/*

 * Copyright (c) 2017, 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 8164512

 * @summary verify if the native library is unloaded when the class loader is GC'ed

 * @build p.Test

 * @run main/othervm/native -Xcheck:jni NativeLibraryTest

 */

import java.io.IOException;

import java.net.MalformedURLException;

import java.net.URL;

import java.net.URLClassLoader;

import java.nio.file.Files;

import java.nio.file.Path;

import java.nio.file.Paths;

public class NativeLibraryTest {

    static final Path CLASSES = Paths.get("classes");

    static int unloadedCount = 0;

    /*

     * Called by JNI_OnUnload when the native library is unloaded

     */

    static void nativeLibraryUnloaded() {

        unloadedCount++;

    }

    public static void main(String... args) throws Exception {

        setup();

        for (int count=1; count <= 5; count++) {

            // create a class loader and load a native library

            runTest();

            // unloading the class loader and native library

            System.gc();

            // give Cleaner thread a chance to unload the native library

            Thread.sleep(100);

            // unloadedCount is incremented when the native library is unloaded

            if (count != unloadedCount) {

                throw new RuntimeException("Expected unloaded=" + count +

                    " but got=" + unloadedCount);

            }

        }

    }

    /*

     * Loads p.Test class with a new class loader and its static initializer

     * will load a native library.

     *

     * The class loader becomes unreachable when this method returns and

     * the native library should be unloaded at some point after the class

     * loader is garbage collected.

     */

    static void runTest() throws Exception {

        // invoke p.Test.run() that loads the native library

        Runnable r = newTestRunnable();

        r.run();

        // reload the native library by the same class loader

        r.run();

        // load the native library by another class loader

        Runnable r1 = newTestRunnable();

        try {

            r1.run();

            throw new RuntimeException("should fail to load the native library" +

                    " by another class loader");

        } catch (UnsatisfiedLinkError e) {}

    }

    /*

     * Loads p.Test class with a new class loader and returns

     * a Runnable instance.

     */

    static Runnable newTestRunnable() throws Exception {

        TestLoader loader = new TestLoader();

        Class<?> c = Class.forName("p.Test", true, loader);

        return (Runnable) c.newInstance();

    }

    static class TestLoader extends URLClassLoader {

        static URL[] toURLs() {

            try {

                return new URL[] { CLASSES.toUri().toURL() };

            } catch (MalformedURLException e) {

                throw new Error(e);

            }

        }

        TestLoader() {

            super("testloader", toURLs(), ClassLoader.getSystemClassLoader());

        }

    }

    /*

     * move p/Test.class out from classpath to the scratch directory

     */

    static void setup() throws IOException {

        String dir = System.getProperty("test.classes", ".");

        Path file = Paths.get("p", "Test.class");

        Files.createDirectories(CLASSES.resolve("p"));

        Files.move(Paths.get(dir).resolve(file),

                   CLASSES.resolve("p").resolve("Test.class"));

    }

}