This implements the userspace binding for RingBuf.
Instead of streaming the samples as heap buffers, the process_ring
function takes a callback to which we pass the event's byte region,
roughly following [libbpf]'s API design. This avoids a copy and allows
marking the consumer pointer in a timely manner.
[libbpf]: https://github.com/libbpf/libbpf/blob/master/src/ringbuf.c
Additionally, integration tests are added to demonstrate the usage
of the new APIs and to ensure that they work end-to-end.
Co-authored-by: William Findlay <william@williamfindlay.com>
Co-authored-by: Tatsuyuki Ishi <ishitatsuyuki@gmail.com>
Andrew Werner