Re: [Discuss-gnuradio] Should return the number of input or the number of output?

[Activecat]

Part of this question has been partially discussed, as below.

On Mon, Mar 10, 2014 at 9:18 PM, Martin Braun <address@hidden> wrote:

OK, I admit I was unclear. Let's try from scratch:
- The return function from work() or general_work() is the amount of
items that were *produced*.

Says, now I need to create a sink block, and I need to highly customize its built-in forecast() function.

Hence I have two choices:-
(i).  Create this as a sink block, then explicitly overwrite its forecast() function in the body of the custom block.

(ii). Create this as a general block.

Question 1:  Will option (i) above work?

Question 2:  If a sink block is implemented as a general block, does it still need to return noutput_items, or just return 0, or doesn't matter at all ?   (I guess it should return 0 because the sink block doesn't produce any output)

 

- In a sync block, the number of items produced is the number of items
consumed, so we can use that to save the developer from manually
consuming(). In other words, in a sync block, the return value is *both*
the number of produced and consumed items.
- Sinks and sources are syncs, therefore the mechanic is always the same.
- Sinks are a special case because they don't produce anything. However,
the scheduler knows the block's io signature, and knows what to do. The
consume/produce mechanic stays the same, for consistency's sake, as with
all other sync blocks.

Hope this clears things up!
M