... could even remove one mutex by using a better algorithm. I think I also
spotted some situation in which a hang could have happened. As I can't fix it
in v4 and less without moving to the new engine, I make no effort in testing
this out. Hangs occur during shutdown, only (if at all). The code changes
should also result in some mild performance improvement. Some bug potential,
but overall the bug potential should have been greatly reduced.
This was a complex manual merge, especially in action.c. So if
there occur some problems, this would be a good point to start
troubleshooting. I run a couple of tests before commiting and
they all went well.
Conflicts:
action.c
action.h
runtime/queue.c
runtime/queue.h
runtime/wti.c
runtime/wti.h
... as it was not even optimal on uniprocessors any longer ;) I keep
the config directive in, maybe we can utilize it again at some later
point in time (questionable).
so far, the last processed message was only freed when the next
one was processed. This has been changed now. More precisely, a
better algorithm has been selected for the queue worker process, which
also involves less overhead than the previous one. The fix for
"free last processed message" as then more or less a side-effect
(easy to do) of the new algorithm.
... but this code has serious problems when terminating the queue, also
it is far from being optimal. I will commit a series of patches (hopefully)
as I am on the path to the final implementation.
There exists a race condition that can lead to a segfault. Thanks
go to vbernetr, who performed the analysis and provided patch, which
I only tweaked a very little bit.
...to enable users to turn off pthread_yield calls which are
counter-productive on multiprocessor machines (but have been
shown to be useful on uniprocessors)
