org.jboss.as.ejb3.component.singleton.SingletonComponent Maven / Gradle / Ivy
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/*
* JBoss, Home of Professional Open Source.
* Copyright 2010, Red Hat, Inc., and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.as.ejb3.component.singleton;
import java.lang.reflect.Method;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.List;
import java.util.Map;
import java.util.concurrent.atomic.AtomicReference;
import javax.ejb.LockType;
import org.jboss.as.ee.component.BasicComponentInstance;
import org.jboss.as.ee.component.Component;
import org.jboss.as.ejb3.component.DefaultAccessTimeoutService;
import org.jboss.as.ejb3.component.EJBBusinessMethod;
import org.jboss.as.ejb3.component.allowedmethods.AllowedMethodsInformation;
import org.jboss.as.ejb3.component.session.SessionBeanComponent;
import org.jboss.as.ejb3.concurrency.AccessTimeoutDetails;
import org.jboss.as.ejb3.concurrency.LockableComponent;
import org.jboss.as.naming.ManagedReference;
import org.jboss.as.server.CurrentServiceContainer;
import org.jboss.invocation.Interceptor;
import org.jboss.invocation.InterceptorFactoryContext;
import org.jboss.msc.service.ServiceContainer;
import org.jboss.msc.service.ServiceController;
import org.jboss.msc.service.ServiceName;
import static org.jboss.as.ejb3.EjbLogger.ROOT_LOGGER;
import static org.jboss.as.ejb3.EjbMessages.MESSAGES;
/**
* {@link Component} representing a {@link javax.ejb.Singleton} EJB.
*
* @author Jaikiran Pai
*/
public class SingletonComponent extends SessionBeanComponent implements LockableComponent {
private volatile SingletonComponentInstance singletonComponentInstance;
private final boolean initOnStartup;
private final Map beanLevelLockType;
private final Map methodLockTypes;
private final Map methodAccessTimeouts;
private final List dependsOn;
private final DefaultAccessTimeoutService defaultAccessTimeoutProvider;
/**
* We can't lock on this because the {@link org.jboss.as.ee.component.BasicComponent#waitForComponentStart()}
* also synchronizes on it, and calls {@link #wait()}.
*/
private final Object creationLock = new Object();
/**
* Construct a new instance.
*
* @param singletonComponentCreateService
* the component configuration
* @param dependsOn
*/
public SingletonComponent(final SingletonComponentCreateService singletonComponentCreateService, final List dependsOn) {
super(singletonComponentCreateService);
this.dependsOn = dependsOn;
this.initOnStartup = singletonComponentCreateService.isInitOnStartup();
this.beanLevelLockType = singletonComponentCreateService.getBeanLockType();
this.methodLockTypes = singletonComponentCreateService.getMethodApplicableLockTypes();
this.methodAccessTimeouts = singletonComponentCreateService.getMethodApplicableAccessTimeouts();
this.defaultAccessTimeoutProvider = singletonComponentCreateService.getDefaultAccessTimeoutService();
}
@Override
protected BasicComponentInstance instantiateComponentInstance(AtomicReference instanceReference, Interceptor preDestroyInterceptor, Map methodInterceptors, final InterceptorFactoryContext interceptorContext) {
// synchronized from getComponentInstance
assert Thread.holdsLock(creationLock);
if (dependsOn != null) {
for (ServiceName serviceName : dependsOn) {
final ServiceController service = (ServiceController) currentServiceContainer().getRequiredService(serviceName);
final Component component = service.getValue();
if (component instanceof SingletonComponent) {
((SingletonComponent) component).getComponentInstance();
}
}
}
return new SingletonComponentInstance(this, instanceReference, preDestroyInterceptor, methodInterceptors);
}
/**
* @return the {@link SingletonComponentInstance}, lazily creating it if necessary.
*/
public SingletonComponentInstance getComponentInstance() {
if (this.singletonComponentInstance == null) {
// Protects from re-entry which can happen if {@link PostConstruct} annotated methods pass a
// view (from {@link SessionContext#getBusinessObject(Class)}) of itself to other EJBs
if (Thread.holdsLock(creationLock))
throw MESSAGES.reentrantSingletonCreation(getComponentName(), getComponentClass().getName());
synchronized (creationLock) {
if (this.singletonComponentInstance == null) {
this.singletonComponentInstance = (SingletonComponentInstance) this.createInstance();
}
}
}
return this.singletonComponentInstance;
}
@Override
public void start() {
getShutDownInterceptorFactory().start();
super.start();
if (this.initOnStartup) {
// Do not call createInstance() because we can't ever assume that the singleton instance
// hasn't already been created.
ROOT_LOGGER.debug(this.getComponentName() + " bean is a @Startup (a.k.a init-on-startup) bean, creating/getting the singleton instance");
this.getComponentInstance();
}
}
@Override
public void stop() {
getShutDownInterceptorFactory().shutdown();
this.destroySingletonInstance();
super.stop();
}
@Override
public LockType getLockType(Method method) {
final EJBBusinessMethod ejbMethod = new EJBBusinessMethod(method);
final LockType lockType = this.methodLockTypes.get(ejbMethod);
if (lockType != null) {
return lockType;
}
// check bean level lock type
final LockType type = this.beanLevelLockType.get(method.getDeclaringClass().getName());
if (type != null) {
return type;
}
// default WRITE lock type
return LockType.WRITE;
}
@Override
public AccessTimeoutDetails getAccessTimeout(Method method) {
final EJBBusinessMethod ejbMethod = new EJBBusinessMethod(method);
final AccessTimeoutDetails accessTimeout = this.methodAccessTimeouts.get(ejbMethod);
if (accessTimeout != null) {
return accessTimeout;
}
// check bean level access timeout
final AccessTimeoutDetails beanTimeout = this.beanLevelAccessTimeout.get(method.getDeclaringClass().getName());
if (beanTimeout != null) {
return beanTimeout;
}
return getDefaultAccessTimeout();
}
@Override
public AccessTimeoutDetails getDefaultAccessTimeout() {
return defaultAccessTimeoutProvider.getDefaultAccessTimeout();
}
private void destroySingletonInstance() {
synchronized (creationLock) {
if (this.singletonComponentInstance != null) {
singletonComponentInstance.destroy();
this.singletonComponentInstance = null;
}
}
}
@Override
public AllowedMethodsInformation getAllowedMethodsInformation() {
return SingletonAllowedMethodsInformation.INSTANCE;
}
private static ServiceContainer currentServiceContainer() {
return AccessController.doPrivileged(new PrivilegedAction() {
@Override
public ServiceContainer run() {
return CurrentServiceContainer.getServiceContainer();
}
});
}
}