shoney.arickathil
efbf2f36ca
- docs/examples/fibers: part 1 is TIMING-FREE and byte-exact — main sends three messages then burns reductions; each budget expiry hands the Counter actor exactly one delivery (cooperative mechanics, preemptive fairness, BEAM's shape); part 2 parks a Sleeper actor mid-receive on the I/O plane while main keeps ticking — the wake lands between ticks, proving a sleeping fiber blocks nobody - the missing "sleeper: up" on the first run was main-return-reap working as specced (main ended before the deadline); the demo's window widened so the wake is observable - scripts/fibers-accept.sh + `just fibers` (8 checks): build, part-1 exact + part-2 ordering invariants on auto/uring/epoll backends, and an ASan-runtime rebuild+run - README points at the doctrine writeup (exploration/fibers) Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
21 lines
1.1 KiB
Markdown
21 lines
1.1 KiB
Markdown
# fibers — the hybrid scheduler, demonstrated
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The smallest program that shows all three legs of the concurrency model
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(the doctrine-depth writeup lives in
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[`docs/plan/exploration/fibers/00-fibers.md`](../../plan/exploration/fibers/00-fibers.md)):
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1. **Reduction-budget eviction** — part 1's output is byte-exact and
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timing-free: main sends three messages, then burns reductions; every
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time its budget expires the counter actor gets a turn and delivers
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exactly one message. Cooperative mechanics, preemptive fairness.
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2. **Actors as the spawn surface** — `spawn Counter { ... }` returns an
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`actor Tick`; `send` moves the message (using it afterwards is a
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compile error); delivery is one message at a time per actor.
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3. **Parking, not blocking** — part 2's sleeper actor calls `time.sleep`
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mid-receive: the fiber parks on the shard's I/O plane (io_uring
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primary, epoll fallback — `WO_IO=uring|epoll` forces either) and
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main keeps ticking while it sleeps.
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Run: `just fibers` (the acceptance gate builds it, checks part 1
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byte-exact, asserts part 2's ordering invariants, and repeats the run on
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both I/O backends plus ASan).
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