I need to write a sort of proxy server and my design is a little like this:
1. Socket server (using Windows Event select model). program has a listener thread listenimng for network events.
2. list of clients (currently indexed by socketid).
3. socket server accepts a new connection and then creates a new thread for each client. The new thread creates a socket connection to end destination server (want a persistent connection).
I have already written the socket server and that works fine. My problem is as new messages come in from clients, how do I pass this message onto the relevant thread (so message can be sent onto to destination server).
In my server I get the address of the final destination server from the client message. I can lookup the client socket from the list of client sockets. But how do I then send the message to the correct thread?
In the threading I have worked with so far, the thread function just runs a loop. Do I call the thread function, passing it the message as a parameter?
Anyone got any good ideas on how to do this?
Could I not just have a map of client socket id and destination server socket id.
After accept on a client socket, connect to destination server and send msg. Save destination server socket id to the map.
Thenceforth, when get a new msg from client, lookup dest server in map and send message to requisite server socket.
Actually, do I need to make this multi-threaded?
Use a messaging or synchronization primitive, such as a queue, mailbox, event signal, etc.
For instance, if each thread has a queue for data to send, you would simply write to this queue. The queue must be thread safe to allow concurrent access.