Propagate the whole context instead of only the current span

[trask]

There are lots of places where we propagate the current span to another thread.

I think we need to change all of these to propagate the whole context instead.

E.g. #503 (comment)

[iNikem]

@trask do you have any suggestions how can I find these "lots of places"?

[trask]

look for calls to Span.Builder.setParent(Span) (there aren't too many of these)

and look for calls to TracingContextUtils.currentContextWith(Span) (unfortunately there are lots of these that are not relevant to this issue, not sure how to filter these better)

[iNikem]

@trask I propose to close this issue now. If there are more places left, they can be addressed on an ongoing basis

[trask]

👍