Rafael Garcia-Suarez <[EMAIL PROTECTED]> writes:
>In an XS module Bar I want to get a pointer on a C function defined in
>an XS module Foo, and preferably at BOOT-time.
>
>I can't make it work; the problem I have is that at run time DynaLoader
>always answers with a "undefined symbol" error, although the Foo module
>has been loaded beforehand. Is there some known trick for this
>situation?
Several, mostly platfrom specific e.g.
dl_open() original with RTLD_GLOBAL
link your loadable with .so of other moduke (or its import library
for Win32's DLLs.
There is a DynaLoader hook "find symbol anywhere" which itterates through
the things it has loaded.
The de-facto way to do it is to dodge the OS ways and use a table of functions.
This scheme was originally devised for DBI and Tk copied it.
Tk automates the process somewhat.
You have a .h file which defines
struct Bar_funcs
Whateever (*barFuncP)(Thing *wibble,int cata);
};
Bar.xs initializes table and stores its address in
something like $Bar::_functionTablePointer;
Foo.xs declares pointer to table and its BOOT: section
initializes it from $Bar::_functionTablePointer;
This can be automated and macros defined to do
(*bar_func_ptr->barFuncP)(wibble,cata)
When source shows
barFunc(wibble,cata)
