1 /* 2 * Copyright (C) 2015 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 import java.io.BufferedReader; 18 import java.io.File; 19 import java.io.FileReader; 20 import java.lang.ref.WeakReference; 21 import java.lang.reflect.Constructor; 22 import java.lang.reflect.Method; 23 24 public class Main { 25 static final String DEX_FILE = System.getenv("DEX_LOCATION") + "/141-class-unload-ex.jar"; 26 static final String LIBRARY_SEARCH_PATH = System.getProperty("java.library.path"); 27 static String nativeLibraryName; 28 29 public static void main(String[] args) throws Exception { 30 nativeLibraryName = args[0]; 31 Class pathClassLoader = Class.forName("dalvik.system.PathClassLoader"); 32 if (pathClassLoader == null) { 33 throw new AssertionError("Couldn't find path class loader class"); 34 } 35 Constructor constructor = 36 pathClassLoader.getDeclaredConstructor(String.class, String.class, ClassLoader.class); 37 try { 38 testUnloadClass(constructor); 39 testUnloadLoader(constructor); 40 // Test that we don't unload if we have a Method keeping the class live. 41 testNoUnloadInvoke(constructor); 42 // Test that we don't unload if we have an instance. 43 testNoUnloadInstance(constructor); 44 // Test JNI_OnLoad and JNI_OnUnload. 45 testLoadAndUnloadLibrary(constructor); 46 // Test that stack traces keep the classes live. 47 testStackTrace(constructor); 48 // Stress test to make sure we dont leak memory. 49 stressTest(constructor); 50 // Test that the oat files are unloaded. 51 testOatFilesUnloaded(getPid()); 52 } catch (Exception e) { 53 e.printStackTrace(); 54 } 55 } 56 57 private static void testOatFilesUnloaded(int pid) throws Exception { 58 BufferedReader reader = new BufferedReader(new FileReader ("/proc/" + pid + "/maps")); 59 String line; 60 int count = 0; 61 Runtime.getRuntime().gc(); 62 System.runFinalization(); 63 while ((line = reader.readLine()) != null) { 64 if (line.contains("@141-class-unload-ex.jar")) { 65 System.out.println(line); 66 ++count; 67 } 68 } 69 System.out.println("Number of loaded unload-ex maps " + count); 70 } 71 72 private static void stressTest(Constructor constructor) throws Exception { 73 for (int i = 0; i <= 100; ++i) { 74 setUpUnloadLoader(constructor, false); 75 if (i % 10 == 0) { 76 Runtime.getRuntime().gc(); 77 } 78 } 79 } 80 81 private static void testUnloadClass(Constructor constructor) throws Exception { 82 WeakReference<Class> klass = setUpUnloadClass(constructor); 83 // No strong references to class loader, should get unloaded. 84 Runtime.getRuntime().gc(); 85 WeakReference<Class> klass2 = setUpUnloadClass(constructor); 86 Runtime.getRuntime().gc(); 87 // If the weak reference is cleared, then it was unloaded. 88 System.out.println(klass.get()); 89 System.out.println(klass2.get()); 90 } 91 92 private static void testUnloadLoader(Constructor constructor) 93 throws Exception { 94 WeakReference<ClassLoader> loader = setUpUnloadLoader(constructor, true); 95 // No strong references to class loader, should get unloaded. 96 Runtime.getRuntime().gc(); 97 // If the weak reference is cleared, then it was unloaded. 98 System.out.println(loader.get()); 99 } 100 101 private static void testStackTrace(Constructor constructor) throws Exception { 102 WeakReference<Class> klass = setUpUnloadClass(constructor); 103 Method stackTraceMethod = klass.get().getDeclaredMethod("generateStackTrace"); 104 Throwable throwable = (Throwable) stackTraceMethod.invoke(klass.get()); 105 stackTraceMethod = null; 106 Runtime.getRuntime().gc(); 107 boolean isNull = klass.get() == null; 108 System.out.println("class null " + isNull + " " + throwable.getMessage()); 109 } 110 111 private static void testLoadAndUnloadLibrary(Constructor constructor) throws Exception { 112 WeakReference<ClassLoader> loader = setUpLoadLibrary(constructor); 113 // No strong references to class loader, should get unloaded. 114 Runtime.getRuntime().gc(); 115 // If the weak reference is cleared, then it was unloaded. 116 System.out.println(loader.get()); 117 } 118 119 private static void testNoUnloadInvoke(Constructor constructor) throws Exception { 120 WeakReference<ClassLoader> loader = 121 new WeakReference((ClassLoader) constructor.newInstance( 122 DEX_FILE, LIBRARY_SEARCH_PATH, ClassLoader.getSystemClassLoader())); 123 WeakReference<Class> intHolder = new WeakReference(loader.get().loadClass("IntHolder")); 124 intHolder.get().getDeclaredMethod("runGC").invoke(intHolder.get()); 125 boolean isNull = loader.get() == null; 126 System.out.println("loader null " + isNull); 127 } 128 129 private static void testNoUnloadInstance(Constructor constructor) throws Exception { 130 WeakReference<ClassLoader> loader = 131 new WeakReference((ClassLoader) constructor.newInstance( 132 DEX_FILE, LIBRARY_SEARCH_PATH, ClassLoader.getSystemClassLoader())); 133 WeakReference<Class> intHolder = new WeakReference(loader.get().loadClass("IntHolder")); 134 Object o = intHolder.get().newInstance(); 135 Runtime.getRuntime().gc(); 136 boolean isNull = loader.get() == null; 137 System.out.println("loader null " + isNull); 138 } 139 140 private static WeakReference<Class> setUpUnloadClass(Constructor constructor) throws Exception { 141 ClassLoader loader = (ClassLoader) constructor.newInstance( 142 DEX_FILE, LIBRARY_SEARCH_PATH, ClassLoader.getSystemClassLoader()); 143 Class intHolder = loader.loadClass("IntHolder"); 144 Method getValue = intHolder.getDeclaredMethod("getValue"); 145 Method setValue = intHolder.getDeclaredMethod("setValue", Integer.TYPE); 146 // Make sure we don't accidentally preserve the value in the int holder, the class 147 // initializer should be re-run. 148 System.out.println((int) getValue.invoke(intHolder)); 149 setValue.invoke(intHolder, 2); 150 System.out.println((int) getValue.invoke(intHolder)); 151 waitForCompilation(intHolder); 152 return new WeakReference(intHolder); 153 } 154 155 private static WeakReference<ClassLoader> setUpUnloadLoader(Constructor constructor, 156 boolean waitForCompilation) 157 throws Exception { 158 ClassLoader loader = (ClassLoader) constructor.newInstance( 159 DEX_FILE, LIBRARY_SEARCH_PATH, ClassLoader.getSystemClassLoader()); 160 Class intHolder = loader.loadClass("IntHolder"); 161 Method setValue = intHolder.getDeclaredMethod("setValue", Integer.TYPE); 162 setValue.invoke(intHolder, 2); 163 if (waitForCompilation) { 164 waitForCompilation(intHolder); 165 } 166 return new WeakReference(loader); 167 } 168 169 private static void waitForCompilation(Class intHolder) throws Exception { 170 // Load the native library so that we can call waitForCompilation. 171 Method loadLibrary = intHolder.getDeclaredMethod("loadLibrary", String.class); 172 loadLibrary.invoke(intHolder, nativeLibraryName); 173 // Wait for JIT compilation to finish since the async threads may prevent unloading. 174 Method waitForCompilation = intHolder.getDeclaredMethod("waitForCompilation"); 175 waitForCompilation.invoke(intHolder); 176 } 177 178 private static WeakReference<ClassLoader> setUpLoadLibrary(Constructor constructor) 179 throws Exception { 180 ClassLoader loader = (ClassLoader) constructor.newInstance( 181 DEX_FILE, LIBRARY_SEARCH_PATH, ClassLoader.getSystemClassLoader()); 182 Class intHolder = loader.loadClass("IntHolder"); 183 Method loadLibrary = intHolder.getDeclaredMethod("loadLibrary", String.class); 184 loadLibrary.invoke(intHolder, nativeLibraryName); 185 waitForCompilation(intHolder); 186 return new WeakReference(loader); 187 } 188 189 private static int getPid() throws Exception { 190 return Integer.parseInt(new File("/proc/self").getCanonicalFile().getName()); 191 } 192 } 193
