/*
 * 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 q.Bridge p.Test
 * @run main/othervm/native -Xcheck:jni NativeLibraryTest
 */

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;
import q.Bridge;

public class NativeLibraryTest {
    static final Path CLASSES = Paths.get("classes");
    static int unloaded = 0;

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

        for (int count=1; count <= 5; count++) {
            reload();
            System.gc();
            // give Cleaner thread a chance to unload the native library
            Thread.sleep(100);

            if (count != unloaded) {
                throw new RuntimeException("Expected unloaded=" + count +
                    " but got=" + unloaded);
            }
        }
    }

    /*
     * 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 reload() throws Exception {
        TestLoader loader = new TestLoader();
        Class<?> c = Class.forName("p.Test", true, loader);
        Bridge b = Bridge.class.cast(c.newInstance());
        if (!b.isLoaded()) {
            throw new RuntimeException("native library not loaded");
        }
    }

    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());
        }
    }

    /*
     * Called by JNI_OnUnload when the native library is unloaded
     */
    static void unload() {
        unloaded++;
    }
}