Callbacks from C into Squeak

dan mr.d.poon at gmail.com
Tue Dec 19 13:15:23 UTC 2006


David T. Lewis wrote:
> On Mon, Dec 18, 2006 at 10:11:46AM +0000, dan wrote:
>> Hi Dave
>>
>> That makes it an overhead 0.15ms per callback, which is acceptable. I 
>> will need to pass back an forth a packed array of floating point numbers 
>> with a few hundred elements in it (representing the state of the system 
>> and its calculated derivative). How could that be achieved without 
>> denting that 0.15ms overhead too much?
>  
> Daniel,
> 
> The only way to find out is to try it. Do you have an example of the
> packed array binary data to work with? We could plug it in to the test
> and see what happens.
> 
> Dave

Hi Dave

The data we would use would be very much like Squeaks FloatArray class, 
except double precision. If we used shared memory, as has been suggested 
in a branch of this thread elsewhere, then it should all be good.

At least I know now what to do in principle. I don't relish doing it in 
Windows though :-(

I spend an hour or so looking at the Fortran maths library to see if I 
could hack it to not use callbacks, but that really is a tall order.

Thanks again (to everyone),

Daniel





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