Lock-free datapath primitives for high-performance packet processing.

Zero-copy buffer pools, SPSC/MPMC ring buffers, cache-line-aligned statistics, and the [CachePadded] primitive — pure, with no VM, VirtIO, or I/O dependencies. Extracted from arcbox-net so any high-throughput consumer (host-side proxy, VM datapath, packet tools) can reuse them.

Performance Targets

• Ring buffer throughput: >100M ops/sec
• Packet pool allocation: O(1) constant time
• Zero memory copies in hot path