001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.camel.spi;
018    
019    /**
020     * A vetoable {@link org.apache.camel.spi.Synchronization}.
021     * <p/>
022     * When using {@link org.apache.camel.spi.Synchronization} they are normally executed
023     * when the {@link org.apache.camel.Exchange} complete at the end. If the {@link org.apache.camel.Exchange}
024     * is processed asynchronously the {@link org.apache.camel.spi.Synchronization} will be handed
025     * over to the next thread. This ensures for example the file consumer will delete the processed file at the very
026     * end, when the {@link org.apache.camel.Exchange} has been completed successfully.
027     * <p/>
028     * However there may be situations where you do not want to handover certain {@link org.apache.camel.spi.Synchronization},
029     * such as when doing asynchronously request/reply over SEDA or VM endpoints.
030     *
031     * @version 
032     */
033    public interface SynchronizationVetoable extends Synchronization {
034    
035        /**
036         * Whether or not handover this synchronization is allowed.
037         * <p/>
038         * For example when an {@link org.apache.camel.Exchange} is being routed
039         * from one thread to another thread, such as using request/reply over SEDA
040         *
041         * @return <tt>true</tt> to allow handover, <tt>false</tt> to deny.
042         */
043        boolean allowHandover();
044    }