Sockets IPC based on IOBuffer

[Sergey Ulanov]

Hello Fuchsia Eng Council,

I'm working on a design for a new sockets IPC mechanism. It intends to improve BSD socket performance on Fuchsia by avoiding blocking FIDL calls for sendmsg() and recvmsg(). The design relies on IOBuffers and will require adding a new IOBuffer discipline. See the current design doc draft for more details. The current version focuses on UDP. We plan to implement similar changes for TCP sockets in the future, but that work is lower priority. TCP sockets will require a separate IOBuffer discipline. 

I'm assuming the new IOBuffer discipline will require an RFC. So I have the following questions:

- Is now the right time to initiate the RFC process?

- Will the Zircon's migration to Rust affect the process?

- Should we bundle two features into one RFC (i.e. the UDP-specific IOBuffer discipline and the TCP-specific IOBuffer discipline) or would it be better to handle each as a separate RFC?

Thank you!