Adapted StructuredTaskScope for Context and cancellation

[Alan Bateman]

On 24/10/2025 13:54, Wesley Hill wrote:
> Hi, and thanks for your work on StructuredTaskScope. I recently 
> adapted it for use in our services to handle (a) propagation of the 
> OpenTelemetry Context, and (b) the richer cancellation model we use. 
> Overall it went fairly well, and I'll give a few details and some 
> minor feedback in case that's of interest.
>
> Background: We have an 
> implementation of io.opentelemetry.context.Context for the usual 
> purposes of passing around tracing, logging, authentication, and other 
> context. We also added a cancellation signal in that Context 
> implementation, very much along the lines of 
> grpc-java's Context/CancellableContext classes (which also makes it 
> similar to golang's Context). Cancelling a parent Context cancels all 
> the child contexts, and a Context can cancel itself when it reaches a 
> Deadline, and callbacks can be registered to run upon cancellation. We 
> do this because thread interruption alone is not a sufficient approach 
> for cancellation when we need to cancel things like HTTP or gRPC 
> calls, JDBC Statements, and other I/O which isn't interruptible. (I 
> understand that it's not a goal of the current structured concurrency 
> JEPs to improve cancellation beyond thread interruption).

Thanks for writing up your experiences. What pain points would have 
remain if somehow OpenTelemetry could use ScopedValues?

-Alan