`COHERENCE.md` §9 grades the worker model "mechanism without identity",
and §0 names step 11 (background-work ownership) as one of the two
remaining thin ends of the golden journey. The mechanism half is solid —
cancellation, supersession, streaming, frame-aware draining, `*workers*`.
The identity half was absent: `PendingJob` carried no description of what
it was doing, `pmacs.workers.dispatch` discarded the registered handler
name three layers above anything that takes one, and §9's "no progress
indicator exists anywhere" was checkable and true.
Framing: `docs/worker-identity-framing.md` (revision 4, approved).
What lands:
**A required `purpose`, on the job and on the process.** Non-optional,
with no `Default`, so the compiler — not a test — is what proves every
dispatcher supplied one. `allocate` / `allocate_with_resource` collapse
into ONE private `JobSpec`-taking funnel (Q#W-1): the two-function split
existed only because one prior lane needed one extra parameter, and a
second lane doing the same produces `allocate_with_resource_and_identity`.
`register_external` gains a `purpose` parameter rather than deriving one,
because its `JobKind` is `McpRequest`/`LspRequest` for every method — a
category, not a description.
**A dispatch-name ambient (Q#W-2), read at that same single funnel.** The
capture point is Rust, not the Lua wrapper layer, because a handler
reaching straight for `pmacs._async._dispatch_*` bypasses the wrappers
entirely — and those are precisely the callers attribution exists for.
Seven rules; the ones that decide whether it is honest:
- **Rule 1 — the extent is NON-YIELDABLE, and that is ENFORCED.** Both
supported yield APIs refuse inside it, modelled on the `commit_to`
refusal already in `async.lua`. The guards reject BEFORE parking and
reject UNCONDITIONALLY: one placed after `_is_complete` would fire only
when a yield really occurred, passing under test and failing
intermittently in production.
- **A raw `coroutine.yield` is NOT covered, and nothing here claims it
is.** R46 is a convention, and the scheduler inspects the yielded value
only after `coroutine.resume` returns — by which point the coroutine has
already suspended — so no refusal sited in a yield helper is ever
consulted. The residual is recorded in the framing §2 and in the
suite's module docs rather than papered over with a test that would
imply coverage this design lacks.
- **Rule 5 — unwind-safe.** A raising handler still pops. A version that
did not would let one failure poison every later dispatch in the session
with a stale name: the feature would stop failing loudly and start lying
silently. The bracketing also has to preserve the tail call it replaced:
`dispatch` was `return handler(args, opts)` and propagated EVERY return
value, so the pop/rethrow runs behind a varargs boundary rather than a
`local ok, result = pcall(...)` that would silently truncate a
multi-value handler. Varargs rather than `table.pack`, because that is
Lua 5.2 surface and LuaJIT is this project's default backend.
- **Rule 6 — compose, do not replace.** `"<name>: <purpose>"`, because
letting the dispatcher's purpose win loses the third party again and
letting the name win discards the only description of the actual work.
**A statusline activity indicator** — the fourth `pmacs.statusline.register`
adopter, after `mode`, `terminal` and `lsp`. A count plus the OLDEST
in-flight job's purpose ("busiest" is not a defined quantity; jobs carry
no cost estimate), and **absent entirely** when idle rather than a
zero-width segment that costs modeline width forever to say nothing is
happening. Gated by one setting, `ui.activity-indicator` (boolean, default
true, Q#W-6) — a permanently-visible modeline element is a preference
someone genuinely holds on day one. No setting for purpose capture
itself: that is substrate.
**NO WIRE CHANGE.** The indicator rides the existing `StatuslineSegments`
vector, so a fourth provider adds an element, not a variant.
`PROTOCOL_VERSION` and `ADVERTISED_PROTOCOL_VERSION` are untouched — which
is the property that lets this run beside the two lanes holding the bump
slot.
**Q#W-7 — a pre-existing defect, repaired here, and NOT one anybody has
observed.** `Handle:await()` refuses inside `pmacs.window.commit_to`
precisely so a coroutine cannot park with the frontend scope pushed
(Journey Stage 1a, Q#JR14b). But `pmacs.async.yield_to_next_tick()` also
yields, is public, and carried no such refusal — so that invariant had a
second entrance, and a coroutine could produce exactly the misrouting the
`await` guard exists to prevent. It gains both refusals here: the same
supported yield helper, the same invariant, the same edit family, so
splitting it would have preserved a known hole without reducing
integration risk.
**Reachability by a real caller is UNPROVEN.** This was found by reading
the guard family while scouting rule 1, not by reproducing a fault. No
production caller is known to yield through that door inside a commit,
and the test pins the guard rather than reproducing a user-visible bug.
Nobody should later cite this commit as evidence the bug was observed in
the wild. Its witness is a PAIR, like rule 1's: the refusal fires **and**
the commit scope is restored afterwards — a guard that raises while
leaving the scope pushed converts a silent fault into a loud one and
fixes neither.
`journey_acceptance` carries the established `commit_to` pins —
forged-destination refusal, scope-and-restore on normal return and on
raise, the await refusal, delivery to the requesting frontend. It passes
**untouched**, which is what says this closed a gap in Journey Stage 1a's
semantics rather than altering them.
What is deliberately NOT here, and why it is worth saying:
- **No `owner`, in any spelling** — not `origin`, not `subsystem` (§3).
Populated from static per-subsystem constants it would be an origin,
not an owner, and would confidently misattribute third-party work to a
builtin at exactly the point §9 wants attribution. A field that asserts
a falsehood is worse than an absent one. The slot stays empty until P3
can fill it with a real package signal.
- **No `parent`** (Q#W-5). An unpopulated field renders as `None`
everywhere and reads as "this job has no parent" rather than "this
system does not track parents". Stage 3 builds the lifetime model and
the field together.
Consequences worth recording:
- `ProcessSpec::new` takes a third argument. The 40-odd call sites are
almost all tests; the three production ones (LSP, MCP, terminal) supply
real descriptions. `pmacs.process.spawn`'s Lua surface keeps `purpose`
OPTIONAL, falling back to the label — requiring it there would break
every existing caller for no coverage the compiler is not already
providing, and a caller's own label is not a fabrication.
- `pmacs.process.list` gains a `purpose` KEY on each row and enumerates
exactly the same processes (Q#W-4). Terminal PTYs stay hidden: three
acceptance suites use `#pmacs.process.list()` as a leak baseline, and
widening the accessor would inflate all three. Stage 2's unified view
owns that decision.
- `statusline_segments_acceptance`'s builtin-provider inventory grows to
`["activity", "mode", "terminal", "lsp"]`. That assertion exists to
grow when a builtin provider is added.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016bqGA6s9tTUFzYpbeW3tai
Levi Neuwirth
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