更新 由于Stackoverflow上的管理员问题，我在MSDN论坛上发布了同样问题的精简版。下面的这个文本使用了MyNetworking.dll，但这不是问题。这是一个非常纤薄的客户端 - 服务器的东西，问题是完全一样的。随意试试=） http://social.msdn.microsoft.com/Forums/en-US/netfxnetcom/thread/d3d33eb9-7dce-4313-929e-a8a63d0f1e03 的 / UPDATE
所以，我有一个奇怪的错误。
通常，我们有一个DLL来处理我们的网络。让我们称之为MyNetworking.dll。我们在服务器和客户端的任何地方都使用它，并且已经使用了5年。到目前为止，我没有遇到任何问题。
我有一个“XMLPoller”，它从MySQL数据库读取XML，将其序列化为byte []数组并通过网络发送。这些特定的XML消息是序列化形式的627字节。
XMLPoller连接到“远程服务器”上的端口（恰好是localhost）并一次发送一个数据包。在数据包nbr 105处，连接已关闭。从XMLPoller发送104个数据包并由服务器接收。 104 x 627 = 65208字节。但是数据包105，当发送的总字节数为65835时，连接将被关闭并显示以下错误：
System.IO.IOException: Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host. ---> System.Net.Sockets.SocketException: An existing connection was forcibly closed by the remote host
at System.Net.Sockets.Socket.EndReceive(IAsyncResult asyncResult)
at System.Net.Sockets.NetworkStream.EndRead(IAsyncResult asyncResult)
这是服务器上的错误。但是，我已经逐步完成了XMLPoller（客户端），我看到最后627个字节被发送（因此发送直到65835个字节）并且我看到客户端没有错误，它通过发送没有问题。
当我调试更多时，我也在客户端中收到此错误：
Unable to read data from the transport connection: An established connection was aborted by the software in your host machine.
我想我已经确认它在客户端中存在错误。我正在逐步完成代码，在服务器上捕获任何异常之前，我在客户端上获得如上所述的例外。
在我看来，服务器从未收到它，得到上面的错误。服务器因客户端上发生的事情而关闭连接。但是，客户端上的错误是在TCPInput中;由于某些原因，流读取数据已经死了？
我没有在MyNetworking.dll中缓冲任何内容。
当我在Socket（服务器上）上获得新连接时，我会执行以下代码：
public void setConnected(Socket thisClient)
{
NetworkStream stream = new NetworkStream(thisClient);
socket = thisClient;
output = new TCPOutput(stream, outputHandler,this);
remoteIP = this.socket.RemoteEndPoint.ToString();
changeState(State.Connected);
try
{
stream.BeginRead(inputBuffer, 0, 5000, new AsyncCallback(OnDataReceived), null);
}
catch (Exception e)
{
this.disconnect();
}
}
然后，OnDataReceived方法（实际接收数据）：
public void OnDataReceived(IAsyncResult asyn)
{
int nbrRead = 0;
byte[] tmp = null;
try
{
nbrRead = stream.EndRead(asyn);
tmp = new byte[nbrRead];
}
catch (Exception e)
{
// *** HERE IS WHERE THE EXCEPTION IS CAUGHT ***
System.Diagnostics.Debugger.Log(0, "Bla1", e.ToString());
this.disconnect();
}
if (nbrRead > 0)
{
try
{
Array.Copy(inputBuffer, 0, tmp, 0, nbrRead);
}
catch(Exception e)
{
System.Diagnostics.Debugger.Log(0, "Bla2", e.ToString());
this.disconnect();
}
preProcessMessage(tmp);
try
{
stream.BeginRead(inputBuffer, 0, 5000, new AsyncCallback(OnDataReceived), new object());
}
catch(Exception e)
{
System.Diagnostics.Debugger.Log(0, "Bla3", e.ToString());
this.disconnect();
}
}
else
this.disconnect();
}
现在我对发生的事情毫无头绪......有什么想法吗？
发送数据的客户端代码：
public bool sendData(byte[] data)
{
if(this.state == State.Connected)
{
if (data != null && data.Length > 0)
{
try
{
//data = Crypto.Encrypt("a1s2d3", data);
outputStream.Write(data, 0, data.Length);
}
catch(Exception e)
{
System.Diagnostics.Debug.WriteLine("ClientHandler.sendData> " + e.ToString());
}
//parent.outDataLog(data.Length);
}
}
return true;
}
我尝试对来自客户端的传出流进行刷新 - 无效：
public bool sendData(byte[] data)
{
if(this.state == State.Connected)
{
if (data != null && data.Length > 0)
{
try
{
//data = Crypto.Encrypt("a1s2d3", data);
outputStream.Write(data, 0, data.Length);
outputStream.Flush();
}
catch(Exception e)
{
System.Diagnostics.Debug.WriteLine("ClientHandler.sendData> " + e.ToString());
}
//parent.outDataLog(data.Length);
}
}
return true;
}
我知道，这段代码很旧，而不是世界上的美女。但它已经工作了5年，所以=）
ClientHandler.cs（实际客户端用于发送的内容等）
using System;
using System.Net.Sockets;
using System.Net;
using System.Threading;
namespace tWorks.tNetworking.tNetworkingCF
{
/// <summary>
/// Summary description for connectionHandler.
/// </summary>
public class ClientHandler
{
#region Fields (17)
string address;
Connector connector;
DataHandler dataHandler;
int id;
TCPInput input;
int interval;
string localAddress;
IPEndPoint localPoint;
int localPort;
NetworkStream outputStream;
public TTCPClientInterface parent;
int port;
tWorks.tNetworking.Protocol.Protocol protocol;
bool reconnect;
string remoteIP;
Socket socket;
public State state;
#endregion Fields
#region Enums (1)
public enum State {Disconnected,Connecting,Connected}
#endregion Enums
#region Constructors (4)
public ClientHandler(int id, TTCPClientInterface parent, Socket socket, tWorks.tNetworking.Protocol.Protocol protocol)
{
this.id=id;
this.parent = parent;
this.protocol = protocol;
dataHandler = new DataHandler(protocol, this);
setConnected(socket);
}
public ClientHandler(int id, TTCPClientInterface parent, Protocol.Protocol protocol)
{
this.id=id;
this.parent = parent;
this.protocol = protocol;
dataHandler = new DataHandler(protocol, this);
state = State.Disconnected;
}
public ClientHandler(int id, TTCPClientInterface parent, Socket socket)
{
this.id=id;
this.parent = parent;
setConnected(socket);
}
public ClientHandler(int id, TTCPClientInterface parent)
{
this.id=id;
this.parent = parent;
this.protocol = null;
changeState(State.Disconnected);
}
#endregion Constructors
#region Delegates and Events (4)
// Delegates (2)
public delegate void ConnectionLostDelegate(string message);
public delegate void exceptionDelegate(Exception ex);
// Events (2)
public event exceptionDelegate ConnectionFailed;
public event ConnectionLostDelegate ConnectionLostEvent;
#endregion Delegates and Events
#region Methods (17)
// Public Methods (16)
public void connect(string address, int port, int retryInterval, bool reestablish)
{
System.Random rand = new Random();
localPort = rand.Next(40000, 60000);
IPAddress localIP = Dns.GetHostEntry(Dns.GetHostName()).AddressList[0]; // new IPAddress(Dns.GetHostByName(Dns.GetHostName()).AddressList[0].Address);
connect(address, port, retryInterval, reestablish, localIP.ToString(), localPort);
}
/// <summary>
/// Will connect to the address and port specified. If connection failed a new attempt will be made according to the Interval parameter.
/// If connection is lost attempts to reastablish it will be made if Reestablish is set to true.
/// </summary>
/// <param name="address"></param>
/// <param name="port"></param>
/// <param name="retryInterval"></param>
/// <param name="reestablish"></param>
public void connect(string address, int port, int retryInterval, bool reestablish, string localAddress, int localPort)
{
this.reconnect = reestablish;
this.address = address;
this.port = port;
this.interval = retryInterval;
this.localAddress = localAddress;
this.localPort = localPort;
changeState(State.Connecting);
connector = new Connector(address, port, this, interval, localPoint, reestablish);
connector.Connect();
}
public void disconnect()
{
reconnect = false;
if (connector != null)
{
connector.stopConnecting();
}
setDisconnected();
}
public void dispose()
{
}
public void failedConnect(Exception e)
{
if (ConnectionFailed != null)
ConnectionFailed(e);
}
public int getID()
{
return this.id;
}
public string getIP()
{
return remoteIP;
}
public bool isConnected()
{
return this.state == State.Connected;
}
public void outDataLog(int nbrBytes)
{
parent.outDataLog(nbrBytes, id);
}
public void preProcessMessage(byte[] data)
{
//data = Crypto.Decrypt("a1s2d3", data);
if(protocol != null)
dataHandler.addData(data);
else
processMessage(data);
}
public void processMessage(byte[] data)
{
parent.processMessage(data,this);
}
public bool sendData(byte[] data)
{
if(this.state == State.Connected)
{
if (data != null && data.Length > 0)
{
try
{
//data = Crypto.Encrypt("a1s2d3", data);
outputStream.Write(data, 0, data.Length);
outputStream.Flush();
}
catch(Exception e)
{
System.Diagnostics.Debug.WriteLine("ClientHandler.sendData> " + e.ToString());
}
//parent.outDataLog(data.Length);
}
}
return true;
}
public void setConnected(Socket thisClient)
{
socket = thisClient;
outputStream = new NetworkStream(thisClient);
input = new TCPInput(outputStream, this);
remoteIP = this.socket.RemoteEndPoint.ToString();
changeState(State.Connected);
}
public void setDisconnected()
{
try
{
if (this.state == State.Connected)
{
changeState(State.Disconnected);
//socket.Shutdown(SocketShutdown.Both);
socket.Close();
}
}
catch { }
if (reconnect)
this.connect(address, port, interval, true, localAddress, localPort);
}
public void stopConnect()
{
connector.stopConnecting();
changeState(State.Disconnected);
}
public override string ToString()
{
string returnString = "(D)";
if(this.state == State.Connected)
returnString = this.getIP();
return returnString;
}
// Private Methods (1)
private void changeState(State state)
{
if (this.state == State.Connected && state == State.Disconnected)
{
if (ConnectionLostEvent != null)
ConnectionLostEvent("Uppkoppling bröts.");
}
this.state = state;
parent.connStateChange(this);
}
#endregion Methods
}
}
这是TCPInput.cs正在侦听传入数据并将其转发给ClientHandler（见上文）：
using System;
using System.Net.Sockets;
using System.Net;
using System.Threading;
namespace tWorks.tNetworking.tNetworkingCF
{
public class TCPInput
{
NetworkStream stream;
ClientHandler client;
public TCPInput(NetworkStream nS, ClientHandler client)
{
stream = nS;
this.client = client;
Thread t = new Thread(new ThreadStart(run));
t.IsBackground = true;
t.Name = "TCPInput";
t.Start();
}
public void run()
{
bool continueRead = true;
byte[] readBuffer = new byte[32768];
byte[] receivedBuffer = null;
int nbrBytesRead = 0;
int receivedBufferPos = 0;
while(continueRead)
{
try
{
nbrBytesRead = 0;
nbrBytesRead = stream.Read(readBuffer, 0, 10000);
receivedBuffer = new byte[nbrBytesRead];
}
catch (Exception e)
{
System.Diagnostics.Debug.WriteLine("TCPInput> Exception when stream.Read: " + e.ToString());
continueRead = false;
}
if(nbrBytesRead > 0)
{
try
{
Array.Copy(readBuffer, 0, receivedBuffer, receivedBufferPos, nbrBytesRead);
}
catch (Exception e)
{
System.Diagnostics.Debug.WriteLine("TCPInput> Exception when Array.Copy: " + e.ToString());
continueRead = false;
}
client.preProcessMessage(receivedBuffer);
}
else
{
// *** I can break here, the nbrOfBytes read is 0 when this whole thing explodes =)
System.Diagnostics.Debug.WriteLine("TCPInput> Number of bytes read == 0! Setting continueRead = false");
continueRead = false;
}
}
client.setDisconnected();
}
}
}
答案 0 :(得分：1)
这个数字（“因此发送直到65835字节”）神奇地接近2^16-1（65535） - 看起来只有一个数据包！
（我假设它只是更大的尺寸，使得事情变成了kaboom！ - 这可以可靠地测试。）
我怀疑有一个无符号的16位变量（在库中）你需要更多范围的东西。也许你可以定期“清空”库的内部或者在多个连接中执行操作？ （好吧，只是试图抛出一些'快速黑客'的想法： - ）
答案 1 :(得分：1)
问题在于您的其他代码，即“客户端”。它在发送所有'数据包'后关闭连接。您必须等到服务器收到所有这些服务器。除了明确协商之外，一种简单的方法是等待服务器关闭连接。
答案 2 :(得分：1)
因此，在经过大量测试并与我的犯罪伙伴讨论后，我们发现不是使用端口21而是使用端口22 - 问题就消失了。
我不知道为什么它会像这样，但确实......
答案 3 :(得分：0)
你为我提出了问题。就像你为什么选择这个服务的知名端口？我不相信巧合，并怀疑你使用“犯罪伙伴”一词可能有更多的真相，我会关心与之相关。
然后我也想知道你为什么假设一个Windows bug而不是MyNetowrking.dll中的一个。当然，你已经用了五年了。但它仍然没有微软提供代码的审查程度。