/*

 * Copyright (c) 2013, 2018, 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.

 */

/*

 * @test

 *

 * @summary converted from VM Testbase metaspace/stressDictionary.

 * VM Testbase keywords: [nonconcurrent, javac]

 *

 * @library /vmTestbase /test/lib

 * @run driver jdk.test.lib.FileInstaller . .

 * @run main/othervm metaspace.stressDictionary.StressDictionary

 */

package metaspace.stressDictionary;

import java.util.*;

import java.lang.management.ManagementFactory;

import java.lang.reflect.InvocationTargetException;

import java.lang.reflect.Method;

import java.util.concurrent.*;

import java.util.concurrent.atomic.AtomicLong;

import nsk.share.gc.GCTestBase;

import nsk.share.test.*;

import vm.share.InMemoryJavaCompiler;

/**

 * There is a data structure named "dictionary" in class BlockFreelist. It stores

 * information about free memory blocks for further reusing. Allocation of new block goes

 * from dictionary only if dictionary is fat enough. (At the moment of test creation this limit is 64K.)

 * So to stress dictionary we should fill it permanently. The easiest way to fill the dictionary

 * is to fail class loading. This failed action will return allocated blocks to dictionary.

 *

 * There are two type of threads in this test: threads, failing classloading and threads,

 * loading regular classes and checking they work properly.

 */

public class StressDictionary extends GCTestBase {

    private class FillingDictionaryWorker implements Callable<Object> {

        @Override

        public Object call() throws Exception {

            while (stresser.continueExecution()) {

                try {

                    byte[] bytecode = generateAndCompile();

                    bytecode[random.nextInt(bytecode.length)] = (byte) 42;

                    classloader.define(bytecode);

                    changeClassloaderIfRequired();

                } catch (Throwable e) {

                    // We can get ClassFormatError, ClassNotFoundException or anything else here

                }

            }

            return null;

        }

    }

    private class RegularWorker implements Callable<Object> {

        @Override

        public Object call() throws Exception {

            while (stresser.continueExecution()) {

                byte[] bytecode = generateAndCompile();

                Class<?> c = classloader.define(bytecode);

                testClass(c);

                changeClassloaderIfRequired();

            }

            return null;

        }

    }

    private static String[] args;

    private static final int DROP_CLASSLOADER_LIMIT = 50000;

    private static final String methodName = "myMethod";

    private static final int NUMBER_OF_CORRUPTING_THREADS = 10;

    private static final int NUMBER_OF_METHOD_CALLS = 50;

    private static final int NUMBER_OF_NOT_CORRUPTING_THREADS = 10;

    private AtomicLong classesCounter = new AtomicLong(0);

    private volatile ClassloaderUnderTest classloader = new ClassloaderUnderTest();

    private Random random;

    private ExecutionController stresser;

    public static void main(String[] args) {

        StressDictionary.args = args;

        Tests.runTest(new StressDictionary(), args);

    }

    public void run() {

        random = new Random(runParams.getSeed());

        stresser = new Stresser(args);

        stresser.start(1);

        List<Callable<Object>> tasks = new LinkedList<Callable<Object>>();

        for (int i = 0; i < NUMBER_OF_CORRUPTING_THREADS; i++) {

            tasks.add(this.new FillingDictionaryWorker());

        }

        for (int i = 0; i < NUMBER_OF_NOT_CORRUPTING_THREADS; i++) {

            tasks.add(this.new RegularWorker());

        }

        ExecutorService executorService = Executors.newCachedThreadPool();

        try {

            executorService.invokeAll(tasks);

        } catch (InterruptedException e) {

            e.printStackTrace();

        }

    }

    private void changeClassloaderIfRequired() {

        if (ManagementFactory.getClassLoadingMXBean().getLoadedClassCount() > DROP_CLASSLOADER_LIMIT) {

          ClassloaderUnderTest newOne = new ClassloaderUnderTest();

          classloader = newOne;

        }

    }

    private byte[] generateAndCompile() {

        Map<String, CharSequence> sources = new HashMap<String, CharSequence>();

        String className = "MyClass" + classesCounter.incrementAndGet();

        sources.put(className, generateSource(className));

        return InMemoryJavaCompiler.compile(sources).values().iterator().next();

    }

    private CharSequence generateSource(String className) {

        return "public class " + className + " { " +

                        "public static String s1 = \"s1" + random.nextInt() + "\"; " +

                                        "public String s2 = \"s2" + random.nextInt() + "\"; " +

                                        "public String " + methodName + "() {return s1 + s2; } " +

                        "}";

    }

    private void testClass(Class<?> clazz) {

        try {

            for (Method m : clazz.getMethods()) {

                if (m.getName().equals(methodName)) {

                    for (int j = 0; j < NUMBER_OF_METHOD_CALLS; j++) {

                        m.invoke(clazz.newInstance());

                    }

                }

            }

        } catch (InstantiationException | IllegalAccessException | InvocationTargetException e) {

            log.error("Class check failed: " + e.getMessage());

            e.printStackTrace();

            setFailed(true);

        }

    }

}