Re: [Discuss-gnuradio] Re: Combining gr.trellis and mod_pkt

[Steven Clark]

> Your msg_source, which is a gr.message_source, is blocked, waiting for
> new messages to arrive. In order to allow the second block chain to
> exit, you need to send it a message that causes it to unblock.  The
> flowgraph scheduler thread that is running this chain will then see
> the indication that it should exit, and do so.
>

Ok, so with Johnathan's help I see that adding a gr.message(1) to the
input queue has a special EOF meaning, and allows things to exit
nicely. Is this stuff documented anywhere?

On a broader note, I find that I often have difficulty finding things
in / navigating the GNURadio source tree. I frequently see some class
or block at the python level, and want to look at its source. I have
no idea if it is defined in C or python, or where it is located. Is
there any way, other than through sheer stumbling around, to figure
out that:
blk2.mod_pkts is defined in gnuradio-core/src/python/gnuradio/blks2impl/pkt.py
gr.msg_queue is defined in gnuradio-core/src/lib/runtime/gr_msg_queue.cc
gr.message_source is defined in gnuradio-core/src/lib/io/gr_message_source.cc
etc.?

This has been a pretty big barrier to entry into GNU Radio for me, and
probably for some others as well.