1 /*
   2  * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 /*
  25  * @test
  26  * @bug 8164512 8191360
  27  * @requires vm.compMode != "Xcomp"
  28  * @summary verify if the native library is unloaded when the class loader is GC'ed
  29  * @build p.Test
  30  * @run main/othervm/native -Xcheck:jni NativeLibraryTest
  31  */
  32 
  33 import java.io.IOException;
  34 import java.net.MalformedURLException;
  35 import java.net.URL;
  36 import java.net.URLClassLoader;
  37 import java.nio.file.Files;
  38 import java.nio.file.Path;
  39 import java.nio.file.Paths;
  40 
  41 public class NativeLibraryTest {
  42     static final Path CLASSES = Paths.get("classes");
  43     static int unloadedCount = 0;
  44 
  45     /*
  46      * Called by JNI_OnUnload when the native library is unloaded
  47      */
  48     static void nativeLibraryUnloaded() {
  49         unloadedCount++;
  50     }
  51 
  52     public static void main(String... args) throws Exception {
  53         setup();
  54 
  55         for (int count=1; count <= 5; count++) {
  56             // create a class loader and load a native library
  57             runTest();
  58             // unloading the class loader and native library
  59             System.gc();
  60             // give Cleaner thread a chance to unload the native library
  61             Thread.sleep(100);
  62 
  63             // unloadedCount is incremented when the native library is unloaded
  64             if (count != unloadedCount) {
  65                 throw new RuntimeException("Expected unloaded=" + count +
  66                     " but got=" + unloadedCount);
  67             }
  68         }
  69     }
  70 
  71     /*
  72      * Loads p.Test class with a new class loader and its static initializer
  73      * will load a native library.
  74      *
  75      * The class loader becomes unreachable when this method returns and
  76      * the native library should be unloaded at some point after the class
  77      * loader is garbage collected.
  78      */
  79     static void runTest() throws Exception {
  80         // invoke p.Test.run() that loads the native library
  81         Runnable r = newTestRunnable();
  82         r.run();
  83 
  84         // reload the native library by the same class loader
  85         r.run();
  86 
  87         // load the native library by another class loader
  88         Runnable r1 = newTestRunnable();
  89         try {
  90             r1.run();
  91             throw new RuntimeException("should fail to load the native library" +
  92                     " by another class loader");
  93         } catch (UnsatisfiedLinkError e) {}
  94     }
  95 
  96     /*
  97      * Loads p.Test class with a new class loader and returns
  98      * a Runnable instance.
  99      */
 100     static Runnable newTestRunnable() throws Exception {
 101         TestLoader loader = new TestLoader();
 102         Class<?> c = Class.forName("p.Test", true, loader);
 103         return (Runnable) c.newInstance();
 104     }
 105 
 106     static class TestLoader extends URLClassLoader {
 107         static URL[] toURLs() {
 108             try {
 109                 return new URL[] { CLASSES.toUri().toURL() };
 110             } catch (MalformedURLException e) {
 111                 throw new Error(e);
 112             }
 113         }
 114 
 115         TestLoader() {
 116             super("testloader", toURLs(), ClassLoader.getSystemClassLoader());
 117         }
 118     }
 119 
 120     /*
 121      * move p/Test.class out from classpath to the scratch directory
 122      */
 123     static void setup() throws IOException {
 124         String dir = System.getProperty("test.classes", ".");
 125         Path file = Paths.get("p", "Test.class");
 126         Files.createDirectories(CLASSES.resolve("p"));
 127         Files.move(Paths.get(dir).resolve(file),
 128                    CLASSES.resolve("p").resolve("Test.class"));
 129     }
 130 }