Re: [Discuss-gnuradio] How to find out if device sink is finished writing samples to radio

Hi Kevin,
Thanks for the answer, unfortunately in my case I want to keep the flowgraph running and I'd need a way to check the state of the block buffers. Maybe I can do that with a custom block before the source or maybe I should rethink my approach.

Adrian

On September 16, 2019 2:42:06 PM UTC, Kevin Reid <kpreid@switchb.org> wrote:

On Mon, Sep 16, 2019 at 4:22 AM Adrian Musceac <kantooon@gmail.com> wrote:

So far I haven't found a way (callback?) to tell when the last sample is out of the flowgraph. I am using the C++ API of GNU radio.

The wait() method of a top_block will block the calling thread until all items have passed through.

Note that this will only succeed if your source blocks indicate there are no more items, by returning -1 (gr::block::WORK_DONE). Vector and file sources and other such standard fixed-length sources do, but if your source is merely emitting no items at this time (e.g. a network source that's not currently receiving packets) the flow graph will still be running waiting for more. I do not know of a way to ask for "when all buffers are currently empty", if that's what you need.