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
