[cu-dev] Ready for review: #40, #100, #101 for transferring over MicroPr

["Nathan Rauh" <nathan.rauh@xxxxxxxxxx>]

Given the amount
of proposed content for Concurrency in Jakarta 10, I've started putting
together pulls for the MicroProfile-related enhancements currently in the
Milestone
3 list,
starting with the ones for copying over API methods around CompletionStage/CompletableFuture.
 The following 3 are ready to start reviewing now (I won't actually
be merging anything until after the release plan is official, and of course
pending approval from the community)

When reviewing
these, it will be helpful to note that MicroProfile class ManagedExecutor
is the equivalent of our ManagedExecutorService,
and MicroProfile
class ThreadContext is the equivalent of our ContextService.

The method signatures
themselves are an exact copy (which will be great for compatibility), except
for the one place where MicroProfile's ManagedExecutor has a getThreadContext
method that returns a ThreadContext, which is switched to ContextService.
The intent behind the MicroProfile method here is so that threadContext/contextService.withContextCapture(completionStage/completableFuture)
can create CompletionStage/CompletableFuture proxies that are backed by
the ManagedExecutor.  But managedExecutor[Service].copy(completionStage/completableFuture)
can already do that.  We can decide if the equivalent getContextService
method is really wanted/needed here, and if not, I can remove it.  To
start out with, I included it in the pull so that you have the opportunity
to see what it would look like if we did include it. Please add your feedback
on it in the review.  I would be happy with either outcome and will
go with the majority on it.

Issue #40Completion stages backed by ManagedExecutorService
pull to review:
https://github.com/eclipse-ee4j/concurrency-api/pull/104

Issue #100ContextService methods for contextualizing individual dependent stage actions
pull to review:
https://github.com/eclipse-ee4j/concurrency-api/pull/138

Issue #101Completion stages backed by a ContextService
pull (also contains
the commit for #100 which is a prereq due to references made in JavaDoc):
https://github.com/eclipse-ee4j/concurrency-api/pull/139
commit that is
unique to this pull to review:
https://github.com/eclipse-ee4j/concurrency-api/pull/139/commits/ba9c817de5e47c4a32ee40c6bd46d97dcb3eea0e