org.apache.activemq.broker.Locker Maven / Gradle / Ivy
/**
* 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.
*/
package org.apache.activemq.broker;
import java.io.IOException;
import org.apache.activemq.Service;
import org.apache.activemq.store.PersistenceAdapter;
/**
* Represents a lock service to ensure that a broker is the only master
*/
public interface Locker extends Service {
/**
* Used by a timer to keep alive the lock.
* If the method returns false the broker should be terminated
* if an exception is thrown, the lock state cannot be determined
*/
boolean keepAlive() throws IOException;
/**
* set the delay interval in milliseconds between lock acquire attempts
*
* @param lockAcquireSleepInterval the sleep interval in miliseconds
*/
void setLockAcquireSleepInterval(long lockAcquireSleepInterval);
/**
* Set the name of the lock to use.
*/
public void setName(String name);
/**
* Specify whether to fail immediately if the lock is already held. When set, the CustomLock must throw an
* IOException immediately upon detecting the lock is already held.
*
* @param failIfLocked true => fail immediately if the lock is held; false => block until the lock can be obtained
* (default).
*/
public void setFailIfLocked(boolean failIfLocked);
/**
* A reference to what is locked
*/
public void setLockable(LockableServiceSupport lockable);
/**
* Optionally configure the locker with the persistence adapter currently used
* You can use persistence adapter configuration details like, data directory
* datasource, etc. to be used by the locker
*
* @param persistenceAdapter
* @throws IOException
*/
public void configure(PersistenceAdapter persistenceAdapter) throws IOException;
}