CoreGraphics blocking? low latency issues


#1

i recently figured that i can not get my guis to not interrupt the audio engine of reaper, no matter what (64 smpls @ 44100 via USB2.0). i searched some stuff on this forum and tried to deactivate coregraphics. voila, no problems at all. it seems other plugins maybe done with juce too and suffer form the same problem (TH1 gives me crackle galore when i open the gui). maybe the os handles coregraphics calls with a too high of a priority, i don’t know, i have an i7 imac, still, might be a performance issue on my side. i don’t have to do very much thought. so its not a matter of an exhausted system. i figured there is a dedicated paper on writing non blocking coregraphics code, which gives me a hint that there may be something going on there. i’ll also investigate further to check wether its a reaper only problem. my paint code is really optimized (opaque,useBufferImage,limit repaint rate, etc) (i used the cpu profiler to be sure) also i do not use locks, so i’m pretty shure its a coregraphics thing. i’ll report on further findings, in the meantime developers (overloud?) may want to update their code or enlighten me if i’m missing something :slight_smile:

cheers!

jm


#2

Interesting… There’s no obvious reason why rendering on one thread should affect audio on another, but who knows what’s going on deep inside the OS!