/*
 * $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk/module-client/src/main/java/org/apache/http/impl/conn/tsccm/PoolEntryRequest.java $
 * $Revision: 652020 $
 * $Date: 2008-04-27 14:23:31 -0700 (Sun, 27 Apr 2008) $
 *
 * ====================================================================
 *
 *  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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */

package org.apache.http.impl.conn.tsccm;

import java.util.concurrent.TimeUnit;

import org.apache.http.conn.ConnectionPoolTimeoutException;

/**
 * Encapsulates a request for a {@link BasicPoolEntry}.
 */
public interface PoolEntryRequest {

    /**
     * Obtains a pool entry with a connection within the given timeout.
     * If {@link #abortRequest()} is called before this completes
     * an {@link InterruptedException} is thrown.
     *
     * @param timeout   the timeout, 0 or negative for no timeout
     * @param tunit     the unit for the <code>timeout</code>,
     *                  may be <code>null</code> only if there is no timeout
     *
     * @return  pool entry holding a connection for the route
     *
     * @throws ConnectionPoolTimeoutException
     *         if the timeout expired
     * @throws InterruptedException
     *         if the calling thread was interrupted or the request was aborted
     */
    BasicPoolEntry getPoolEntry(
            long timeout, 
            TimeUnit tunit) throws InterruptedException, ConnectionPoolTimeoutException;

    /**
     * Aborts the active or next call to
     * {@link #getPoolEntry(long, TimeUnit)}.
     */
    void abortRequest();
    
}
