/*
 * Copyright (c) 2013, 2026, 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.metaspace;

import java.lang.invoke.VarHandle;
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.*;
import gc.testlibrary.PerfCounter;
import gc.testlibrary.PerfCounters;

/* @test id=Serial-64
 * @bug 8014659
 * @requires vm.gc.Serial
 * @requires vm.bits == "64"
 * @library /test/lib /
 * @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:+UseCompressedOops -XX:+UsePerfData -XX:+UseSerialGC gc.metaspace.TestMetaspacePerfCounters
 */

/* @test id=Parallel-64
 * @bug 8014659
 * @requires vm.gc.Parallel
 * @requires vm.bits == "64"
 * @library /test/lib /
 * @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:+UseCompressedOops -XX:+UsePerfData -XX:+UseParallelGC gc.metaspace.TestMetaspacePerfCounters
 */

/* @test id=G1-64
 * @bug 8014659
 * @requires vm.gc.G1
 * @requires vm.bits == "64"
 * @library /test/lib /
 * @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:+UseCompressedOops -XX:+UsePerfData -XX:+UseG1GC gc.metaspace.TestMetaspacePerfCounters
 */

/* @test id=Shenandoah-64
 * @bug 8014659
 * @requires vm.gc.Shenandoah
 * @requires vm.bits == "64"
 * @library /test/lib /
 * @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:+UseCompressedOops -XX:+UsePerfData -XX:+UseShenandoahGC gc.metaspace.TestMetaspacePerfCounters
 */

/* @test id=Epsilon-64
 * @bug 8014659
 * @requires vm.gc.Epsilon
 * @requires vm.bits == "64"
 * @library /test/lib /
 * @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:+UnlockExperimentalVMOptions -XX:+UseCompressedOops  -XX:+UsePerfData -XX:+UseEpsilonGC gc.metaspace.TestMetaspacePerfCounters
 */

/* @test id=Serial-32
 * @bug 8014659
 * @requires vm.gc.Serial
 * @requires vm.bits == "32"
 * @library /test/lib /
 * @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:+UsePerfData -XX:+UseSerialGC gc.metaspace.TestMetaspacePerfCounters
 */

/* @test id=Parallel-32
 * @bug 8014659
 * @requires vm.gc.Parallel
 * @requires vm.bits == "32"
 * @library /test/lib /
 * @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:+UsePerfData -XX:+UseParallelGC gc.metaspace.TestMetaspacePerfCounters
 */

/* @test id=G1-32
 * @bug 8014659
 * @requires vm.gc.G1
 * @requires vm.bits == "32"
 * @library /test/lib /
 * @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:+UsePerfData -XX:+UseG1GC gc.metaspace.TestMetaspacePerfCounters
 */

/* @test id=Shenandoah-32
 * @bug 8014659
 * @requires vm.gc.Shenandoah
 * @requires vm.bits == "32"
 * @library /test/lib /
 * @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:+UsePerfData -XX:+UseShenandoahGC gc.metaspace.TestMetaspacePerfCounters
 */


/* @test id=Epsilon-32
 * @bug 8014659
 * @requires vm.gc.Epsilon
 * @requires vm.bits == "32"
 * @library /test/lib /
 * @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:+UsePerfData -XX:+UnlockExperimentalVMOptions -XX:+UseEpsilonGC gc.metaspace.TestMetaspacePerfCounters
 */

class PerfCounterSnapshot {
    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();
    }

    public long minCapacity;
    public long maxCapacity;
    public long capacity;
    public long used;

    public void get(String ns) throws Exception {
        minCapacity = getMinCapacity(ns);
        maxCapacity = getMaxCapacity(ns);
        used = getUsed(ns);
        capacity = getCapacity(ns);
    }

    public boolean consistentWith(PerfCounterSnapshot other) {
        return (minCapacity == other.minCapacity) && (maxCapacity == other.maxCapacity) &&
            (used == other.used) && (capacity == other.capacity);
    }
}

public class TestMetaspacePerfCounters {
    public static Class<?> fooClass = null;
    private static final String[] counterNames = {"minCapacity", "maxCapacity", "capacity", "used"};

    public static void main(String[] args) throws Exception {
        String metaspace = "sun.gc.metaspace";
        String ccs = "sun.gc.compressedclassspace";

        checkPerfCounters(metaspace);
        checkPerfCounters(ccs);
        checkUsedIncreasesWhenLoadingClass(ccs);
    }

    private static void checkPerfCounters(String ns) throws Exception {
        PerfCounterSnapshot snap1 = new PerfCounterSnapshot();
        PerfCounterSnapshot snap2 = new PerfCounterSnapshot();

        final int MaxAttempts = 10;

        for (int attempts = 0; ; attempts++) {
            snap1.get(ns);
            VarHandle.fullFence();
            snap2.get(ns);

            if (snap1.consistentWith(snap2)) {
              // Got a consistent snapshot for examination.
              break;
            } else if (attempts == MaxAttempts) {
              throw new Exception("Failed to get stable reading of metaspace performance counters after " + attempts + " tries");
            }
        }

        assertGTE(snap1.minCapacity, 0L);
        assertGTE(snap1.used, snap1.minCapacity);
        assertGTE(snap1.capacity, snap1.used);
        assertGTE(snap1.maxCapacity, snap1.capacity);
    }

    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();
        PerfCounterSnapshot before = new PerfCounterSnapshot();
        before.get(ns);
        fooClass = compileAndLoad("Foo", "public class Foo { }");
        System.gc();
        PerfCounterSnapshot after = new PerfCounterSnapshot();
        after.get(ns);

        assertGT(after.used, before.used);
    }

    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);
    }

}
