Hands-On Concurrency with Rust

Reference counting

Reference-counting memory reclamation associates a piece of protected data with an atomic counter. Every thread reading or writing to that protected data increases the counter on acquisition and decreases the counter on de-acquisition. The thread to decrease the counter and find it as zero is the last to hold the data and may either mark the data as available for reclamation or deallocate it immediately. This should, hopefully, sound familiar. The Rust standard library ships with std::sync::Arc—discussed in Chapter 4, Sync and Send – the Foundation of Rust Concurrency, and Chapter 5, Locks – Mutex, Condvar, Barriers and RWLock, especially—to fulfill this exact need. While we discussed the usage of Arc, we did not discuss ...