolean isUsingCompressedClassPointers() {

        return Platform.is64bit() && InputArguments.contains("-XX:+UseCompressedClassPointers");

    }

    private static long getMinCapacity(String ns) throws Exception {

        return PerfCounters.findByName(ns + ".minCapacity").longValue();

    }

    private static long getCapacity(String ns) throws Exception {

        return PerfCounters.findByName(ns + ".capacity").longValue();

    }

    private static long getMaxCapacity(String ns) throws Exception {

        return PerfCounters.findByName(ns + ".maxCapacity").longValue();

    }

    private static long getUsed(String ns) throws Exception {

        return PerfCounters.findByName(ns + ".used").longValue();

    }

    private static long currentGCCount() {

        long gcCount = 0;

        for (GarbageCollectorMXBean bean : gcBeans) {

            gcCount += bean.getCollectionCount();

        }

        return gcCount;

    }

}