Work Stealing

ELI5 - The Vibe Check

Work stealing is how a pool of worker threads keeps itself busy without a manager micromanaging every task. Each worker has its own queue of jobs it works through, but the moment a worker runs out of work, it sneaks over and steals a task off the back of a busier worker's queue instead of sitting idle. Nobody's ever left with nothing to do while somebody else is drowning.

Real Talk

Work stealing is a scheduling strategy where each worker thread maintains its own local deque of tasks, primarily pushing and popping from one end for cache locality, while idle workers steal tasks from the opposite end of another worker's queue when their own queue is empty. It achieves good load balancing with far less lock contention than a single shared task queue, and is the scheduling model behind Go's goroutine scheduler, Rust's Rayon, and Java's ForkJoinPool.

When You'll Hear This

"Go's runtime uses work stealing so goroutines balance across cores automatically." / "Rayon's work-stealing scheduler is why that parallel iterator scales so well."