[dinnertime]

Congrats on your release!

One question I have is, how exactly does it record and what are the boundaries of the recording?

For example does it only record the userland execution of a single process, or does it have broader boundaries like including kernel code and/or execution of multiple processes? How does it handle shared memory regions that may be modified outside of the recording?

[alehander42]

We are currently working on two "backends" where recording works in different ways.

For the scripting languages and smart contract/ZK languages, we instrument the interpreters using high level hooking API-s or direct patches, and we produce a trace.

For system languages, we directly build on top of RR[1] recordings for now: RR can record multiple processes, and it works in userland. IIRC it doesn't support modifications of shared memory outside of the recording. It's very well documented in their paper: Engineering Record And Replay For Deployability: Extended Technical Report[2].

1: https://rr-project.org/

2: https://arxiv.org/abs/1705.05937