C#中TCP通信的服务器端口繁忙问题

Question

i have used TCP communication in C# for client server communication.

Many of the clients are trying to connect to TCP server at a time.

i am facing server port busy issue. below is my server and client code.

is there any way, i can solve the server port busy issue.

Server Code
     /// <summary>
        /// 
        /// </summary>
        public void initializeListener(int iPortNumber,int iActivationPortNumber)
        {
            try
            {
                // BLTablePrototype.TablePrototypeDetails();
                System.Net.IPHostEntry ipHostInfo = Dns.Resolve(Dns.GetHostName());
                System.Net.IPAddress ipaddress = ipHostInfo.AddressList[0];

                serverSocket = new TcpListener(ipaddress, iPortNumber);

                try
                {
                    serverSocket.Stop();

                }
                catch { }

                serverSocket.Start();

                Common.BLConstants.isListnerStarted = true;



                //StartAccept();
                //WaitForClients();
            }
            catch (Exception ex)
            {

            }
        }


        public void ReceiveTCP()
        {  
            try
            {
                while (true)
                {
                    if (serverSocket.Pending())
                    {
                        TcpClient client = client = serverSocket.AcceptTcpClient();                        
                        if (client.Connected)
                        {
                            Thread thread = new Thread(WorkThread);
                            thread.Start(client);
                        }                      
                    }
                    else
                    {
                        Thread.Sleep(30000);
                    }
                }

            }
            catch (Exception ex)
            {

            }

        }


client Code

  client = new TcpClient();
                var result = client.BeginConnect(Wipro.EUA.Library.Cryptography.Decrypt(Common.BLConstants.strServerIPAddress), iPortnumber, null, null);
                result.AsyncWaitHandle.WaitOne(TimeSpan.FromSeconds(2));

                if (client.Connected)
                {

                    byte[] SendingBuffer = Encoding.UTF8.GetBytes(XElement.ToString());
                    netstream = client.GetStream();

                    int NoOfPackets = Convert.ToInt32(Math.Ceiling(Convert.ToDouble(SendingBuffer.Length) / Convert.ToDouble(BLConstants.iBufferSize)));
                    int TotalLength = (int)SendingBuffer.Length, CurrentPacketLength, FinalLength = 0, RemainingLength = TotalLength;
                    for (int k = 0; k < NoOfPackets; k++)
                    {
                        if (RemainingLength > BLConstants.iBufferSize)
                        {
                            if (k == 0)
                                CurrentPacketLength = k * BLConstants.iBufferSize;
                            else
                                CurrentPacketLength = k * BLConstants.iBufferSize;

                            FinalLength = CurrentPacketLength + BLConstants.iBufferSize;
                            RemainingLength = TotalLength - FinalLength;
                            netstream.Write(SendingBuffer, CurrentPacketLength, BLConstants.iBufferSize);
                        }
                        else
                        {
                            CurrentPacketLength = FinalLength;
                            netstream.Write(SendingBuffer, CurrentPacketLength, TotalLength - CurrentPacketLength);
                        }
                    }
                }

                client.EndConnect(result);
                isSuccess = true;

i have used TCP communication in C# for client server communication.

Many of the clients are trying to connect to TCP server at a time.

i am facing server port busy issue. below is my server and client code.

is there any way, i can solve the server port busy issue.

Answer 1

The issue as @MickyD commented, is the line:

Thread.Sleep(30000);

You accept only one connection and then sleeps for 30 seconds. Obviously, clients that will try to connect during those 30 seconds, will not get a reponse (timeout).

Actually, the solution is very simple.
You don't need all that login with the Pending and Sleep
It's enough to use only AcceptTcpClient .

AcceptTcpClient is a blocking method. It will block until a connection arrives.

The reason for using Pending is if you don't want to block, but you are blocking any way with the Thread.Sleep(30000)

All this is covered by the documentation :

AcceptTcpClient is a blocking method that returns a TcpClient that you can use to send and receive data. Use the Pending method to determine if connection requests are available in the incoming connection queue if you want to avoid blocking.

Also, you don't need to check if the client is connected(You are getting a connected connection...) So, your loop can become simpler:

while (true)
{
    TcpClient client = client = serverSocket.AcceptTcpClient();                        
    Thread thread = new Thread(WorkThread);
    thread.Start(client);
}