[PD-dev] help with d_ugen.c

Hi, list

I'm reading through d_ugen.c and I mostly understand what it says. I was wondering if anybody has already written a paper to tell what is in the Pd DSP internals, such as scheduling the DSP tree, or data caching strategies.

I am most curious about the behavior of "borrowed signals" and signals that are on the signal_freelist and signal_usedlist. Am I correct in assuming these are the data structures used to determine caching of data between DSP perform routines? Is there a way to specify an external with a "borrowed" signal on the inlet, but having an output signal that is not borrowed (or vice-versa)?

Chuck