ohair@286: /* mkos@408: * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved. ohair@286: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. ohair@286: * ohair@286: * This code is free software; you can redistribute it and/or modify it ohair@286: * under the terms of the GNU General Public License version 2 only, as ohair@286: * published by the Free Software Foundation. Oracle designates this ohair@286: * particular file as subject to the "Classpath" exception as provided ohair@286: * by Oracle in the LICENSE file that accompanied this code. ohair@286: * ohair@286: * This code is distributed in the hope that it will be useful, but WITHOUT ohair@286: * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or ohair@286: * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License ohair@286: * version 2 for more details (a copy is included in the LICENSE file that ohair@286: * accompanied this code). ohair@286: * ohair@286: * You should have received a copy of the GNU General Public License version ohair@286: * 2 along with this work; if not, write to the Free Software Foundation, ohair@286: * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. ohair@286: * ohair@286: * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA ohair@286: * or visit www.oracle.com if you need additional information or have any ohair@286: * questions. ohair@286: */ ohair@286: ohair@286: package com.sun.xml.internal.bind.v2.runtime.reflect.opt; ohair@286: ohair@286: import java.lang.reflect.InvocationTargetException; ohair@286: import java.lang.reflect.Method; ohair@286: import java.lang.ref.WeakReference; ohair@286: import java.security.AccessController; ohair@286: import java.security.PrivilegedAction; ohair@286: import java.util.concurrent.locks.Lock; ohair@286: import java.util.concurrent.locks.ReentrantReadWriteLock; ohair@286: import java.util.HashMap; ohair@286: import java.util.Map; ohair@286: import java.util.WeakHashMap; ohair@286: import java.util.logging.Level; ohair@286: import java.util.logging.Logger; ohair@286: ohair@286: import com.sun.xml.internal.bind.Util; ohair@286: import com.sun.xml.internal.bind.v2.runtime.reflect.Accessor; ohair@286: ohair@286: /** ohair@286: * A {@link ClassLoader} used to "inject" optimized accessor classes ohair@286: * into the VM. ohair@286: * ohair@286: *

ohair@286: * Its parent class loader needs to be set to the one that can see the user ohair@286: * class. ohair@286: * ohair@286: * @author Kohsuke Kawaguchi ohair@286: */ ohair@286: final class Injector { ohair@286: ohair@286: /** ohair@286: * {@link Injector}s keyed by their parent {@link ClassLoader}. ohair@286: * ohair@286: * We only need one injector per one user class loader. ohair@286: */ ohair@286: private static final ReentrantReadWriteLock irwl = new ReentrantReadWriteLock(); ohair@286: private static final Lock ir = irwl.readLock(); ohair@286: private static final Lock iw = irwl.writeLock(); ohair@286: private static final Map> injectors = ohair@286: new WeakHashMap>(); ohair@286: private static final Logger logger = Util.getClassLogger(); ohair@286: ohair@286: /** ohair@286: * Injects a new class into the given class loader. ohair@286: * ohair@286: * @return null ohair@286: * if it fails to inject. ohair@286: */ ohair@286: static Class inject(ClassLoader cl, String className, byte[] image) { ohair@286: Injector injector = get(cl); ohair@286: if (injector != null) { ohair@286: return injector.inject(className, image); ohair@286: } else { ohair@286: return null; ohair@286: } ohair@286: } ohair@286: ohair@286: /** ohair@286: * Returns the already injected class, or null. ohair@286: */ ohair@286: static Class find(ClassLoader cl, String className) { ohair@286: Injector injector = get(cl); ohair@286: if (injector != null) { ohair@286: return injector.find(className); ohair@286: } else { ohair@286: return null; ohair@286: } ohair@286: } ohair@286: ohair@286: /** ohair@286: * Gets or creates an {@link Injector} for the given class loader. ohair@286: * ohair@286: * @return null ohair@286: * if it fails. ohair@286: */ ohair@286: private static Injector get(ClassLoader cl) { ohair@286: Injector injector = null; ohair@286: WeakReference wr; ohair@286: ir.lock(); ohair@286: try { ohair@286: wr = injectors.get(cl); ohair@286: } finally { ohair@286: ir.unlock(); ohair@286: } ohair@286: if (wr != null) { ohair@286: injector = wr.get(); ohair@286: } ohair@286: if (injector == null) { ohair@286: try { ohair@286: wr = new WeakReference(injector = new Injector(cl)); ohair@286: iw.lock(); ohair@286: try { ohair@286: if (!injectors.containsKey(cl)) { ohair@286: injectors.put(cl, wr); ohair@286: } ohair@286: } finally { ohair@286: iw.unlock(); ohair@286: } ohair@286: } catch (SecurityException e) { ohair@286: logger.log(Level.FINE, "Unable to set up a back-door for the injector", e); ohair@286: return null; ohair@286: } ohair@286: } ohair@286: return injector; ohair@286: } ohair@286: /** ohair@286: * Injected classes keyed by their names. ohair@286: */ ohair@286: private final Map classes = new HashMap(); ohair@286: private final ReentrantReadWriteLock rwl = new ReentrantReadWriteLock(); ohair@286: private final Lock r = rwl.readLock(); ohair@286: private final Lock w = rwl.writeLock(); ohair@286: private final ClassLoader parent; ohair@286: /** ohair@286: * True if this injector is capable of injecting accessors. ohair@286: * False otherwise, which happens if this classloader can't see {@link Accessor}. ohair@286: */ ohair@286: private final boolean loadable; ohair@286: private static final Method defineClass; ohair@286: private static final Method resolveClass; ohair@286: private static final Method findLoadedClass; ohair@286: ohair@286: static { ohair@286: try { ohair@286: defineClass = ClassLoader.class.getDeclaredMethod("defineClass", String.class, byte[].class, Integer.TYPE, Integer.TYPE); ohair@286: resolveClass = ClassLoader.class.getDeclaredMethod("resolveClass", Class.class); ohair@286: findLoadedClass = ClassLoader.class.getDeclaredMethod("findLoadedClass", String.class); ohair@286: } catch (NoSuchMethodException e) { ohair@286: // impossible ohair@286: throw new NoSuchMethodError(e.getMessage()); ohair@286: } ohair@286: AccessController.doPrivileged(new PrivilegedAction() { ohair@286: mkos@408: @Override ohair@286: public Void run() { ohair@286: // TODO: check security implication ohair@286: // do these setAccessible allow anyone to call these methods freely?s ohair@286: defineClass.setAccessible(true); ohair@286: resolveClass.setAccessible(true); ohair@286: findLoadedClass.setAccessible(true); ohair@286: return null; ohair@286: } ohair@286: }); ohair@286: } ohair@286: ohair@286: private Injector(ClassLoader parent) { ohair@286: this.parent = parent; ohair@286: assert parent != null; ohair@286: ohair@286: boolean loadableCheck = false; ohair@286: ohair@286: try { ohair@286: loadableCheck = parent.loadClass(Accessor.class.getName()) == Accessor.class; ohair@286: } catch (ClassNotFoundException e) { ohair@286: // not loadable ohair@286: } ohair@286: ohair@286: this.loadable = loadableCheck; ohair@286: } ohair@286: ohair@286: @SuppressWarnings("LockAcquiredButNotSafelyReleased") ohair@286: private Class inject(String className, byte[] image) { ohair@286: if (!loadable) // this injector cannot inject anything ohair@286: { ohair@286: return null; ohair@286: } ohair@286: ohair@286: boolean wlocked = false; ohair@286: boolean rlocked = false; ohair@286: try { ohair@286: ohair@286: r.lock(); ohair@286: rlocked = true; ohair@286: ohair@286: Class c = classes.get(className); ohair@286: ohair@286: // Unlock now during the findLoadedClass process to avoid ohair@286: // deadlocks ohair@286: r.unlock(); ohair@286: rlocked = false; ohair@286: ohair@286: //find loaded class from classloader ohair@286: if (c == null) { ohair@286: ohair@286: try { ohair@286: c = (Class) findLoadedClass.invoke(parent, className.replace('/', '.')); ohair@286: } catch (IllegalArgumentException e) { ohair@286: logger.log(Level.FINE, "Unable to find " + className, e); ohair@286: } catch (IllegalAccessException e) { ohair@286: logger.log(Level.FINE, "Unable to find " + className, e); ohair@286: } catch (InvocationTargetException e) { ohair@286: Throwable t = e.getTargetException(); ohair@286: logger.log(Level.FINE, "Unable to find " + className, t); ohair@286: } ohair@286: ohair@286: if (c != null) { ohair@286: ohair@286: w.lock(); ohair@286: wlocked = true; ohair@286: ohair@286: classes.put(className, c); ohair@286: ohair@286: w.unlock(); ohair@286: wlocked = false; ohair@286: ohair@286: return c; ohair@286: } ohair@286: } ohair@286: ohair@286: if (c == null) { ohair@286: ohair@286: r.lock(); ohair@286: rlocked = true; ohair@286: ohair@286: c = classes.get(className); ohair@286: ohair@286: // Unlock now during the define/resolve process to avoid ohair@286: // deadlocks ohair@286: r.unlock(); ohair@286: rlocked = false; ohair@286: ohair@286: if (c == null) { ohair@286: ohair@286: // we need to inject a class into the ohair@286: try { ohair@286: c = (Class) defineClass.invoke(parent, className.replace('/', '.'), image, 0, image.length); ohair@286: resolveClass.invoke(parent, c); ohair@286: } catch (IllegalAccessException e) { ohair@286: logger.log(Level.FINE, "Unable to inject " + className, e); ohair@286: return null; ohair@286: } catch (InvocationTargetException e) { ohair@286: Throwable t = e.getTargetException(); ohair@286: if (t instanceof LinkageError) { ohair@286: logger.log(Level.FINE, "duplicate class definition bug occured? Please report this : " + className, t); ohair@286: } else { ohair@286: logger.log(Level.FINE, "Unable to inject " + className, t); ohair@286: } ohair@286: return null; ohair@286: } catch (SecurityException e) { ohair@286: logger.log(Level.FINE, "Unable to inject " + className, e); ohair@286: return null; ohair@286: } catch (LinkageError e) { ohair@286: logger.log(Level.FINE, "Unable to inject " + className, e); ohair@286: return null; ohair@286: } ohair@286: ohair@286: w.lock(); ohair@286: wlocked = true; ohair@286: ohair@286: // During the time we were unlocked, we could have tried to ohair@286: // load the class from more than one thread. Check now to see ohair@286: // if someone else beat us to registering this class ohair@286: if (!classes.containsKey(className)) { ohair@286: classes.put(className, c); ohair@286: } ohair@286: ohair@286: w.unlock(); ohair@286: wlocked = false; ohair@286: } ohair@286: } ohair@286: return c; ohair@286: } finally { ohair@286: if (rlocked) { ohair@286: r.unlock(); ohair@286: } ohair@286: if (wlocked) { ohair@286: w.unlock(); ohair@286: } ohair@286: } ohair@286: } ohair@286: ohair@286: private Class find(String className) { ohair@286: r.lock(); ohair@286: try { ohair@286: return classes.get(className); ohair@286: } finally { ohair@286: r.unlock(); ohair@286: } ohair@286: } ohair@286: }