/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.activemq.jms.pool;
import java.util.List;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.atomic.AtomicBoolean;
import javax.jms.Connection;
import javax.jms.IllegalStateException;
import javax.jms.JMSException;
import javax.jms.Session;
import org.apache.commons.pool.KeyedPoolableObjectFactory;
import org.apache.commons.pool.impl.GenericKeyedObjectPool;
import org.apache.commons.pool.impl.GenericObjectPool;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Holds a real JMS connection along with the session pools associated with it.
* <p/>
* Instances of this class are shared amongst one or more PooledConnection object and must
* track the session objects that are loaned out for cleanup on close as well as ensuring
* that the temporary destinations of the managed Connection are purged when all references
* to this ConnectionPool are released.
*/
public class ConnectionPool {
private static final transient Logger LOG = LoggerFactory.getLogger(ConnectionPool.class);
protected Connection connection;
private int referenceCount;
private long lastUsed = System.currentTimeMillis();
private final long firstUsed = lastUsed;
private boolean hasExpired;
private int idleTimeout = 30 * 1000;
private long expiryTimeout = 0l;
private boolean useAnonymousProducers = true;
private final AtomicBoolean started = new AtomicBoolean(false);
private final GenericKeyedObjectPool<SessionKey, PooledSession> sessionPool;
private final List<PooledSession> loanedSessions = new CopyOnWriteArrayList<PooledSession>();
public ConnectionPool(Connection connection) {
this.connection = wrap(connection);
// Create our internal Pool of session instances.
this.sessionPool = new GenericKeyedObjectPool<SessionKey, PooledSession>(
new KeyedPoolableObjectFactory<SessionKey, PooledSession>() {
@Override
public void activateObject(SessionKey key, PooledSession session) throws Exception {
ConnectionPool.this.loanedSessions.add(session);
}
@Override
public void destroyObject(SessionKey key, PooledSession session) throws Exception {
ConnectionPool.this.loanedSessions.remove(session);
session.getInternalSession().close();
}
@Override
public PooledSession makeObject(SessionKey key) throws Exception {
Session session = makeSession(key);
return new PooledSession(key, session, sessionPool, key.isTransacted(), useAnonymousProducers);
}
@Override
public void passivateObject(SessionKey key, PooledSession session) throws Exception {
ConnectionPool.this.loanedSessions.remove(session);
}
@Override
public boolean validateObject(SessionKey key, PooledSession session) {
return true;
}
}
);
}
// useful when external failure needs to force expiry
public void setHasExpired(boolean val) {
hasExpired = val;
}
protected Session makeSession(SessionKey key) throws JMSException {
return connection.createSession(key.isTransacted(), key.getAckMode());
}
protected Connection wrap(Connection connection) {
return connection;
}
protected void unWrap(Connection connection) {
}
public void start() throws JMSException {
if (started.compareAndSet(false, true)) {
try {
connection.start();
} catch (JMSException e) {
started.set(false);
throw(e);
}
}
}
public synchronized Connection getConnection() {
return connection;
}
public Session createSession(boolean transacted, int ackMode) throws JMSException {
SessionKey key = new SessionKey(transacted, ackMode);
PooledSession session;
try {
session = sessionPool.borrowObject(key);
} catch (Exception e) {
IllegalStateException illegalStateException = new IllegalStateException(e.toString());
illegalStateException.initCause(e);
throw illegalStateException;
}
return session;
}
public synchronized void close() {
if (connection != null) {
try {
sessionPool.close();
} catch (Exception e) {
} finally {
try {
connection.close();
} catch (Exception e) {
} finally {
connection = null;
}
}
}
}
public synchronized void incrementReferenceCount() {
referenceCount++;
lastUsed = System.currentTimeMillis();
}
public synchronized void decrementReferenceCount() {
referenceCount--;
lastUsed = System.currentTimeMillis();
if (referenceCount == 0) {
// Loaned sessions are those that are active in the sessionPool and
// have not been closed by the client before closing the connection.
// These need to be closed so that all session's reflect the fact
// that the parent Connection is closed.
for (PooledSession session : this.loanedSessions) {
try {
session.close();
} catch (Exception e) {
}
}
this.loanedSessions.clear();
unWrap(getConnection());
expiredCheck();
}
}
/**
* Determines if this Connection has expired.
* <p/>
* A ConnectionPool is considered expired when all references to it are released AND either
* the configured idleTimeout has elapsed OR the configured expiryTimeout has elapsed.
* Once a ConnectionPool is determined to have expired its underlying Connection is closed.
*
* @return true if this connection has expired.
*/
public synchronized boolean expiredCheck() {
boolean expired = false;
if (connection == null) {
return true;
}
if (hasExpired) {
if (referenceCount == 0) {
close();
expired = true;
}
}
if (expiryTimeout > 0 && System.currentTimeMillis() > firstUsed + expiryTimeout) {
hasExpired = true;
if (referenceCount == 0) {
close();
expired = true;
}
}
// Only set hasExpired here is no references, as a Connection with references is by
// definition not idle at this time.
if (referenceCount == 0 && idleTimeout > 0 && System.currentTimeMillis() > lastUsed + idleTimeout) {
hasExpired = true;
close();
expired = true;
}
return expired;
}
public int getIdleTimeout() {
return idleTimeout;
}
public void setIdleTimeout(int idleTimeout) {
this.idleTimeout = idleTimeout;
}
public void setExpiryTimeout(long expiryTimeout) {
this.expiryTimeout = expiryTimeout;
}
public long getExpiryTimeout() {
return expiryTimeout;
}
public int getMaximumActiveSessionPerConnection() {
return this.sessionPool.getMaxActive();
}
public void setMaximumActiveSessionPerConnection(int maximumActiveSessionPerConnection) {
this.sessionPool.setMaxActive(maximumActiveSessionPerConnection);
}
public boolean isUseAnonymousProducers() {
return this.useAnonymousProducers;
}
public void setUseAnonymousProducers(boolean value) {
this.useAnonymousProducers = value;
}
/**
* @return the total number of Pooled session including idle sessions that are not
* currently loaned out to any client.
*/
public int getNumSessions() {
return this.sessionPool.getNumIdle() + this.sessionPool.getNumActive();
}
/**
* @return the total number of Sessions that are in the Session pool but not loaned out.
*/
public int getNumIdleSessions() {
return this.sessionPool.getNumIdle();
}
/**
* @return the total number of Session's that have been loaned to PooledConnection instances.
*/
public int getNumActiveSessions() {
return this.sessionPool.getNumActive();
}
/**
* Configure whether the createSession method should block when there are no more idle sessions and the
* pool already contains the maximum number of active sessions. If false the create method will fail
* and throw an exception.
*
* @param block
* Indicates whether blocking should be used to wait for more space to create a session.
*/
public void setBlockIfSessionPoolIsFull(boolean block) {
this.sessionPool.setWhenExhaustedAction(
(block ? GenericObjectPool.WHEN_EXHAUSTED_BLOCK : GenericObjectPool.WHEN_EXHAUSTED_FAIL));
}
public boolean isBlockIfSessionPoolIsFull() {
return this.sessionPool.getWhenExhaustedAction() == GenericObjectPool.WHEN_EXHAUSTED_BLOCK;
}
@Override
public String toString() {
return "ConnectionPool[" + connection + "]";
}
}