/*
* Copyright 1999,2005 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.xmlrpc.common;
import java.util.ArrayList;
import java.util.List;
import org.apache.xmlrpc.XmlRpcLoadException;
import org.apache.xmlrpc.client.XmlRpcClientWorker;
/** A factory for {@link org.apache.xmlrpc.client.XmlRpcClientWorker}
* instances.
*/
public abstract class XmlRpcWorkerFactory {
private final XmlRpcWorker singleton = newWorker();
private final XmlRpcController controller;
private final List pool = new ArrayList();
private int numThreads;
/** Creates a new instance.
* @param pController The client controlling the factory.
*/
public XmlRpcWorkerFactory(XmlRpcController pController) {
controller = pController;
}
/** Creates a new worker instance.
* @return New instance of {@link XmlRpcClientWorker}.
*/
protected abstract XmlRpcWorker newWorker();
/** Returns the factory controller.
* @return The controller, an instance of
* {@link org.apache.xmlrpc.client.XmlRpcClient}, or
* {@link org.apache.xmlrpc.server.XmlRpcServer}.
*/
public XmlRpcController getController() {
return controller;
}
/** Returns a worker for synchronous processing.
* @return An instance of {@link XmlRpcClientWorker}, which is ready
* for use.
* @throws XmlRpcLoadException The clients maximum number of concurrent
* threads is exceeded.
*/
public synchronized XmlRpcWorker getWorker() throws XmlRpcLoadException {
int max = controller.getMaxThreads();
if (max > 0 && numThreads == max) {
throw new XmlRpcLoadException("Maximum number of concurrent requests exceeded: " + max);
}
++numThreads;
if (max == 0) {
return singleton;
}
if (pool.size() == 0) {
return newWorker();
} else {
return (XmlRpcClientWorker) pool.remove(pool.size() - 1);
}
}
/** Called, when the worker did its job. Frees resources and
* decrements the number of concurrent requests.
* @param pWorker The worker being released.
*/
public synchronized void releaseWorker(XmlRpcClientWorker pWorker) {
--numThreads;
int max = controller.getMaxThreads();
if (pWorker == singleton) {
// Do nothing, it's the singleton
} else {
if (pool.size() < max) {
pool.add(pWorker);
}
}
}
/** Returns the number of currently running requests.
* @return Current number of concurrent requests.
*/
public synchronized int getCurrentRequests() {
return numThreads;
}
}