001    /*
002    * Copyright 2004 The Apache Software Foundation
003    *
004    * Licensed under the Apache License, Version 2.0 (the "License");
005    * you may not use this file except in compliance with the License.
006    * You may obtain a copy of the License at
007    *
008    *     http://www.apache.org/licenses/LICENSE-2.0
009    *
010    * Unless required by applicable law or agreed to in writing, software
011    * distributed under the License is distributed on an "AS IS" BASIS,
012    * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013    * See the License for the specific language governing permissions and
014    * limitations under the License.
015    */
016    package javax.servlet;
017    
018    /**
019     * Ensures that servlets handle
020     * only one request at a time. This interface has no methods.
021     *
022     * <p>If a servlet implements this interface, you are <i>guaranteed</i>
023     * that no two threads will execute concurrently in the
024     * servlet's <code>service</code> method. The servlet container
025     * can make this guarantee by synchronizing access to a single
026     * instance of the servlet, or by maintaining a pool of servlet
027     * instances and dispatching each new request to a free servlet.
028     *
029     * <p>Note that SingleThreadModel does not solve all thread safety
030     * issues.  For example, session attributes and static variables can
031     * still be accessed by multiple requests on multiple threads
032     * at the same time, even when SingleThreadModel servlets are used.
033     * It is recommended that a developer take other means to resolve
034     * those issues instead of implementing this interface, such as
035     * avoiding the usage of an instance variable or synchronizing
036     * the block of the code accessing those resources.
037     * This interface is deprecated in Servlet API version 2.4.
038     *
039     *
040     * @author      Various
041     * @version     $Version$
042     *
043     * @deprecated  As of Java Servlet API 2.4, with no direct
044     *      replacement.
045     */
046    
047    public interface SingleThreadModel {
048    }