Hands-On Concurrency with Rust

Safety by exclusion

Let's talk about Mutex. Mutexes provide MUTual EXclusion among threads. Rust's Mutex works just as you'd expect coming from other programming languages. Any thread that calls a lock on a Mutex will acquire the lock or block until such a time as the thread that holds the mutex unlocks it. The type for lock is lock(&self) -> LockResult<MutexGuard<T>>. There's a neat trick happening here. LockResult<Guard> is Result<Guard>, PoisonError<Guard>>. That is, the thread that acquires a mutex lock actually gets a result, which containers the MutexGuard<T> on success or a poisoned notification. Rust poisons its mutexes when the holder of the mutex crashes, a tactic that helps prevent the continued operation of a multi-threaded propagation ...