On Friday, July 01, 2011 at 07:26 pm, Kartik Thakore wrote: > What is the closure-over-dlfunc-pointer trick? Can I see an example of > this someplace?
See load_func() and build_thunk() in: http://cpansearch.perl.org/src/CHROMATIC/P5NCI-0.31/lib/P5NCI.pm ... and generate_function() in: http://cpansearch.perl.org/src/CHROMATIC/P5NCI-0.31/build_lib/P5NCI/GenerateXS.pm In short, P5NCI takes the name of a function in a shared library and its signature. It uses dlfunc to get that function's pointer *and* the pointer to an XS function which can handle that signature. Then it builds a closure which calls the XS function, passing the shared library's function pointer as well as @_. The XS function handles the conversion of the contents of @_, then calls the shared library function, converts any return value, and returns. For an API like most of SDL or especially OpenGL, you pay a much, much smaller cost. -- c
