Boost logo

Boost :

Subject: Re: [boost] [review] Dataflow Library
From: Phil Endecott (spam_from_boost_dev_at_[hidden])
Date: 2008-09-07 08:40:33

Michael Caisse wrote:
> Phil Endecott wrote:

>> And while thinking about hardware description languages, note also
>> that they don't expose any sort of dataflow model even though the
>> underlying circuit often has that sort of structure.

> I don't think I understand. Verilog supports dataflow modeling and for anything
> non-trivial is the main mode of modeling. What am I missing?

In Verilog (or VHDL), if I have two components that I want to "pipe"
together I need to declare a wire that will be the channel for the
communication and then declare the two components with this wire
connected to the appropriate port. Something like this:

   wire[7:0] a;
   ExampleSource src (.the_output(a));
   ExampleSink sink (.the_input(a));

As far as I am aware, neither language has syntax to pipe them together
more concisely, i.e.

   ExampleSource src >>= ExampleSink sink;

> I think questioning a library's audience and usefulness is a requirement but I am
> surprised at the number of people who don't see how/why dynamic dataflow is useful.
> Are you questioning the value of dataflow modeling or this specific library?

I am questioning it all, but with an open mind ready to be convinced of
its value.

> I use a dataflow framework that is driven from XML description files. The framework
> utilizes dynamically loaded components as Stjepan has described in an earlier post.
> The framework has been deployed in applications ranging from digital video/audio
> systems to aviation flight/meteorology equipment in international airports.
> I hope to have an opportunity to review the Dataflow library.

Please do! As soon as some people who actually know something about
Dataflow start posting comments then I will shut up. My comments are
intended really just to provoke debate.

Regards, Phil.

Boost list run by bdawes at, gregod at, cpdaniel at, john at