/*
 *
 * 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.qpid.management.wsdm.common;

/**
 *	Thread session manager used to handle thread-scoped sessions.
 *
 * @author Andrea Gazzarini
 */
public final class ThreadSessionManager 
{
    private static ThreadSessionManager instance = new ThreadSessionManager();

    private ThreadLocal<ThreadSession> sessions;

    /**
     * Builds and initializes a new manager. 
     */
    private ThreadSessionManager() 
    {
        this.sessions = new ThreadLocal<ThreadSession>();
    }

    /**
     * Returns the singleton instance of this manager.
     * 
     * @return the singleton instance of this manager.
     */
    public static ThreadSessionManager getInstance()
    {
        return instance;
    }

     /**
      * Returns (or create and returns) the session associated with the 
      * current thread.
      * 
     * @return the thread session.
     */
    public ThreadSession getSession()
    {
        ThreadSession session = (ThreadSession) sessions.get();
        if (session == null) 
        {
            session = new ThreadSession();
            sessions.set(session);
        }
        return session;
    }
}