When v.u.g. stops is first aborts the generation background fiber by
requesting abort on the internal abort source and signalling the fiber
in case it's waiting. Right now v.u.g.::stop() is defer-scheduled last
in main(), so this move doesn't change much -- when stop_signal fires,
it will kick the v.u.g.::do_abort() just a bit earlier, there's nothing
that would happen after it before real ::stop() is called that depends
on it.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
967ebacaa4