udp: add experimental io_uring implementation (#131)

* WIP: add udp uring support

* WIP: fix udp uring address parsing

* WIP: udp uring: resubmit recv when needed

* WIP: udp uring: add OutMessageStorage, send swarm responses

* WIP: udp uring: increase ring entries to 1024

* WIP: udp uring: add constants

* WIP: udp uring: use sqpoll, avoid kernel calls

* WIP: udp uring: disable sqpoll

* WIP: udp uring: use VecDeque for local responses

* udp uring: enable setup_coop_taskrun

* udp uring: add RecvMsgStorage

* udp: improve split of uring and mio implementations

* udp uring: clean up

* udp uring: initial ipv6 support

* udp uring: improve helper structs

* udp uring: clean up, use constants for important data

* udp: share create_socket fn between implementations

* udp uring: improve send buffer free index finding

* udp uring: work on SendBuffers.try_add

* udp uring: split into modules

* udp uring: Rename RecvMsgMultiHelper to RecvHelper

* udp uring: improve SendBuffers

* udp uring: fix copyright attribution in buf_ring module

* udp uring: stop always consuming 100% cpu

* udp uring: clean up

* udp uring: add handle_recv_cqe

* udp uring: move local_responses into SocketWorker

* udp uring: move timeout_timespec into SocketWorker

* Update TODO

* udp: make io-uring optional

* Update TODO

* udp uring: enqueue timeout before sends

* udp uring: move likely empty buffer tracking logic into SendBuffers

* udp uring: improve error handling and logging

* udp uring: keep one timeout submitted at a time

* udp uring: update pending_scrape_valid_until

* udp uring: add second timeout for cleaning

* Update TODO

* udp uring: store resubmittable squeue entries in a Vec

* udp uring: add comment, remove a log statement

* Update TODO

* Update TODO

* udp: io_uring: fall back to mio if io_uring support not recent enough

* udp: uring: add bytes_received statistics

* udp: uring: add bytes_sent statistics

* udp: uring: add more statistics

* Update TODO

* udp: uring: improve SendBuffers code

* udp: uring: remove unneeded squeue sync calls

* udp: uring: replace buf_ring impl with one from tokio-uring

* udp: uring: store ring in TLS so it can be used in Drop impls

* udp: uring: store BufRing in SocketWorker

* udp: uring: silence buf_ring dead code warnings, improve comment

* Update TODO

* udp: uring: improve CurrentRing docs, use anonymous struct field

* udp: uring: improve ring setup

* udp: uring: get ipv6 working

* udp: uring: make ring entry count configurable, use more send entries

* udp: uring: log number of pending responses (info level)

* udp: uring: improve comment on send_buffer_entries calculation

* udp: improve config comments

* udp: uring: add to responses stats when they are confirmed as sent

* Update TODO

* udp: uring: enable IoUring setup_submit_all

* Update README

scripts/run-aquatic-udp.sh

@@ -2,4 +2,4 @@
 
 . ./scripts/env-native-cpu-without-avx-512
 
-cargo run --profile "release-debug" -p aquatic_udp -- $@
+cargo run --profile "release-debug" -p aquatic_udp --features "io-uring" -- $@