shoney.arickathil
ab8ef64cd9
- five stories under docs/stories/runtime-v2/: 1 streaming subprocess (42's follow-up; five forks incl. the mailbox-cap collision), 2 PTY, 3 signals-as-events (signalfd lean), 4 termios adoption, 5 SCM_RIGHTS fd passing; 00-story states the arc — the plane learned sockets in 8/11/35, files in 6, this adds processes/terminals/signals - build order 1 -> 2 -> 3; 4 and 5 startable alone; all readiness: refine, brainstormed on demand - board: Five tracks; "▸ runtime-v2" pending section; wmux section now points at it; graph section 6 nodes carry runtime-v2 numbers + links - wmux stories re-reference the track; prefix `rt2` claimed - linkcheck: 0 broken Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> (cherry picked from commit e0451cb4889bb3d03429c0276d03c090269a5ced)
2.6 KiB
Story — runtime-v2: the runtime beyond sockets
The fifth track. Where databasev2/ takes
the database beyond RAM, this track takes the I/O plane beyond sockets:
processes, terminals and signals — the third of the native surface
the runtime never learned. Iterations 8/11/35 taught it sockets, the
program-mode stdlib taught it files, and iteration
42 (bounded
subprocess, ✅ on master 2026-09-01) opened this arc from inside the
language track before the arc had a name.
Numbering restarts at 1 and is local to this track; frontmatter carries
track: runtime-v2. Status rules are the repo's, unchanged.
The problem, stated once
A shard's plane multiplexes fds it created itself — listeners, accepted
sockets, and (since 42) the pipe/pidfd bundle of a one-shot child. That
is not enough for any program whose job is other programs: a long-lived
child's output has no path into an actor, a pseudo-terminal cannot be
allocated or resized, a signal cannot become a message, a tty the
process was GIVEN cannot be adopted into raw mode, and an fd cannot
cross a unix socket. Five seams, each builtin-sized, each in
runtime/src/ with a types.ml table row as its entire compiler cost
(the 42 precedent — no emit.ml change).
The iterations
| # | Iteration | What it adds |
|---|---|---|
| 1 | streaming subprocess | a long-lived child as a first-class peer: output in, stdin out, exit as a notice |
| 2 | PTY | openpty, controlling terminal, resize ioctls — a child that believes it owns a terminal |
| 3 | signals as events | SIGWINCH/SIGCHLD/… as mailbox messages — the seam 42 deferred to its real consumer |
| 4 | termios adoption | the process's OWN tty into raw mode and back — adopting a terminal it was given |
| 5 | fd passing | SCM_RIGHTS over unix sockets — detach/attach's foundation, and the Wayland stage's later |
Build order is 1 → 2 → 3 (each leans on the last); 4 and 5 have no incoming edges and are startable alone. Edges live in dependency graph section 6.
The driving workload
wmux/ — the terminal multiplexer — consumes all
five; that track owns the product, this one owns the seams. Sibling
consumers per iteration are named in each story (skillhost 28, the zen
CDP driver, the alacritty Wayland stage). The doctrine carried over from
42: every resource a ceiling, every violation a refusal by name, no
zombie and no orphan ever, .dev/reference/tmux as the measured
reference.