fstephany wrote > > I'm also a bit lost between all the different options (plugins, > NativeBoost, FFI, Alien). >
I also found this confusing, so let me tell my recent experience and my conclusion. I have written bindings to the SDL game programming library for use with Pharo. SDL is cross-platform, and I want to support Mac (most of all), Windows (one must), and Linux (if I must). As far as I can tell, Alien is not cross-platform and not maintained, so I have not spent time investigating it. Following Igor Stasenko's OpenGLSpecs package, I wrote an SDLSpecs package which parses the relevant C header files and then writes either an NB or FFI callout class tree. I need to define a few structures, make a class pool with some constants, and then define lots of callouts, many of which take references to structures (like 'foo(struct x*)'). I was able to make both work, more or less, on my Macbook Pro, using stock Pharo 1.3 images and Igor's NBCog.app. I found NB to be a nicer programmer experience but I found that the FFI just works. There are a lot of gratuitous differences, but: * NB requires a VM compiled with a separate plugin (that I built from source with no trouble -- Igor has done splendid work with CMakeVMMaker). * NB should be faster than the FFI at pretty much everything, but I can't say since I haven't measured. * NB has useful primitives for determining if your external objects are still valid and for determining the current operating system (I intend to use these even if I don't use NB). * NB has very few tests and examples and essentially no documentation. * NB has a simple conceptual model, but it is still not as simple as the FFI model. * NB uses variableByteClasses to great advantage -- this is very cool. * NB makes it easy to crash your image, since you are evaluating native code in image. * NB is still, to my eye, raw and untested on Mac. I had problems with stack alignments in bizarre places, and NB's interaction with garbage collection basically ended my attempts to use it. * NB is basically impossible to debug if you aren't very strong with x86 assembly (I'm not even strong with x86 assembly), and the stack manipulations rendered GDB pretty much useless for me. * NB does not integrate well with the Pharo tools -- I think the MethodTrailers are screwing up references, implementors, and source views, but I haven't investigated. * NB does not seem to support indirections very easily -- I struggled to understand how to interface to foreign C functions with specs like 'foo(struct x)', 'foo(struct x *)' and 'foo(struct x **)', and eventually gave up. I wanted to help Igor with the NB project, but the NB-OpenGL Mac bindings crash horribly for me, and although I was able to fix them, it I just don't hack enough x86 assembly to figure out all the tricks Igor is doing. The thought of making it all work on 3 platforms, and fix all the tool integration, was just too much for me. In conclusion, I prefer the FFI. It is old, cross platform, well tested, somewhat documented, and reliable. I think Igor has done some amazing work and I do not want to bash his project (and certainly not his code -- the man's a magician) but the fancy features are not necessary for my project. fstephany wrote > > Will this interface handle callbacks ? > I do not need callbacks so cannot speak to this issue. Yours, Nick Alexander -- View this message in context: http://forum.world.st/Best-way-for-FFI-in-Pharo-tp4275467p4276356.html Sent from the Pharo Smalltalk mailing list archive at Nabble.com.
