[Development] QPromise cancellation

[Arno Rehn]

On 28.01.2026 13:00, Arno Rehn wrote:
> On 28.01.2026 12:37, Ivan Solovev wrote:
>> I must admit that I did not look at the CallOutInterface when trying to
>> solve the problem. So, I'd be interested to have a look at a WIP patch.
>> Maybe we could find a way to fit it nicely into the implementation.
>> Even though in general I agree that QFuture internals are already
>> too complicated.
> 
> I'll come up with something, but likely not today anymore. Tracking 
> lifetimes across the implicitly shared state is gonna be... "fun".
> 
> OTOH, maybe we can unify some of the continuation/CallOutInterface stuff 
> while we're at it. Only

https://codereview.qt-project.org/c/qt/qtbase/+/708578

This was easier than expected. QFutures are already linked in a 
doubly-linked list. Once the inner future is available, we just have to 
relink the chain elements.

In a similar way we can propagate this to the inner futures of whenAll() 
and whenAny(), just that the doubly-linked list then becomes a tree.

Cheers,
Arno

-- 
Arno Rehn
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