Is it possible for me to accept a connection and have it die withouit my knowing, then accept antoher connection on the same socket number?

Question

Is it possible for me to accept a connection and have it die withouit my knowing, then accept another connection on the same socket number?

I've got a thread to do protocol parsing and response creation. I've got another thread to handle all my network IO and one more thread to handle new incomcing connection requests. That makes three threads total. Using select in the IO thread, I get a failure and have to search for the dead socket. I am afraid there is the case that accept might want to accept a new connection on a socket number that was previous dead.

I'd assume this can't happen until I "shutdown() || close();" the socket that may be dead on the server side. If it could happen, is the only solution to setup mutexes to halt everything while I sort out what sockets have gone bonkers?

Thanks, Chenz

Answer 1

A socket descriptor wont get reused until you close it.

Assuming we're talking TCP, then if the remote side closes its send side of the connection then you'll get a recv() returning 0 bytes to tell you of this. Since TCP support half closed connections you could still be able to send data to the remote side of the connection (if your application level protocol is made that way) or you might take the fact that the remote side has closed its send side as an indication that you should do the same.

You use shutdown() to close either your send side or your recv side or both sides of the connection. You use close() to close the socket and release the handle/descriptor for reuse.

So, in answer to your question. No, you wont be able to accept another connection with the same socket descriptor until you call close() on the descriptor that you already have.

You MAY accept a connection on a new socket descriptor; but that's probably not a problem for you.