diff --git a/packages/compiler/test/ts7/baselines/order-parity/tests/corpus/7381-als-async-generator-steps.ts.json b/packages/compiler/test/ts7/baselines/order-parity/tests/corpus/7381-als-async-generator-steps.ts.json new file mode 100644 index 000000000..47f93314d --- /dev/null +++ b/packages/compiler/test/ts7/baselines/order-parity/tests/corpus/7381-als-async-generator-steps.ts.json @@ -0,0 +1,6 @@ +{ + "order": [ + "/tests/corpus/7381-als-async-generator-steps.ts" + ], + "diags": [] +} diff --git a/packages/compiler/test/ts7/baselines/order-parity/tests/corpus/7382-als-async-generator-steps.mjs.json b/packages/compiler/test/ts7/baselines/order-parity/tests/corpus/7382-als-async-generator-steps.mjs.json new file mode 100644 index 000000000..5f55ba7bd --- /dev/null +++ b/packages/compiler/test/ts7/baselines/order-parity/tests/corpus/7382-als-async-generator-steps.mjs.json @@ -0,0 +1,6 @@ +{ + "order": [ + "/tests/corpus/7382-als-async-generator-steps.mjs" + ], + "diags": [] +} diff --git a/packages/runtime/src/scr_async.c b/packages/runtime/src/scr_async.c index 90e7dd04f..e6184ed9b 100644 --- a/packages/runtime/src/scr_async.c +++ b/packages/runtime/src/scr_async.c @@ -715,11 +715,13 @@ static void scr_als_prefix_end(ScrFiber *f) { } } -/* A synchronous generator has no context of its own: each step runs in its - * resumer's execution, as Node runs it. A fiber-backed one switches to its - * own slot, so its step starts from the resumer's store and a store it - * enters is the resumer's after the step (scr_als_prefix_end on the way - * back); a stackless one runs in the resumer's slot (scr_gen_coro_hop). */ +/* A generator step runs in its resumer's execution, as Node runs it. A + * fiber-backed generator switches to its own slot, so its step starts from + * the resumer's store and a store it enters is the resumer's after the + * step (scr_als_prefix_end on the way back); a stackless synchronous one + * runs in the resumer's slot (scr_gen_coro_hop). An async generator's step + * starts the same way, and after an await it continues in its own copy of + * the context, as an async function's body does after its prefix. */ static void scr_als_step_begin(ScrFiber *f) { ScrAlsCtx **slot = SCR_ALS_SLOT(); if (f->als != *slot) { @@ -5303,6 +5305,10 @@ struct ScrGen { * since that return takes its own turn to await x. */ bool return_queued; bool return_awaited; + /* The AsyncLocalStorage context of a return() request deferred at a + * yield (+1): the body's unwind runs in it, as Node resumes it from the + * return value's await. */ + ScrAlsCtx *return_ctx; #ifdef SCR_WORKERS bool context_abandoned; #endif @@ -5406,6 +5412,7 @@ void scr_gen_release(ScrGen *g) { scr_gen_slot_reset(&g->in); scr_gen_slot_reset(&g->ret); scr_gen_exc_reset(&g->async_error); + scr_als_ctx_release(g->return_ctx); if (g->fiber != NULL) { if (g->state == SCR_GEN_UNSTARTED) { /* Never ran: nothing on the stack owns anything — clean teardown. @@ -5760,6 +5767,12 @@ __attribute__((always_inline)) static inline void scr_gen_switched_back(ScrGen * if (release) scr_gen_release(g); } +/* Out of line, so the hop that synchronous generators share stays as it + * was: an async generator's step begins from its resumer's context and + * hands the prefix's context back at its first suspension. */ +static __attribute__((noinline)) void scr_async_gen_step_begin(ScrFiber *f) { scr_als_step_begin(f); } +static __attribute__((noinline)) void scr_async_gen_step_end(ScrFiber *f) { scr_als_prefix_end(f); } + #ifndef __wasi__ /* The stackless form of the hop: the coroutine frame runs on this stack * until its next yield or its final suspension returns here. `retain` @@ -5768,14 +5781,17 @@ __attribute__((always_inline)) static inline void scr_gen_switched_back(ScrGen * __attribute__((always_inline)) static inline void scr_gen_coro_hop(ScrGen *g, bool retain) { ScrFiber *f = g->fiber; if (retain) scr_gen_retain(g); + /* A synchronous generator has no AsyncLocalStorage context of its own: + * its step runs in the resumer's slot, as Node runs it in the execution + * that called next(). An async generator's step runs in its own slot, + * which a new step (not the continuation after an await) starts from the + * resumer's context (scr_als_step_begin). */ + if (g->is_async && g->state != SCR_GEN_AWAITING) scr_async_gen_step_begin(f); g->state = SCR_GEN_RUNNING; f->resumer = scr_current; ScrAlsCtx **resumer_slot = scr_als_active; scr_current = f; scr_exc_swap_cell(&f->exc); - /* A synchronous generator has no AsyncLocalStorage context of its own: - * its step runs in the resumer's slot, as Node runs it in the execution - * that called next(). An async generator's step runs in its own. */ if (g->is_async) scr_als_active = &f->als; if (f->coro == NULL) f->entry(f, f->argpack); else scr_coro_resume(f->coro); @@ -5786,6 +5802,7 @@ __attribute__((always_inline)) static inline void scr_gen_coro_hop(ScrGen *g, bo scr_current = me; scr_exc_swap_cell(me != NULL ? &me->exc : NULL); scr_als_active = resumer_slot; + if (g->is_async) scr_async_gen_step_end(f); scr_gen_switched_back(g, f, retain, true); } @@ -5806,8 +5823,10 @@ static void scr_gen_switch_in(ScrGen *g) { } #endif scr_gen_retain(g); + /* Each step starts from the resumer's context; an async generator's + * continuation after an await keeps its own. */ + if (!g->is_async || g->state != SCR_GEN_AWAITING) scr_als_step_begin(f); g->state = SCR_GEN_RUNNING; - if (!g->is_async) scr_als_step_begin(f); #ifdef _WIN32 ScrCtx here = scr_win_self(); #elif defined(__wasi__) @@ -5979,6 +5998,25 @@ void scr_gen_resume_throw(ScrGen *g) { static void scr_async_gen_start_queued(ScrGen *g); +/* Runs fn(g) with `ctx` (borrowed) as the active AsyncLocalStorage + * context. A settlement job runs from the loop: a request queued behind + * another starts in the context of the step before it (Node drains the + * queue in the generator's own execution), and a deferred return() in its + * call's. */ +static __attribute__((noinline)) void scr_async_gen_in_context(ScrGen *g, ScrAlsCtx *ctx, + void (*fn)(ScrGen *)) { + ScrAlsCtx **slot = SCR_ALS_SLOT(); + ScrAlsCtx *prev = *slot; + *slot = scr_als_ctx_retain(ctx); + fn(g); + scr_als_restore(prev); +} + +/* Starts the queued requests in the context of the step before them. */ +static __attribute__((noinline)) void scr_async_gen_start_queued_in_own(ScrGen *g) { + scr_async_gen_in_context(g, g->fiber != NULL ? g->fiber->als : NULL, scr_async_gen_start_queued); +} + static void scr_async_gen_schedule_settle(ScrGen *g) { if (g->settle_queued) return; ScrFiber *job = scr_mem_calloc(sizeof *job); @@ -6026,6 +6064,11 @@ static bool scr_async_gen_settles_now(ScrGen *g) { return false; } +static __attribute__((noinline)) void scr_async_gen_capture_return_ctx(ScrGen *g) { + scr_als_ctx_release(g->return_ctx); + g->return_ctx = scr_als_ctx_retain(*SCR_ALS_SLOT()); +} + static void scr_async_gen_run_active(ScrGen *g, ScrAsyncGenRequest *req) { const bool was_done = g->state == SCR_GEN_DONE; if (req->mode == SCR_AG_NEXT) { @@ -6041,6 +6084,7 @@ static void scr_async_gen_run_active(ScrGen *g, ScrAsyncGenRequest *req) { /* At a yield, AsyncGeneratorYield awaits the return value before * the body resumes, so finally blocks run one turn later. */ g->return_queued = true; + scr_async_gen_capture_return_ctx(g); scr_async_gen_schedule_settle(g); return; } @@ -6071,6 +6115,16 @@ static void scr_async_gen_run_active(ScrGen *g, ScrAsyncGenRequest *req) { } } +static void scr_async_gen_resume_returning(ScrGen *g); + +/* The deferred return() resumes in its call's context. */ +static __attribute__((noinline)) void scr_async_gen_resume_returning_in_context(ScrGen *g) { + ScrAlsCtx *ctx = g->return_ctx; + g->return_ctx = NULL; + scr_async_gen_in_context(g, ctx, scr_async_gen_resume_returning); + scr_als_ctx_release(ctx); +} + /* The return() request's await has taken its turn: resume the body with * the return completion. */ static void scr_async_gen_resume_returning(ScrGen *g) { @@ -6203,12 +6257,12 @@ static void scr_async_gen_job(ScrGen *g) { } if (g->return_queued) { scr_gen_retain(g); - scr_async_gen_resume_returning(g); + scr_async_gen_resume_returning_in_context(g); scr_gen_release(g); return; } scr_async_gen_finish_active(g, false); - scr_async_gen_start_queued(g); + scr_async_gen_start_queued_in_own(g); } static void scr_async_gen_resume_ready(ScrGen *g) { @@ -6222,11 +6276,11 @@ static void scr_async_gen_resume_ready(ScrGen *g) { scr_gen_switch_in(g); if (g->async_error.kind != SCR_EXC_NONE) { scr_async_gen_finish_active(g, true); - scr_async_gen_start_queued(g); + scr_async_gen_start_queued_in_own(g); } else if (g->state != SCR_GEN_AWAITING) { if (scr_async_gen_settles_now(g)) { scr_async_gen_finish_active(g, false); - scr_async_gen_start_queued(g); + scr_async_gen_start_queued_in_own(g); } else { scr_async_gen_schedule_settle(g); } diff --git a/tests/corpus/7381-als-async-generator-steps.ts b/tests/corpus/7381-als-async-generator-steps.ts new file mode 100644 index 000000000..4f6ace58d --- /dev/null +++ b/tests/corpus/7381-als-async-generator-steps.ts @@ -0,0 +1,133 @@ +// AsyncLocalStorage contexts of async generator steps. Each step starts in +// the context of the next(), return() or throw() call that resumes it, +// whatever context created the generator; a store the step enters before +// its first await is the caller's after the call, and after an await the +// step keeps its own copy. A request queued behind a running step starts +// in that step's context, and a return() at a yield unwinds in the +// return() call's context. Covers yield*, for await with break, and two +// generators resumed in turn. +import { AsyncLocalStorage } from "node:async_hooks"; + +const store = new AsyncLocalStorage(); +const lines: string[] = []; +const log = (what: string): void => { + lines.push(`${what}: ${store.getStore() ?? "none"}`); +}; + +async function* steps(): AsyncGenerator { + log("body start"); + yield 1; + log("after the first yield"); + await null; + log("after an await"); + store.enterWith("inside"); + yield 2; + log("after the second yield"); + yield 3; + log("body end"); +} +const it = store.run("create", () => steps()); +await store.run("next-1", () => it.next()); +log("caller after next-1"); +await store.run("next-2", () => it.next()); +log("caller after next-2"); +await store.run("next-3", () => it.next()); +await store.run("next-4", () => it.next()); + +async function* prefixes(): AsyncGenerator { + store.enterWith("prefix"); + yield 1; + store.enterWith("step-2"); + await null; + log("after an await in step 2"); + yield 2; +} +await store.run("outer", async () => { + const gen = prefixes(); + const first = gen.next(); + log("synchronously after next"); + await first; + log("after awaiting next"); + const second = gen.next(); + log("synchronously after the second next"); + await second; + log("after awaiting the second next"); +}); + +async function* queued(): AsyncGenerator { + log("queued start"); + yield 1; + log("queued resumed"); + yield 2; +} +const q = queued(); +await Promise.all([store.run("q-1", () => q.next()), store.run("q-2", () => q.next())]); + +async function* inner(): AsyncGenerator { + log("inner start"); + yield "a"; + log("inner resumed"); + yield "b"; +} +async function* outerGen(): AsyncGenerator { + log("outer start"); + yield* inner(); + log("outer after yield*"); +} +const delegating = outerGen(); +await store.run("o-1", () => delegating.next()); +await store.run("o-2", () => delegating.next()); +await store.run("o-3", () => delegating.next()); + +async function* catching(): AsyncGenerator { + try { + yield 1; + } catch (e) { + log(`caught ${(e as Error).message}`); + yield 2; + } +} +const c = catching(); +await store.run("t-1", () => c.next()); +await store.run("t-2", () => c.throw(new Error("boom"))); + +async function* finallyGen(): AsyncGenerator { + try { + yield 1; + } finally { + log("finally"); + } +} +const f = finallyGen(); +await store.run("n", () => f.next()); +await store.run("return-call", () => f.return()); + +async function* endless(): AsyncGenerator { + let i = 0; + try { + while (true) { + log(`endless ${i}`); + yield i++; + } + } finally { + log("endless finally"); + } +} +await store.run("loop", async () => { + for await (const v of endless()) { + if (v === 1) break; + } +}); + +async function* named(name: string): AsyncGenerator { + log(`${name} 1`); + yield 1; + log(`${name} 2`); + yield 2; +} +const a = named("A"); +const b = named("B"); +await Promise.all([store.run("a-1", () => a.next()), store.run("b-1", () => b.next())]); +await Promise.all([store.run("b-2", () => b.next()), store.run("a-2", () => a.next())]); + +for (const line of lines) console.log(line); diff --git a/tests/corpus/7382-als-async-generator-steps.mjs b/tests/corpus/7382-als-async-generator-steps.mjs new file mode 100644 index 000000000..bbabdb592 --- /dev/null +++ b/tests/corpus/7382-als-async-generator-steps.mjs @@ -0,0 +1,43 @@ +// AsyncLocalStorage contexts of async generator steps from JavaScript: +// steps start in the context of the call that resumes them, a store a step +// enters before its first await is the caller's, queued requests start in +// the running step's context, and return() at a yield unwinds in the +// return() call's context. +import { AsyncLocalStorage } from "node:async_hooks"; +const s = new AsyncLocalStorage(); +const lines = []; +const g = (t) => lines.push(`${t}: ${s.getStore() ?? "none"}`); +async function* gen() { + g("body start"); + yield 1; + g("after first yield"); + await null; + g("after await"); + s.enterWith("inside"); + yield 2; + g("after second yield"); + yield 3; + g("body end"); +} +const it = s.run("create", () => gen()); +await s.run("next1", () => it.next()); +g("caller after next1"); +await s.run("next2", () => it.next()); +g("caller after next2"); +await s.run("next3", () => it.next()); +await s.run("next4", () => it.next()); +// concurrent next calls queued +async function* gen2() { g("g2 start"); yield 1; g("g2 resumed"); yield 2; } +const it2 = gen2(); +const p1 = s.run("q1", () => it2.next()); +const p2 = s.run("q2", () => it2.next()); +await Promise.all([p1, p2]); +// for await +async function* gen3() { for (let i = 0; i < 2; i++) { g("g3 step " + i); yield i; } } +await s.run("for-await", async () => { for await (const v of gen3()) g("loop body " + v); }); +// return/throw +async function* gen4() { try { yield 1; } finally { g("g4 finally"); } } +const it4 = gen4(); +await s.run("n", () => it4.next()); +await s.run("ret", () => it4.return()); +for (const line of lines) console.log(line); diff --git a/tests/harness/corpus-costs/7381-als-async-generator-steps.ts.json b/tests/harness/corpus-costs/7381-als-async-generator-steps.ts.json new file mode 100644 index 000000000..3f7384f20 --- /dev/null +++ b/tests/harness/corpus-costs/7381-als-async-generator-steps.ts.json @@ -0,0 +1 @@ +{ "plain": 3500, "san": 6000 } diff --git a/tests/harness/corpus-costs/7382-als-async-generator-steps.mjs.json b/tests/harness/corpus-costs/7382-als-async-generator-steps.mjs.json new file mode 100644 index 000000000..3f7384f20 --- /dev/null +++ b/tests/harness/corpus-costs/7382-als-async-generator-steps.mjs.json @@ -0,0 +1 @@ +{ "plain": 3500, "san": 6000 }