moduo之服务器TcpServer

简介

TcpServer实现了多线程主从Reactor服务器

结构

Acceptor新连接回调：

void newConnection(int sockfd, const InetAddress& peerAddr);

TcpConnection的四个回调

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; }
  
void removeConnection(const TcpConnectionPtr& conn);

事件循环线程池线程启动初始回调：

void setThreadInitCallback(const ThreadInitCallback& cb)
  { threadInitCallback_ = cb; }

Acceptor连接回调

• 从事件循环池中轮循方式选取一个
• 创建TcpConnection，将TcpServer设置的connectionCallback_, messageCallback_和writeCompleteCallback_传递到TcpConnection，同时设置关闭连接的回调removeConnection
• 创建连接建立的任务connectEstablished放入连接事件循环的队列中异步执行

void TcpServer::newConnection(int sockfd, const InetAddress& peerAddr)
{
  loop_->assertInLoopThread();
  EventLoop* ioLoop = threadPool_->getNextLoop();
  char buf[64];
  snprintf(buf, sizeof buf, "-%s#%d", ipPort_.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(ioLoop,
                                          connName,
                                          sockfd,
                                          localAddr,
                                          peerAddr));
  connections_[connName] = conn;
  conn->setConnectionCallback(connectionCallback_);
  conn->setMessageCallback(messageCallback_);
  conn->setWriteCompleteCallback(writeCompleteCallback_);
  conn->setCloseCallback(
      std::bind(&TcpServer::removeConnection, this, _1)); // FIXME: unsafe
  ioLoop->runInLoop(std::bind(&TcpConnection::connectEstablished, conn));
}

连接建立回调connectEstablished

• 设置连接状态为kConnected
• 事件通道绑定连接对象，开启读事件
• 执行事件回调connectionCallback_

void TcpConnection::connectEstablished()
{
  loop_->assertInLoopThread();
  assert(state_ == kConnecting);
  setState(kConnected);
  channel_->tie(shared_from_this());
  channel_->enableReading();

  connectionCallback_(shared_from_this());
}

关闭连接回调

• 添加任务removeConnectionInLoop到acceptor所在的事件循环队列中异步执行
• 连接容器中删除对应连接
• 添加任务connectDestroyed到连接所在的事件循环队列中异步执行

void TcpServer::removeConnection(const TcpConnectionPtr& conn)
{
  // FIXME: unsafe
  loop_->runInLoop(std::bind(&TcpServer::removeConnectionInLoop, this, conn));
}

void TcpServer::removeConnectionInLoop(const TcpConnectionPtr& conn)
{
  loop_->assertInLoopThread();
  LOG_INFO << "TcpServer::removeConnectionInLoop [" << name_
           << "] - connection " << conn->name();
  size_t n = connections_.erase(conn->name());
  (void)n;
  assert(n == 1);
  EventLoop* ioLoop = conn->getLoop();
  ioLoop->queueInLoop(
      std::bind(&TcpConnection::connectDestroyed, conn));
}