/*
 * Copyright 2012 The Netty Project
 *
 * The Netty Project 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 io.netty.util.concurrent;

import java.util.Iterator;
import java.util.concurrent.Callable;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

/**
 * The {@link EventExecutorGroup} is responsible to provide {@link EventExecutor}'s to use via its
 * {@link #next()} method. Beside this it also is responsible to handle their live-cycle and allows
 * to shut them down in a global fashion.
 *
 */
public interface EventExecutorGroup extends ScheduledExecutorService, Iterable<EventExecutor> {

    /**
     * Returns one of the {@link EventExecutor}s that belong to this group.
     */
    EventExecutor next();

    /**
     * Returns a read-only {@link Iterator} over all {@link EventExecutor}, which are handled by this
     * {@link EventExecutorGroup} at the time of invoke this method.
     */
    @Override
    Iterator<EventExecutor> iterator();

    @Override
    Future<?> submit(Runnable task);

    @Override
    <T> Future<T> submit(Runnable task, T result);

    @Override
    <T> Future<T> submit(Callable<T> task);

    @Override
    ScheduledFuture<?> schedule(Runnable command, long delay, TimeUnit unit);

    @Override
    <V> ScheduledFuture<V> schedule(Callable<V> callable, long delay, TimeUnit unit);

    @Override
    ScheduledFuture<?> scheduleAtFixedRate(Runnable command, long initialDelay, long period, TimeUnit unit);

    @Override
    ScheduledFuture<?> scheduleWithFixedDelay(Runnable command, long initialDelay, long delay, TimeUnit unit);
}