Re: [Discuss-gnuradio] Scheduler Question

[Michael Dickens]

Hi Almohanad - From my (now old) memory of the GR runtime scheduler (STS and 
TBP), I believe you are roughly correct in the technical terminology, except 
that the schedules are not guaranteed to be periodic.  They are opportunistic / 
aperiodic: process as much data as "makes sense" given the blocks constraints 
and how much data is available and how much output space is available.  Tom 
(et.al.) have done some work on the TBP scheduler more recently than my 
memories, so maybe they have been tweaked to be truly periodic?

That said, I do not believe either scheduler was created specifically with 
those terms or concepts in mind; I believe the current scheduler(s) were 
programmed as they are because they work well and were original creations.  
They might have been influenced by reading others works on SDF and the like, 
but I really doubt there was any true intent on recreating others works.

Again, these are memories that I believe are correct; but then who knows.  I 
believe Eric Blossom wrote both of the schedulers, and he's no longer around on 
this list to answer more officially (though I understand that folks do interact 
with him in person). - MLD

On Feb 27, 2013, at 1:54 AM, Almohanad Fayez <address@hidden> wrote:

> I've been reading through the code in gnuradio-core/runtime for a few days to 
> understand the internal workings of the gnuradio scheduler.  It seems to me 
> that gnuradio was originally based on a synchronous dataflow (sdf) model of 
> computation and the single thread schedule is an SDF sequential runtime 
> schedule, or a periodic admissible sequential schedule (PASS), and the thread 
> per block schedule is a parallel SDF scheduler, or a parallel admissible 
> parallel schedule (PAPS).
> 
> Does this sound like an accurate description of the schedulers and underlying 
> gnuradio model of computation or am I reading too much into it?  thanks