Fold the made-up Addr<A> back into the pid, where it belonged. The typed
handle IS the pid now.
- RawPid { index, generation }: today's Pid, renamed — the raw numbers, the key
for identity-only plumbing and the heterogeneous monitor/link/pg tables.
- Pid<A = Erased>: RawPid + phantom actor type. Both an identity and a direct,
identity-bound address; when A: Addressable a send delivers A::Msg to exactly
this incarnation (next phase). Hand-written impls (eq/hash/fmt on the raw
only, no A bounds); fn()->A phantom keeps it Copy+Send+Sync for any A.
- Erased: uninhabited, deliberately NOT Addressable, so a typed send to a
Pid<Erased> won't compile — that's what send_dyn (section 4.6) will be for. It
is the default type arg, so every plain "Pid" written today still compiles as
Pid<Erased>; that, plus the fact that nothing destructures pid fields, is why
an identity change touching 18 files cascaded to zero internal edits.
- Addr<A> deleted; Name<M> / the Phase-2 registry unchanged (they key on raw).
Per the call to make the consumers take typed pids: the user-facing identity
APIs — monitor, link, unlink, request_stop, spawn_under(supervisor), pg::join,
pg::leave — are now generic over A and erase at the boundary; their bodies are
byte-for-byte unchanged. Pure plumbing (unpark, set_current_pid,
register_supervisor_channel) stays erased — it only ever sees internal identity.
Phase 1's Addr tests become Pid<A> tests (identity/copy/erase/Debug, Send+Sync).
Full suite + order-checker green, warning-free across all targets.
Rip out the old name<->pid bimap; rebuild registry.rs as the live mailbox
directory. A name resolves to a SINGLE actor (many-per-label is pg's job); that
actor owns a SET of typed channels (channels are typed, so no single mailbox),
keyed by message TypeId. Resolution: name -> pid (one actor) -> Mailbox ->
channel for type M. Same name + different type parameter selects different
channels of the one actor, so capability separation (§4.7) needs no new type.
- register<M>(Name<M>, Sender<M>): captures the current actor's channel under a
name (one step, per decision). Adds channels cumulatively; NameTaken only vs a
different LIVE holder; stale/dangling bindings pruned on contact.
- send<M>(Name<M>, msg): the payoff — resolve, clone the Sender UNDER the Leaf
lock, release, then send (Leaf -> Channel; a send can unpark). Returns the msg
on Unresolved / NoChannel / Closed.
- whereis -> single live pid; unregister frees only the name (mailbox/other
names survive). name_of (reverse lookup) dropped — deferred to introspection.
- Contained erasure: each channel is Box<dyn Any+Send> filed under TypeId::of M
and downcast to its own keying type, so the downcast can't fail on good data
(debug-asserted via the stored type_name). Phantom M on Name re-imposes type.
- One Leaf RawMutex (the fold), so a name send stays on a single Leaf — two
Leaves at once is a hard panic. runtime.rs field/init unchanged (same Registry
name + new()).
tests/registry.rs rewritten for the new semantics: send-by-name delivery,
many typed channels on one actor, same-name/different-type routing, NameTaken,
takeover across slot reuse, Unresolved/NoChannel. Also fold in a Phase 1 fixup:
the phantom test key was an enum whose variants tripped dead-code under the test
build (only caught now that I run -D warnings on --tests). Full suite +
order-checker green, warning-free across all targets.
Add the value-token layer for typed addressing, ahead of the handle table:
- Addressable { type Msg }: minimal actor-type -> message-type hook (decision
(a)). Raw actors are closures over channels; GenServer is multi-message and
stays addressed via ServerRef. This gives the single-message actors a key.
- Addr<A>: direct, identity-bound address (RFC's Pid<A>, renamed to avoid the
collision with the non-generic Pid identity). Plain Pid + PhantomData<fn()->A>.
- Name<A>: durable, re-resolving address; const-constructible (Name::new).
Both tokens are Copy + Send + Sync regardless of key (phantom is fn()->T), with
hand-written trait impls so no spurious T: Copy/Eq bounds leak in. No behavior
yet; send/resolve/storage land in later phases. Addr::new is #[cfg(test)] until
Phase 2 has a real (non-test) caller. Unit tests cover identity/copy/eq/debug
and Send+Sync.
- add RFC 013 as the up-next item, sequenced before send_after
- mark process groups shipped (RFC 012, b78311b..56f2fc5)
- note send_after now depends on 013 for Dest; cross-link clustering name-addressing
A plain-actor example showing the one thing process groups are for: a live
membership view that self-heals on death. Two workers join a group; one dies
and is evicted by the death hook with no deregistration call; one leaves
voluntarily. Runs under cargo test --doc.
(Deliberately not a worker-pool-with-dispatch example: pg is membership and
liveness, not a message router — routing a job to a picked pid needs a
pid->handle map that pg does not provide, so a dispatch example would document
the adapter, not pg.)
members/pick now filter through a lock-free, generation-checked slot-word
read (live(), identical to the registry's guard) so a member that is already
dead but whose Down has not yet been drained is never *returned*. Eviction
stays the monitor's job (reap_group); this is the belt-and-braces read guard.
- members_where / first_member_where take an is_live oracle and replace the
unconditional first_member; members_of becomes test-only (raw enumeration).
- Unit test: the backstop hides a member the monitor has not yet reaped, and
does not itself evict (storage still holds it until reap).
Full suite green, warning-free.
Wire eviction to actor death via the monitor subsystem, using drain-on-
contact (no scheduler hot-path hook).
- Each membership now carries its own Monitor alongside the group entry;
join() installs monitor(pid) (registration races finalize_actor under the
cold lock, as every monitor does) and a redundant join tears its extra
monitor back down.
- reap_group: every group op drains the touched group's monitors with a
non-blocking try_recv (a delivered Down or closed channel = dead) and, on
the first death, sweeps that pid out of *every* group via remove_where —
so a death vanishes from all its groups on next contact.
- Lock discipline: monitor()/demonitor() (cold = Leaf) run outside the group
lock; try_recv (Channel) runs under it, permitted by the Leaf->Channel
order; evicted/rejected monitors are dropped after the lock releases so no
receiver-drop wakeup runs under it. Validated by the debug-build lock-order
checker passing under the integration tests.
- remove_where now returns the evicted monitors (for deferred drop) and
preserves intra-group insertion order.
- Tests: unit (synthetic monitors) for reap live/dead/closed + sweep;
integration (real actors) for death-vanishes-from-every-group, pick on an
all-dead group, peer survival, leave isolation, dead-at-join eviction.
Outstanding: a miri pass (cargo +nightly miri test --lib pg::) is untried —
first build exceeds the sandbox window and the futex RawMutex may need a miri
shim; the mechanical Leaf->Channel checker is the primary soundness guard.
Add a process-groups module (name -> multiset<Member>) sibling to the
registry, plus the cluster-shaped identity it is keyed on.
- NodeId/Incarnation u32 newtypes; Member { node, incarnation, pid } at
final (BEAM NEW_PID_EXT-shaped) layout.
- Config::node_id/incarnation builder setters beside wake_slot, defaulting
to a fixed single-node value; threaded through RuntimeInner::new.
- process_groups: RawMutex<ProcessGroups> on RuntimeInner, Leaf class,
mirroring the registry field.
- remove_where: the one dumb predicate-eviction primitive (no liveness wired
yet; first caller is the Phase 2 death hook).
- Public surface (join/leave/members/pick) in pre-liveness/pre-monitor form,
Pid-shaped; node/incarnation filled from runtime identity.
- Structural unit tests on synthetic members: idempotent join, multiset
semantics across groups, generation-distinct members, leave + empty-group
pruning, predicate sweep, incarnation-sweep shape.
- Compact v0.9 (Wake-path latency) into Shipped; record the RFC 004 spinning
excision as a deviation (preserved on branch rfc-004-spinning).
- Drop the v0.7 entry, folding its reference into the Shipped history pointer.
- Promote Process groups from Later into the up-next slot v0.9 vacated;
Per-switch cost now leads Later/Highest priority.
The spinning experiment is excised from master. Drops the two dedicated v0.9
sections describing it. Inline RFC-004 mentions in the v0.9 intro and the
queue-topology decision record are intentionally left for a manual short-term
-plan pass.
Carries forward the non-spin parts of the dropped spin-tooling commit:
- .gitignore: __pycache__/ and *.pyc
- sweep.py: generic vs-tokio comparison summary (no spin_sweep coupling)
The spin_sweep README docs from that commit are intentionally left behind.
The profile was captured against the spin-enabled build. With the RFC 004
spinning experiment excised from master, the ~12% hot-path futex_wake it
attributed to the spinning submit-rule no longer exists (idle wait is back to
thread::sleep). Add a provenance note, mark the futex_wake row/finding as
excised spin machinery, and drop the now-moot 'gate the submit wake' lead.
Spin-independent findings (shims ~1%, schedule_loop + run-queue ~33%) unchanged.
smarm-agent