This could be useful for periodic tracing/profiling as well. Simply have a second instance with all debugging symbols and tracing enabled, but only accept() a client every X seconds.
Sadly it doesn't work like that.. if 2 processes have the same port number bound, then approximately 50% of clients will hash onto the second receive queue. If the debug process only accepts a few connections every so often, then nearly 50% of traffic will essentially be dropped on the floor
It's also not possible to occasionally listen and unlisten.. that causes the hash modulus to change, sending traffic to the wrong sockets and (most likely) resetting all existing connections