/*
    * 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.channel;
  
  import io.netty.util.NettyRuntime;
  import io.netty.util.concurrent.DefaultThreadFactory;
  import io.netty.util.concurrent.MultithreadEventExecutorGroup;
  import io.netty.util.internal.SystemPropertyUtil;
  import io.netty.util.internal.logging.InternalLogger;
  import io.netty.util.internal.logging.InternalLoggerFactory;
  
  import java.util.concurrent.ThreadFactory;
  
  /**
   * Abstract base class for {@link EventLoopGroup} implementations that handles their tasks with multiple threads at
   * the same time.
   */
  public abstract class MultithreadEventLoopGroup extends MultithreadEventExecutorGroup implements EventLoopGroup {
  
      private static final InternalLogger logger = InternalLoggerFactory.getInstance(MultithreadEventLoopGroup.class);
  
      private static final int DEFAULT_EVENT_LOOP_THREADS;
  
      static {
          DEFAULT_EVENT_LOOP_THREADS = Math.max(1, SystemPropertyUtil.getInt(
                  "io.netty.eventLoopThreads", NettyRuntime.availableProcessors() * 2));
  
          if (logger.isDebugEnabled()) {
              logger.debug("-Dio.netty.eventLoopThreads: {}", DEFAULT_EVENT_LOOP_THREADS);
          }
      }
  
      /**
       * @see MultithreadEventExecutorGroup#MultithreadEventExecutorGroup(int, ThreadFactory, Object...)
       */
      protected MultithreadEventLoopGroup(int nThreads, ThreadFactory threadFactory, Object... args) {
          super(nThreads == 0? DEFAULT_EVENT_LOOP_THREADS : nThreads, threadFactory, args);
      }
  
      @Override
      protected ThreadFactory newDefaultThreadFactory() {
          return new DefaultThreadFactory(getClass(), Thread.MAX_PRIORITY);
      }
  
      @Override
      public EventLoop next() {
          return (EventLoop) super.next();
      }
  
      @Override
      public ChannelFuture register(Channel channel) {
          return next().register(channel);
      }
  
      @Override
      public ChannelFuture register(Channel channel, ChannelPromise promise) {
          return next().register(channel, promise);
      }
  }