com.mpush.netty.server.NettyTCPServer.java Source code

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/*
 * (C) Copyright 2015-2016 the original author or authors.
 *
 * 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.
 *
 * Contributors:
 *   ohun@live.cn ()
 */

package com.mpush.netty.server;

import com.mpush.api.service.BaseService;
import com.mpush.api.service.Listener;
import com.mpush.api.service.Server;
import com.mpush.api.service.ServiceException;
import com.mpush.netty.codec.PacketDecoder;
import com.mpush.netty.codec.PacketEncoder;
import com.mpush.tools.config.CC;
import com.mpush.tools.thread.ThreadNames;
import io.netty.bootstrap.ServerBootstrap;
import io.netty.buffer.PooledByteBufAllocator;
import io.netty.channel.*;
import io.netty.channel.epoll.EpollEventLoopGroup;
import io.netty.channel.epoll.EpollServerSocketChannel;
import io.netty.channel.epoll.Native;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.util.concurrent.DefaultThreadFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.nio.channels.spi.SelectorProvider;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.atomic.AtomicReference;

/**
 * Created by ohun on 2015/12/22.
 *
 * @author ohun@live.cn
 */
public abstract class NettyTCPServer extends BaseService implements Server {

    private final Logger logger = LoggerFactory.getLogger(this.getClass());

    public enum State {
        Created, Initialized, Starting, Started, Shutdown
    }

    protected final AtomicReference<State> serverState = new AtomicReference<>(State.Created);

    protected final int port;
    protected EventLoopGroup bossGroup;
    protected EventLoopGroup workerGroup;

    public NettyTCPServer(int port) {
        this.port = port;
    }

    public void init() {
        if (!serverState.compareAndSet(State.Created, State.Initialized)) {
            throw new ServiceException("Server already init");
        }
    }

    @Override
    public boolean isRunning() {
        return serverState.get() == State.Started;
    }

    @Override
    public void stop(Listener listener) {
        if (!serverState.compareAndSet(State.Started, State.Shutdown)) {
            if (listener != null)
                listener.onFailure(new ServiceException("server was already shutdown."));
            logger.error("{} was already shutdown.", this.getClass().getSimpleName());
            return;
        }
        logger.info("try shutdown {}...", this.getClass().getSimpleName());
        if (bossGroup != null)
            bossGroup.shutdownGracefully().syncUninterruptibly();//?main reactor
        if (workerGroup != null)
            workerGroup.shutdownGracefully().syncUninterruptibly();//??sub reactor
        logger.info("{} shutdown success.", this.getClass().getSimpleName());
        if (listener != null) {
            listener.onSuccess(port);
        }
    }

    @Override
    public void start(final Listener listener) {
        if (!serverState.compareAndSet(State.Initialized, State.Starting)) {
            throw new ServiceException("Server already started or have not init");
        }
        if (useNettyEpoll()) {
            createEpollServer(listener);
        } else {
            createNioServer(listener);
        }
    }

    private void createServer(Listener listener, EventLoopGroup boss, EventLoopGroup work,
            ChannelFactory<? extends ServerChannel> channelFactory) {
        /***
         * NioEventLoopGroup ??I/O?
         * Netty????EventLoopGroup??????
         * ?2NioEventLoopGroup
         * ???boss??
         * ???worker???
         * boss?worker
         * ???Channels??EventLoopGroup
         * ???
         */
        this.bossGroup = boss;
        this.workerGroup = work;

        try {
            /**
             * ServerBootstrap ?NIO??
             * ??Channel
             */
            ServerBootstrap b = new ServerBootstrap();

            /**
             * groupjava.lang.IllegalStateException: group not set
             */
            b.group(bossGroup, workerGroup);

            /***
             * ServerSocketChannelNIOselector?
             * Channel?.
             */
            b.channelFactory(channelFactory);

            /***
             * ?????Channel
             * ChannelInitializer?
             * ?Channel
             * ?NettyServerHandler??Channel
             * ChannelPipeline??
             * ??????pipeline
             * ??????
             */
            b.childHandler(new ChannelInitializer<Channel>() { // (4)
                @Override
                public void initChannel(Channel ch) throws Exception {//?
                    initPipeline(ch.pipeline());
                }
            });

            initOptions(b);

            /***
             * ???
             */
            b.bind(port).addListener(future -> {
                if (future.isSuccess()) {
                    serverState.set(State.Started);
                    logger.info("server start success on:{}", port);
                    if (listener != null)
                        listener.onSuccess(port);
                } else {
                    logger.error("server start failure on:{}", port, future.cause());
                    if (listener != null)
                        listener.onFailure(future.cause());
                }
            });
        } catch (Exception e) {
            logger.error("server start exception", e);
            if (listener != null)
                listener.onFailure(e);
            throw new ServiceException("server start exception, port=" + port, e);
        }
    }

    private void createNioServer(Listener listener) {
        EventLoopGroup bossGroup = getBossGroup();
        EventLoopGroup workerGroup = getWorkerGroup();

        if (bossGroup == null) {
            NioEventLoopGroup nioEventLoopGroup = new NioEventLoopGroup(getBossThreadNum(), getBossThreadFactory(),
                    getSelectorProvider());
            nioEventLoopGroup.setIoRatio(100);
            bossGroup = nioEventLoopGroup;
        }

        if (workerGroup == null) {
            NioEventLoopGroup nioEventLoopGroup = new NioEventLoopGroup(getWorkThreadNum(), getWorkThreadFactory(),
                    getSelectorProvider());
            nioEventLoopGroup.setIoRatio(getIoRate());
            workerGroup = nioEventLoopGroup;
        }

        createServer(listener, bossGroup, workerGroup, getChannelFactory());
    }

    private void createEpollServer(Listener listener) {
        EventLoopGroup bossGroup = getBossGroup();
        EventLoopGroup workerGroup = getWorkerGroup();

        if (bossGroup == null) {
            EpollEventLoopGroup epollEventLoopGroup = new EpollEventLoopGroup(getBossThreadNum(),
                    getBossThreadFactory());
            epollEventLoopGroup.setIoRatio(100);
            bossGroup = epollEventLoopGroup;
        }

        if (workerGroup == null) {
            EpollEventLoopGroup epollEventLoopGroup = new EpollEventLoopGroup(getWorkThreadNum(),
                    getWorkThreadFactory());
            epollEventLoopGroup.setIoRatio(getIoRate());
            workerGroup = epollEventLoopGroup;
        }

        createServer(listener, bossGroup, workerGroup, EpollServerSocketChannel::new);
    }

    /***
     * option()??NioServerSocketChannel??
     * childOption()???ServerChannel
     * ?NioServerSocketChannel
     */
    protected void initOptions(ServerBootstrap b) {
        //b.childOption(ChannelOption.SO_KEEPALIVE, false);// 

        /**
         * Netty 4ByteBufJava jemalloc Facebook
         * Netty?????GC????
         * ???
         * Netty???
         */
        b.option(ChannelOption.ALLOCATOR, PooledByteBufAllocator.DEFAULT);
        b.childOption(ChannelOption.ALLOCATOR, PooledByteBufAllocator.DEFAULT);
    }

    public abstract ChannelHandler getChannelHandler();

    protected ChannelHandler getDecoder() {
        return new PacketDecoder();
    }

    protected ChannelHandler getEncoder() {
        return PacketEncoder.INSTANCE;//?, ?
    }

    /**
     * ?
     *
     * @param pipeline
     */
    protected void initPipeline(ChannelPipeline pipeline) {
        pipeline.addLast("decoder", getDecoder());
        pipeline.addLast("encoder", getEncoder());
        pipeline.addLast("handler", getChannelHandler());
    }

    /**
     * netty ExecutorThreadPerTaskExecutor
     * SingleThreadEventExecutor#doStartThread
     * <p>
     * eventLoop.execute(runnable);
     * ???
     * ??
     * ?(startThread())???
     * ???
     *
     * @return
     */
    protected ThreadFactory getBossThreadFactory() {
        return new DefaultThreadFactory(getBossThreadName());
    }

    protected ThreadFactory getWorkThreadFactory() {
        return new DefaultThreadFactory(getWorkThreadName());
    }

    protected int getBossThreadNum() {
        return 1;
    }

    protected int getWorkThreadNum() {
        return 0;
    }

    protected String getBossThreadName() {
        return ThreadNames.T_BOSS;
    }

    protected String getWorkThreadName() {
        return ThreadNames.T_WORKER;
    }

    protected int getIoRate() {
        return 70;
    }

    protected boolean useNettyEpoll() {
        if (CC.mp.core.useNettyEpoll()) {
            try {
                Native.offsetofEpollData();
                return true;
            } catch (UnsatisfiedLinkError error) {
                logger.warn("can not load netty epoll, switch nio model.");
            }
        }
        return false;
    }

    public EventLoopGroup getBossGroup() {
        return bossGroup;
    }

    public EventLoopGroup getWorkerGroup() {
        return workerGroup;
    }

    public ChannelFactory<? extends ServerChannel> getChannelFactory() {
        return NioServerSocketChannel::new;
    }

    public SelectorProvider getSelectorProvider() {
        return SelectorProvider.provider();
    }
}