The manager is now a harness service on the well-known .device_manager
endpoint. Every driver spawns supervised; drivers with an assignment must
hello (device-manager-protocol, versioned) within a deadline enforced by
a timer sweep. Exit reasons drive the restart decision: clean exits stay
down, faults restart with 300/600/1200ms backoff, and three fast deaths
mark a driver failed instead of respawning forever. usb-xhci-bus is the
first conforming driver; the crash-test fixture claims a device, hellos,
and faults on purpose — each respawn re-proving claim release on death
through the manager's own path. maximum_tasks grows 16 -> 32: the
initial-ramdisk sweep (15 binaries at once) was intermittently
overflowing the static pool.
Signals are statements delivered as coalescing notifications to the
endpoint a process nominates with signal_bind — never a hijacked stack,
never a question (liveness is the zero-length ping the harness answers).
process_signal is supervisor-or-self gated, like kill; unbound targets
accumulate a pending mask delivered on bind. timer_bind is the missing
timed wait: a one-shot deadline landing in the same replyWait as
everything else — what stop(), hello deadlines, and restart backoff are
built from. runtime.service.run folds requests, signals, and
notifications into callbacks; the VFS conversion deletes its hand-rolled
loop and gains the whole lifecycle contract. The signals scenario drives
ping, reload, terminate->exited, the timer, and the deaf-child
deadline->killed path from ring 3. docs/process-lifecycle.md increments
1-4 are now as-built.
process_subscribe adds an endpoint to a bounded, ref-counted subscriber
table; every death posts the same badge encoding a supervisor's exit
notification uses, equally late, so subscribers observe a fully-released
child. A dying subscriber's own subscriptions are removed first — it never
hears about itself. The VFS is the first subscriber: open handles now
record their owner and are swept when the owner dies, because a service
must never depend on clients cleaning up after themselves
(docs/process-lifecycle.md). Proven by the vfs-client-death scenario.
The kernel records an ExitReason at all three death sites — clean exit,
fault (classified by vector), and process_kill — into a bounded ring
before the exit notification posts, so a supervisor's query never races
the notice. process_exit_reason is gated by the same supervisor check as
kill; runtime.process.exitReason is the stable interface. This is the
input restart policy reads (docs/process-lifecycle.md iron rule 2).
Every path out of a process (exit, fault, kill) now releases its device
claims alongside its IRQ and MSI bindings, so a restarted driver can claim
its hardware again — the cleanup half of process-lifecycle.md's iron rule 1.
MSI vectors were already swept by irq.releaseOwner; claims were the gap.
The claim-release test proves kill -> release -> re-claim, plus the broker
release in isolation.
Signals over IPC (POSIX concepts, message delivery), published exit events,
the stable runtime.process interface, and the device manager as tree +
matcher + supervisor. All open questions settled; docs/m17-m18-plan.md is
the phase-by-phase execution plan.
Daniel Samson