Put a ring on it: a lock-free MPMC ring buffer
4 days ago
- #concurrency
- #lock-free
- #performance
- Ring buffers are fixed-size queues that drop old data when full, useful in high-performance scenarios.
- Traditional ring buffers struggle with multiple producers and consumers (MPMC) due to contention issues.
- A lock-free MPMC ring buffer is introduced, leveraging atomic operations for scalability.
- The design uses epochs to track operations, ensuring linearizable ordering without locks.
- Compare-and-swap (CAS) operations are key to managing contention between threads.
- The implementation includes mechanisms to handle thread suspension and contention gracefully.
- Memory ordering and atomic operations are critical for correctness in concurrent environments.
- Performance testing reveals the importance of balancing enqueuers and dequeuers to minimize drops.
- The solution is extended to support arbitrary-sized records by using a secondary buffer.
- Memory barriers and compiler optimizations must be carefully managed to avoid subtle bugs.