[PD] udpsend performance issue

Matteo Sisti Sette matteosistisette at gmail.com
Sun May 8 19:48:42 CEST 2011


If I send a few hundreds packed OSC messages with [udpsend], it blocks 
for about 100-200 milliseconds or more (I see the message "udpsend 
blocked for xxx milliseconds" in the console, and I notice the effects).

I know that this is a lot of messages and I can (and have to) optimize 
things by avoiding sending unnecessary data, but:

I have replaced [udpsend] with a [netsend 1] (this is by no means a 
workaround, just a test to compare performance) and if I send the very 
same messages (which actually means sending much more bytes), netsend 
does _not_ block for such a long time. It doesn't print any such message 
(and netsend does print it if it blocks for a significant time) and I 
don't notice any delay. I have verified that it is actually sending the 

So I wonder, is there an intrinsic reason why udspend takes much more 
time than netsend to send a certainly smaller amount of data? Or is 
udpsend simply implemented in a less efficient way? Does anybody know 
where the bottleneck is and if there is a way to eliminate it?


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