Muppet <[EMAIL PROTECTED]> writes:
>Dirk Koopman said:
>> So how do I find them and then set them (probably thru DynaLoader)? They
>> are (at least for now) just simple ints.
>
>You could use tie'd scalars for this. Create your perl-level variables from
>perl, passing the c names to your tie, and tie them all to the same class. In
>the FETCH and STORE routines, do the dlsym lookup and load or store the value.
> If they'll be changed a lot, you might instead cache their addresses after
>doing the dlsym lookup in TIESCALAR.
If you can know the names of variables at XS build time a trick that works
well is #define to produce something that looks like a function
#define setFoo(x) foo = (x)
MODULE ...
void setFoo(int x)
Then normal XS wrapper gets created.
and perl code can say
setFoo(42);
>
>I've used this trick to tie a perl hash-like object to a fancy C key-query
>object, and it didn't take a lot of code. I have *not* done it for scalars,
>but i'm guessing it wouldn't be too hard.
For scalars it is possible to do direct MAGIC get/set with a bit less
overhead than a full tie.
But if you have to lookup names at run time then tying ONE hash to
the XS code is a good plan so that
$tiedHash{varname} = 42;
Calls STORE passing key and value,
STORE does a dlsym() on the "key" gets a pointer and pokes value.
