Re: [Discuss-gnuradio] gr-audio-osx ToDo

[Eric Blossom]

On Tue, Apr 04, 2006 at 08:47:51PM -0500, Michael Dickens wrote:
> I have 3 things to do on gr-audio-osx (enumerated below), but those can 
> be "ToDo's" or whatever; I would really like to get this code available 
> for others to try, as feedback on compiling and other issues would make 
> it installation robust.  The blocks seems to work just fine for 
> everyone who's gotten them to compile ... they say that the FM audio on 
> a good station is amazingly crisp!
> 
> But compiling has been an issue since it -seems- like gnu's libtool 
> somewhere between 1.5.10 and 1.5.20 has been updated to better handle 
> Darwin stuff and thus there -seems- like a need for the later version 
> (or even more recent, but I haven't tried 1.5.22 yet since 1.5.20 works 
> for me).  I can't be 100% sure that this was the issue.  Here are the 3 
> things to do:
> 
> 1) Fix a bug in the way an omni_semaphore is being used (actually, make 
> it an omni_mutex I think).
> 
> 2) Fix the transfer buffer between the various threads; I wrote my own 
> version which is thread-safe, but I think GR has one available - which 
> would be better for me to use.  It's just a simple circular ("ring") 
> buffer with thread protection using omni_semaphore's and omni_mutex'es. 
>  Is GR's circular buffer thread-safe?

You can just use a gr_buffer and gr_buffer_reader.  See the
gr-audio-portaudio code for an example.  Since you've got a singler
reader and writer there are no mutex required for access control.  We
use a semaphore to signal the reader/writer about space available.

> 3) Add in the code in "source" to "watch" for the user changing the 
> input device in the OS, and handling this change so that there is at 
> worst a quick blip during the switch over (but at least the program 
> doesn't crash).

OK.

I guess the other thing to do is to see if gr-audio-portaudio "just works" ;)

Eric