TserverSocket 分析3

2/ stNonBlocking

介绍stNonBlocking之前，要先介绍TserverClientWinSocket

TServerClientWinSocket.Create 中

  inherited Create(Socket);

  if FServerWinSocket.ASyncStyles <> [] then DoSetAsyncStyles;

 

TserverClientWinSocket 是从TcustomWinSocket继承下来的

  FASyncStyles := [asRead, asWrite, asConnect, asClose];

 

接下来看TCustomWinSocket.DoSetAsyncStyles

  if FAsyncStyles <> [] then

  begin

    Msg := CM_SOCKETMESSAGE;

    Wnd := Handle;

  end;

  WSAAsyncSelect(FSocket, Wnd, Msg, Longint(Byte(FAsyncStyles)));

使用了WSAAsyncSelect 用一个窗口来接受CM_SOCKETMESSAGE 消息来标示网络消息，消息类型 在TCustomWinSocket.Create中设置为 FASyncStyles := [asRead, asWrite, asConnect, asClose];asRead, asWrite, asConnect, asClose就是接受的网络消息类型。

 

TCustomWinSocket.CMSocketMessage函数来出来消息CM_SOCKETMESSAGE

  with Message do

    if CheckError then

      case SelectEvent of

        FD_CONNECT: Connect(Socket);

        FD_CLOSE: Disconnect(Socket);

        FD_READ: Read(Socket);

        FD_WRITE: Write(Socket);

        FD_ACCEPT: Accept(Socket);

      end;

根据网络类型调用不同的函数

 

现在开始stNonBlocking类型的研究

TServerWinSocket.Listen 中

  inherited Listen(Name, Address, Service, Port, QueueSize, ServerType = stThreadBlocking);

调用的父类的Listen

TCustomWinSocket.Listen中

  FSocket := socket(PF_INET, SOCK_STREAM, IPPROTO_IP);

  if FSocket = INVALID_SOCKET then raise ESocketError.CreateRes(@sCannotCreateSocket);

  try

    Event(Self, seLookUp);

    if Block then

    begin

      FAddr := InitSocket(Name, Address, Service, Port, False);

      DoListen(QueueSize);

    end else

      AsyncInitSocket(Name, Address, Service, Port, QueueSize, False)；

初始化socket ，然后调用了AsyncInitSocket

AsyncInitSocket就是用递归的来实现了端口，地址的解析，最后调用DoListen

TCustomWinSocket.DoListen 中

  CheckSocketResult(bind(FSocket, FAddr, SizeOf(FAddr)), 'bind');

  DoSetASyncStyles;

  if QueueSize > SOMAXCONN then QueueSize := SOMAXCONN;

  Event(Self, seListen);

  CheckSocketResult(Winsock.listen(FSocket, QueueSize), 'listen');

  FLookupState := lsIdle;

  FConnected := True;

绑定端口，监听，

在DoSetASyncStyles中用WSAAsyncSelect实现用窗口接受网络事件消息，不过事件类型在

 TServerWinSocket.Create中初始化为asAccept , FAsyncStyles := [asAccept];

TserverWinSocket重载了Accept函数TServerWinSocket.Accept中

    ClientWinSocket := WinSock.accept(Socket, @Addr, @Len);

    if ClientWinSocket <> INVALID_SOCKET then

    begin

      ClientSocket := GetClientSocket(ClientWinSocket);

      if Assigned(FOnSocketEvent) then

        FOnSocketEvent(Self, ClientSocket, seAccept);

接受socket，把socket转换为TserverClientWinSocket

TServerWinSocket.GetClientSocket中

Result := TServerClientWinSocket.Create(Socket, Self);

产生了一个TserverClientWinSocket对象，按照我们开始研究的时候，TserverClientWinSocket生成一个窗口自动接受socket消息。

 

总结：

TserverWinSocket创建一个窗口只接受accept网络消息，当消息来了后accept客户端的socket，把客户端的socket转换成TserverClientWinSocket，TserverClientWinSocket也创建一个窗口接受asRead, asWrite, asConnect, asClose网络消息。