959845bd30
The canonical sx block-body lambda is `(params) { stmts }` (and
`(params) -> Ret { stmts }`); the arrow form `=>` is for EXPRESSION bodies
(`(params) => expr`). The arrow-block hybrid `(params) => { .. }` was being
used in 33 files — convert all of them by dropping the `=>`. The two forms are
exactly equivalent (verified: identical IR and identical runtime values — the
block tail is the value with or without a `-> Ret`), so this is a pure source
cleanup: no `.ir` churn, and the only snapshot change is 0923's diagnostic
COLUMN (a negative narrowing test whose error span shifted by the removed `=> `).
Arrow EXPRESSION bodies (`=> expr`, `=> .{..}`, `=> [..]`) and `=>` inside
comments/strings were left untouched. Migrated across examples/concurrency,
examples/{closures,ffi-objc,generics,optionals,types}, issues/, and the stdlib
(io.sx, sched.sx). Suite 855/0.
87 lines
3.5 KiB
Plaintext
87 lines
3.5 KiB
Plaintext
// Stream B2 — the SUSPENDING `context.io.async` layer over the M:1 fiber
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// scheduler (PLAN-IO-UNIFY: the unified async stack — the bespoke `go`/`wait` was
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// retired in Phase 5). In contrast with 1805's `context.io.async` UNDER THE
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// BLOCKING `Io` (which runs each worker INLINE to completion — no interleaving),
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// here the scheduler is installed as `context.io`, so `context.io.async(work)`
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// runs `work` as a REAL fiber and `await()` SUSPENDS the caller until it finishes
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// — a worker that yields mid-body lets a sibling run first (cooperative
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// interleaving).
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//
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// `work` is a NULLARY worker: any inputs are captured in the lambda at the call
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// site (no `..args` pack crosses the fiber boundary — that would hit issue 0156
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// Part 2). Outputs flow OUT through pointers captured in the worker (the shared
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// `Log` struct), since closure capture-by-value does not write back.
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//
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// What this proves:
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// - REAL suspend + interleave: worker A records 1, YIELDS; worker B then records
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// 2 and completes; A resumes, records 3, completes → interleave order 1 2 3.
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// - awaited VALUES: A returns 42, B returns 100 (recorded after both awaits).
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// → sequence: 1 2 3 42 100.
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// - cancel rides the `!` channel (model (a), like 1806): a canceled worker's
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// `await()` raises `.Canceled`, taken by the `or` default → -99.
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//
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// `wait` must run inside a fiber (it parks `self.current`), so the "main task"
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// is itself a `s.spawn(...)` fiber that drives the two `go` tasks.
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//
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// aarch64-macOS-pinned (the scheduler's asm + guard-page mmap constants are
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// per-arch / Apple-specific): runs end-to-end on a matching host, ir-only on a
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// mismatch.
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#import "modules/std.sx";
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sched :: #import "modules/std/sched.sx";
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Log :: struct { seq: [16]i64; n: i64; }
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rec :: (l: *Log, v: i64) { l.seq[l.n] = v; l.n = l.n + 1; }
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main :: () -> i64 {
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lg : Log = .{ n = 0 }; // seq[] zero-filled
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s := sched.Scheduler.init();
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ps := @s;
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pl := @lg;
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// The coordinator fiber: drives two async workers, awaits both, then exercises
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// cancel. It runs as a fiber so `await` has a `self.current` to park. The
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// scheduler is installed as `context.io`, so the unified async layer reaches it.
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push .{ io = xx s } {
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ps.spawn(() {
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// Worker A yields mid-body so B interleaves before A completes.
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a := context.io.async(() -> (i64, !) {
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rec(pl, 1);
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ps.yield_now(); // suspend A; B (already spawned) runs to completion
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rec(pl, 3);
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42
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});
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// Worker B runs straight through (no yield).
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b := context.io.async(() -> (i64, !) {
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rec(pl, 2);
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100
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});
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// Await both — suspends the coordinator fiber until each completes.
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va := a.await() or { -1 };
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vb := b.await() or { -1 };
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rec(pl, va);
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rec(pl, vb);
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// Cancel case: cancel before the worker runs; `await` raises .Canceled
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// off the sticky flag, the `or` default (-99) is taken.
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c := context.io.async(() -> (i64, !) => 7);
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c.cancel();
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rec(pl, c.await() or { -99 });
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});
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ps.run();
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}
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// Interleaving + value contract: 1 2 3 42 100, then the cancel default -99.
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print("sequence:");
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i := 0;
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while i < lg.n {
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print(" {}", lg.seq[i]);
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i = i + 1;
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}
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print("\n");
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print("spawned: {}\n", s.n_spawned);
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return 0;
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}
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