vm: support shared microtask queues - #65582
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Add `vm.MicrotaskQueue` and `options.microtaskQueue` to allow multiple contexts to share an explicit V8 microtask queue and let users control synchronous checkpoint draining. Fixes: nodejs#65555 Signed-off-by: Alessio Attilio <alessio.attilio@protonmail.com> Assisted-by: Antigravity
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Aug 27, 2026
| * `microtaskQueue` {vm.MicrotaskQueue} A microtask queue created with | ||
| [`new vm.MicrotaskQueue()`][] or [`vm.createMicrotaskQueue()`][]. If | ||
| specified, microtasks scheduled inside this context will be placed on this | ||
| queue, allowing multiple contexts to share the same microtask queue. |
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You could make this an alternative value for microtaskMode, but if not, you should definitely document how these options interact
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This PR introduces vm.MicrotaskQueue and the options.microtaskQueue setting in node:vm, allowing multiple contexts to share an explicit V8 microtask queue and giving authors synchronous control over draining via queue.runMicrotasks(). This enables standards-compliant event loop integration such as HTML window and same-agent iframe microtask checkpointing without premature queue draining.
Fixes: #65555