Performance of CancellationToken::clone VS CancellationToken::child_token with large amount of tasks

[ultimaweapon]

Let's say I have 1 million of tasks that need to be canceled with a single CancellationToken. Which one is better in term of performance? All tasks have a main loop similar to the following code:

loop {
    select! {
        biased; // Stop immediately when shutdown.
        _ = running.cancelled() => break,
        // There are other statements here depend on task's job.
    }
}

[Darksonn]

The clone() and child_token() methods do not do the same thing. The child token allows you to perform partial cancellations because child.cancel() does not affect the parent, but parent.cancel() will affect the child.

If you do not require partial cancellations, do not use child_token(). In that case, clone() is far more efficient.

[ultimaweapon]

Thanks!