The child log ledger encodes an admitted entry to UTF-8 once to charge its
serialized cost, so a maxLogBytes approaching addressSpaceMb lets a legitimate
near-budget log entry breach RLIMIT_AS and die as worker-exit instead of
truncating. Two runtime fixes were tried and both traded one resource bound for
another: an exact serialized-cost check is either a full encode (the allocation
being avoided) or a per-character Python loop that burns the CPU budget (a 10 MB
write hits SIGXCPU under cpuSeconds:1). The breach is a property of the
maxLogBytes/addressSpaceMb pair, not any write, so reject the incompatible pair
at load — maxLogBytes must stay within one eighth of the addressSpaceMb byte
count — and revert _LogStream to its original character-count buffering, which
is memory-safe once the budget fits the address space. The check runs on every
platform since the incompatibility is a config-value property, not a runtime one.
Replace the child-flood regression tests (which asserted the reverted runtime
behavior) with a load-rejection test. The host-side accrueStrayCost UTF-8
per-lead validation and its tests are unaffected. Update the note and zh pair.
accrueStrayCost accepted any 0x80-0xBF continuation, so a CESU-8 surrogate
(ED A0 80) or overlong (E0 80 80) — structurally well-formed but illegal, and
as cheap to flood as 0xFF — was charged its structural width 3 while
toString('utf8') renders each byte as its own U+FFFD (cost 9). Validate each
lead's first-continuation range (WHATWG E0/ED/F0/F4 bounds) and charge 3 per
byte of any sequence outside it, folding a broken prefix to one U+FFFD.
The child _LogStream newline path had the same char-vs-serialized gap the
newline-free trigger had: its per-line fit checks (first reconstructed line and
each subsequent line) compared character count against the serialized-byte
budget, so a control-char line passed and _logs.push encoded it whole, breaching
RLIMIT_AS. Route every check through _fragment_cost_upto, which sums per-char
costs from _json_char_cost over a start/end sub-range without slicing or
encoding and stops at the budget.
Decline arrival-order stray flushing: the two pipes' data events interleave
nondeterministically and logs carries no cross-pipe ordering guarantee, so a
fixed drain order is as valid as any and an arrival-tick branch could not be
covered without a flaky test.
Add CESU-8/overlong, newline-path-flood, and all-lead-class reassembly
regression tests; fix the note's now-inaccurate CESU/illegal-byte claims and a
fixture byte-count comment; sync the zh pair.
The child-log-flood regression built one 30M-char argument string, which under
the 64 MB addressSpaceMb died on RLIMIT_AS during construction (exit 120) before
the flush trigger under test could run, so it failed on Linux CI. Write the
flood in 1 MiB chunks under a 512 MiB address space instead: the argument str is
never itself the allocation under test, the fixed serialized-cost trigger keeps
the pending tail bounded to a few MiB, and the run completes at the marker; the
pre-fix char-count trigger accumulates the whole ~200 MiB and its ~1.2 GiB
settlement encode breaches RLIMIT_AS. Mirrors the addressSpaceMb budget the
existing oversized-completion tests use.
The host stray-capture cost function charged illegal UTF-8 bytes (0x80-0xC1,
0xF5-0xFF, and orphaned multibyte leads) the raw 1, but toString('utf8')
renders each as U+FFFD (3 serialized bytes). A b"\xff" flood was undercounted
threefold, so the residual grew to a full budget's worth of raw bytes before
flushing and, near a large maxLogBytes, expanded toward a ~1 GiB peak in the
flush's concat plus toString. Replace serializedBufferCost with accrueStrayCost,
a cross-chunk UTF-8 walker that charges each byte its decoded serialized width;
carry its sequence state on each StrayBuffer.
The child _LogStream had the same-family bug: its early-flush trigger compared
_pending_chars (character count) against remaining (a serialized-byte budget),
so a 30M-NUL newline-free flood stayed under a 50 MB char trigger yet encoded to
~180 MB at settlement, breaching RLIMIT_AS as worker-exit. Track _pending_cost
via the _JSON_BYTE_COST table and trigger on it; keep _pending_chars for the
char-based slice bounds.
Correct the note's surrogate claim (only the string-walking jsonStringCostUpTo
charges a lone surrogate six bytes; the byte walker never sees one). Shrink the
post-truncation fixture below PIPE_BUF for a deterministic single callback. List
the shared stdout/stderr budget as a third honest fail-before exception
(cross-pipe arrival timing is nondeterministic). Add illegal-UTF-8,
broken-multibyte, and child-log-flood regression tests; sync the zh pair.
The stray-sealing regression test asserted copied < 2 MiB — about 4x the
defended sealed shape, so reverting the seal to a re-merge (or removing it)
left the test green. Measured both shapes as the fd-3 sibling does: the sealed
shape copies ~120 KB, the re-merge shape ~538 KB. Tighten the bound to 256 KiB,
which sits between them, and record the measurements in the comment and the
Agent Note so the fail-before claim holds.
stdout and stderr each checked their pending serialized cost against the full
logBudget independently, so both could retain nearly a budget's worth of
newline-free residual at once — double the intended peak, up to ~512 MiB near
the ceiling. The flush threshold now reads the COMBINED cost of both pipes and
flushes both when it crosses, since they share one ledger.
Remove the post-truncation admit() v8-ignore: captureStray's per-line loop
makes that branch deterministically reachable within one data callback (a chunk
whose first newline-terminated line exhausts the budget hits it on the second),
so it is measured by a new regression test rather than ignored.
Refresh two stray-output test comments that still named the removed
StringDecoder; the raw-chunk buffer reassembles a split multibyte sequence by
concatenating before it decodes, and the end flush renders a stranded partial
as U+FFFD via toString('utf8').
Three follow-ups the review caught in the stray-capture rewrite, plus a cost
undercount shared with the log ledger.
Seal the stray fragment list into blocks past MAX_PENDING_CHUNKS, mirroring the
fd-3 reader: a program pacing single-byte os.write(1, ...) calls otherwise
accumulates one live Buffer per write, and the per-object overhead no byte
count sees exhausts the host heap far below the budget.
Flush the residual by its running SERIALIZED cost (serializedBufferCost, a
per-byte lower bound) rather than raw byte count: a control-char-dense
newline-free flood serializes several-fold, so a raw-byte threshold let it grow
to a full budget's worth of raw bytes — up to ~6x what the ledger admits —
before flushStray concat/decoded the whole ~256 MiB residual at once.
Charge a lone surrogate its full six escaped bytes (\uXXXX under ES2019
well-formed JSON.stringify) in both jsonStringCostUpTo and serializedBufferCost,
not the three bytes Buffer.byteLength reports for U+FFFD: a forged log frame
flooding \ud800 escapes was undercharged by half and admitted ~2x maxLogBytes.
Key the sync-spawn leak assertion off the exact bootstrap path from the mocked
spawn's argv, immune to a sibling worker's concurrent staging. Refresh the
stale load-check comment that named the replaced JSON.stringify mechanism.
Add lone-surrogate, stray-sealing, and companion regression tests (per-file
100% coverage); update the Agent Note and zh pair.
The line-aggregating stray capture from the previous round regressed three
ways the review caught. Rewrite it on the fd-3 reader's raw-Buffer-chunk
shape: accumulate chunks with a byte counter and split on the raw 0x0a byte,
so a large newline-free write no longer re-copies the residual and re-scans
from index 0 per chunk (both O(N^2)). Meter each admitted entry by serialized
cost through a new jsonStringCostUpTo that walks to the cap and stops, so a
near-budget control-char-dense line never allocates the sixfold-inflated
JSON.stringify result the old ledger did (the critical: ~1.6 GiB transient
under a large maxLogBytes). Flush the residual explicitly in the closeDeadline
handler before it destroys the streams, so a setsid escapee's path (which
fires no end) does not drop a leader's final newline-free diagnostic.
Harden the sync-spawn leak assertion to a set difference against a pre-run
snapshot, immune to a parallel worker's concurrent tmpdir create/delete.
Decline the round-2 request to enforce the fd-3 ceiling per-frame: the counter
check must precede Buffer.concat to prevent ~2x memory doubling (two
regression tests assert this), and the batch-edge false reject it would fix is
reachable only at a maxLogBytes/maxValueBytes configured within one pipe read
of the 256 MiB ceiling, far past the defaults. Documented at the check and in
the note Alternatives.
Add flood, NUL-flood, short-escape, and closeDeadline-flush regression tests
(restoring per-file 100% coverage); update the Agent Note and zh pair.
The line-aggregating stray capture added two branches — the post-truncation
early return and the residual-overflow admit — that the aggregation and
split tests did not exercise, so per-file coverage dropped below 100%. A
2 MB newline-free native write under a 4 KiB maxLogBytes drives the residual
across the budget (admit-and-truncate) and then short-circuits later chunks,
asserting the captured output ends at the truncation marker and stays under
budget rather than buffering the whole flood.
Wrap spawn and the fd-3 narrowing so a synchronous throw (ENAMETOOLONG on
an over-PATH_MAX pythonBin, EMFILE) removes the run's staging directory and
resolves the same worker-exit class as the async error event, instead of
rejecting run() and leaking the directory.
Aggregate native stdout/stderr by real newline rather than by Node data
chunk: logs entries are joined with "\n" downstream, so a newline-free
write larger than one pipe read no longer reads back with spurious breaks.
The ledger still bounds a newline-free flood.
Track a running scan offset in both frame readers so a large frame
accumulated across chunks is scanned once, not re-scanned from 0 per chunk.
Reword the deadline hard-bound v8-ignore to state its real environment
dependence (PID-1-doesn't-reap container, zombie survivor) and cross-ref
the note's rejected signal-0 alternative; fix settle comments that quoted
the pre-qualification teardown contract; document the capMessage vs
_cap_message billing split on both sides; guard the dispose-after-resolve
heartbeat assertion against a vacuous 0===0 pass; reuse
_TRUNCATION_MARKER_BYTES; note the abandoned-call pending-entry bound.
Update the Agent Note Decision/Testing/Alternatives/Consequences for the
above and record the confirmed-empty finalize as a second honest
fail-before exception; sync the zh pair.
The closed-loop reply-pump guard now ships with a deterministic regression test:
a worker thread abandons a binding so its loop closes, the host answers that call
before a later binding, and the pump must survive the closed-loop
call_soon_threadsafe to deliver the later reply (host-gated ordering makes it
deterministic; unguarding the pump hangs the later binding to the wall clock).
Align the quiescence self-description with the shipped setsid limitation:
teardown()'s JSDoc and the Agent Note's Problem line now qualify "no subprocess
outlives the fiber" to subprocesses that stay in the child's process group, with
a setsid()-escape exception pointing at the README. Tighten the setsid-orphan
fixture's self-timeout to 5s and its upper-bound assertion to <4000ms so a failed
deadline backstop is a sharper red. Register the new regression tests in the note.
The child reads these byte budgets through int(...), which silently floors a
float, so maxLogBytes: 3.5 would truncate at 3 bytes child-side while the host
meters and marks at 3.5 — the two sides enforcing different public config. Gate
them to integers at load, as the worker backend does; correct the stale comment
that claimed the int()-truncated caps needed no gate. Adds a regression test.
The SIGXCPU timeout message changed from "CPU budget (Ns) exhausted" to name the
configured value as a ceiling; two existing timeout tests asserted the old text.
Assert "CPU time exhausted" to match.
Raising maxValueBytes' load bound to ceiling-envelope assumed both budgets are
metered in serialized (JSON-escaped) bytes, which held for completion values and
logs but not the diagnostic: _cap_message capped by raw UTF-8, so a control-heavy
message near maxValueBytes could serialize sixfold and breach the fd-3 frame
ceiling — the silent worker-exit inversion the load check prevents. _cap_message
now accumulates per-byte serialized cost (new _JSON_BYTE_COST table) and cuts the
prefix that fits. Also reword the host SIGXCPU timeout message to name cpuSeconds
as the configured ceiling rather than a budget a stricter inherited RLIMIT_CPU
soft may undercut. Adds a control-heavy-diagnostic regression test.
The group-reap poll folded its deadline arm into the empty-group arm, so a host
event loop blocked past graceMs + CLOSE_REAP_MARGIN_MS would run the overdue
poll before the grace SIGKILL timer: the group is still non-empty, the deadline
has passed, and the shared arm cancelled the never-fired SIGKILL and finalized —
releasing a SIGTERM-ignoring same-group survivor for good. Split the arms: empty
group cancels the moot timer and finalizes; deadline-with-non-empty-group sends
SIGKILL itself (idempotent if the timer already ran) before finalizing. Adds a
regression test that busy-blocks the loop past both timers and asserts the
survivor's heartbeat freezes.
settle() dropped the run from `live` eagerly, before the grace-window SIGKILL
reaped a same-group survivor. A dispose() racing a just-resolved run() then
snapshotted an empty `live` and returned while the descendant was still alive,
so teardown's "no subprocess outlives the fiber" (and its JSDoc) was false for
that window. The run now stays in `live` until the process-group poll confirms
the group empty, at which point it is both dropped from `live` and its finished
promise resolved. Adds a regression test asserting dispose() of a completed run
with a same-group survivor returns only after the survivor stops executing.
The settlement-time CPU recheck compared spent CPU against the configured
cpuSeconds, but _clamped may have lowered the effective soft limit to a stricter
inherited value. A program that traps SIGXCPU, burns past the inherited soft,
and returns inside the soft-to-hard gap was checked against the configured value
and falsely reported successful, bypassing the inherited limit. The recheck now
uses the clamped cpu_soft. Adds a regression test that inherits a 1s soft CPU
limit and asserts a SIGXCPU-trapping over-burn is a timeout, not a success.
Two further review findings on the CPython backend:
- The grace-window SIGKILL timer was left armed after settlement, so on a
normal completion a kill(-pid) could fire up to graceMs later and strike a
recycled pgid once the kernel reused the leader's pid. settle() now clears
the timer the moment the process group is confirmed empty (the normal path
and when the poll sees the survivor gone), bounding the reuse window to the
genuine-survivor case where the group cannot be empty to reuse.
- _clamped bounded rlimits by the inherited hard limit only, silently raising
an inherited soft limit stricter than the request (loosening RLIMIT_AS or
deferring RLIMIT_CPU SIGXCPU). It now clamps each side against its own
inherited counterpart and pins soft under hard, keeping the strictest of
configured and inherited. Adds an inherited-soft-limit regression test.
Agent Note expanded to seven fixes with the two new rejected alternatives;
zh pair re-recorded.
Two review findings on the CPython backend:
- Disposal could return while a same-group descendant that ignores SIGTERM
but releases the inherited pipes was still alive: the leader's close fired
and the previous fix relied on an unref'd SIGKILL timer that a short-lived
host never fires, reparenting the survivor to init. settle() now withholds
the run's finished promise on a ref'd process-group poll until the SIGKILL
has emptied the group (bounded by graceMs + margin, zero-cost when already
empty), so teardown's "await each child's exit" holds.
- A binding called from a model worker thread via asyncio.run created its
reply Future on that thread's loop, but _pump_replies completed it directly
from the main loop; asyncio.Future is not thread-safe across loops, so the
call hung to the wall clock. Replies now complete via the owning loop's
call_soon_threadsafe, and a lock serializes the id claim/write/advance.
Tests: the same-group reap case now asserts a heartbeat file stops (robust
whether the killed descendant is reaped or a zombie, so it holds where PID 1
does not wait() orphans); a cross-loop case runs a binding from a worker
thread and asserts the reply round-trips instead of timing out. Agent Note
expanded to all six fixes with rejected alternatives; zh pair re-recorded.
The frame-ceiling cap test asserted the old (ceiling-envelope)/6 bound and
its 44739232 message. The load bound is now ceiling-envelope because both
budgets are metered in already-escaped bytes; assert 268435392.
Address review findings on the CPython backend:
- CRITICAL: a model program could leave a descendant in the child's own
process group that ignores SIGTERM but releases the inherited pipes, so
the leader's `close` fired and settle() cancelled the pending SIGKILL
before it escalated — run()/dispose() returned while that child lived.
kill() now unrefs the grace timer and settle() no longer clears it, so
the SIGKILL reaches the whole group; killGroup swallows ESRCH when the
group is already gone (the normal case). Adds a real-subprocess
regression test.
- WARNING: the maxLogBytes/maxValueBytes load bound divided the frame
ceiling by 6 for escape expansion, but both budgets are metered in
already-escaped serialized bytes, so a payload occupies at most
cap+envelope on the wire. Bound is now ceiling-envelope; drop the unused
escape constant.
- Narrow the runtime.spec.ts header to "no subprocess mocks" (it mocks
node:fs.copyFileSync for staging-failure cases).
- Use full-width punctuation in the README.zh.md prose per translation
rules; re-record the pair.
The package README (both languages) still described this layer as
protocol-only with the PythonCodeRuntime implementation deferred to a
later PR, contradicting the shipped code. Rewrite the intro to describe
the registered runtime, add a Configuration section for every Config cap,
and drop the "implementation not in this layer" limitation. Also pin the
residual-detach fixture's size invariant: the byteLength assertion only
holds above Node's Buffer pool threshold.
Land the PythonCodeRuntime implementation on top of the fd-3 protocol
seam: python3 -I per run, binding namespace over fd 3, RLIMIT_CPU/AS,
wall-clock timer, and SIGTERM->grace->SIGKILL process-group teardown,
with the real-subprocess integration suite.
Fixes three defects surfaced on the source PR's review before they ship:
- boot-write failure resolved a worker-exit through finish()/settle()
that read wallTimer/onAbort/live in their TDZ, rejecting run() instead;
the boot write now runs after those bindings and the v8-ignore that hid
the branch is removed.
- log capture serialized against settlement with no lock while model
daemon threads keep writing; LogBuffer now owns one shared re-entrant
lock taken by write/flush_line/push.
- the fd-3 line residual was a subarray view pinning the whole joined
frame; it is copied into a right-sized Buffer via detachResidual so
pendingBytes measures what is retained.
Rename UnionCoversRoster/RosterCoversUnion to UnionSubsetOfRoster/RosterSubsetOfUnion so
the names read in the same direction as their extends clauses, share the python3 -I -B
flags between the two mirror probes, and align the README and Agent Note prose with the
checkDoneValue JSDoc: the escaped-size scan is the metering itself, not deferred work.
Regenerate docs/module-graph.md, which listed code-runtime-python twice.
- Drop the review-history narrative from checkDoneValue's JSDoc (the "in the
previous implementation … now avoids" clause); state the current contract only.
- Assert encodeJsonPlain on the same 100k-deep value the metering test uses:
its headline contract is stack-safety (JSON.stringify would throw), but no
test exercised the encoder on a deep value.
Address the latest review round:
- WireFrameShapesCoverUnions checked only union ⊆ roster, so removing a frame
from a message union (e.g. dropping ReplyErr from ReplyMessage) left the check
true while the public TS union diverged from the wire. Replace it with a
bidirectional equivalence between MessageFrames and the roster's message-frame
value types (nested Namespace/ErrorClass/DoneErrorField excluded): both a frame
added to a union without a roster entry and a frame removed from a union now
fail typecheck (both verified).
- The mirror e2e's python3 probes imported protocol.py without -B, writing
py/__pycache__/*.pyc into the (un-ignored) source tree. Add -B to both.
- Refresh the metering prose (checkDoneValue JSDoc + README both sides + Agent
Note both sides): the incremental-work list no longer says "per-key
JSON.stringify" now that jsonStringBytesUpTo scans without stringifying;
re-record the README and Agent Note i18n pairings.
Two review findings on checkDoneValue's metering and the wire-mirror binding:
- The string/key byte check used a decoded-length lower bound and then called
JSON.stringify, which materializes the ~6x escaped copy before the over-budget
check — the hundreds-of-MB spike the metered walk exists to avoid. Add
jsonStringBytesUpTo, a non-allocating scan that computes the exact escaped
UTF-8 size (matching JSON.stringify byte for byte, including surrogate pairs
vs lone surrogates) and bails the instant it crosses the remaining budget; use
it for both string values and object keys.
- The frame roster in WIRE_FRAME_FIELD_ROLES was hand-written, so a frame added
to ChildToHost/ReplyMessage without a roster entry slipped past. Introduce
WireFrameShapes (name -> interface) as the canonical roster the roles map is
bound against, plus a WireFrameShapesCoverUnions compile-time assertion that
every message-union member appears in it (verified: adding a frame to a union
without a WireFrameShapes entry fails typecheck).
Address the remaining review findings on the wire-mirror layer:
- Export PROTOCOL_FD from protocol.ts as the TS-side source of truth the host
wires, and assert the Python constant against it in the mirror e2e instead of
a bare literal 3, so an fd drift on either side is caught.
- Correct the FrameFieldRoles JSDoc to point at the actual assertion site
(WIRE_FRAME_FIELD_ROLES's satisfies clause, not WIRE_FRAME_FIELDS).
- Drop the redundant explicit type annotation on WIRE_FRAME_FIELDS (the trailing
`as` cast already types it; Object.fromEntries returns an index signature).
- Refresh the mirror-test comment to describe the roles-map binding (a TS-side
add/remove/rename/optionality-flip fails typecheck; a Python-side change fails
the comparison).
The previous mirror binding (FrameFields<keyof T>) only checked membership: it
could not see a TS-side optionality flip (truncated? -> truncated leaves keyof
unchanged) or a field added on one side, so the "depends on the TS
declaration" claim was overstated.
- Promote the inline frame shapes (Namespace, ErrorClass, DoneErrorField,
RunMessage, and the two Reply variants) to named interfaces so every frame
binds uniformly.
- Derive FrameFields from RequiredKeys<T>/OptionalKeys<T>, so `required` and
`optional` each accept only that side's keys. An optionality flip or a rename
now fails typecheck (verified: flipping LogMessage.truncated to required
errors at the constant).
- Enumerate EVERY public TypedDict in py/protocol.py in the mirror e2e (not a
name list taken from the TS side) and assert both the frame roster and each
frame's required/optional sets by exact equality, so a frame or field present
on only one side of the wire fails the test.
Two gaps from the previous round's fixes:
- checkDoneValue flagged a non-lossless number but skipped counting its encoded
bytes, so a value over budget ONLY through that number classified as
non-lossless instead of over-budget (e.g. [Infinity] at cap 3, whose encoding
is 10 bytes). Count the scalar's bytes even when flagging, so the budget check
wins as the JSDoc promises. Add cap-3 regression cases.
- The mirror e2e compared the Python TypedDict keys against a hand-written
constant, so a field change on the TS side alone would not fail it, and the
reply frames were not probed at all. Introduce WIRE_FRAME_FIELDS in
protocol.ts, bound to each frame interface's key set via `satisfies` (a
renamed/removed field breaks typecheck — verified), and drive the mirror test
from it, now covering ReplyOk/ReplyErr too. The test therefore fails on
one-sided drift from either language.
Address the two standing review suggestions in this layer rather than deferring
them to PR #4:
- Extend tests/protocol-mirror.e2e.ts to read each py/protocol.py TypedDict's
required/optional key set and assert it against the wire field names
src/protocol.ts declares (global included, via functional TypedDict). The
round-12 class of drift — a renamed/dropped field, or one side making a field
optional the other requires — now fails a test instead of relying on review.
Field types remain review-guarded (no mechanical TS/Python equivalent).
- Drop the forward references to PR #4's internal mechanisms from this layer's
prose: the "256 MiB frame ceiling" figure and the "(index.ts)" fd-3 pinning
citation become an abstract "host-side inbound frame-size cap" so the JSDoc,
spec, README, and Agent Note describe only what this layer owns.
Update both README sides and the Agent Note (both languages) to state the
mirror is now executable, and re-record their i18n pairings.
checkDoneValue returned non-lossless the instant it hit a non-finite/negative-
zero number, before finishing the budget metering. A value that is BOTH over-
budget and non-lossless then classified by member order: `["<huge>", 1e400]`
gave non-lossless while `[1e400, "<huge>"]` gave over-budget — the same value,
two verdicts — which would drive the consumer to emit invalid-output vs
output-limit non-deterministically, contradicting the JSDoc promise that an
over-budget value is rejected as over-budget regardless. Record the number
violation in a flag and let metering finish; return non-lossless only once the
whole value is confirmed within budget. Add a regression test asserting both
member orders classify as over-budget.
- Replace four raw U+0000 bytes in protocol.spec.ts string literals with the
\0 escape so the source stays plain text (a bare NUL makes text tools treat
the file as binary); the runtime value is unchanged, so the bytes:8 NUL-escape
assertion still holds.
- Sync the Agent Note (both languages) with the corrected checkDoneValue
contract: the walk bounds only the incremental allocation it would add, not
the frame width, which is already parsed and capped upstream by the host's
fd-3 receive buffer. Drop the "prevents a hundreds-of-MB allocation" overclaim
that the code JSDoc already retracted. Re-record the note i18n pairing.
checkDoneValue cannot bound object width sublinearly: JS has no lazy own-key
iterator (for...in materializes the key set), and done.value is already
JSON.parse'd before the check runs, so the frame's width is paid upstream. The
genuine width bound is the host's fixed 256 MiB fd-3 receive buffer (a later
stack layer). Reword the JSDoc and branch comments to claim only what holds —
the traversal caps the INCREMENTAL allocation the check would add (escaped
strings, enqueued children, per-key stringify) and refuses over-budget before
those secondary allocations — and drop the mid-count micro-check that JS cannot
honor. Replace the Proxy test (whose ownKeys allocated a 2M array, proving
nothing) with assertions that an over-budget string/array/object is refused
before its escaped copy or child enqueue.
The object branch counted every own key before applying the size bound, so a
forged done.value with millions of keys and a small cap forced an O(frame)
walk — contradicting the O(cap) guarantee the comment promised and able to
block the host event loop. Bail mid-count the instant the running minimum
encoding (braces + 4 bytes/entry + commas) crosses maxBytes, and drop the now
-redundant post-count check the loop subsumes. Add a Proxy-based test proving
a 2M-key object enumerates fewer than 1000 keys under a 64-byte cap.
Also correct the checkDoneValue JSDoc: per-scalar byte length is measured via
scalarJson (exact BigInt digits for beyond-safe integers), not JSON.stringify.
- Drop a CALL frame whose id is negative zero: it passes Number.isFinite but
the reply re-serializes it as `0`, colliding with a real call id `0`. The
honest child never issues `-0`.
- Document that validateChildFrame preserves a forged done frame's value and
error together on purpose, so consumers must check error before value.
- Cover the log-frame `truncated` rebuild branch: assert a literal-true flag
rides along and any other value (1, string, false) is dropped, closing the
protocol.ts branch the coverage gate flagged.
- Correct encodeJsonPlain's JSDoc: it matches compact JSON.stringify EXCEPT on
a beyond-safe-range integral double, where it emits the exact BigInt digits
(`...846976`) rather than the rounded `...847000` — the divergence the
"emits exact digits" test pins.
- Declare py/protocol.py's `global`-bearing frames (Namespace, CallMessage)
with functional TypedDict syntax so they carry the real wire key instead of
a `global_` attribute the wire never sends, and split optional-field messages
(Namespace/LogMessage/DoneMessage) into a required base plus a total=False
subclass so `type` and other required fields cannot be dropped. Widen
HostToChild to include the boot and run frames the host sends before replies.
- Reword the mirror e2e's py/ directory assertion to describe the source-tree
layout it actually checks.
Introduce @deepseek-ai/dsh-code-runtime-python with the versionless
JSON-lines protocol between the Node host and the CPython subprocess:
the host-side hostile-frame codec (validateChildFrame, encodeJsonPlain,
checkDoneValue, hasUnsafeIntegerToken, hasNonLosslessNumber,
logTruncationMarker) and the Python-side wire-vocabulary mirror
(py/protocol.py).
This is the protocol layer of the code-runtime-python stack, split from
#436 and based on the multi-language seam extension. The PythonCodeRuntime
implementation and its Python JSON codec land in the backend-core PR on
top of this branch.
Ship the minimal buildable package skeleton (package.json, tsconfig,
tsdown, barrel index, invariant companion, bilingual README) because the
workspace-constraint, coverage, and invariant-topology gates require the
package to exist and build the moment its directory does; the backend-core
PR extends those files rather than creating them.
Align py/protocol.py with src/protocol.ts (the round-12 review of #436
found LogMessage.truncated, DoneMessage.error.kind, and Namespace.errorClass
stale) and guard the two runtime-executed surfaces (PROTOCOL_FD and the log
truncation marker) with a real-python3 cross-language mirror e2e test.
Chinesezjc