Re: [Discuss-gnuradio] Unable to find USRP

[Berndt Josef Wulf]

>
> This is similar to the problem I had with the audio device that doesn't
> permit it to be opened by two or more processes, see the lines containing
> EBUSY. I will try to figure out which part of benchmark_usb.py doesn't
> close the ugen device.
>

The problem is that benchmark_usb.py opens usrp.sink() and usrp.source(), both 
which use the open() calls to access the device. On *BSD this is not possible 
and is exactly the some problem as seen with the audio.sink() and 
audio.source() function that I hacked around.

A possible generic solution to this is to acquire the filedescriptor for the 
device which is then used by the subsequent calls. e.g.:

usrp_dev = usrp.open()   <- instantiate device
sink = usrp.sink(usrp_dev, ....)  <- open source
source = usrp.source(usrp_dev, .....) <- open sink

similar for other sink/source devices that are used with GnuRadio.

Else, *BSD will not be able to run scripts that use sink and source of the 
same device simultaneously..

cheerio Berndt
-- 
Every man who says frankly and fully what he thinks is doing a public service.
[Leslie Stephen]