crossbeam (Rust)
Collection of tools for concurrent Rust programming. Key components: crossbeam-channel (multi-producer multi-consumer channels, superior to std::sync::mpsc), crossbeam-deque (work-stealing deques used by Rayon), epoch-based memory reclamation, atomic data structures, and scoped threads that can borrow stack data. The foundation for Rayon's parallel iterators.
Score Breakdown
⚙ Agent Friendliness
🔒 Security
Memory safety guaranteed by Rust's type system and borrow checker. Lock-free algorithms are formally verified for correctness. No network access. No known security issues.
⚡ Reliability
Best When
You need multi-producer multi-consumer channels, work-stealing, or lock-free data structures for CPU-bound parallel Rust code.
Avoid When
You're writing async Rust with Tokio — use tokio::sync::mpsc/broadcast/watch for async-native channels.
Use Cases
- • Use crossbeam-channel for MPMC message passing between threads with both bounded and unbounded variants
- • Implement work-stealing task queues with crossbeam-deque for custom parallel executor designs
- • Use scoped threads (crossbeam::thread::scope) to spawn threads that can safely borrow local stack variables
- • Select over multiple channels simultaneously with crossbeam_channel::select! macro (like Go's select)
- • Build lock-free data structures using crossbeam's epoch-based garbage collection for safe memory reclamation
Not For
- • Async/await concurrent code — crossbeam is sync/thread-based; use Tokio channels for async contexts
- • Simple single-producer single-consumer queues — std::sync::mpsc is sufficient and simpler
- • Non-Rust applications — crossbeam is Rust-only
Interface
Authentication
Library with no auth requirement.
Pricing
Free and open source.
Agent Metadata
Known Gotchas
- ⚠ crossbeam channels are NOT compatible with Tokio async — using crossbeam_channel::Receiver in async code blocks the executor thread; use tokio::sync::mpsc in async contexts
- ⚠ select! macro with crossbeam blocks the current thread — it's synchronous; for async select, use tokio::select!
- ⚠ Bounded channels (channel(n)) block the sender when full — distinguish blocking vs non-blocking send (try_send) for back-pressure vs drop decisions
- ⚠ Scoped threads in crossbeam::scope can borrow outer variables — the scope closure must return before borrows are released; any panic inside scope will propagate
- ⚠ Disconnected channel errors occur when all senders or receivers are dropped — agents must handle RecvError::Disconnected and SendError(T) as normal operation, not bugs
- ⚠ crossbeam-epoch for custom lock-free structures requires careful pin() hygiene — holding an epoch::Guard across code that may block causes memory reclamation stalls
Alternatives
Full Evaluation Report
Detailed scoring breakdown, competitive positioning, security analysis, and improvement recommendations for crossbeam (Rust).
Scores are editorial opinions as of 2026-03-06.