Hi Yann, 2017-07-21 1:05 GMT+02:00 Yann Ylavic <ylavic....@gmail.com>:
> On Fri, Jul 14, 2017 at 9:52 PM, Yann Ylavic <ylavic....@gmail.com> wrote: > > > > So overall, this patch may introduce the need for more workers than > > before, what was (wrongly) done by the listener thread has to be done > > somewhere anyway... > > That patch didn't work (as reported by Stefan Pribe) and I now don't > feel the need to debug it further, see below. > > > > > Finally, I think there is room for improvements like batching > > shutdowns in the same worker if there is no objection on the approach > > so far. > > That's the way to go IMO, here is a new patch which is much simpler > and effective I think. > It is indeed much simpler to follow even for people like me with not enough experience in mpm-event's code :) > The idea is that when nonblocking is required (i.e. in the listener), > connections to flush and close are atomically pushed/popped to/from a > chain (linked list) by the listener/some worker. > > So start_lingering_close_nonblocking() simply fills the chain (this is > atomic/nonblocking), and any worker thread which is done with its > current connection will empty the chain while calling > start_lingering_close_blocking() for each connection. > > To prevent starvation of deferred lingering closes, the listener may > create a worker at the of its loop, when/if the chain is (fully) > filled. > IIUC the trick is to run "(have_idle_worker && push2worker(NULL) == APR_SUCCESS)" that reserves a worker that in turn eventually checks the defer_linger_chain as part of its new code. This also seems sto leverage workers_were_busy that will prioritize lingering closes over ka connections right? (or at least try to) > While the previous patch potentially induced some overhead in the > number workers and thread contexts switches, I think this new one much > better in this regard. > > What do you think of it? > I like it, from a first look I'd +1 it but as said above I am not really authoritative for mpm-event's code :) Let's see how Stefan's tests go! Thanks for this work. Luca
