Question

I’m trying to build a simple multithreaded tcp server. The client connects and sends data to server, the server responds and waits for data again. The problem is I need the server to listen for incoming data in separate thread and be able to send command to client any time (for example to notify about new update). As far as I understood, when ever client sends data to server, if server doesn’t respond with any data, client app doesn’t let me send more data, server simply doesn’t receive them. If I send data ether way around, does the data need to be ‘acknowledged’ for tcpclient?

Here’s the source for the server: http://csharp.net-informations.com/communications/files/print/csharp-multi-threaded-server-socket_print.htm

How can I make the server send command to a client in separate thread outside the “DoChat” functions loop? or do I have to handle everything in that thread? Do I have to respond to each request client sends me? Thanks!

Answer 1

The problem is I need the server to listen for incoming data in separate thread

No, there is an async API. You can polll a list of threads to see which ahve new data waiting, obcviously to be done froa worker thread.

As far as I understood, when ever client sends data to server, if server doesn’t respond with any
data, client app doesn’t let me send more data, server simply doesn’t receive them.

That is a lot more crap programming than the way sockets work. Sockets are totally ok with streaming ata in sending and receiving direction att the same time.

How can I make the server send command to a client in separate thread outside the “DoChat”
functions

Wel, me diong your job costs money.

BUT: The example is retarded. As in- totally anti pattern. One thread per client? You will run into memroy problems and perforamnce problems once 1000+ clients connect. You get tons of context switches.

Second, the client is not async because it is not written so. Mayy I suggest giong to the documentation, reading up on sockts an trying to build that yourself? THEN come back with questions that show more than “i just try to copy paste”.

With proper programming this is totally normal. I have a similar application in development, sending data lall the time to the client and getting commands from the client to modify the data stream. Works liek a charm.

If I send data ether way around, does the data need to be ‘acknowledged’ for tcpclient?

Yes and no. No, not for TCP – TCP does it’Äs wn handshake under the hoods. Yes, if your protocol decides it has to, which is a programmer level design decision. It may or may not be necesssary, depending on the content of the data. Sometimes the acknowledgement provides more information (timestamp server side, tracking numer) and is not pure ly there for “I got it”.