8bacb2b01c
A cancelled async worker now abandons its body at its next suspend instead
of running to completion.
- Cancel-flag back-ref (D4): SpawnOpts.cancel_flag (core.sx) + Fiber.cancel_flag
(sched.sx), set from opts.cancel_flag in Scheduler.spawn_raw; async passes
xx @f.canceled (the Future.canceled Atomic(bool) erased to *void).
- Delivery: Scheduler.suspend_raw consults fiber_canceled(self.current) PRE-park
(raise without parking — no deadlock if cancel landed before the worker ran)
and POST-resume (cancel landed while parked), raising error.Canceled.
cancel(f) flips the sticky flag, marks .canceled, and wakes the worker.
- async worker is failable Closure() -> ($R, !); the completion closure
f.value = worker() catch {…} marks .canceled/.failed and wakes the awaiter,
so post-suspend side effects never run. New failable io.sleep(ms) is the
cancellation point.
- Compiler: a -> ! fn whose only error source is try-ing a protocol method
(io.suspend_raw) was wrongly flagged 'declared ! but never errors';
collectErrorSites now marks a try of a non-identifier callee as a dynamic
(opaque) error source, suppressing the warning.
- Two UAFs found by adversarial review and fixed: (1) cancel-before-park
orphaned io.sleep's armed timer — suspend_raw's pre-park raise now evicts the
current fiber's timer/waiter first; (2) cancel(f) could wake a reaped worker —
now only wakes when was_pending.
Migrated 1805/1806/1824 to failable workers. Lock: example 1825 (seq: 1 -99,
post-suspend line never runs); byte-identical on aarch64-macOS + aarch64-linux.
.ir churn is the SpawnOpts layout change (type-table string renumbering).
830 KiB
830 KiB