CancellationToken should flow from Silo.StopAsync to Grain.OnDeactivateAsync

[bill-poole]

The CancellationToken passed to the Silo.StopAsync(CancellationToken) method should flow to the CancellationToken passed to the Grain.OnDeactivateAsync(DeactivationReason, CancellationToken) method such that cancelling the CancellationToken passed to the StopAsync method cancels the CancellationToken passed to the OnDeactivateAsync method.

[ghost]

We're moving this issue to the 4.0-Planning milestone for future evaluation / consideration. Because it's not immediately obvious that this is a bug in our framework, we would like to keep this around to collect more feedback, which can later help us determine the impact of it. We will re-evaluate this issue, during our next planning meeting(s). If we later determine, that the issue has no community involvement, or it's very rare and low-impact issue, we will close it - so that the team can focus on more important and high impact issues.

[ReubenBond]

We should do this. Thanks for reporting it, @bill-poole.

Implementation note:

• Add CancellationToken parameters to Catalog.Deactivate* methods
• Either add a silo-wide set of cancellation tokens (ShuttingDown for when shutdown begins + Aborting for when the StopAsync cancellation is cancelled) or something else. Similar to Microsoft.Extensions.Hosting.IHostApplicationLifetime.
• Use a CancellationTokenSource.CreateLinkedTokenSource to link the regular deactivation timeout cancellation with the silo abort cancellation

[ArminShoeibi]

Do you need a hand @ReubenBond? if it is okay I can work on this issue.

[ReubenBond]

@ArminShoeibi thank you for the offer. Yes, help would be appreciated. Please message on Discord if you'd like to talk about it: https://aka.ms/orleans/discord