/*

 * Copyright (c) 2016, 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 test;

import java.lang.module.Configuration;

import java.lang.module.ModuleFinder;

import java.lang.reflect.Layer;

import java.lang.reflect.Method;

import java.lang.reflect.Module;

import java.nio.file.Path;

import java.nio.file.Paths;

import java.util.*;

import java.util.concurrent.Callable;

import java.util.concurrent.ExecutorService;

import java.util.concurrent.Executors;

import java.util.concurrent.Future;

public class MainGC {

    private static final Path MODS_DIR = Paths.get(System.getProperty("jdk.module.path"));

    static final String MODULE_NAME = "jdk.translet";

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

        ModuleFinder finder = ModuleFinder.of(MODS_DIR);

        Layer layerBoot = Layer.boot();

        Configuration cf = layerBoot

                .configuration()

                .resolveRequires(ModuleFinder.of(), finder, Set.of(MODULE_NAME));

        Module testModule = MainGC.class.getModule();

        ClassLoader scl = ClassLoader.getSystemClassLoader();

        // Create an unique module/class loader in a layer above the boot layer.

        // Export this module to the jdk.test/test package.

        // Add a read edge from module jdk.test to this module.

        Callable<Void> task = new Callable<Void>() {

            @Override

            public Void call() throws Exception {

                Layer layer = Layer.boot().defineModulesWithOneLoader(cf, scl);

                Module transletModule = layer.findModule(MODULE_NAME).get();

                testModule.addExports("test", transletModule);

                testModule.addReads(transletModule);

                Class<?> c = layer.findLoader(MODULE_NAME).loadClass("translet.MainGC");

                Method method = c.getDeclaredMethod("go");

                method.invoke(null);

                return null;

            }

        };

        List<Future<Void>> results = new ArrayList<>();

        // Repeatedly create the layer above stressing the exportation of

        // package jdk.test/test to several different modules.

        ExecutorService pool = Executors.newFixedThreadPool(Math.min(100, Runtime.getRuntime().availableProcessors()*10));

        try {

            for (int i = 0; i < 10000; i++) {

                results.add(pool.submit(task));

                // At specified intervals, force a GC. This provides an

                // opportunity to verify that both the module jdk.test's reads

                // and the package test's, which is defined to jdk.test, exports

                // lists are being walked.

                if (i == 3000 || i == 6000 || i == 9000) {

                    System.gc();

                }

            }

        } finally {

            pool.shutdown();

        }

        int passed = 0;

        int failed = 0;

        // The failed state should be 0, the created modules in layers above the

        // boot layer should be allowed access to the contents of the jdk.test/test

        // package since that package was exported to the transletModule above.

        for (Future<Void> result : results) {

            try {

                result.get();

                passed++;

            } catch (Throwable x) {

                x.printStackTrace();

                failed++;

            }

        }

        System.out.println("passed: " + passed);

        System.out.println("failed: " + failed);

    }

    public static void callback() { }

}