Arbitrary or variable numbers of inputs or outputs

Forgot to copy the list.

---------- Forwarded message ----------
From: Johnathan C. [email protected]
Date: Wed, Apr 1, 2009 at 9:17 AM
Subject: Re: [Discuss-gnuradio] arbitrary or variable numbers of
inputs or outputs
To: Dimitris S. [email protected]

On Wed, Apr 1, 2009 at 8:57 AM, Dimitris S. [email protected]

Lately I’ve been getting a strange error message when running a python
graph that contains the wfm_rcv_pll block:

Exception RuntimeError: ‘maximum recursion depth exceeded while
calling a Python object’ in <type ‘exceptions.AttributeError’> ignored

The above is a known bug triggered when using Python 2.6.

gr.io_signature(1, 2, gr.sizeof_float)) # Output signature

RuntimeError: Hierarchical blocks do not yet support arbitrary or
variable numbers of inputs or outputs (wfm_rcv_pll)

This is a new warning message recently added to indicate the requested
io signature for a hierarchical block is unsupported (but will be in
the future at some point.) Hierarchical blocks currently only support
a fixed number of inputs or outputs; the above signature is declaring
that it is possible to have either 1 or 2 outputs connected to the

It turns out the blks2.wfm_rcv_pll hierarchical block was declaring
this to support either mono or stereo output, but really only had
stereo outputs. Everything worked okay, but now the stricter checking
on signatures catches the mistaken io signature declaration. I’m going
to changed the signature to 2, 2 and this message will go away.

We do plan to support variable io signatures in hierarchical blocks
(hence the ‘yet’ in the error message).