Function abortSignal

lib/internal/abort_controller.js:492–540

(signal, reason)

// https://dom.spec.whatwg.org/#dom-abortsignal-abort
function abortSignal(signal, reason) {
  // 1. If signal is aborted, then return.
  if (signal[kAborted]) return;

  // 2. Set signal's abort reason to reason if it is given;
  //    otherwise to a new "AbortError" DOMException.
  signal[kAborted] = true;
  signal[kReason] = reason;

  // 3. Let dependentSignalsToAbort be a new list.
  const dependentSignalsToAbort = ObjectSetPrototypeOf([], null);

  // 4. For each dependentSignal of signal's dependent signals:
  signal[kDependantSignals]?.forEach((s) => {
    const dependentSignal = s.deref();
    // 1. If dependentSignal is not aborted, then:
    if (dependentSignal && !dependentSignal[kAborted]) {
      // 1. Set dependentSignal's abort reason to signal's abort reason.
      dependentSignal[kReason] = reason;
      dependentSignal[kAborted] = true;
      // 2. Append dependentSignal to dependentSignalsToAbort.
      ArrayPrototypePush(dependentSignalsToAbort, dependentSignal);
    }
  });

  // 5. Run the abort steps for signal
  runAbort(signal);

  // 6. For each dependentSignal of dependentSignalsToAbort,
  //    run the abort steps for dependentSignal.
  for (let i = 0; i < dependentSignalsToAbort.length; i++) {
    const dependentSignal = dependentSignalsToAbort[i];
    runAbort(dependentSignal);
  }

  // Clean up the signal from gcPersistentSignals
  gcPersistentSignals.delete(signal);

  // If this is a composite signal, also remove all of its source signals from gcPersistentSignals
  // when they get dereferenced from the signal's kSourceSignals set
  if (signal[kComposite] && signal[kSourceSignals]) {
    signal[kSourceSignals].forEach((sourceWeakRef) => {
      const sourceSignal = sourceWeakRef.deref();
      if (sourceSignal) {
        gcPersistentSignals.delete(sourceSignal);
      }
    });
  }
}

// To run the abort steps for an AbortSignal signal
function runAbort(signal) {