[Discuss-gnuradio] Multiplie top blocks

[Dominik Auras]

Hi!

During the buildup phase of my gnuradio scripts (in __init__ of classes that 
inherit from top_block or some classes that are initialized from a topblock 
instance), I try to use gnuradio to convert some data. E.g. I use gr.fft to do 
FFT on some constant data, or apply the function of some special blocks to 
other constant data. With the old hierblock2 etc., that worked fine for me. 

We've been working with an old gnuradio revision to not break up the system 
upon changes to the trunk. But now, it is time to get to a newer revision 
(skipping about 2000 revisions). After porting everything to your new top_block 
structure, now I encounter the problem that creation of several top blocks is 
not allowed. Actually, the second or later created topblock should be 
terminated before the first will be started, but I use the other blocks during 
setup of the "main" topblock.

How can I solve this problem? I don't like to recode so that every 
initialization is done before creating the main block, since this forces me to 
have knowledge of internals outside this block. Is there any smart way to have 
the signal interrupt handler for example just tied to the currently running 
block, e.g. allowing several top blocks to be created, but only one to be 
running? Maybe to defer the registering of the handler until start of the 
implementation.

Any suggestions are welcome!

Greetings
Dominik