A clock made of branches
Summary
Farid Zakaria explores time inside a deterministic VM (Rewind), comparing two clocks: exit time (advances only at exits) and counter time (advances per conditional branch). The article discusses how to measure time via the instruction stream, demonstrates using perf to count instructions and branches, and argues that counter time is a closer, deterministic representation of real-world time. It also situates these ideas with diagrams, memes, and references to related work like the rr debugger.