muduo源码剖析之TcpServer服务端
简介
TcpServer拥有Acceptor类，新连接到达时new TcpConnection后续客户端和TcpConnection类交互。TcpServer管理连接和启动线程池，用Acceptor接受连接。
服务端封装 - muduo的server端维护了多个tcpconnection
注意TcpServer本身不带Channel，而是使用Acceptor的Channel
成员及属性解析
主要接口
回调setters
这些回调函数会在新连接建立时传递给TcpConnction对象
start
启动threadPool_线程池
在runInLoop中执行acceptor的listen
这里专门设置了一个started_标记，防止多次运行start
核心实现：newConnection
从accept回调中获得的fd动态创建新的TcpConnection对象
为连接对象注册各类回调函数
将连接对象存入connectionMap_映射表里
主要成员
loop
这个loop也是acceptor的loop
acceptor
threadPool
一个EventLoopThreadPool，用来存放io线程的EventLoopThread
socket
服务端用来监听的socket
ConnectionMap
一个连接名和实例（TcpConnectionPtr）的映射容器
TcpServer中回调的传递示意简图：
源码剖析
源码已经编写注释
TcpServer.h
// Copyright 2010, Shuo Chen. All rights reserved.
// http://code.google.com/p/muduo/
//
// Use of this source code is governed by a BSD-style license
// that can be found in the License file.
// Author: Shuo Chen (chenshuo at chenshuo dot com)
//
// This is a public header file, it must only include public header files.
#ifndef MUDUO_NET_TCPSERVER_H
#define MUDUO_NET_TCPSERVER_H
#include "muduo/base/Atomic.h"
#include "muduo/base/Types.h"
#include "muduo/net/TcpConnection.h"
#include
namespace muduo
{
namespace net
{
class Acceptor;
class EventLoop;
class EventLoopThreadPool;
///
/// TCP server, supports single-threaded and thread-pool models.
///
/// This is an interface class, so don't expose too much details.
class TcpServer : noncopyable
{
public:
typedef std::function<void(EventLoop*)> ThreadInitCallback;
enum Option
{
kNoReusePort,//不设置端口复用
kReusePort,//设置端口复用
};
//TcpServer(EventLoop* loop, const InetAddress& listenAddr);
TcpServer(EventLoop* loop,//mainloop
const InetAddress& listenAddr,
const string& nameArg,
Option option = kNoReusePort);
~TcpServer(); // force out-line dtor, for std::unique_ptr members.
const string& ipPort() const { return ipPort_; }
const string& name() const { return name_; }
EventLoop* getLoop() const { return loop_; }
/// Set the number of threads for handling input.
///
/// Always accepts new connection in loop's thread.
/// Must be called before @c start
/// @param numThreads
/// - 0 means all I/O in loop's thread, no thread will created.
/// this is the default value.
/// - 1 means all I/O in another thread.
/// - N means a thread pool with N threads, new connections
/// are assigned on a round-robin basis.
void setThreadNum(int numThreads);//设置subloop数量
void setThreadInitCallback(const ThreadInitCallback& cb)//设置subloop线程初始化时调用的函数
{ threadInitCallback_ = cb; }
/// valid after calling start()
std::shared_ptr<EventLoopThreadPool> threadPool()//返回EventLoopThread线程池
{ return threadPool_; }
/// Starts the server if it's not listening.
///
/// It's harmless to call it multiple times.
/// Thread safe.
void start();
/// Set connection callback.
/// Not thread safe.
void setConnectionCallback(const ConnectionCallback& cb)
{ connectionCallback_ = cb; }
/// Set message callback.
/// Not thread safe.
void setMessageCallback(const MessageCallback& cb)
{ messageCallback_ = cb; }
/// Set write complete callback.
/// Not thread safe.
void setWriteCompleteCallback(const WriteCompleteCallback& cb)
{ writeCompleteCallback_ = cb; }
private:
/// Not thread safe, but in loop
void newConnection(int sockfd, const InetAddress& peerAddr);
/// Thread safe.
void removeConnection(const TcpConnectionPtr& conn);
/// Not thread safe, but in loop
void removeConnectionInLoop(const TcpConnectionPtr& conn);
typedef std::map<string, TcpConnectionPtr> ConnectionMap;
EventLoop* loop_; // the acceptor loop
const string ipPort_;
const string name_;
std::unique_ptr<Acceptor> acceptor_; // avoid revealing Acceptor
std::shared_ptr<EventLoopThreadPool> threadPool_;
ConnectionCallback connectionCallback_;
MessageCallback messageCallback_;
WriteCompleteCallback writeCompleteCallback_;
ThreadInitCallback threadInitCallback_;
AtomicInt32 started_;
// always in loop thread
int nextConnId_;
ConnectionMap connections_;
};
} // namespace net
} // namespace muduo
#endif // MUDUO_NET_TCPSERVER_H
TcpServer.cc
// Copyright 2010, Shuo Chen. All rights reserved.
// http://code.google.com/p/muduo/
//
// Use of this source code is governed by a BSD-style license
// that can be found in the License file.
// Author: Shuo Chen (chenshuo at chenshuo dot com)
#include "muduo/net/TcpServer.h"
#include "muduo/base/Logging.h"
#include "muduo/net/Acceptor.h"
#include "muduo/net/EventLoop.h"
#include "muduo/net/EventLoopThreadPool.h"
#include "muduo/net/SocketsOps.h"
#include