hazelcast-master/hazelcast/src/main/java/com/hazelcast/core/LifecycleService.java
/*
 * Copyright (c) 2008-2023, Hazelcast, Inc. All Rights Reserved.
 *
 * Licensed 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 com.hazelcast.core;

import javax.annotation.Nonnull;
import java.util.UUID;

/**
 * LifecycleService allows you to shutdown, terminate, and listen to {@link LifecycleEvent}s
 * on HazelcastInstance.
 */
public interface LifecycleService {

    /**
     * Checks whether or not the instance is running.
     *
     * @return {@code true}, if instance is active and running, {@code false} otherwise
     */
    boolean isRunning();

    /**
     * Gracefully shuts down HazelcastInstance. It's different from {@link #terminate()}
     * in that it waits for partition operations to complete.
     */
    void shutdown();

    /**
     * Terminate HazelcastInstance ungracefully. Does not wait for partition operations, forces immediate shutdown.
     * Use {@link #shutdown()} for graceful shutdown.
     */
    void terminate();

    /**
     * Add a listener object to listen for lifecycle events.
     *
     * @param lifecycleListener the listener object
     * @return the listener ID
     */
    @Nonnull UUID addLifecycleListener(@Nonnull LifecycleListener lifecycleListener);

    /**
     * Removes a lifecycle listener.
     *
     * @param registrationId the listener ID returned by {@link #addLifecycleListener(LifecycleListener)}
     * @return true if the listener is removed successfully, false otherwise
     */
    boolean removeLifecycleListener(@Nonnull UUID registrationId);
}
