curator-master/curator-recipes/src/main/java/org/apache/curator/framework/recipes/leader/LeaderSelectorListener.java
/*
 * 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.curator.framework.recipes.leader;

import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.state.ConnectionState;
import org.apache.curator.framework.state.ConnectionStateListener;

/**
 * Notification for leadership
 *
 * @see LeaderSelector
 */
public interface LeaderSelectorListener extends ConnectionStateListener {
    /**
     * Called when your instance has been granted leadership. This method
     * should not return until you wish to release leadership.
     *
     * <p>It is guaranteed that there is no concurrent executions of this
     * method.</p>
     *
     * <p>It is guaranteed that this method will be interrupted if
     * {@link #stateChanged(CuratorFramework, ConnectionState)}
     * throws {@link CancelLeadershipException}. After interrupted, this
     * method should exit(either return or throw) promptly, otherwise it
     * will block following elections.</p>
     *
     * @param client the client
     * @throws Exception any errors
     */
    public void takeLeadership(CuratorFramework client) throws Exception;
}
