On Thu, Jun 28, 2012 at 10:40 AM, Jorge <jo...@jorgechamorro.com> wrote: > On 28/06/2012, at 08:22, Jeroen Janssen wrote: >> On Jun 28, 1:18 am, Ben Noordhuis <i...@bnoordhuis.nl> wrote: >>>>> No. What pattern do you use? Something like this? >>> >>>>> if (!ev_async_pending(w)) >>>>> ev_async_send(w); >>> >>>> Ben, I think this should just be the default behaviour of libuv. >>> >>> Agreed. Though I still would like to know if that's the actual pattern >>> that Jorge uses. :-) >> >> I think you can see the relevant code at >> https://github.com/xk/node-threads-a-gogo/blob/master/src/threads_a_gogo.cc > > Yes, here: > > https://github.com/xk/node-threads-a-gogo/blob/master/src/threads_a_gogo.cc#L202 > https://github.com/xk/node-threads-a-gogo/blob/master/src/threads_a_gogo.cc#L281 > https://github.com/xk/node-threads-a-gogo/blob/master/src/threads_a_gogo.cc#L646 > https://github.com/xk/node-sound/blob/master/src/sound.cc#L509 > https://github.com/xk/node-sound/blob/master/src/sound.cc#L1014 > > But ev_async_pending is a macro that expands to this: > > if (!(+(&watcher)->sent)) ev_async_send(ev_default_loop_uc_ (), &watcher); > > which is not a function call, soooo.... it's not a good idea to make it "the > default behaviour", because if you do that the check would be made inside > uv_async_send() so the function call would happen always which is exactly > what one's trying to avoid when using ev_async_pending.
I'm not that worried about the function call overhead. The reason that you're seeing a slowdown is that uv_async_send() is always making a syscall now.
