/*
 *
 * Copyright (c) 2006 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.qpid.client;

import javax.jms.IllegalStateException;
import javax.jms.JMSException;
import java.util.concurrent.atomic.AtomicBoolean;

/**
 * Provides support for orderly shutdown of an object.
 */
public abstract class Closeable
{
    /**
     * We use an atomic boolean so that we do not have to synchronized access to this flag. Synchronizing
     * access to this flag would mean have a synchronized block in every method.
     */
    protected final AtomicBoolean _closed = new AtomicBoolean(false);

    protected void checkNotClosed() throws JMSException
    {
        if (_closed.get())
        {
            throw new IllegalStateException("Object " + toString() + " has been closed");
        }
    }

    public boolean isClosed()
    {
        return _closed.get();
    }

    public abstract void close() throws JMSException;
}
