Crossbeam is a collection of tools for concurrent programming in Rust.
The project addresses the challenges of writing safe, efficient concurrent code by providing low-level primitives and higher-level abstractions. It offers atomics like AtomicCell for thread-safe memory locations, lock-free data structures including work-stealing deques and bounded or unbounded queues, an epoch-based garbage collector for managing memory in concurrent scenarios, thread synchronization primitives such as channels and reader-writer locks, and utilities like exponential backoff and cache-line padding. The modular design splits functionality across focused subcrates that can be used independently or together through the main umbrella crate.
Crossbeam suits projects that need battle-tested concurrency primitives without building them from scratch. It is particularly valuable for task schedulers and work-stealing systems through its deque implementation, for message-passing architectures via its channels, and for lock-free data structure development through its epoch-based garbage collection. The tool supports both standard and no_std environments, making it applicable to embedded and systems programming contexts. Developers should note that an experimental skiplist subcrate exists outside the main crate for those needing concurrent maps and sets based on lock-free skip lists.
The project maintains a stable release cadence with a minimum supported Rust version that is updated with accompanying minor version releases. Development activity shows consistent engagement with community contributions, with labeled issues guiding new contributors toward both straightforward starter tasks and areas where maintainer feedback is actively sought.
