Interface ICancellationToken

Cancellation notification can be propagated by passing the same instance into cancellable callee async functions.

remarks

Like the concept of "Task cooperative cancellation" introduced in .NET Framework, when the async function implementation wants to support cancellation, it should accept an extra optional parameter of type ICancellationToken.

In your function implementation, you should do at least one of the following

• Check for cancellation with ICancellationToken.isCancellationRequested or ICancellationToken.throwIfCancellationRequested;
• Pass the cancellation token into the callee functions that supports cancellation with ICancellationToken;
• Subscribe for the cancellation event with ICancellationToken.subscribe.

async function doSomeWork(ct?: ICancellationToken) {
  ct.throwIfCancellationRequested();
  // do something
  await delay(1000, ct);
  // do something else
}

see

CancellationTokenSource