Member Avatar for krosty4782

Hi!

Im having a problem in the next line:

i = socket.Receive(buffer)

buffer is defined as: byte[] buffer = new byte[1024];

It crash when its waiting for the answer.

In c++ im sending this:

len = send(sock,"hola",4,0);

Any idea?

Thanks

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  • Latest Post Latest Post by krosty4782

Dani AI

Generated

As later reported, the real problem was a second Receive loop running on a different thread. Two concurrent readers on the same Socket lead to races, blocking surprises, and hard-to-debug failures. 's request for more code was the right move — knowing whether multiple threads call Receive is one of the first things to check.

Key points and best practices:

  • Only one thread/callback should call Receive/Read for a given socket. If multiple components need the data, have a single reader that dispatches messages to a thread-safe queue or event.
  • Always use the integer return value from Receive. A return of 0 means the peer closed the connection. Decode only the bytes actually read (Encoding.GetString(buffer, 0, bytesRead)).
  • Use try/catch around socket ops and log SocketException details (SocketErrorCode / Message). That makes the real failure mode visible.
  • Consider nonblocking modes, a ReceiveTimeout, or async APIs (BeginReceive/EndReceive, ReceiveAsync, or NetworkStream.ReadAsync) instead of blocking calls on arbitrary threads.
  • Agree on framing between sender and receiver (length prefix or delimiter). A C++ call like send(sock,"hola",4,0) sends exactly 4 bytes (no NUL); both sides must expect the same framing.

Example receiver pattern (one dedicated reader):

var buf = new byte[1024];
try {
    while (true) {
        int n = socket.Receive(buf, 0, buf.Length, SocketFlags.None);
        if (n == 0) break; // remote closed
        string msg = Encoding.UTF8.GetString(buf, 0, n);
        messageQueue.Enqueue(msg); // single reader hands off work
    }
} catch (SocketException ex) {
    // log ex.SocketErrorCode and ex.Message
}

Troubleshooting tips: add logging around thread entry/exit for any receive loops, use Socket.Available or Poll to inspect readiness, and capture packet traces (e.g., Wireshark) to confirm what the peer actually sends.

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Member Avatar for Momerath

Do you open the socket? We'll need more code to see what might be the problem.

Member Avatar for krosty4782

Yeah, socket is well open beacuse first i tried to send a string, and the string go well.

getSocket(numsock).socketSend("filemanager"); --> this is ok, beacuse server recive the string.
 Console.WriteLine(getSocket(numsock).socketRecv()); --> I will put down the method code
public string socketRecv()
        {
             buffer = new byte[1024];
                        i = socket.Receive(buffer); --> Here crash 
                        string recibido = System.Text.Encoding.UTF8.GetString(buffer);
                        return recibido;

        }
Edited by krosty4782 because: n/a
Member Avatar for krosty4782

Solved !!
I had a loop o "receive()" in other thread of other class xD

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