- introspect::StackInfo { reserve, guard, depth_high_water,
parks_since_shrink, shrinks } as ActorInfo.stack; re-exported at crate
root beside ActorInfo.
- All reads lock-free: geometry from the c6 diag slot atomics, depth =
top - hwm (the §2 sampled high-water; doc spells out sampled-not-exact
and that 0 means never-descheduled-at-depth), counters straight off the
§3 atomics. Coherence for the incarnation rides read_slot's existing
generation check, same as overruns/messages_received.
- Slot::stack_introspect(): one pub(crate) tuple accessor beside the other
counter accessors.
- Exact RSS deliberately absent per RFC (mincore = debug tooling only,
never a runtime path); stack_shape(pid) untouched (cold-lock exact
variant from c2).
- tests/introspect.rs: defaults surface (64 KiB reserve / 1 MiB guard /
sampled ~32 KiB depth / gate park counted / zero shrinks) + live shrink
counters (spike visible pre-shrink; shrinks>=1, cooldown counter reset,
hwm reset after crossing COOLDOWN) read mid-run -- post-join the slot
reclaim correctly hides the incarnation, which the first draft of the
test learned the hard way.
FLAGGED (Claude-solo calls):
- Nested StackInfo struct over five flat ActorInfo fields (grain break;
the five fields are one concern and ActorInfo is already 12 fields).
- Field names reserve/guard/shrinks (RFC says stack_reserve/stack_guard/
shrink count; the stack_ prefix is redundant inside StackInfo).
Accumulate on-CPU cycles per actor as ActorInfo.budget_cycles, behind
the off-by-default budget-accounting feature (D6) — a reductions-style
work metric for relative comparison across runs.
- Approximate by design (per Mark): charge now - slice-start once at the
yield point, reusing the timestamp reset_timeslice already sets, so
one RDTSC per resume not two. Wake-slot resumes inherit the slice and
so slightly over-attribute the chain's time to the woken actor — noise
that averages out; we trade exactness for half the hot-path cost.
- Field/ActorInfo member are unconditional (keeps the snapshot shape
stable across the feature flag, D1); only the accumulation is gated,
so default builds are byte-identical and pay nothing. Reads return 0
when off. Single-writer Relaxed like the other counters; reset in
reset_counters (D7).
Matrix: default + feature-on + rq-mpmc + rq-striped + release + trace all
green; loom unaffected (feature off under --cfg loom).
Tally each dequeued message against the receiving actor, surfaced as
ActorInfo.messages_received (the 'is this actor draining slower than its
mailbox fills' signal).
- messages-received, not sent (D4): the receiver counts on its own
thread, so it's a single-writer Relaxed load+store on a hot Slot
AtomicU64, no atomic RMW (D5); reuses the stashed *const Slot from 2a.
- Incremented at all six channel dequeue-success sites (recv,
recv_timeout x2, recv_match, try_recv_match, try_recv) via
preempt::note_message_received; no-op outside an actor (null slot).
- Resets with overruns in reset_counters across the three lifecycle
sites (D7).
Matrix: debug default + rq-mpmc + rq-striped + release green; loom
slot_state/run_queue models pass (the 3 send_after_to loom failures are
pre-existing at fc014c4 — plain #[test]s under --cfg loom, not Chunk 2).
Tally overruns at the slice-expiry site in preempt.rs (the RFC 006
signal), surfaced as ActorInfo.overruns.
- Counter is a hot-region AtomicU64 on Slot, single-writer Relaxed
load+store (no atomic RMW), read Relaxed by the snapshot (D5).
- Reached from the rare expiry branch via a stashed *const Slot in a
preempt thread-local, set/cleared on the same resume/return boundary
as CURRENT_STOP — one TLS load, no runtime lookup. Shared infra for
the messages-received counter next.
- Reset in all three slot-lifecycle sites: Slot::vacant, reclaim_slot,
install_actor (standing invariant, D7) — per-incarnation counts.
tree() / tree_from() fold a Chunk-1 snapshot into a forest by grouping
each actor under its parent pid — one O(n) pass, no new reads. tree_from
is public so a held (or synthetic) snapshot can be folded without a
second scan.
- D8: actors parented at ROOT_PID are genuine roots; an actor whose
recorded parent is absent from the snapshot is re-rooted under the
sentinel and flagged orphaned, so the forest stays total. take()-on-
place doubles as a guard against re-entering a node.
- D9: the edge is parent/spawned-by, documented as not necessarily
supervision.
snapshot() / actor_info() return owned ActorInfo over the slab: pid,
names, fine-grained scheduling state, parent edge, trap flag, mailbox
depth, and monitor/link/joiner counts. Pure reads, no hot-path change.
- ActorState maps the packed slot word (no new storage); introspect.rs.
- D1: RuntimeSnapshot carries SNAPSHOT_FORMAT_VERSION from day one.
- D2: per-slot tearing (ps semantics); actor_info coherent per actor.
- D3: mailbox depth included. Registry channels now stored behind an
ErasedSender trait (downcast for clone_sender + type-erased
queued_len); depth summed over published channels under the registry
Leaf (Leaf -> Channel), kept out of the cold-lock pass so no two
Leaves are ever held at once. Depth covers published channels only.
- Done slots surface as root-less tombstones.
smarm-agent