| /* |
| * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package com.sun.xml.internal.bind.v2.runtime.reflect.opt; |
| |
| import java.lang.reflect.InvocationTargetException; |
| import java.lang.reflect.Method; |
| import java.lang.ref.WeakReference; |
| import java.security.AccessController; |
| import java.security.PrivilegedAction; |
| import java.util.concurrent.locks.Lock; |
| import java.util.concurrent.locks.ReentrantReadWriteLock; |
| import java.util.HashMap; |
| import java.util.Map; |
| import java.util.WeakHashMap; |
| import java.util.logging.Level; |
| import java.util.logging.Logger; |
| |
| import com.sun.xml.internal.bind.Util; |
| import com.sun.xml.internal.bind.v2.runtime.reflect.Accessor; |
| import java.lang.reflect.Field; |
| import java.security.CodeSource; |
| import java.security.PrivilegedActionException; |
| import java.security.PrivilegedExceptionAction; |
| import java.security.ProtectionDomain; |
| |
| /** |
| * A {@link ClassLoader} used to "inject" optimized accessor classes |
| * into the VM. |
| * |
| * <p> |
| * Its parent class loader needs to be set to the one that can see the user |
| * class. |
| * |
| * @author Kohsuke Kawaguchi |
| */ |
| final class Injector { |
| |
| /** |
| * {@link Injector}s keyed by their parent {@link ClassLoader}. |
| * |
| * We only need one injector per one user class loader. |
| */ |
| private static final ReentrantReadWriteLock irwl = new ReentrantReadWriteLock(); |
| private static final Lock ir = irwl.readLock(); |
| private static final Lock iw = irwl.writeLock(); |
| private static final Map<ClassLoader, WeakReference<Injector>> injectors = |
| new WeakHashMap<ClassLoader, WeakReference<Injector>>(); |
| private static final Logger logger = Util.getClassLogger(); |
| |
| /** |
| * Injects a new class into the given class loader. |
| * |
| * @return null |
| * if it fails to inject. |
| */ |
| static Class inject(ClassLoader cl, String className, byte[] image) { |
| Injector injector = get(cl); |
| if (injector != null) { |
| return injector.inject(className, image); |
| } else { |
| return null; |
| } |
| } |
| |
| /** |
| * Returns the already injected class, or null. |
| */ |
| static Class find(ClassLoader cl, String className) { |
| Injector injector = get(cl); |
| if (injector != null) { |
| return injector.find(className); |
| } else { |
| return null; |
| } |
| } |
| |
| /** |
| * Gets or creates an {@link Injector} for the given class loader. |
| * |
| * @return null |
| * if it fails. |
| */ |
| private static Injector get(ClassLoader cl) { |
| Injector injector = null; |
| WeakReference<Injector> wr; |
| ir.lock(); |
| try { |
| wr = injectors.get(cl); |
| } finally { |
| ir.unlock(); |
| } |
| if (wr != null) { |
| injector = wr.get(); |
| } |
| if (injector == null) { |
| try { |
| wr = new WeakReference<Injector>(injector = new Injector(cl)); |
| iw.lock(); |
| try { |
| if (!injectors.containsKey(cl)) { |
| injectors.put(cl, wr); |
| } |
| } finally { |
| iw.unlock(); |
| } |
| } catch (SecurityException e) { |
| logger.log(Level.FINE, "Unable to set up a back-door for the injector", e); |
| return null; |
| } |
| } |
| return injector; |
| } |
| /** |
| * Injected classes keyed by their names. |
| */ |
| private final Map<String, Class> classes = new HashMap<>(); |
| private final ReentrantReadWriteLock rwl = new ReentrantReadWriteLock(); |
| private final Lock r = rwl.readLock(); |
| private final Lock w = rwl.writeLock(); |
| private final ClassLoader parent; |
| /** |
| * True if this injector is capable of injecting accessors. |
| * False otherwise, which happens if this classloader can't see {@link Accessor}. |
| */ |
| private final boolean loadable; |
| private static Method defineClass; |
| private static Method resolveClass; |
| private static Method findLoadedClass; |
| private static Object U; |
| |
| static { |
| try { |
| Method[] m = AccessController.doPrivileged( |
| new PrivilegedAction<Method[]>() { |
| @Override |
| public Method[] run() { |
| return new Method[]{ |
| getMethod(ClassLoader.class, "defineClass", String.class, byte[].class, Integer.TYPE, Integer.TYPE), |
| getMethod(ClassLoader.class, "resolveClass", Class.class), |
| getMethod(ClassLoader.class, "findLoadedClass", String.class) |
| }; |
| } |
| } |
| ); |
| defineClass = m[0]; |
| resolveClass = m[1]; |
| findLoadedClass = m[2]; |
| } catch (Throwable t) { |
| try { |
| U = AccessController.doPrivileged(new PrivilegedExceptionAction() { |
| @Override |
| public Object run() throws Exception { |
| Class u = Class.forName("sun.misc.Unsafe"); |
| Field theUnsafe = u.getDeclaredField("theUnsafe"); |
| theUnsafe.setAccessible(true); |
| return theUnsafe.get(null); |
| } |
| }); |
| defineClass = AccessController.doPrivileged(new PrivilegedExceptionAction<Method>() { |
| @Override |
| public Method run() throws Exception { |
| try { |
| return U.getClass().getMethod("defineClass", |
| new Class[]{String.class, |
| byte[].class, |
| Integer.TYPE, |
| Integer.TYPE, |
| ClassLoader.class, |
| ProtectionDomain.class}); |
| } catch (NoSuchMethodException | SecurityException ex) { |
| throw ex; |
| } |
| } |
| }); |
| } catch (SecurityException | PrivilegedActionException ex) { |
| Logger.getLogger(Injector.class.getName()).log(Level.SEVERE, null, ex); |
| } |
| } |
| } |
| |
| private static Method getMethod(final Class<?> c, final String methodname, final Class<?>... params) { |
| try { |
| Method m = c.getDeclaredMethod(methodname, params); |
| m.setAccessible(true); |
| return m; |
| } catch (NoSuchMethodException e) { |
| throw new NoSuchMethodError(e.getMessage()); |
| } |
| } |
| |
| private Injector(ClassLoader parent) { |
| this.parent = parent; |
| assert parent != null; |
| |
| boolean loadableCheck = false; |
| |
| try { |
| loadableCheck = parent.loadClass(Accessor.class.getName()) == Accessor.class; |
| } catch (ClassNotFoundException e) { |
| // not loadable |
| } |
| |
| this.loadable = loadableCheck; |
| } |
| |
| @SuppressWarnings("LockAcquiredButNotSafelyReleased") |
| private Class inject(String className, byte[] image) { |
| if (!loadable) // this injector cannot inject anything |
| { |
| return null; |
| } |
| |
| boolean wlocked = false; |
| boolean rlocked = false; |
| try { |
| |
| r.lock(); |
| rlocked = true; |
| |
| Class c = classes.get(className); |
| |
| // Unlock now during the findLoadedClass process to avoid |
| // deadlocks |
| r.unlock(); |
| rlocked = false; |
| |
| //find loaded class from classloader |
| if (c == null && findLoadedClass != null) { |
| |
| try { |
| c = (Class) findLoadedClass.invoke(parent, className.replace('/', '.')); |
| } catch (IllegalArgumentException | IllegalAccessException e) { |
| logger.log(Level.FINE, "Unable to find " + className, e); |
| } catch (InvocationTargetException e) { |
| Throwable t = e.getTargetException(); |
| logger.log(Level.FINE, "Unable to find " + className, t); |
| } |
| |
| if (c != null) { |
| |
| w.lock(); |
| wlocked = true; |
| |
| classes.put(className, c); |
| |
| w.unlock(); |
| wlocked = false; |
| |
| return c; |
| } |
| } |
| |
| if (c == null) { |
| |
| r.lock(); |
| rlocked = true; |
| |
| c = classes.get(className); |
| |
| // Unlock now during the define/resolve process to avoid |
| // deadlocks |
| r.unlock(); |
| rlocked = false; |
| |
| if (c == null) { |
| |
| // we need to inject a class into the |
| try { |
| if (resolveClass != null) { |
| c = (Class) defineClass.invoke(parent, className.replace('/', '.'), image, 0, image.length); |
| resolveClass.invoke(parent, c); |
| } else { |
| c = (Class) defineClass.invoke(U, className.replace('/', '.'), image, 0, image.length, parent, Injector.class.getProtectionDomain()); |
| } |
| } catch (IllegalAccessException e) { |
| logger.log(Level.FINE, "Unable to inject " + className, e); |
| return null; |
| } catch (InvocationTargetException e) { |
| Throwable t = e.getTargetException(); |
| if (t instanceof LinkageError) { |
| logger.log(Level.FINE, "duplicate class definition bug occured? Please report this : " + className, t); |
| } else { |
| logger.log(Level.FINE, "Unable to inject " + className, t); |
| } |
| return null; |
| } catch (SecurityException e) { |
| logger.log(Level.FINE, "Unable to inject " + className, e); |
| return null; |
| } catch (LinkageError e) { |
| logger.log(Level.FINE, "Unable to inject " + className, e); |
| return null; |
| } |
| |
| w.lock(); |
| wlocked = true; |
| |
| // During the time we were unlocked, we could have tried to |
| // load the class from more than one thread. Check now to see |
| // if someone else beat us to registering this class |
| if (!classes.containsKey(className)) { |
| classes.put(className, c); |
| } |
| |
| w.unlock(); |
| wlocked = false; |
| } |
| } |
| return c; |
| } finally { |
| if (rlocked) { |
| r.unlock(); |
| } |
| if (wlocked) { |
| w.unlock(); |
| } |
| } |
| } |
| |
| private Class find(String className) { |
| r.lock(); |
| try { |
| return classes.get(className); |
| } finally { |
| r.unlock(); |
| } |
| } |
| } |