/*
* Copyright (C) 2015 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.lang.ref.WeakReference;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
public class Main {
static final String DEX_FILE = System.getenv("DEX_LOCATION") + "/141-class-unload-ex.jar";
static final String LIBRARY_SEARCH_PATH = System.getProperty("java.library.path");
static String nativeLibraryName;
public static void main(String[] args) throws Exception {
nativeLibraryName = args[0];
Class<?> pathClassLoader = Class.forName("dalvik.system.PathClassLoader");
if (pathClassLoader == null) {
throw new AssertionError("Couldn't find path class loader class");
}
Constructor<?> constructor =
pathClassLoader.getDeclaredConstructor(String.class, String.class, ClassLoader.class);
try {
testUnloadClass(constructor);
testUnloadLoader(constructor);
// Test that we don't unload if we have an instance.
testNoUnloadInstance(constructor);
// Test JNI_OnLoad and JNI_OnUnload.
testLoadAndUnloadLibrary(constructor);
// Test that stack traces keep the classes live.
testStackTrace(constructor);
// Stress test to make sure we dont leak memory.
stressTest(constructor);
// Test that the oat files are unloaded.
testOatFilesUnloaded(getPid());
// Test that objects keep class loader live for sticky GC.
testStickyUnload(constructor);
} catch (Exception e) {
e.printStackTrace();
}
}
private static void testOatFilesUnloaded(int pid) throws Exception {
System.loadLibrary(nativeLibraryName);
// Stop the JIT to ensure its threads and work queue are not keeping classes
// artifically alive.
stopJit();
doUnloading();
System.runFinalization();
BufferedReader reader = new BufferedReader(new FileReader ("/proc/" + pid + "/maps"));
String line;
int count = 0;
while ((line = reader.readLine()) != null) {
if (line.contains("@141-class-unload-ex.jar")) {
System.out.println(line);
++count;
}
}
System.out.println("Number of loaded unload-ex maps " + count);
startJit();
}
private static void stressTest(Constructor<?> constructor) throws Exception {
for (int i = 0; i <= 100; ++i) {
setUpUnloadLoader(constructor, false);
if (i % 10 == 0) {
Runtime.getRuntime().gc();
}
}
}
private static void doUnloading() {
// Do multiple GCs to prevent rare flakiness if some other thread is keeping the
// classloader live.
for (int i = 0; i < 5; ++i) {
Runtime.getRuntime().gc();
}
}
private static void testUnloadClass(Constructor<?> constructor) throws Exception {
WeakReference<Class> klass = setUpUnloadClassWeak(constructor);
// No strong references to class loader, should get unloaded.
doUnloading();
WeakReference<Class> klass2 = setUpUnloadClassWeak(constructor);
doUnloading();
// If the weak reference is cleared, then it was unloaded.
System.out.println(klass.get());
System.out.println(klass2.get());
}
private static void testUnloadLoader(Constructor<?> constructor)
throws Exception {
WeakReference<ClassLoader> loader = setUpUnloadLoader(constructor, true);
// No strong references to class loader, should get unloaded.
doUnloading();
// If the weak reference is cleared, then it was unloaded.
System.out.println(loader.get());
}
private static void testStackTrace(Constructor<?> constructor) throws Exception {
Class<?> klass = setUpUnloadClass(constructor);
WeakReference<Class> weak_klass = new WeakReference(klass);
Method stackTraceMethod = klass.getDeclaredMethod("generateStackTrace");
Throwable throwable = (Throwable) stackTraceMethod.invoke(klass);
stackTraceMethod = null;
klass = null;
doUnloading();
boolean isNull = weak_klass.get() == null;
System.out.println("class null " + isNull + " " + throwable.getMessage());
}
private static void testLoadAndUnloadLibrary(Constructor<?> constructor) throws Exception {
WeakReference<ClassLoader> loader = setUpLoadLibrary(constructor);
// No strong references to class loader, should get unloaded.
doUnloading();
// If the weak reference is cleared, then it was unloaded.
System.out.println(loader.get());
}
private static Object testNoUnloadHelper(ClassLoader loader) throws Exception {
Class<?> intHolder = loader.loadClass("IntHolder");
return intHolder.newInstance();
}
static class Pair {
public Pair(Object o, ClassLoader l) {
object = o;
classLoader = new WeakReference<ClassLoader>(l);
}
public Object object;
public WeakReference<ClassLoader> classLoader;
}
private static Pair testNoUnloadInstanceHelper(Constructor<?> constructor) throws Exception {
ClassLoader loader = (ClassLoader) constructor.newInstance(
DEX_FILE, LIBRARY_SEARCH_PATH, ClassLoader.getSystemClassLoader());
Object o = testNoUnloadHelper(loader);
return new Pair(o, loader);
}
private static void testNoUnloadInstance(Constructor<?> constructor) throws Exception {
Pair p = testNoUnloadInstanceHelper(constructor);
doUnloading();
// If the class loader was unloded too early due to races, just pass the test.
boolean isNull = p.classLoader.get() == null;
System.out.println("loader null " + isNull);
}
private static Class<?> setUpUnloadClass(Constructor<?> constructor) throws Exception {
ClassLoader loader = (ClassLoader) constructor.newInstance(
DEX_FILE, LIBRARY_SEARCH_PATH, ClassLoader.getSystemClassLoader());
Class<?> intHolder = loader.loadClass("IntHolder");
Method getValue = intHolder.getDeclaredMethod("getValue");
Method setValue = intHolder.getDeclaredMethod("setValue", Integer.TYPE);
// Make sure we don't accidentally preserve the value in the int holder, the class
// initializer should be re-run.
System.out.println((int) getValue.invoke(intHolder));
setValue.invoke(intHolder, 2);
System.out.println((int) getValue.invoke(intHolder));
waitForCompilation(intHolder);
return intHolder;
}
private static Object allocObjectInOtherClassLoader(Constructor<?> constructor)
throws Exception {
ClassLoader loader = (ClassLoader) constructor.newInstance(
DEX_FILE, LIBRARY_SEARCH_PATH, ClassLoader.getSystemClassLoader());
return loader.loadClass("IntHolder").newInstance();
}
// Regression test for public issue 227182.
private static void testStickyUnload(Constructor<?> constructor) throws Exception {
String s = "";
for (int i = 0; i < 10; ++i) {
s = "";
// The object is the only thing preventing the class loader from being unloaded.
Object o = allocObjectInOtherClassLoader(constructor);
for (int j = 0; j < 1000; ++j) {
s += j + " ";
}
// Make sure the object still has a valid class (hasn't been incorrectly unloaded).
s += o.getClass().getName();
o = null;
}
System.out.println("Too small " + (s.length() < 1000));
}
private static WeakReference<Class> setUpUnloadClassWeak(Constructor<?> constructor)
throws Exception {
return new WeakReference<Class>(setUpUnloadClass(constructor));
}
private static WeakReference<ClassLoader> setUpUnloadLoader(Constructor<?> constructor,
boolean waitForCompilation)
throws Exception {
ClassLoader loader = (ClassLoader) constructor.newInstance(
DEX_FILE, LIBRARY_SEARCH_PATH, ClassLoader.getSystemClassLoader());
Class<?> intHolder = loader.loadClass("IntHolder");
Method setValue = intHolder.getDeclaredMethod("setValue", Integer.TYPE);
setValue.invoke(intHolder, 2);
if (waitForCompilation) {
waitForCompilation(intHolder);
}
return new WeakReference(loader);
}
private static void waitForCompilation(Class<?> intHolder) throws Exception {
// Load the native library so that we can call waitForCompilation.
Method loadLibrary = intHolder.getDeclaredMethod("loadLibrary", String.class);
loadLibrary.invoke(intHolder, nativeLibraryName);
// Wait for JIT compilation to finish since the async threads may prevent unloading.
Method waitForCompilation = intHolder.getDeclaredMethod("waitForCompilation");
waitForCompilation.invoke(intHolder);
}
private static WeakReference<ClassLoader> setUpLoadLibrary(Constructor<?> constructor)
throws Exception {
ClassLoader loader = (ClassLoader) constructor.newInstance(
DEX_FILE, LIBRARY_SEARCH_PATH, ClassLoader.getSystemClassLoader());
Class<?> intHolder = loader.loadClass("IntHolder");
Method loadLibrary = intHolder.getDeclaredMethod("loadLibrary", String.class);
loadLibrary.invoke(intHolder, nativeLibraryName);
waitForCompilation(intHolder);
return new WeakReference(loader);
}
private static int getPid() throws Exception {
return Integer.parseInt(new File("/proc/self").getCanonicalFile().getName());
}
public static native void stopJit();
public static native void startJit();
}