1 /*
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3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5  * This code is free software; you can redistribute it and/or modify it
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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
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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
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22  */
23 
24 /**
25  * @test
26  * @bug     6799583
27  *
28  * @summary Test verifes that LogManager shutdown hook does not cause
29  *          an application classloader leaks.
30  *
31  * @run     main/othervm ClassLoaderLeakTest
32  */
33 
34 import java.io.File;
35 import java.lang.ref.WeakReference;
36 import java.lang.reflect.Constructor;
37 import java.lang.reflect.Method;
38 import java.net.MalformedURLException;
39 import java.net.URL;
40 import java.net.URLClassLoader;
41 import java.util.concurrent.CountDownLatch;
42 import java.util.logging.Logger;
43 
44 public class ClassLoaderLeakTest {
45 
46     private static CountDownLatch doneSignal;
47     private static CountDownLatch launchSignal;
48     private static ThreadGroup appsThreadGroup;
49     private static Throwable launchFailure = null;
50 
main(String[] args)51     public static void main(String[] args) {
52         appsThreadGroup = new ThreadGroup("MyAppsThreadGroup");
53         doneSignal = new CountDownLatch(1);
54         launchSignal = new CountDownLatch(1);
55 
56         Runnable launcher = new Runnable() {
57             public void run() {
58                 try {
59                     ClassLoader cl =
60                         Thread.currentThread().getContextClassLoader();
61                     Class<?> appMain = cl.loadClass("AppTest");
62                     Method launch =
63                         appMain.getDeclaredMethod("launch", doneSignal.getClass());
64 
65                     Constructor<?> c = appMain.getConstructor();
66 
67                     Object o = c.newInstance();
68 
69                     launch.invoke(o, doneSignal);
70 
71                 } catch (Throwable e) {
72                     launchFailure = e;
73                 } finally {
74                     launchSignal.countDown();
75                 }
76             }
77         };
78 
79         /* prepare test  class loader */
80         URL pwd = null;
81         try {
82             pwd = new File(System.getProperty("test.classes",".")).toURI().toURL();
83         } catch (MalformedURLException e) {
84             throw new RuntimeException("Test failed.", e);
85         }
86         URL[] urls = new URL[] { pwd };
87 
88          MyClassLoader appClassLoader = new MyClassLoader(urls, "test0");
89          WeakReference<MyClassLoader> ref =
90                  new WeakReference<>(appClassLoader);
91 
92 
93          Thread appThread = new Thread(appsThreadGroup, launcher, "AppThread-0");
94          appThread.setContextClassLoader(appClassLoader);
95 
96          appThread.start();
97          appClassLoader = null;
98          launcher = null;
99          appThread = null;
100 
101          /* wait for laucnh completion */
102          try {
103              launchSignal.await();
104          } catch (InterruptedException e) {
105          }
106 
107          /* check if launch failed */
108          if (launchFailure != null) {
109              throw new RuntimeException("Test failed.", launchFailure);
110          }
111 
112          /* wait for test app excution completion */
113          try {
114              doneSignal.await();
115          } catch (InterruptedException e) {
116          }
117 
118          /* give a chence to GC */
119          waitAndGC(5);
120 
121          if (ref.get() != null) {
122              throw new RuntimeException("Test failed: classloader is still alive");
123          }
124 
125          System.out.println("Test passed.");
126     }
127 
128     private static class MyClassLoader extends URLClassLoader {
129 
130         private static boolean verbose =
131             Boolean.getBoolean("verboseClassLoading");
132         private String uniqClassName;
133 
MyClassLoader(URL[] urls, String uniq)134         public MyClassLoader(URL[] urls, String uniq) {
135             super(urls);
136 
137             uniqClassName = uniq;
138         }
139 
loadClass(String name)140         public Class<?> loadClass(String name) throws ClassNotFoundException {
141             if (verbose) {
142                 System.out.printf("%s: load class %s\n", uniqClassName, name);
143             }
144             if (uniqClassName.equals(name)) {
145                 return Object.class;
146             }
147             return super.loadClass(name);
148         }
149 
toString()150         public String toString() {
151             return "MyClassLoader(" + uniqClassName + ")";
152         }
153     }
154 
waitAndGC(int sec)155     private static void waitAndGC(int sec) {
156         int cnt = sec;
157         System.out.print("Wait ");
158         while (cnt-- > 0) {
159             try {
160                 Thread.sleep(1000);
161             } catch (InterruptedException e) {
162             }
163             // do GC every 3 seconds
164             if (cnt % 3 == 2) {
165                 System.gc();
166                 System.out.print("+");
167             } else {
168                 System.out.print(".");
169             }
170             //checkErrors();
171         }
172         System.out.println("");
173     }
174 }
175 
176 
177 class AppTest {
AppTest()178     public AppTest() {
179 
180     }
181 
launch(CountDownLatch done)182     public void launch(CountDownLatch done) {
183         Logger log = Logger.getLogger("app_test_logger");
184         log.fine("Test app is launched");
185 
186         done.countDown();
187     }
188 }
189