/*
* Copyright (c) 1998-2010 Caucho Technology -- all rights reserved
*
* This file is part of Resin(R) Open Source
*
* Each copy or derived work must preserve the copyright notice and this
* notice unmodified.
*
* Resin Open Source is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* Resin Open Source 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, or any warranty
* of NON-INFRINGEMENT. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with Resin Open Source; if not, write to the
*
* Free Software Foundation, Inc.
* 59 Temple Place, Suite 330
* Boston, MA 02111-1307 USA
*
* @author Scott Ferguson
*/
package com.caucho.loader;
import java.lang.reflect.Constructor;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.ArrayList;
import java.util.Hashtable;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.AtomicReference;
import java.util.logging.Level;
import java.util.logging.Logger;
import com.caucho.config.ConfigException;
import com.caucho.lifecycle.Lifecycle;
import com.caucho.loader.enhancer.ScanListener;
import com.caucho.loader.enhancer.ScanManager;
import com.caucho.loader.module.ArtifactManager;
import com.caucho.management.server.EnvironmentMXBean;
import com.caucho.util.ResinThreadPoolExecutor;
/**
* Class loader which checks for changes in class files and automatically
* picks up new jars.
*
* <p>DynamicClassLoaders can be chained creating one virtual class loader.
* From the perspective of the JDK, it's all one classloader. Internally,
* the class loader chain searches like a classpath.
*/
public class EnvironmentClassLoader extends DynamicClassLoader
{
private static Logger _log;
private static final Object _childListenerLock = new Object();
// listeners invoked at the start of any child environment
private static EnvironmentLocal<ArrayList<EnvironmentListener>> _childListeners;
// listeners invoked when a Loader is added
private static EnvironmentLocal<ArrayList<AddLoaderListener>> _addLoaderListeners;
// The owning bean
private EnvironmentBean _owner;
// Class loader specific attributes
private ConcurrentHashMap<String,Object> _attributes
= new ConcurrentHashMap<String,Object>(8);
private ArrayList<ScanListener> _scanListeners;
private ArrayList<ScanRoot> _pendingScanRoots = new ArrayList<ScanRoot>();
private AtomicReference<ArtifactManager> _artifactManagerRef
= new AtomicReference<ArtifactManager>();
private ArtifactManager _artifactManager;
// Array of listeners
// server/306i - can't be weak reference, instead create WeakStopListener
private ArrayList<EnvironmentListener> _listeners
= new ArrayList<EnvironmentListener>();
private WeakStopListener _stopListener;
// The state of the environment
private volatile Lifecycle _lifecycle = new Lifecycle();
private boolean _isConfigComplete;
private EnvironmentAdmin _admin;
private Throwable _configException;
/**
* Creates a new environment class loader.
*/
protected EnvironmentClassLoader(ClassLoader parent, String id)
{
super(parent);
if (id != null)
setId(id);
// initializeEnvironment();
initListeners();
}
/**
* Creates a new environment class loader.
*/
public static EnvironmentClassLoader create()
{
ClassLoader parent = Thread.currentThread().getContextClassLoader();
String id = null;
return create(parent, id);
}
/**
* Creates a new environment class loader.
*/
public static EnvironmentClassLoader create(String id)
{
ClassLoader parent = Thread.currentThread().getContextClassLoader();
return create(parent, id);
}
/**
* Creates a new environment class loader.
*/
public static EnvironmentClassLoader create(ClassLoader parent)
{
String id = null;
return create(parent, id);
}
/**
* Creates a new environment class loader.
*/
public static EnvironmentClassLoader create(ClassLoader parent, String id)
{
String className = System.getProperty("caucho.environment.class.loader");
if (className != null) {
try {
Class<?> cl = Thread.currentThread().getContextClassLoader().loadClass(className);
Constructor<?> ctor = cl.getConstructor(new Class[] { ClassLoader.class, String.class});
Object instance = ctor.newInstance(parent, id);
return (EnvironmentClassLoader) instance;
}
catch (Exception e) {
e.printStackTrace();
}
}
return new EnvironmentClassLoader(parent, id);
}
/**
* Returns the environment's owner.
*/
public EnvironmentBean getOwner()
{
return _owner;
}
/**
* Sets the environment's owner.
*/
public void setOwner(EnvironmentBean owner)
{
_owner = owner;
}
/**
* Sets the config exception.
*/
public void setConfigException(Throwable e)
{
if (_configException == null)
_configException = e;
}
/**
* Gets the config exception.
*/
public Throwable getConfigException()
{
return _configException;
}
/**
* Returns true if the environment is active
*/
public boolean isActive()
{
return _lifecycle.isActive();
}
/**
* Returns the admin
*/
public EnvironmentMXBean getAdmin()
{
return _admin;
}
/**
* Initialize the environment.
*/
@Override
public void init()
{
super.init();
initEnvironment();
}
protected void initEnvironment()
{
}
/**
* Returns the named attributes
*/
public Object getAttribute(String name)
{
if (_attributes != null)
return _attributes.get(name);
else
return null;
}
/**
* Sets the named attributes
*/
public Object setAttribute(String name, Object obj)
{
if (obj == null) {
if (_attributes == null)
return null;
else
return _attributes.remove(name);
}
if (_attributes == null)
_attributes = new ConcurrentHashMap<String,Object>(8);
return _attributes.put(name, obj);
}
/**
* Sets the named attributes
*/
public Object putIfAbsent(String name, Object obj)
{
if (obj == null)
throw new NullPointerException();
if (_attributes == null)
_attributes = new ConcurrentHashMap<String,Object>(8);
return _attributes.putIfAbsent(name, obj);
}
/**
* Removes the named attributes
*/
public Object removeAttribute(String name)
{
if (_attributes == null)
return null;
else
return _attributes.remove(name);
}
/**
* Adds a listener to detect environment lifecycle changes.
*/
public void addListener(EnvironmentListener listener)
{
synchronized (_listeners) {
for (int i = _listeners.size() - 1; i >= 0; i--) {
EnvironmentListener oldListener = _listeners.get(i);
if (listener == oldListener) {
return;
}
else if (oldListener == null)
_listeners.remove(i);
}
_listeners.add(listener);
}
if (_lifecycle.isStarting()) {
listener.environmentBind(this);
}
if (_lifecycle.isStarting() && _isConfigComplete) {
listener.environmentStart(this);
}
}
/**
* Adds self as a listener.
*/
private void initListeners()
{
ClassLoader parent = getParent();
for (; parent != null; parent = parent.getParent()) {
if (parent instanceof EnvironmentClassLoader) {
EnvironmentClassLoader loader = (EnvironmentClassLoader) parent;
if (_stopListener == null)
_stopListener = new WeakStopListener(this);
loader.addListener(_stopListener);
return;
}
}
}
/**
* Adds a listener to detect environment lifecycle changes.
*/
public void removeListener(EnvironmentListener listener)
{
if (_listeners == null)
return;
synchronized (_listeners) {
for (int i = _listeners.size() - 1; i >= 0; i--) {
EnvironmentListener oldListener = _listeners.get(i);
if (listener == oldListener) {
_listeners.remove(i);
return;
}
else if (oldListener == null)
_listeners.remove(i);
}
}
}
/**
* Adds a child listener.
*/
void addChildListener(EnvironmentListener listener)
{
synchronized (_childListenerLock) {
if (_childListeners == null)
_childListeners = new EnvironmentLocal<ArrayList<EnvironmentListener>>();
ArrayList<EnvironmentListener> listeners
= _childListeners.getLevel(this);
if (listeners == null) {
listeners = new ArrayList<EnvironmentListener>();
_childListeners.set(listeners, this);
}
listeners.add(listener);
}
if (_lifecycle.isStarting() && _isConfigComplete) {
listener.environmentStart(this);
}
}
/**
* Removes a child listener.
*/
void removeChildListener(EnvironmentListener listener)
{
synchronized (_childListenerLock) {
if (_childListeners == null)
return;
ArrayList<EnvironmentListener> listeners
= _childListeners.getLevel(this);
if (listeners != null)
listeners.remove(listener);
}
}
/**
* Returns the listeners.
*/
protected ArrayList<EnvironmentListener> getEnvironmentListeners()
{
ArrayList<EnvironmentListener> listeners;
listeners = new ArrayList<EnvironmentListener>();
// add the descendant listeners
if (_childListeners != null) {
synchronized (_childListenerLock) {
ClassLoader loader;
for (loader = this; loader != null; loader = loader.getParent()) {
if (loader instanceof EnvironmentClassLoader) {
ArrayList<EnvironmentListener> childListeners;
childListeners = _childListeners.getLevel(loader);
if (childListeners != null)
listeners.addAll(childListeners);
}
}
}
}
if (_listeners == null)
return listeners;
synchronized (_listeners) {
for (int i = 0; i < _listeners.size(); i++) {
EnvironmentListener listener = _listeners.get(i);
if (listener != null)
listeners.add(listener);
else {
_listeners.remove(i);
i--;
}
}
}
return listeners;
}
/**
* Adds a child listener.
*/
public void addLoaderListener(AddLoaderListener listener)
{
synchronized (_childListenerLock) {
if (_addLoaderListeners == null)
_addLoaderListeners = new EnvironmentLocal<ArrayList<AddLoaderListener>>();
ArrayList<AddLoaderListener> listeners
= _addLoaderListeners.getLevel(this);
if (listeners == null) {
listeners = new ArrayList<AddLoaderListener>();
_addLoaderListeners.set(listeners, this);
}
if (! listeners.contains(listener)) {
listeners.add(listener);
}
}
listener.addLoader(this);
}
/**
* Returns the listeners.
*/
protected ArrayList<AddLoaderListener> getLoaderListeners()
{
ArrayList<AddLoaderListener> listeners;
listeners = new ArrayList<AddLoaderListener>();
if (_addLoaderListeners == null)
return listeners;
// add the descendent listeners
synchronized (_childListenerLock) {
ClassLoader loader;
for (loader = this; loader != null; loader = loader.getParent()) {
if (loader instanceof EnvironmentClassLoader) {
ArrayList<AddLoaderListener> childListeners;
childListeners = _addLoaderListeners.getLevel(loader);
if (childListeners != null)
listeners.addAll(childListeners);
}
}
}
return listeners;
}
/**
* Adds a listener to detect class loader changes.
*/
@Override
protected void configureEnhancerEvent()
{
ArrayList<AddLoaderListener> listeners = getLoaderListeners();
for (int i = 0;
listeners != null && i < listeners.size();
i++) {
AddLoaderListener listener = listeners.get(i);
if (listener.isEnhancer())
listeners.get(i).addLoader(this);
}
}
/**
* Adds a listener to detect class loader changes.
*/
@Override
protected void configurePostEnhancerEvent()
{
ArrayList<AddLoaderListener> listeners = getLoaderListeners();
for (int i = 0;
listeners != null && i < listeners.size();
i++) {
AddLoaderListener listener = listeners.get(i);
if (! listener.isEnhancer())
listeners.get(i).addLoader(this);
}
}
/**
* Adds the URL to the URLClassLoader.
*/
@Override
public void addURL(URL url)
{
if (containsURL(url))
return;
super.addURL(url);
_pendingScanRoots.add(new ScanRoot(url, null));
}
/**
* Adds a virtual module root for scanning.
*
* @param rootPackage
*/
public void addScanPackage(URL url, String rootPackage)
{
if (! containsURL(url)) {
super.addURL(url);
}
_pendingScanRoots.add(new ScanRoot(url, rootPackage));
sendAddLoaderEvent();
}
/**
* Tells the classloader to scan the root classpath.
*/
@Override
public void scanRoot()
{
super.scanRoot();
ClassLoader parent = getParent();
if (parent instanceof EnvironmentClassLoader)
return;
if (parent instanceof URLClassLoader) {
URLClassLoader urlParent = (URLClassLoader) parent;
for (URL url : urlParent.getURLs()) {
String name = url.toString();
if (name.endsWith(".jar")) {
_pendingScanRoots.add(new ScanRoot(url, null));
}
}
return;
}
}
/**
* Adds a scan listener.
*/
public void addScanListener(ScanListener listener)
{
if (_scanListeners == null)
_scanListeners = new ArrayList<ScanListener>();
int i = 0;
for (; i < _scanListeners.size(); i++) {
if (listener.getScanPriority() < _scanListeners.get(i).getScanPriority())
break;
}
_scanListeners.add(i, listener);
ArrayList<URL> urlList = new ArrayList<URL>();
for (URL url : getURLs()) {
if (isScanRootAvailable(url))
urlList.add(url);
}
if (urlList.size() > 0) {
try {
make();
} catch (Exception e) {
log().log(Level.WARNING, e.toString(), e);
if (_configException == null)
_configException = e;
}
ArrayList<ScanListener> selfList = new ArrayList<ScanListener>();
selfList.add(listener);
ScanManager scanManager = new ScanManager(selfList);
for (URL url : urlList) {
scanManager.scan(this, url, null);
}
}
}
private boolean isScanRootAvailable(URL url)
{
for (ScanRoot scanRoot : _pendingScanRoots) {
if (url.equals(scanRoot.getUrl()))
return false;
}
return true;
}
/**
* Returns the artifact manager
*/
public ArtifactManager createArtifactManager()
{
if (_artifactManager == null) {
ArtifactManager manager = new ArtifactManager(this);
_artifactManagerRef.compareAndSet(null, manager);
_artifactManager = _artifactManagerRef.get();
}
return _artifactManager;
}
/**
* Returns the artifact manager
*/
public ArtifactManager getArtifactManager()
{
return _artifactManager;
}
/**
* Returns any import class, e.g. from an artifact
*/
@Override
protected Class<?> findImportClass(String name)
{
if (_artifactManager != null)
return _artifactManager.findImportClass(name);
else
return null;
}
/**
* Get resource from an artifact
*/
@Override
protected URL getImportResource(String name)
{
if (_artifactManager != null)
return _artifactManager.getImportResource(name);
else
return null;
}
@Override
protected void buildImportClassPath(ArrayList<String> cp)
{
if (_artifactManager != null)
_artifactManager.buildImportClassPath(cp);
}
/**
* Applies the action to all visible environment modules. The
* action may apply to the same environment more than once.
*/
public void applyVisibleModules(EnvironmentApply apply)
{
apply.apply(this);
for (ClassLoader parent = getParent();
parent != null;
parent = parent.getParent()) {
if (parent instanceof EnvironmentClassLoader) {
EnvironmentClassLoader env = (EnvironmentClassLoader) parent;
env.applyVisibleModules(apply);
break;
}
}
if (_artifactManager != null)
_artifactManager.applyVisibleModules(apply);
}
/**
* Called when the <class-loader> completes.
*/
@Override
public void validate()
{
super.validate();
}
@Override
public void scan()
{
configureEnhancerEvent();
ArrayList<ScanRoot> rootList = new ArrayList<ScanRoot>(_pendingScanRoots);
_pendingScanRoots.clear();
try {
int rootListSize = rootList.size();
if (_scanListeners != null && rootListSize > 0) {
try {
make();
} catch (Exception e) {
log().log(Level.WARNING, e.toString(), e);
if (_configException == null)
_configException = e;
}
ScanManager scanManager = new ScanManager(_scanListeners);
for (int i = 0; i < rootListSize; i++) {
ScanRoot root = rootList.get(i);
scanManager.scan(this, root.getUrl(), root.getPackageName());
}
}
// configureEnhancerEvent();
} catch (Exception e) {
if (_configException == null)
_configException = e;
throw ConfigException.create(e);
}
}
/**
* Starts the config phase of the environment.
*/
private void config()
{
sendAddLoaderEvent();
ArrayList<EnvironmentListener> listeners = getEnvironmentListeners();
int size = listeners.size();
for (int i = 0; listeners != null && i < size; i++) {
EnvironmentListener listener = listeners.get(i);
if (listener instanceof EnvironmentEnhancerListener) {
EnvironmentEnhancerListener enhancerListener
= (EnvironmentEnhancerListener) listener;
enhancerListener.environmentConfigureEnhancer(this);
}
}
for (int i = 0; listeners != null && i < size; i++) {
EnvironmentListener listener = listeners.get(i);
listener.environmentConfigure(this);
}
// _isConfigComplete = true;
}
/**
* Starts the config phase of the environment.
*/
private void bind()
{
config();
ArrayList<EnvironmentListener> listeners = getEnvironmentListeners();
int size = listeners.size();
for (int i = 0; listeners != null && i < size; i++) {
EnvironmentListener listener = listeners.get(i);
listener.environmentBind(this);
}
_isConfigComplete = true;
}
/**
* Marks the environment of the class loader as started. The
* class loader itself doesn't use this, but a callback might.
*/
public void start()
{
if (! _lifecycle.toStarting()) {
startListeners();
return;
}
sendAddLoaderEvent();
bind();
if (_artifactManager != null)
_artifactManager.start();
startListeners();
_admin = new EnvironmentAdmin(this);
_admin.register();
_lifecycle.toActive();
}
private void startListeners()
{
ArrayList<EnvironmentListener> listeners = getEnvironmentListeners();
int size = listeners.size();
for (int i = 0; listeners != null && i < size; i++) {
EnvironmentListener listener = listeners.get(i);
listener.environmentStart(this);
}
}
/**
* Stops the environment, closing down any resources.
*
* The resources are closed in the reverse order that they're started
*/
@Override
public void stop()
{
if (! _lifecycle.toDestroy())
return;
ArrayList<EnvironmentListener> listeners = getEnvironmentListeners();
Thread thread = Thread.currentThread();
ClassLoader oldLoader = thread.getContextClassLoader();
thread.setContextClassLoader(this);
try {
// closing down in reverse
if (listeners != null) {
for (int i = listeners.size() - 1; i >= 0; i--) {
EnvironmentListener listener = listeners.get(i);
try {
listener.environmentStop(this);
} catch (Throwable e) {
log().log(Level.WARNING, e.toString(), e);
}
}
}
} finally {
thread.setContextClassLoader(oldLoader);
// drain the thread pool for GC
ResinThreadPoolExecutor.getThreadPool().stopEnvironment(this);
}
}
/**
* Destroys the class loader.
*/
@Override
public void destroy()
{
try {
WeakStopListener stopListener = _stopListener;
_stopListener = null;
// make sure it's stopped first
stop();
super.destroy();
ClassLoader parent = getParent();
for (; parent != null; parent = parent.getParent()) {
if (parent instanceof EnvironmentClassLoader) {
EnvironmentClassLoader loader = (EnvironmentClassLoader) parent;
loader.removeListener(stopListener);
}
}
} finally {
_owner = null;
_attributes = null;
_listeners = null;
_scanListeners = null;
_artifactManager = null;
_stopListener = null;
EnvironmentAdmin admin = _admin;
_admin = null;
if (admin != null)
admin.unregister();
}
}
@Override
public String toString()
{
StringBuilder sb = new StringBuilder();
sb.append(getClass().getSimpleName());
sb.append("[");
sb.append(getId());
if (! _lifecycle.isActive()) {
sb.append(",");
sb.append(_lifecycle.getStateName());
}
sb.append("]");
return sb.toString();
}
private static final Logger log()
{
if (_log == null)
_log = Logger.getLogger(EnvironmentClassLoader.class.getName());
return _log;
}
static class ScanRoot {
private final URL _url;
private final String _pkg;
ScanRoot(URL url, String pkg)
{
_url = url;
_pkg = pkg;
}
URL getUrl()
{
return _url;
}
String getPackageName()
{
return _pkg;
}
@Override
public String toString()
{
return getClass().getSimpleName() + "[" + _url + "," + _pkg + "]";
}
}
}