/*

 * Copyright (c) 2013, 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

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 */

import java.util.List;

import java.lang.management.ManagementFactory;

import java.lang.management.MemoryManagerMXBean;

import java.lang.management.MemoryPoolMXBean;

import java.lang.management.MemoryUsage;

import java.lang.management.RuntimeMXBean;

import java.lang.management.ManagementFactory;

/* @test TestMetaspaceMemoryPool

 * @bug 8000754

 * @summary Tests that a MemoryPoolMXBeans is created for metaspace and that a

 *          MemoryManagerMXBean is created.

 * @run main/othervm -XX:+IgnoreUnrecognizedVMOptions -XX:-UseCompressedOops TestMetaspaceMemoryPool

 * @run main/othervm -XX:+IgnoreUnrecognizedVMOptions -XX:-UseCompressedOops -XX:MaxMetaspaceSize=60m TestMetaspaceMemoryPool

 */

public class TestMetaspaceMemoryPool {

    public static void main(String[] args) {

        verifyThatMetaspaceMemoryManagerExists();

        verifyMemoryPool(getMemoryPool("Metaspace"), isFlagDefined("MaxMetaspaceSize"));

        if (runsOn64bit()) {

            if (usesCompressedOops()) {

                MemoryPoolMXBean cksPool = getMemoryPool("Compressed Class Space");

                verifyMemoryPool(cksPool, true);

            }

        }

    }

    private static boolean runsOn64bit() {

        return !System.getProperty("sun.arch.data.model").equals("32");

    }

    private static boolean usesCompressedOops() {

        return isFlagDefined("+UseCompressedOops");

    }

    private static boolean isFlagDefined(String name) {

        RuntimeMXBean runtimeMxBean = ManagementFactory.getRuntimeMXBean();

        List<String> args = runtimeMxBean.getInputArguments();

        for (String arg : args) {

            if (arg.startsWith("-XX:" + name)) {

                return true;

            }

        }

        return false;

    }

    private static void verifyThatMetaspaceMemoryManagerExists() {

        List<MemoryManagerMXBean> managers = ManagementFactory.getMemoryManagerMXBeans();

        for (MemoryManagerMXBean manager : managers) {

            if (manager.getName().equals("Metaspace Manager")) {

                return;

            }

        }

        throw new RuntimeException("Expected to find a metaspace memory manager");

    }

    private static MemoryPoolMXBean getMemoryPool(String name) {

        List<MemoryPoolMXBean> pools = ManagementFactory.getMemoryPoolMXBeans();

        for (MemoryPoolMXBean pool : pools) {

            if (pool.getName().equals(name)) {

                return pool;

            }

        }

        throw new RuntimeException("Expected to find a memory pool with name " + name);

    }

    private static void verifyMemoryPool(MemoryPoolMXBean pool, boolean isMaxDefined) {

        MemoryUsage mu = pool.getUsage();

        assertDefined(mu.getInit(), "init");

        assertDefined(mu.getUsed(), "used");

        assertDefined(mu.getCommitted(), "committed");

        if (isMaxDefined) {

            assertDefined(mu.getMax(), "max");

        } else {

            assertUndefined(mu.getMax(), "max");

        }

    }

    private static void assertDefined(long value, String name) {

        assertTrue(value != -1, "Expected " + name + " to be defined");

    }

    private static void assertUndefined(long value, String name) {

        assertEquals(value, -1, "Expected " + name + " to be undefined");

    }

    private static void assertEquals(long actual, long expected, String msg) {

        assertTrue(actual == expected, msg);

    }

    private static void assertTrue(boolean condition, String msg) {

        if (!condition) {

            throw new RuntimeException(msg);

        }

    }

}