- park.c/park.h: one event loop per shard. io_uring PRIMARY (raw
io_uring_setup/io_uring_enter, uapi structs mirrored, 5.4-floor ops:
POLL_ADD for fd readiness, TIMEOUT for sleeps, user_data = the fiber);
epoll+deadline-scan FALLBACK behind the startup probe; WO_IO=
uring|epoll forces either so CI proves both on one kernel
- park protocol: a blocking builtin fills cur->park_* and returns
WO_SYS_PARKED; resume either RE-EXECUTES it (fd readiness: accept/
read/write retry) or continues PAST it (sleep: result preset,
park_done=1 — re-executing would restart the full duration)
- sysio: listener + accepted fds nonblocking (accept4 SOCK_NONBLOCK);
accept/read park on EAGAIN; write parks on EAGAIN with its partial
progress carried across the retry in park_wr_at; sleep parks on a
deadline — with ONE fiber the plane's wait IS the blocking call,
program mode is the degenerate case, not a special one
- scheduler: NEXT_RUNNABLE waits on the plane when the queue empties;
a stop interrupting the wait reaps EVERY fiber (queued and parked)
and returns the clean-stop status; parked fibers are GC roots and
fib_reap_all drains them
- proof: full battery green on the uring path (oop-e2e 92/0,
log-watcher 7/0 incl. the mcp accept/read/write loop, employee 8/0,
web-app 21/0, deps 8/0), WO_IO=epoll battery green (log-watcher 7/0,
web-app 21/0), WO_IO=uring forced green, LW_SOAK=8 10/0 (fd + RSS
flatness holds over parked I/O)
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
