Oh, and I really like threads...

On Tue, Sep 21, 2010 at 3:39 PM, Daniel Ferguson <
danieljayfergu...@gmail.com> wrote:

> Thank you for asking these questions.
>
> The motivation was to further simplify the interface, whilst maintaining
> sensor generic-ness.
> And then the plan, barring course changing discussions, would be to build a
> sensor specific layer on top of that.
>
> My main reason for threads is so read requests can be continually
> submitted, and the process to be transparent.
> In using libusb with isochronous transfers, in conjunction with the
> scenario written below,  I have to submit many read requests in order to
> keep up with the data coming from the device. So, this code abstracts that
> away.
>
> I can't justify why there is a writer thread..
>
> The scenario:
> Testing has been with device side code that continually increments a value
> and sends it.
> the incremented value is 4 bytes, and is within a 128 byte isoc packet(up
> to 1023 bytes). The idea that there are "isoc packets" and "sensor packets",
> where the former can be much larger than the latter creates an idiom where
> each isoc packet is a batch in an of itself. By leveraging that, my
> justification for reader threads could be moot depending on sensor packet
> sizes and sampling rates.
>
> Finally:
> Let's say, which is more or less true, that we have no isoc infrastructure,
> other than a few light hearted examples in the repo.
> I'd like to hear some ideas on how to go about building the infrastructure
> to accomplish end to end communication.
> I'd like to continue moving this effort forward in a way that fosters
> round-table discussions and motivated by general consensus.
> I expect replies...or else... i'll continue in my wayward direction.
>
> P.S.:
> Realistically, the effort I have put in may have yielded no result other
> than an increased understanding by me.
> I consider that a big win.
>
> Cheers,
> Daniel
>
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> On Tue, Sep 21, 2010 at 1:53 PM, ja...@minilop.net <ja...@minilop.net>wrote:
>
>> Hello! It looks like you're building an interface for high-performance
>> isoc transfers, so that's cool. I don't understand what motivated it
>> though, so I have a couple of questions.
>>
>> What led you to choose creating a thread for reads and writes? On
>> reviewing the libusb 1.0 documentation it looks like the asynchronous
>> API does everything I think you want without worrying about
>> synchronizing across threads; so what did I miss?
>>
>> What difficulty did you encounter in using libusb that you're trying
>> to solve with a higher-level abstraction? Is there some way libusb
>> could be improved that would be easier than writing and maintaining a
>> separate library?
>>
>> Thanks,
>> Jamey
>>
>
>
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