File transfer from multiple clients - one server

Question

I am new to the windows socket programming using C# and i want to create an application that runs under multiple clients with one server. The server will wait for the incoming connection from client and assign a new port to each connection. Server should accept the file transfer from multiple clients. The transferring file can be about 10-20 MB.

I went through many tutorials and examples but they do transfer in one-to-one pattern. I was able to connect the multiple clients to one server and sending the text through it. The server is accepting the clients connection and their sent text messages but I have no idea transferring the files in same pattern.

I will be a great help if there is any tutorials, examples or guide that help me understand the file transfer from multiple clients to single server.

Why invent something new? Implement an FTP server, and have the clients connect to it. There are thousands of examples of this out there. — JamieMeyer, Jun 18 '14 at 04:01
I dont want two way transfer. Only client can transfer the file and the file will be sorted in different structure by the server with db implementation. Any idea about this? — user456064, Jun 18 '14 at 06:53
You have complete control of the the client and server, correct. A file upload via the client should work perfectly via FTP.. And, you can disable downloads in your server. — JamieMeyer, Jun 18 '14 at 07:10
do you have any good examples or tutorials for FTP server and client based on C#. I can find many such in google but i would like to get your suggestion. — user456064, Jun 19 '14 at 01:15

score -1 · Answer 1 · edited Feb 07 '23 at 15:10

it's quite easy actually Save the incoming connections in an array. start a new thread that gets the data from the socket and put it in an output buffer (make sure it's threadsafe) and that's it

edit 18-6-2014 here is a c++ example from my network class it is not perfect but you will get the idea m_clientList is a vector in which I save the connections but I don't know if c# has a vector something like a list will work to

DWORD WINAPI Network::ServerAcceptConnections(LPVOID lpParam)
{
    Network* network = (Network*) lpParam;
    SOCKET new_socket;
    char *message;
    int c = sizeof(struct sockaddr_in);
    
    DWORD dwWaitResult;
    Sleep(100);
    while (true)
    {
        new_socket = accept(pNetwork->m_s , (struct sockaddr *)&pNetwork->m_client, &c);

        if (new_socket != INVALID_SOCKET )
        {
            dwWaitResult = WaitForSingleObject( 
            pNetwork->m_ClientListMutex,    // handle to mutex
            INFINITE);  // no time-out interval
            if (dwWaitResult == WAIT_OBJECT_0)
            {
                __try 
                { 
                    //Reply to the client
                    if (network->m_clientList.size() < network->m_maxConnections)
                    {
                        if(network->m_debugModus) print("DEBUG MODUS: Connection accepted\r\n");
                        network->m_clientList.push_back(new_socket);
                        message = NETWORK_CLASS_CONNECTION_SUCCES;
                        Message out;
                        out.client = new_socket;
                        out.message = message;
                        out.size = strlen(message);
                        pNetwork->SendData(out);
                    }
                    else
                    {
                        if(pNetwork->m_debugModus) printf("DEBUG MODUS: Max connections reached\r\n");
                        message = NETWORK_CLASS_MAX_CONNECTIONS;

                        pNetwork->Send(new_socket, message, strlen(message));
                        closesocket(new_socket);
                    }
                } 

                __finally { 
                    // Release ownership of the mutex object
                    if (! ReleaseMutex(network->m_ClientListMutex)) 
                    { 
                        if(pNetwork->m_debugModus) printf("DEBUG MODUS: AcceptConnections: Cant Relese the Mutex\r\n");
                    } 
                } 
            }   
            else if (dwWaitResult == WAIT_ABANDONED)
            {
                if(network->m_debugModus) print("DEBUG MODUS: SendDataThread: The thread got ownership of an abandoned mutex\r\n");
                return FALSE; 
            }
        }
        else
        {
            if(pNetwork->m_debugModus) printf("DEBUG MODUS: accept failed with error code : %d\r\n" , WSAGetLastError());
        }
    }
    return TRUE;
}

depends on the aplication if he knows that there will be only 10 clients use that are there more use a vector or somthing like that — Robert Stevens, Jun 18 '14 at 01:17
-1: wish I could downvote twice. .NET has the `List` type and many other expandable lists. There is little value in using an array. — John Saunders, Jun 18 '14 at 04:43

File transfer from multiple clients - one server

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