Main.java revision b6e20ae17d0881a66c22532e4152ce6779454a92
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 17import java.io.BufferedReader; 18import java.io.File; 19import java.io.FileReader; 20import java.lang.ref.WeakReference; 21import java.lang.reflect.Constructor; 22import java.lang.reflect.Method; 23 24public class Main { 25 static final String DEX_FILE = System.getenv("DEX_LOCATION") + "/141-class-unload-ex.jar"; 26 static String nativeLibraryName; 27 28 public static void main(String[] args) throws Exception { 29 nativeLibraryName = args[0]; 30 Class pathClassLoader = Class.forName("dalvik.system.PathClassLoader"); 31 if (pathClassLoader == null) { 32 throw new AssertionError("Couldn't find path class loader class"); 33 } 34 Constructor constructor = 35 pathClassLoader.getDeclaredConstructor(String.class, ClassLoader.class); 36 try { 37 testUnloadClass(constructor); 38 testUnloadLoader(constructor); 39 // Test that we don't unload if we have a Method keeping the class live. 40 testNoUnloadInvoke(constructor); 41 // Test that we don't unload if we have an instance. 42 testNoUnloadInstance(constructor); 43 // Test JNI_OnLoad and JNI_OnUnload. 44 testLoadAndUnloadLibrary(constructor); 45 // Test that stack traces keep the classes live. 46 testStackTrace(constructor); 47 // Stress test to make sure we dont leak memory. 48 stressTest(constructor); 49 // Test that the oat files are unloaded. 50 testOatFilesUnloaded(getPid()); 51 } catch (Exception e) { 52 System.out.println(e); 53 } 54 } 55 56 private static void testOatFilesUnloaded(int pid) throws Exception { 57 BufferedReader reader = new BufferedReader(new FileReader ("/proc/" + pid + "/maps")); 58 String line; 59 int count = 0; 60 Runtime.getRuntime().gc(); 61 System.runFinalization(); 62 while ((line = reader.readLine()) != null) { 63 if (line.contains("@141-class-unload-ex.jar")) { 64 System.out.println(line); 65 ++count; 66 } 67 } 68 System.out.println("Number of loaded unload-ex maps " + count); 69 } 70 71 private static void stressTest(Constructor constructor) throws Exception { 72 for (int i = 0; i <= 100; ++i) { 73 setUpUnloadLoader(constructor, false); 74 if (i % 10 == 0) { 75 Runtime.getRuntime().gc(); 76 } 77 } 78 } 79 80 private static void testUnloadClass(Constructor constructor) throws Exception { 81 WeakReference<Class> klass = setUpUnloadClass(constructor); 82 // No strong references to class loader, should get unloaded. 83 Runtime.getRuntime().gc(); 84 WeakReference<Class> klass2 = setUpUnloadClass(constructor); 85 Runtime.getRuntime().gc(); 86 // If the weak reference is cleared, then it was unloaded. 87 System.out.println(klass.get()); 88 System.out.println(klass2.get()); 89 } 90 91 private static void testUnloadLoader(Constructor constructor) 92 throws Exception { 93 WeakReference<ClassLoader> loader = setUpUnloadLoader(constructor, true); 94 // No strong references to class loader, should get unloaded. 95 Runtime.getRuntime().gc(); 96 // If the weak reference is cleared, then it was unloaded. 97 System.out.println(loader.get()); 98 } 99 100 private static void testStackTrace(Constructor constructor) throws Exception { 101 WeakReference<Class> klass = setUpUnloadClass(constructor); 102 Method stackTraceMethod = klass.get().getDeclaredMethod("generateStackTrace"); 103 Throwable throwable = (Throwable) stackTraceMethod.invoke(klass.get()); 104 stackTraceMethod = null; 105 Runtime.getRuntime().gc(); 106 boolean isNull = klass.get() == null; 107 System.out.println("class null " + isNull + " " + throwable.getMessage()); 108 } 109 110 private static void testLoadAndUnloadLibrary(Constructor constructor) throws Exception { 111 WeakReference<ClassLoader> loader = setUpLoadLibrary(constructor); 112 // No strong references to class loader, should get unloaded. 113 Runtime.getRuntime().gc(); 114 // If the weak reference is cleared, then it was unloaded. 115 System.out.println(loader.get()); 116 } 117 118 private static void testNoUnloadInvoke(Constructor constructor) throws Exception { 119 WeakReference<ClassLoader> loader = 120 new WeakReference((ClassLoader) constructor.newInstance( 121 DEX_FILE, ClassLoader.getSystemClassLoader())); 122 WeakReference<Class> intHolder = new WeakReference(loader.get().loadClass("IntHolder")); 123 intHolder.get().getDeclaredMethod("runGC").invoke(intHolder.get()); 124 boolean isNull = loader.get() == null; 125 System.out.println("loader null " + isNull); 126 } 127 128 private static void testNoUnloadInstance(Constructor constructor) throws Exception { 129 WeakReference<ClassLoader> loader = 130 new WeakReference((ClassLoader) constructor.newInstance( 131 DEX_FILE, ClassLoader.getSystemClassLoader())); 132 WeakReference<Class> intHolder = new WeakReference(loader.get().loadClass("IntHolder")); 133 Object o = intHolder.get().newInstance(); 134 Runtime.getRuntime().gc(); 135 boolean isNull = loader.get() == null; 136 System.out.println("loader null " + isNull); 137 } 138 139 private static WeakReference<Class> setUpUnloadClass(Constructor constructor) throws Exception { 140 ClassLoader loader = (ClassLoader) constructor.newInstance( 141 DEX_FILE, ClassLoader.getSystemClassLoader()); 142 Class intHolder = loader.loadClass("IntHolder"); 143 Method getValue = intHolder.getDeclaredMethod("getValue"); 144 Method setValue = intHolder.getDeclaredMethod("setValue", Integer.TYPE); 145 // Make sure we don't accidentally preserve the value in the int holder, the class 146 // initializer should be re-run. 147 System.out.println((int) getValue.invoke(intHolder)); 148 setValue.invoke(intHolder, 2); 149 System.out.println((int) getValue.invoke(intHolder)); 150 waitForCompilation(intHolder); 151 return new WeakReference(intHolder); 152 } 153 154 private static WeakReference<ClassLoader> setUpUnloadLoader(Constructor constructor, 155 boolean waitForCompilation) 156 throws Exception { 157 ClassLoader loader = (ClassLoader) constructor.newInstance( 158 DEX_FILE, ClassLoader.getSystemClassLoader()); 159 Class intHolder = loader.loadClass("IntHolder"); 160 Method setValue = intHolder.getDeclaredMethod("setValue", Integer.TYPE); 161 setValue.invoke(intHolder, 2); 162 if (waitForCompilation) { 163 waitForCompilation(intHolder); 164 } 165 return new WeakReference(loader); 166 } 167 168 private static void waitForCompilation(Class intHolder) throws Exception { 169 // Load the native library so that we can call waitForCompilation. 170 Method loadLibrary = intHolder.getDeclaredMethod("loadLibrary", String.class); 171 loadLibrary.invoke(intHolder, nativeLibraryName); 172 // Wait for JIT compilation to finish since the async threads may prevent unloading. 173 Method waitForCompilation = intHolder.getDeclaredMethod("waitForCompilation"); 174 waitForCompilation.invoke(intHolder); 175 } 176 177 private static WeakReference<ClassLoader> setUpLoadLibrary(Constructor constructor) 178 throws Exception { 179 ClassLoader loader = (ClassLoader) constructor.newInstance( 180 DEX_FILE, ClassLoader.getSystemClassLoader()); 181 Class intHolder = loader.loadClass("IntHolder"); 182 Method loadLibrary = intHolder.getDeclaredMethod("loadLibrary", String.class); 183 loadLibrary.invoke(intHolder, nativeLibraryName); 184 waitForCompilation(intHolder); 185 return new WeakReference(loader); 186 } 187 188 private static int getPid() throws Exception { 189 return Integer.parseInt(new File("/proc/self").getCanonicalFile().getName()); 190 } 191} 192