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 class docstring still credited the GIL plus per-frame PIPE_BUF atomicity for
serializing writes, which _write_lock's full-write loop already superseded. State
the current contract (writers serialized by _write_lock around a full-write loop)
and drop the double blank line under the binding-replies note heading.
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.
A binding called from a worker thread records that thread's loop for its reply.
If the thread finished and closed its loop before the host reply arrived,
_pump_replies' call_soon_threadsafe onto the closed loop raises RuntimeError;
unguarded, that ends the pump task and strands every later reply. Wrap the
schedule in a try/except that drops the moot reply (nothing awaits it) and keeps
the pump serving.
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.
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.