Forking with a listening socket

I'd like to make sure about the correctness of the way I try to use accept() on a socket.

I know that in Linux it's safe to listen() on a socket, fork() N children and then recv() the packets in all of them without any synchronisation from the user side (the packets get more or less load-balanced between the children). But that's UDP.

Does the same property hold for TCP and listen(), fo开发者_开发知识库rk(), accept()? Can I just assume that it's ok to accept on a shared socket created by the parent, even when other children do the same? Is POSIX, BSD sockets or any other standard defining it somewhere?

If you fork() and then accept() in your children only one child process is going to call accept() on a connection and then process it. This is pre-forking and the connections won't be shared among the children.

You can do a standard one child per connection scheme by reversing the order and accepting and forking. However both of these techniques are for efficiency, balancing, etc., not for sharing a particular connection.

TCP is different from UDP. It would be inadvisable to do that in TCP as you will almost certainly end up with a mess. A given received message can be spread over one or more packets and it would be more of a pain for multiple process to coordinate than would be to have one child handle the connection.