/*

 * 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.

 */

/*

 * @test

 * @bug 8151486

 * @summary Call Class.forName() on the system classloader from a class loaded

 *          from a custom classloader.

 * @library /lib/testlibrary

 * @build jdk.testlibrary.Utils JarUtils

 * @build ClassForName ClassForNameLeak

 * @run main/othervm/policy=test.policy -Djava.security.manager ClassForNameLeak

 */

import java.lang.ref.PhantomReference;

import java.lang.ref.Reference;

import java.lang.ref.ReferenceQueue;

import java.net.URL;

import java.net.URLClassLoader;

import java.nio.file.FileSystems;

import java.nio.file.Files;

import java.nio.file.Path;

import java.nio.file.Paths;

import java.util.List;

import java.util.concurrent.Callable;

import java.util.concurrent.ExecutorService;

import java.util.concurrent.Executors;

import java.util.concurrent.Future;

import java.util.stream.Collectors;

import java.util.stream.Stream;

import jdk.testlibrary.Utils;

/*

 * Create .jar, load ClassForName from .jar using a URLClassLoader

 */

public class ClassForNameLeak {

    private static final long TIMEOUT = (long)(5000.0 * Utils.TIMEOUT_FACTOR);

    private static final String TESTCLASSES = System.getProperty("test.classes", ".");

    private static final String CLASSFILENAME = "ClassForName.class";

    private static final int THREADS = 10;

    private static final ReferenceQueue<ClassLoader> rq = new ReferenceQueue<>();

    // Use a new classloader to load the ClassForName class, then run its

    // Runnable.

    public static PhantomReference<ClassLoader> loadAndRun(Path jarFilePath)

            throws Exception {

        ClassLoader classLoader = new URLClassLoader(

                new URL[]{jarFilePath.toUri().toURL()}) {

            @Override public String toString() { return "LeakedClassLoader"; }

        };

        Class<?> loadClass = Class.forName("ClassForName", true, classLoader);

        ((Runnable) loadClass.newInstance()).run();

        PhantomReference<ClassLoader> ref = new PhantomReference<>(classLoader, rq);

        System.out.println("returning phantom ref: " + ref + " to " + classLoader);

        return ref;

    }

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

        // Create a temporary .jar file containing ClassForName.class

        Path testClassesDir = Paths.get(TESTCLASSES);

        Path jarFilePath = Files.createTempFile("cfn", ".jar");

        JarUtils.createJarFile(jarFilePath, testClassesDir, CLASSFILENAME);

        jarFilePath.toFile().deleteOnExit();

        // Remove the ClassForName.class file that jtreg built, to make sure

        // we're loading from the tmp .jar

        Path classFile = FileSystems.getDefault().getPath(TESTCLASSES,

                                                          CLASSFILENAME);

        Files.delete(classFile);

        // Make simultaneous calls to the test method, to stress things a bit

        ExecutorService es = Executors.newFixedThreadPool(THREADS);

        List<Callable<PhantomReference<ClassLoader>>> callables =

                Stream.generate(() -> {

                    Callable<PhantomReference<ClassLoader>> cprcl = () -> {

                        return loadAndRun(jarFilePath);

                    };

                    return cprcl;

                }).limit(THREADS).collect(Collectors.toList());

        List<Future<PhantomReference<ClassLoader>>> refs = es.invokeAll(callables);

        // Give the GC a chance to enqueue the PhantomReferences

        for (int i = 0; i < 10; i++) {

            System.gc();

        }

        // Make sure all PhantomReferences to the leaked classloader are enqueued

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

            Reference rmRef = rq.remove(TIMEOUT);

            if (rmRef == null) {

                throw new RuntimeException("ClassLoader was never enqueued!");

            } else {

                System.out.println("Enqueued " + rmRef);

            }

        }

        System.out.println("All Classloaders successfully enqued");

    }

}