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.activemq.store.jdbc;
018    
019    import java.io.IOException;
020    
021    import org.apache.activemq.Service;
022    
023    /**
024     * Represents some kind of lock service to ensure that a broker is the only master
025     * 
026     * 
027     */
028    public interface DatabaseLocker extends Service {
029    
030        /**
031         * allow the injection of a jdbc persistence adapter
032         * @param adapter the persistence adapter to use
033         * @throws IOException 
034         */
035        void setPersistenceAdapter(JDBCPersistenceAdapter adapter) throws IOException;
036        
037        /**
038         * Used by a timer to keep alive the lock.
039         * If the method returns false the broker should be terminated
040         */
041        boolean keepAlive();
042    
043        /**
044         * set the delay interval in milliseconds between lock acquire attempts
045         * @param lockAcquireSleepInterval the sleep interval in miliseconds
046         */
047        void setLockAcquireSleepInterval(long lockAcquireSleepInterval);
048        
049    }