10057 WSA異常時SendBuf通過插座

Question

客戶：

//is called when the client tries to log in 
    procedure TLogin_Form.btnLoginClick(Sender: TObject); 
    var LoginQuery: TQuery; 
    begin 
     //If socket not open, open it 
     if not LoginSocket.Active then 
     begin 
      LoginSocket.Open; 
     end; 

     //create package 
     LoginQuery.Login := ledtName.Text; 
     LoginQuery.Passwort := ledtPasswort.Text; 
     LoginQuery.IP := LoginSocket.Socket.LocalAddress; 
     //send package 
     LoginSocket.Socket.SendBuf(LoginQuery, SizeOf(LoginQuery)); 
    end; 

服務器：

//This procedure is executed when I click on start server button 
    procedure TServer_Form.btnStartStopClick(Sender: TObject); 
    begin 
     //If not open, open it 
     if not ServerSocket.Active then 
     begin 
      btnStartStop.Caption := 'stop server'; 
      //Open ServerSocket 
      ServerSocket.Open; 
     end 
     else 
     begin 
     //If Socket open, close it, but watch for active connctions. 
     if ServerSocket.Socket.ActiveConnections > 0 then 
      begin 
      ShowMessage('Clients still logged in'); 
      end 
     else 
      begin 
      //If no clients connected, close socket 
      ServerSocket.Close; 
      end; 
     end; 
    end; 

    //This procedure is called to verify weather the user is logged in and to send the verification back 
    procedure UserCheckExist(Login, Passwort: string); 
    var LoginReply: TReply; 
    begin 
     begin 
      //Connect to DB 
      DBConnect(true); 
      DM.AQ_LOGIN.Close; 
      DM.AQ_LOGIN.SQL.Clear; 
      //Count of BLOGINs 
      DM.AQ_LOGIN.SQL.Add('select count(BLOGIN) from BENU where BLOGIN = ''' + Login + ''' AND BPW = ''' + Passwort + ''''); 
      DM.AQ_LOGIN.Open; 
      //LoginReply.Action tells the client then what to do with the LoginReply.Value 
      LoginReply.Action := 0; 
      //if user unique 
      if DM.AQ_LOGIN.Fields[0].AsInteger = 1 then 
      begin 
       //LoginReply.Value = 1 means the client is allowed to log in 
       LoginReply.Value := 1; 
       //THIS RETURNS THE WSA 10057 EXCEPTION of user is unique 
       Server_Form.ServerSocket.Socket.SendBuf(LoginReply, SizeOf(LoginReply)); 
      end 
      else 
      begin 
       //LoginReply.Value = 0 means the client is NOT allowed to log in 
       LoginReply.Value := 0; 

       //THIS RETURNS THE WSA 10057 EXCEPTION if user is NOT unique 
       Server_Form.ServerSocket.Socket.SendBuf(LoginReply, SizeOf(LoginReply)); 
      end; 
      //Close ADOQuery 
      DM.AQ_LOGIN.Close; 
      //Close DB Connection 
      DBConnect(false); 
     end; 
    end; 

    //Is called when something is in the socket connection 
    procedure TServer_Form.ServerSocketClientRead(Sender: TObject; 
     Socket: TCustomWinSocket); 
    var Query: TQuery; 
    begin 
     //Reads from the Socket (cant use ServerSocket.Socket.ReceiveBuf whysoever, but this is another thread) 
     Socket.ReceiveBuf(Query, SizeOf(Query)); 
     case Query.Action of 
     //If Query.Action = 0, which means the client tries to login call UserCheckExist 
     0: UserCheckExist(Query.Login, Query.Passwort); 
     //Otherwise, getfuckedup 
     else ShowMessage('Query Action not defined'); 
     end; 
    end; 

一個奇怪的是，我必須從客戶端兩次發送登錄+ PW 。

第一次發送（客戶端），我在服務器上得到onClientConnect和onAccept。 我第二次發送（客戶端），服務器執行代碼，直到我標記的行。我得到了10057 WSA例外。

爲什麼我得到這個錯誤？奇怪的是，如果我打開服務器上的服務器之前，我得到異常說'套接字未打開'的線路上，我得到它反正

Answer 1

您所顯示的代碼不會在兩個客戶端和服務器端由於您的代碼中的一些錯誤。當TClientSocket設置爲ctNonBlocking模式（我假設您正在使用）時，Open（）將不會觸發OnConnect事件，直到btnLoginClick（）退出並且流已返回到消息隊列之後纔會觸發OnConnect事件。在OnConnect事件觸發之前，從套接字讀取或寫入數據是無效的。所以你應該將你的發送代碼移入OnConnect事件本身。您還需要考慮到SendBuf（）可能無法將單個數據包中的所有數據發送出去。如果SendBuf（）返回-1，WSAGetLastError（）事後返回WSAEWOULDBLOCK（如果OnError事件沒有被觸發，它將始終爲真），那麼數據不會被完整發送。您必須在任何地方緩衝任何未發送的字節，然後等待OnWrite事件觸發，然後再嘗試將已緩衝的字節或其他任何事物寫入套接字。

至於你的服務器代碼，你正試圖將出站數據寫入錯誤的對象。您必須使用OnRead事件提供的TCustomWinSocket對象讀取和寫入數據。您正試圖將數據寫入服務器的TServerWinSocket對象，而不是任何連接的客戶端的有效套接字端點。您還需要查看ReceiveBuf（）的返回值以便處理部分傳輸。

嘗試更多的東西像下面這樣：

常見：

type 
    // helper class that holds buffered input/output data 
    SocketBuffers = class 
    public 
    constructor Create; 
    destructor Destroy; 
    Inbound: TMemoryStream; 
    Outbound: TMemoryStream; 
    end; 

constructor SocketBuffers.Create; 
begin 
    inherited; 
    Inbound := TMemoryStream.Create; 
    Outbound := TMemoryStream.Create; 
end; 

destructor SocketBuffers.Destroy; 
begin 
    Inbound.Free; 
    Outbound.Free; 
    inherited; 
end; 

// removes processed bytes from a buffer 
procedure CompactBuffer(Buffer: TMemoryStream); 
begin 
    if Buffer.Position > 0 then 
    begin 
    // bytes have been processed, remove them from the buffer... 
    if Buffer.Position < Buffer.Size then 
    begin 
     // move unprocessed bytes to the front of the buffer... 
     Move(Pointer(Longint(Buffer.Memory)+Buffer.Position)^, Buffer.Memory^, Buffer.Size - Buffer.Position); 
     // reduce the buffer size just the remaining bytes... 
     Buffer.Size := Buffer.Size - Buffer.Position; 
    end else 
    begin 
     // all bytes have been processed, clear the buffer... 
     Buffer.Clear; 
    end; 
    end; 
end; 

// sends raw bytes to the specified socket, buffering any unsent bytes 
function SendDataToSocket(Socket: TCustomWinSocket; Data: Pointer; DataSize: Integer; Buffer: TMemoryStream): Integer; 
var 
    DataPtr: PByte; 
    NumSent: Integer; 
begin 
    Result := 0; 
    DataPtr := PByte(Data); 
    if DataSize > 0 then 
    begin 
    if Buffer.Size = 0 then 
    begin 
     // the buffer is empty, send as many bytes as possible... 
     repeat 
     NumSent := Socket.SendBuf(DataPtr^, DataSize); 
     if NumSent <= 0 then Break; // error or disconnected 
     Inc(DataPtr, NumSent); 
     Dec(DataSize, NumSent); 
     Inc(Result, NumSent); 
     until DataSize = 0; 
     if DataSize = 0 then Exit; // nothing left to send or buffer 
    end; 
    // add unsent bytes to the end of the buffer... 
    Buffer.Seek(0, soFromEnd); 
    Buffer.WriteBuf(DataPtr^, DataSize); 
    Inc(Result, DataSize); 
    end; 
end; 

// sends buffered bytes to the specified socket 
procedure SendBufferToSocket(Socket: TCustomWinSocket; Buffer: TMemoryStream); 
var 
    DataPtr: PByte; 
    NumSent: Integer; 
begin 
    // start at the beginning of the buffer 
    Buffer.Position := 0; 
    DataPtr := PByte(Buffer.Memory); 
    while Buffer.Position < Buffer.Size do 
    begin 
    NumSent := Socket.SendBuf(DataPtr^, Buffer.Size - Buffer.Position); 
    if NumSent <= 0 then Break; // error or disconnected 
    Inc(DataPtr, NumSent); 
    Buffer.Seek(NumSent, soFromCurrent); 
    end; 
    // remove bytes that were sent... 
    CompactBuffer(Buffer); 
end; 

// reads raw bytes from the specified socket ands buffers them 
procedure ReadBufferFromSocket(Socket: TCustomWinSocket; Buffer: TMemoryStream); 
var 
    NumRecv: Integer; 
    OldSize: Integer; 
begin 
    repeat 
    NumRecv := Socket.ReceiveLength; 
    if NumRecv <= 0 then Exit; // error or no data available 

    // increase the size of the buffer 
    OldSize := Buffer.Size; 
    Buffer.Size := Buffer.Size + NumRecv; 

    // read bytes into the new memory space 
    NumRecv := Socket.ReceiveBuf(Pointer(Longint(Buffer.Memory)+OldSize)^, NumRecv); 
    if NumRecv <= 0 then 
    begin 
     // nothing read, free the unused memory 
     Buffer.Size := OldSize; 
     Exit; 
    end; 
    until False; 
end; 

客戶：

var 
    Buffers: SocketBuffers = nil; 

procedure TLogin_Form.FormCreate(Sender: TObject); 
begin 
    Buffers := SocketBuffers.Create; 
end; 

procedure TLogin_Form.FormDestroy(Sender: TObject); 
begin 
    LoginSocket.Close; 
    Buffers.Free; 
end; 

procedure TLogin_Form.btnLoginClick(Sender: TObject); 
begin 
    if not LoginSocket.Active then 
    begin 
    Buffers.Inbound.Clear; 
    Buffers.Outbound.Clear; 
    LoginSocket.Open; 
    end; 
end; 

procedure TLogin_Form.LoginSocketConnect(Sender: TObject; Socket: TCustomWinSocket); 
var 
    LoginQuery: TQuery; 
begin 
    LoginQuery.Login := ledtName.Text; 
    LoginQuery.Passwort := ledtPasswort.Text; 
    LoginQuery.IP := LoginSocket.Socket.LocalAddress; 

    // send query, buffering unsent bytes if needed... 
    SendDataToSocket(Socket, @LoginQuery, SizeOf(LoginQuery), Buffers.Outbound); 
end; 

procedure TLogin_Form.LoginSocketRead(Sender: TObject; Socket: TCustomWinSocket); 
var 
    Buffer: TmemoryStream; 
    Available: Integer; 
    Query: TQuery; 
begin 
    Buffer := Buffers.Inbound; 

    // read available bytes into the buffer... 
    ReadBufferFromSocket(Socket, Buffer); 

    // process complete queries, ignore unfinished queries until later... 
    Buffer.Position := 0; 
    repeat 
    Available := Buffer.Size - Buffer.Position; 
    if Available < SizeOf(Query) then Break; 
    Buffer.ReadBuf(Query, SizeOf(Query)); 
    // process query as needed ... 
    until False; 

    // remove processed bytes from the buffer... 
    CompactBuffer(Buffer); 
end; 

procedure TLogin_Form.LoginSocketWrite(Sender: TObject; Socket: TCustomWinSocket); 
begin 
    // can send any buffered bytes now... 
    SendBufferToSocket(Socket, Buffers.Outbound); 
end; 

服務器：

procedure TServer_Form.btnStartStopClick(Sender: TObject); 
begin 
    if not ServerSocket.Active then 
    begin 
    btnStartStop.Caption := 'stop server'; 
    ServerSocket.Open; 
    end 
    else if ServerSocket.Socket.ActiveConnections > 0 then 
    begin 
    ShowMessage('Clients still logged in'); 
    end 
    else 
    begin 
    ServerSocket.Close; 
    end; 
end; 

procedure UserCheckExist(Socket: TCustomWinSocket; Login, Password: string); 
var 
    LoginReply: TReply; 
begin 
    ... 
    LoginReply.Value := ...; 

    // send query, buffering unsent bytes if needed... 
    SendDataToSocket(Socket, @LoginReply, Sizeof(LoginReply), SocketBuffers(Socket.Data).Outbound); 
    ... 
end; 


procedure TServer_Form.ServerSocketClientConnect(Sender: TObject; Socket: TCustomWinSocket); 
begin 
    Socket.Data := SocketBuffers.Create; 
end; 

procedure TServer_Form.ServerSocketClientDisconnect(Sender: TObject; Socket: TCustomWinSocket); 
begin 
    SocketBuffers(Socket.Data).Free; 
    Socket.Data := nil; 
end; 

procedure TServer_Form.ServerSocketClientRead(Sender: TObject; Socket: TCustomWinSocket); 
var 
    Buffer: TmemoryStream; 
    Available: Integer; 
    Query: TQuery; 
begin 
    Buffer := SocketBuffers(Socket.Data).Inbound; 

    // read available bytes into the buffer... 
    ReadBufferFromSocket(Socket, Buffer); 

    // process complete queries, ignore unfinished queries until later... 
    Buffer.Position := 0; 
    repeat 
    Available := Buffer.Size - Buffer.Position; 
    if Available < SizeOf(Query) then Break; 
    Buffer.ReadBuf(Query, SizeOf(Query)); 
    // process query as needed ... 
    case Query.Action of 
     0: UserCheckExist(Socket, Query.Login, Query.Password); 
     ... 
    end; 
    until False; 

    // remove processed bytes from the buffer... 
    CompactBuffer(Buffer); 
end; 

procedure TServer_Form.ServerSocketClientWrite(Sender: TObject; Socket: TCustomWinSocket); 
begin 
    // can send any buffered bytes now... 
    SendBufferToSocket(Socket, SocketBuffers(Socket.Data).Outbound); 
end;