Channels vs Mutex

Start with the idea

A channel moves ownership between threads, so there is nothing left to lock and the flow of data is visible in the code. A mutex keeps one copy that several threads mutate in place, which is better when the state is genuinely shared and read far more often than written. Choosing by shape rather than by habit is the answer being looked for.

A channel and a mutex organize ownership in different ways. With a channel, producers send owned messages to a receiver that handles them. This works well when one task can own the state and commands describe the changes. A mutex lets multiple tasks access one shared object, with exclusive access while a guard is held. This works well when callers need immediate coordinated reads or updates to a shared invariant. Neither is universally faster or simpler; the workload and failure path decide.

Consider an order book.