runtime: run syscall/js finalizers on wasm without a manual GC (#5545)

* runtime: run syscall/js finalizers on wasm without a manual GC * runtime: address review feedback on finalizer idle GC * runtime: clear a finished task's args pointer so its arguments are collectable * runtime: skip the finalizer scan with a per-block registration bit * runtime: guard the finalizer registration bitmap with gcLock * testdata: cover finalizer invariants on every scheduler * main_test: limit the finalizer scheduler variants to linux and darwin * testdata: wait for the finalizer queue to drain before asserting * testdata: make the finalizer counters atomic and wait for a known drain count * runtime: add finalizer bookkeeping asserts under runtime_asserts * runtime: address finalizer GC review feedback * testdata: strengthen blocked stack finalizer test * runtime: fix finalizer cleanup edge cases * runtime: decouple wasm export scheduling from finalizers * runtime: avoid redundant wakeups for re-entrant wasm exports * runtime: simplify finalizer comments
2026-09-01 10:19:01 +00:00 · 2026-08-26 15:03:44 -03:00
parent 8d6240a5e6
commit 31fff2c9a3
22 changed files with 1048 additions and 56 deletions
@@ -0,0 +1,74 @@
+const fs = require('fs');
+
+require('../targets/wasm_exec.js');
+
+let finalized = 0;
+let backgroundRuns = 0;
+let instance;
+const go = new Go();
+const sleepTicks = go.importObject.gojs['runtime.sleepTicks'];
+let zeroRearms = 0;
+go.importObject.gojs['runtime.sleepTicks'] = timeout => {
+    if (Number(timeout) === 0) {
+        zeroRearms++;
+    }
+    return sleepTicks(timeout);
+};
+go.importObject.tester = {
+    finalizerRan: () => {
+        finalized++;
+    },
+    backgroundRan: () => {
+        backgroundRuns++;
+    },
+    callNestedExport: () => {
+        instance.exports.launchBackground();
+    },
+};
+
+WebAssembly.instantiate(fs.readFileSync(process.argv[2]), go.importObject).then(async result => {
+    instance = result.instance;
+    await go.run(instance);
+
+    const topLevelRearms = zeroRearms;
+    instance.exports.launchBackground();
+    if (backgroundRuns !== 0) {
+        throw new Error('wasm export ran a background goroutine before returning');
+    }
+    if (zeroRearms !== topLevelRearms + 1) {
+        throw new Error('top-level wasm export did not schedule exactly one wakeup');
+    }
+    for (let i = 0; i < 500 && backgroundRuns === 0; i++) {
+        await new Promise(resolve => setTimeout(resolve, 1));
+    }
+    if (backgroundRuns !== 1) {
+        throw new Error('wasm scheduler did not resume after an export without finalizers');
+    }
+
+    instance.exports.installNestedCallback();
+    const nestedRearms = zeroRearms;
+    global.nestedExportCallback();
+    if (zeroRearms !== nestedRearms) {
+        throw new Error('re-entrant wasm export scheduled a redundant wakeup');
+    }
+    if (backgroundRuns !== 2) {
+        throw new Error('outer scheduler did not drain work from a re-entrant wasm export');
+    }
+
+    instance.exports.registerFinalizers();
+    if (backgroundRuns !== 2) {
+        throw new Error('wasm export ran an unrelated goroutine before returning');
+    }
+    for (let i = 0; i < 500 && (finalized === 0 || backgroundRuns < 3); i++) {
+        await new Promise(resolve => setTimeout(resolve, 1));
+    }
+    if (finalized === 0) {
+        throw new Error('no wasm-export finalizer ran after returning to JavaScript');
+    }
+    if (backgroundRuns !== 3) {
+        throw new Error('wasm scheduler did not resume after a finalizer export');
+    }
+}).catch(err => {
+    console.error(err);
+    process.exit(1);
+});