33muduo_net库源码分析（九）

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1.TcpServer/TcpConnection

（1）Acceptor类的主要功能是socket、bind、listen

（2）一般来说，在上层应用程序中，我们不直接使用Acceptor，而是把它作为TcpServer的成员TcpServer还包含了一个TcpConnection列表

（3）TcpConnection与Acceptor类似，有两个重要的数据成员，Socket与Channel

2.时序图

3.代码

1.TcpConnection.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_TCPCONNECTION_H
#define MUDUO_NET_TCPCONNECTION_H

#include <muduo/base/Mutex.h>
#include <muduo/base/StringPiece.h>
#include <muduo/base/Types.h>
#include <muduo/net/Callbacks.h>
//#include <muduo/net/Buffer.h>
#include <muduo/net/InetAddress.h>

//#include <boost/any.hpp>
#include <boost/enable_shared_from_this.hpp>
#include <boost/noncopyable.hpp>
#include <boost/scoped_ptr.hpp>
#include <boost/shared_ptr.hpp>

namespace muduo
{
namespace net
{

class Channel;
class EventLoop;
class Socket;

///
/// TCP connection, for both client and server usage.
///
/// This is an interface class, so don't expose too much details.
class TcpConnection : boost::noncopyable,
                      public boost::enable_shared_from_this<TcpConnection>
{
 public:
  /// Constructs a TcpConnection with a connected sockfd
  ///
  /// User should not create this object.
  TcpConnection(EventLoop* loop,
                const string& name,
                int sockfd,
                const InetAddress& localAddr,
                const InetAddress& peerAddr);
  ~TcpConnection();

  EventLoop* getLoop() const { return loop_; }
  const string& name() const { return name_; }
  const InetAddress& localAddress() { return localAddr_; }
  const InetAddress& peerAddress() { return peerAddr_; }
  bool connected() const { return state_ == kConnected; }

  void setConnectionCallback(const ConnectionCallback& cb)
  { connectionCallback_ = cb; }

  void setMessageCallback(const MessageCallback& cb)
  { messageCallback_ = cb; }

  // called when TcpServer accepts a new connection
  void connectEstablished();   // should be called only once

 private:
  enum StateE { /*kDisconnected, */kConnecting, kConnected/*, kDisconnecting*/ };
  void handleRead(Timestamp receiveTime);
  void setState(StateE s) { state_ = s; }

  EventLoop* loop_;			// 所属EventLoop
  string name_;				// 连接名
  StateE state_;  // FIXME: use atomic variable
  // we don't expose those classes to client.
  boost::scoped_ptr<Socket> socket_;
  boost::scoped_ptr<Channel> channel_;
  InetAddress localAddr_;
  InetAddress peerAddr_;
  ConnectionCallback connectionCallback_;
  MessageCallback messageCallback_;
};

typedef boost::shared_ptr<TcpConnection> TcpConnectionPtr;

}
}

#endif  // MUDUO_NET_TCPCONNECTION_H

2.TcpConnection.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/TcpConnection.h>

#include <muduo/base/Logging.h>
#include <muduo/net/Channel.h>
#include <muduo/net/EventLoop.h>
#include <muduo/net/Socket.h>
#include <muduo/net/SocketsOps.h>

#include <boost/bind.hpp>

#include <errno.h>
#include <stdio.h>

using namespace muduo;
using namespace muduo::net;
/*
void muduo::net::defaultConnectionCallback(const TcpConnectionPtr& conn)
{
  LOG_TRACE << conn->localAddress().toIpPort() << " -> "
            << conn->peerAddress().toIpPort() << " is "
            << (conn->connected() ? "UP" : "DOWN");
}

void muduo::net::defaultMessageCallback(const TcpConnectionPtr&,
                                        Buffer* buf,
                                        Timestamp)
{
  buf->retrieveAll();
}
*/
TcpConnection::TcpConnection(EventLoop* loop,
                             const string& nameArg,
                             int sockfd,
                             const InetAddress& localAddr,
                             const InetAddress& peerAddr)
  : loop_(CHECK_NOTNULL(loop)),
    name_(nameArg),
    state_(kConnecting),
    socket_(new Socket(sockfd)),
    channel_(new Channel(loop, sockfd)),
    localAddr_(localAddr),
    peerAddr_(peerAddr)/*,
    highWaterMark_(64*1024*1024)*/
{
  // 通道可读事件到来的时候，回调TcpConnection::handleRead，_1是事件发生时间
  channel_->setReadCallback(
      boost::bind(&TcpConnection::handleRead, this, _1));
  LOG_DEBUG << "TcpConnection::ctor[" <<  name_ << "] at " << this
            << " fd=" << sockfd;
  socket_->setKeepAlive(true);
}

TcpConnection::~TcpConnection()
{
  LOG_DEBUG << "TcpConnection::dtor[" <<  name_ << "] at " << this
            << " fd=" << channel_->fd();
}

void TcpConnection::connectEstablished()
{
  loop_->assertInLoopThread();
  assert(state_ == kConnecting);
  setState(kConnected);
  channel_->tie(shared_from_this());
  channel_->enableReading();	// TcpConnection所对应的通道加入到Poller关注

  connectionCallback_(shared_from_this());
}

void TcpConnection::handleRead(Timestamp receiveTime)
{
  /*
  loop_->assertInLoopThread();
  int savedErrno = 0;
  ssize_t n = inputBuffer_.readFd(channel_->fd(), &savedErrno);
  if (n > 0)
  {
    messageCallback_(shared_from_this(), &inputBuffer_, receiveTime);
  }
  else if (n == 0)
  {
    handleClose();
  }
  else
  {
    errno = savedErrno;
    LOG_SYSERR << "TcpConnection::handleRead";
    handleError();
  }
  */
  loop_->assertInLoopThread();
  char buf[65536];
  ssize_t n = ::read(channel_->fd(), buf, sizeof buf);
  messageCallback_(shared_from_this(), buf, n);
}

3.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/Types.h>
#include <muduo/net/TcpConnection.h>

#include <map>
#include <boost/noncopyable.hpp>
#include <boost/scoped_ptr.hpp>

namespace muduo
{
namespace net
{

class Acceptor;
class EventLoop;

///
/// TCP server, supports single-threaded and thread-pool models.
///
/// This is an interface class, so don't expose too much details.
class TcpServer : boost::noncopyable
{
 public:
  //typedef boost::function<void(EventLoop*)> ThreadInitCallback;

  //TcpServer(EventLoop* loop, const InetAddress& listenAddr);
  TcpServer(EventLoop* loop,
            const InetAddress& listenAddr,
            const string& nameArg);
  ~TcpServer();  // force out-line dtor, for scoped_ptr members.

  const string& hostport() const { return hostport_; }
  const string& name() const { return name_; }

  /// Starts the server if it's not listenning.
  ///
  /// It's harmless to call it multiple times.
  /// Thread safe.
  void start();

  /// Set connection callback.
  /// Not thread safe.
  // 设置连接到来或者连接关闭回调函数
  void setConnectionCallback(const ConnectionCallback& cb)
  { connectionCallback_ = cb; }

  /// Set message callback.
  /// Not thread safe.
  // 设置消息到来回调函数
  void setMessageCallback(const MessageCallback& cb)
  { messageCallback_ = cb; }


 private:
  /// Not thread safe, but in loop
  void newConnection(int sockfd, const InetAddress& peerAddr);

  typedef std::map<string, TcpConnectionPtr> ConnectionMap;

  EventLoop* loop_;  // the acceptor loop
  const string hostport_;		// 服务端口
  const string name_;			// 服务名
  boost::scoped_ptr<Acceptor> acceptor_; // avoid revealing Acceptor
  ConnectionCallback connectionCallback_;
  MessageCallback messageCallback_;
  bool started_;
  // always in loop thread
  int nextConnId_;				// 下一个连接ID
  ConnectionMap connections_;	// 连接列表
};

}
}

#endif  // MUDUO_NET_TCPSERVER_H

4.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 <boost/bind.hpp>

#include <stdio.h>  // snprintf

using namespace muduo;
using namespace muduo::net;

TcpServer::TcpServer(EventLoop* loop,
                     const InetAddress& listenAddr,
                     const string& nameArg)
  : loop_(CHECK_NOTNULL(loop)),
    hostport_(listenAddr.toIpPort()),
    name_(nameArg),
    acceptor_(new Acceptor(loop, listenAddr)),
    /*threadPool_(new EventLoopThreadPool(loop)),
    connectionCallback_(defaultConnectionCallback),
    messageCallback_(defaultMessageCallback),*/
    started_(false),
    nextConnId_(1)
{
  // Acceptor::handleRead函数中会回调用TcpServer::newConnection
  // _1对应的是socket文件描述符，_2对应的是对等方的地址(InetAddress)
  acceptor_->setNewConnectionCallback(
      boost::bind(&TcpServer::newConnection, this, _1, _2));
}

TcpServer::~TcpServer()
{
  loop_->assertInLoopThread();
  LOG_TRACE << "TcpServer::~TcpServer [" << name_ << "] destructing";
}

// 该函数多次调用是无害的
// 该函数可以跨线程调用
void TcpServer::start()
{
  if (!started_)
  {
    started_ = true;
  }

  if (!acceptor_->listenning())
  {
	// get_pointer返回原生指针
    loop_->runInLoop(
        boost::bind(&Acceptor::listen, get_pointer(acceptor_)));
  }
}

void TcpServer::newConnection(int sockfd, const InetAddress& peerAddr)
{
  loop_->assertInLoopThread();
  char buf[32];
  snprintf(buf, sizeof buf, ":%s#%d", hostport_.c_str(), nextConnId_);
  ++nextConnId_;
  string connName = name_ + buf;

  LOG_INFO << "TcpServer::newConnection [" << name_
           << "] - new connection [" << connName
           << "] from " << peerAddr.toIpPort();
  InetAddress localAddr(sockets::getLocalAddr(sockfd));
  // FIXME poll with zero timeout to double confirm the new connection
  // FIXME use make_shared if necessary
  TcpConnectionPtr conn(new TcpConnection(loop_,
                                          connName,
                                          sockfd,
                                          localAddr,
                                          peerAddr));
  connections_[connName] = conn;
  conn->setConnectionCallback(connectionCallback_);
  conn->setMessageCallback(messageCallback_);

  conn->connectEstablished();
}

5.Reactor_test.08.cc

#include <muduo/net/TcpServer.h>
#include <muduo/net/EventLoop.h>
#include <muduo/net/InetAddress.h>

#include <stdio.h>

using namespace muduo;
using namespace muduo::net;

void onConnection(const TcpConnectionPtr& conn)
{
  if (conn->connected())
  {
    printf("onConnection(): new connection [%s] from %s\n",
           conn->name().c_str(),
           conn->peerAddress().toIpPort().c_str());
  }
  else
  {
    printf("onConnection(): connection [%s] is down\n",
           conn->name().c_str());
  }
}

void onMessage(const TcpConnectionPtr& conn,
               const char* data,
               ssize_t len)
{
  printf("onMessage(): received %zd bytes from connection [%s]\n",
         len, conn->name().c_str());
}

int main()
{
  printf("main(): pid = %d\n", getpid());

  InetAddress listenAddr(8888);
  EventLoop loop;

  TcpServer server(&loop, listenAddr, "TestServer");
  server.setConnectionCallback(onConnection);
  server.setMessageCallback(onMessage);
  server.start();

  loop.loop();
}