/*
* 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 Reza Rahman
*/
package com.caucho.config.gen;
import static javax.ejb.ConcurrencyManagementType.CONTAINER;
import java.io.IOException;
import java.util.HashMap;
import java.util.concurrent.TimeUnit;
import javax.ejb.AccessTimeout;
import javax.ejb.ConcurrencyManagement;
import javax.ejb.Lock;
import javax.ejb.LockType;
import com.caucho.config.Configurable;
import com.caucho.config.types.Period;
import com.caucho.java.JavaWriter;
import com.caucho.util.L10N;
/**
* Represents EJB lock type specification interception. The specification gears
* it towards EJB singletons, but it can be used for other bean types.
*/
public class LockCallChain extends AbstractCallChain {
private static final int DEFAULT_TIMEOUT = 10000;
private EjbCallChain _next;
private boolean _isContainerManaged;
private LockType _lockType;
private long _lockTimeout;
private TimeUnit _lockTimeoutUnit;
public LockCallChain(BusinessMethodGenerator businessMethod, EjbCallChain next)
{
super(next);
_next = next;
_isContainerManaged = true;
_lockType = null;
_lockTimeout = DEFAULT_TIMEOUT;
_lockTimeoutUnit = TimeUnit.MILLISECONDS;
}
/**
* Sets the lock timeout.
*
* @param timeout
* The timeout period.
*/
@Configurable
public void setTimeout(Period timeout)
{
_lockTimeout = timeout.getPeriod();
}
/**
* Returns true if the business method has a lock annotation.
*/
@Override
public boolean isEnhanced()
{
return (_isContainerManaged && (_lockType != null));
}
/**
* Introspects the method for locking attributes.
*/
@Override
public void introspect(ApiMethod apiMethod, ApiMethod implementationMethod)
{
ApiClass apiClass = apiMethod.getDeclaringClass();
ConcurrencyManagement concurrencyManagementAnnotation
= apiClass.getAnnotation(ConcurrencyManagement.class);
if ((concurrencyManagementAnnotation != null)
&& (concurrencyManagementAnnotation.value() != CONTAINER)) {
_isContainerManaged = false;
return;
}
ApiClass implementationClass = null;
if (implementationMethod != null) {
implementationClass = implementationMethod.getDeclaringClass();
}
Lock lockAttribute = getAnnotation(Lock.class, apiMethod, apiClass,
implementationMethod, implementationClass);
if (lockAttribute != null) {
_lockType = lockAttribute.value();
}
AccessTimeout accessTimeoutAttribute
= getAnnotation(AccessTimeout.class,
apiMethod, apiClass,
implementationMethod, implementationClass);
if (accessTimeoutAttribute != null) {
_lockTimeout = accessTimeoutAttribute.timeout();
_lockTimeoutUnit = accessTimeoutAttribute.unit();
}
}
/**
* Generates the class prologue.
*/
@Override
public void generateMethodPrologue(JavaWriter out,
HashMap<String,Object> map)
throws IOException
{
if ((_isContainerManaged && (_lockType != null))
&& (map.get("caucho.ejb.lock") == null)) {
map.put("caucho.ejb.lock", "done");
out.println();
out.println("private transient final java.util.concurrent.locks.ReentrantReadWriteLock _readWriteLock = new java.util.concurrent.locks.ReentrantReadWriteLock();");
}
_next.generateMethodPrologue(out, map);
}
/**
* Generates the method interception code.
*/
@Override
public void generatePreTry(JavaWriter out) throws IOException
{
// TODO Is this too much code to be in-lined?
if (_isContainerManaged && (_lockType != null)) {
out.println();
switch (_lockType) {
case READ:
if (_lockTimeout != -1) {
out.println("com.caucho.config.util.LockUtil.lockRead("
+ "_readWriteLock.readLock(),"
+ _lockTimeoutUnit.toMillis(_lockTimeout)
+ ");");
} else {
out.println("_readWriteLock.readLock().lock();");
}
break;
case WRITE:
if (_lockTimeout != -1) {
out.println("com.caucho.config.util.LockUtil.lockWrite("
+ "_readWriteLock,"
+ _lockTimeoutUnit.toMillis(_lockTimeout)
+ ");");
} else {
out.println("com.caucho.config.util.LockUtil.lockWrite("
+ "_readWriteLock);");
}
break;
}
}
super.generatePreTry(out);
}
/**
* Generates the method interception code.
*/
@Override
public void generateFinally(JavaWriter out) throws IOException
{
super.generateFinally(out);
if (_isContainerManaged && (_lockType != null)) {
switch (_lockType) {
case READ:
out.println();
out.println("_readWriteLock.readLock().unlock();");
break;
case WRITE:
out.println();
out.println("_readWriteLock.writeLock().unlock();");
break;
}
}
}
protected void generateNext(JavaWriter out) throws IOException
{
_next.generateCall(out);
}
}