RFR: 8210889: Some service thread cleanups can be starved

[Thomas Schatzl]

Hi,

On Tue, 2018-09-18 at 20:46 -0400, Kim Barrett wrote:
> Please review this small change to the ServiceThread.  When checking
> for work to be done, rather than immediately doing the first kind of
> work found, instead determine all pending work and then do all known
> pending work.  This avoids the possibility of frequently available
> work early in the sequence of checks from leading to starvation of
> work associated with later checks.

Looks good. Maybe the comment could be improved because it does not
answer why we do not want short-circuiting in this case. It only seems
to describe what the code does.

Thanks,
  Thomas