On Thu, Jun 08, 2006 at 12:38:02AM -0400, David Lapsley wrote: > > >* p60, 4.8.1: "In order to support real-time scheduling, a mechanism is > >required that will allow m-block s to relinquish control of a processor > >after a certain number of processor cycles have been used (we will refer > >to this number of processor cycles as the scheduling quantum )." and > >"The gr single threaded scheduler will run until it walks all the > >incoming data (one scheduling quantum worth) through the graph to the > >final sink, at which point it returns." > > I believe these two statements are consistent. The two cases are: > > * A generic m-block (no GNU Radio blocks inside it): in this case, the > > processing inside the m-block must relinquish control of the processor > after "quantum" processor cycles. > > * An m-block enclosing a GNU Radio flow graph: in this case, the > enclosing m-block will pass a block of data that should take one > quantum's worth of processor cycles to pass through the GNU Radio flow > graph. > > In either case, the m-block is relinquishing processor control after one > quantum's worth of cycles. > > >--> These seem in conflict with each other. Further, the only obvious > >reference in 4.8.2 to the relinquishing of control is the "yield()" > >function. Maybe: The "gr single threaded scheduler" is run in a > >separate thread from the executing m-block, and the m-block sleeps for a > >set time (the "scheduling quantum") ... it will wake up if the thread > >finishes or if the sleep returns, at which point it checks the state of > >the thread, and either yields to the m-scheduler, or returns the > >gr-scheduler's data. > > Yes. The "gr single threaded scheduler" runs in its own thread. The > sequence you suggest should work just fine.
Nope. gr_single_threaded_scheduler (or something above it) will be called from the handle_message callback of the mblock, and thus will execute on the mblock's thread. FWIW, I think all this stuff about scheduler quanta is confusing, and should be deleted. I'm assuming that everything is "run to completion". If you want a shorter interval until completion, bite off smaller chunks. I don't think any of this really needs to be in the doc, but will fall out as an implementation detail. Eric _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
