Re: [Discuss-gnuradio] How is processor time given to blocks?

[Eric Blossom]

On Wed, Jul 21, 2010 at 10:43:52AM -0700, Sean Jordan wrote:
> On Wed, Jul 21, 2010 at 10:37 AM, Eric Blossom <address@hidden> wrote:
> 
> > On Wed, Jul 21, 2010 at 10:15:29AM -0700, Sean Jordan wrote:
> > > I am fairly new to gnuradio and am working on some of my own blocks. I am
> > > trying to understand how the blocks are given control of the cpu. I am
> > using
> > > the grc interface. I currently think that each block runs till it is done
> > > then gives control to the next block, then when all blocks have run the
> > > process starts over. However I set some flags that have caused me to
> > > question that understanding. A better explanation of how the system works
> > > would be much appreciated.
> > >
> > > Thanks, Sean
> >
> > This is somewhat simplified, but reasonably close:
> >
> >  With the thread-per-block scheduler, blocks are "available to
> >  run" whenever there is input available on its inputs and output
> >  space available in the downstream buffer.
> >
> > When the block actually runs is dependent on the underlying OS
> scheduler.  In user space, everything is controlled with condition
> variables and their associated mutexes.  With the thread-per-block
> scheduler there is almost always more than 1 block running
> simultaneously.
> 
> >
> > Eric

> Thanks, with this in mind, I need in my application for only one block to be
> running at a time. Is there any way for that to be specified?

No.  

Why would you want only a single block running at a time?
Needless to say, you want to avoid shared state.

Eric