My experience with Structured Concurrency

[Alan Bateman]

On 15/08/2025 19:44, David Alayachew wrote:
> :
>
> So, when someone recently challenged me to use Joiners (rather than 
> the old STS preview versions I was used to), I started creating 
> Joiners to handle all sorts of failure and outcomes. At first, a lot 
> of them could be handled by the Joiner.awaitUntil(), where I would 
> just check and see if the task failed, then handle the error. But as I 
> got further and further along, I started needing to add state to my 
> Joiners in order to get the failure handling that I wanted. For 
> example, if a certain number of timeouts occur, cancel the scope. 
> Well, that necessitates an AtomicNumber.
>
I assume you mean allUntil(Predicate), which is intended to make it easy 
to create a Joiner that implements a cancellation policy. Joiners are 
inherently stateful as many will accumulate results or exceptions, or 
maybe just count failures.  With allUntil then it does mean that the 
predicate may not be pure function, is that the reason for the 
hesitation? Beyond allUntil does mean implementing the Joiner interface. 
I think your mails are pondering whether there is something between 
allUntil and implementing Joiner yourself. I don't think we've had 
enough feedback to date to know if there is something needed there. One 
thing that would help is if your could enumerate a few of the Joiners 
that you implemented. I'm wondering if they are general purpose of very 
specific.

-Alan