1. Slight Problem...
Hello,
There is a slight problem using 'define_c_func()' for use
with virtual functions, and that is...
YOU CANT *UNDEFINE* THEM !!!!!!
Or did i miss something somewhere?
Take care for now,
Al
2. Re: Slight Problem...
Al Getz wrote:
> There is a slight problem using 'define_c_func()' for use
> with virtual functions, and that is...
>
> YOU CANT *UNDEFINE* THEM !!!!!!
>
>
>
> Or did i miss something somewhere?
Why do you want to undefine a function?
Regards,
Rob Craig
Rapid Deployment Software
http://www.RapidEuphoria.com
3. Re: Slight Problem...
Andy Serpa wrote:
> In my personal wrapper for Berkeley DB, each virtual function pointer is
> an offset of a handle to a database object. These objects are created
> and destroyed all the time. In other words, you don't determine the
> pointer until just before you call the function, and likely you'll never
> use that particular pointer ever again.
>
> With fptr.e, I just peek a certain offset from the handle to get the
> pointer, and then call the function. I could now do this in pure
> Euphoria, but I'd have to define the function before each & every call,
> which presumably uses up permanent memory somewhere. Maybe you could
> refine that enhancement so we can call functions by pointer without
> defining them first -- just pass the pointer...
Al Getz wrote:
> Here's what i'm looking at: ...
> [example where it might be useful
> to undefine C/machine functions]
It's true that define_c_func/proc will allocate a bit
of space each time you call them. Basically just enough
for the routine name and the parameter type information.
(If you call the Euphoria routine_id() function
many times with the same identifier, you will get the
same routine id returned, with no extra space allocated.)
Thanks both of you for pointing this out.
I think you are both doing somewhat unusual things
and I hope Matt's fptr.e will help for now.
I'll consider what to do, if anything, about freeing the
information that define_c_func/proc collects.
Normally you'd have to link with tens of thousands of
different C/asm routines before it would eat up
a significant amount of memory. But both of you have
special cases that I'll have to consider. Even with
an undefine function, the time overhead of defining/undefining
might be too much for calling a small fast routine.
Regards,
Rob Craig
Rapid Deployment Software
http://www.RapidEuphoria.com
