lat_rpc is a client/server program that measures interprocess communication latencies. The benchmark
passes a token back and forth between the two processes (this sort of benchmark is frequently referred to
as a ``hot potato'' benchmark). No other work is done in the processes.
This benchmark may be compared to the TCP and UDP forms of the same benchmark to accurately see the cost
of using RPC versus the cost of using plain old TCP or UDP sockets. It is worth noting that the RPC form
is passing back and forth a single byte, not some long complicated record.
lat_rpc has three forms of usage: as a server (-s), as a client (lat_rpc localhost), and as a shutdown
(lat_rpc -S localhost).
The client form may specify the protocol over which the RPCs are performed. The default is to measure
performance for both udp and tcp.