Three Threads, One Terminal: Concurrency in Rust with Channels and Atomics

This is part of a series of posts about building b.roll, a terminal session recorder and search tool written in Rust. If you're just joining, here are the previous posts: Building a 12-Command CLI in 120 Lines with clap Derive Macros Spawning a PTY in Rust: How broll Captures Your Terminal Without You Noticing When broll records a terminal session, three things need to happen at the same time: keystrokes must flow into the shell, the shell's output must appear on screen, and that output must be processed and stored in a database. Doing all three sequentially would mean dropped keystrokes and laggy rendering. So broll uses three threads, coordinated through channels and atomics. This post walks through the concurrency architecture of broll's recorder, explaining each primitive: std::thread::spawn, mpsc channels, Arc, AtomicBool, AtomicU16, Ordering, move closures, and signal_hook for terminal resize handling. All code is from src/recorder/mod.rs. The Three-Thread Architecture Here is th