Re: [Discuss-gnuradio] GNU-Radio Companion Python flowgraph - return signal that it is finished?

[Andrew Payne]

Thanks Kevin. I ended up calling the python method os.stat.st_size on
the IQ file that the flowgraph will transmit, converted that file size
to a time duration in seconds considering the sample size and rate,
start the flowgraph, then have a sleep function that checks for a flag
every 100 milliseconds to stop the flowgraph if necessary.  I always
do a tb.stop() followed by a tb.wait(), because I assume that .stop()
is not blocking but .wait() is blocking and this is the best practice
way to prematurely stop a flowgraph.  Or is the .wait() necessary?

Thanks.


On Sat, Sep 28, 2019 at 10:43 PM Kevin Reid <address@hidden> wrote:
>
> On Sat, Sep 28, 2019 at 6:34 PM Andrew Payne <address@hidden> wrote:
>>
>> I have a short IQ file that I simply want to play once without repeating, 
>> and I want the calling Python code to "know" when it's completed after 
>> commanding the GR class instance to start via a call to tb.start(), if tb is 
>> the class instance variable.
>
>
> Call
>     tb.start()
>     tb.wait()
>     tb.stop()
> in that order. The call to wait() will block until the flow graph finishes.
>
> If you need to do something else while waiting, you can create another thread 
> from Python (threading.Thread) and either have it call tb.wait() or have it 
> do the other work, whichever suits your application.