Hi all, I've just spent some hours running into the osgDB code, and some littles things are more clear but there is the big question I cannot answer :
The method DynamicLibrary::PROC_ADDRESS DynamicLibrary::getProcAddress(const std::string& procName) is for me the only one which the loader must use each time a plugin dll have to be loaded. But, there is no utilization, at no place ! So how can the osgDB core find the good methods in the dLL without using this method ? I'm not a c++ master, but for now, I feel lost in the c++ myst ... Thanks. Regards, Vincent. 2009/5/13 Vincent Bourdier <[email protected]> > Hi Ismail, > > Not sure to understand all you explained, I didn't find a simple answer to > my questions. > I know that the getProcAdress return a void*, but I was asking about the > osg getProcAdress, and if is there any way different than the cast to get > the function usable ... and to know how this is used in the plugins because > I didn't found any code using it. > > Thanks. > > Regards, > Vincent. > > 2009/5/13 Ismail Pazarbasi <[email protected]> > > On Wed, May 13, 2009 at 9:47 AM, Vincent Bourdier >> <[email protected]> wrote: >> > Hi all, >> > >> > I'm currently making a dynamic lib for my application, and so I use the >> > osgDB::DynamicLibrary class to load the lib and find the Proc_adress >> but, >> > there are some points I would like to understand more : >> > >> > 1. >> > The osgDB::DynamicLibrary::PROC_ADDRESS is just a void* so to use the >> adress >> > as a function as expected, I need to cast it : >> > >> > >> > typedef int (*Pupdate) (const char* path, const char* id, >> bool >> > first_time); >> > Pupdate update; >> > update = (Pupdate) dll->getProcAddress("update"); >> > >> > If I do not cast, the compiler do not want to use a void* when I call >> the >> > function next... >> > >> > It is the behavior/use you were expecting when writing this class ? or >> is >> > there someting else to use, avoiding the cast ... >> > A little precision : this code have to work on every osg supported >> > plateform. (win and linux at least) >> > >> > >> > 2. >> > Next, I just have red a lot of code on osgDB, writers, plugins ... etc >> but I >> > didn't found the rela "connection" between the osgDB core and the >> plugins. >> > >> > What I've understood is : >> > The core, using the file termination, load the DLL (if exists). >> > But the getProcAdress is never used ... so how did the core call the dll >> > read/write function without the ProcAdress ? >> > >> > >> > Any help would a very apreciated :-) >> > >> > Thanks. >> > >> > Regards, >> > Vincent. >> > >> > >> > _______________________________________________ >> > osg-users mailing list >> > [email protected] >> > >> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >> > >> > >> >> Hi Vincent, >> >> void* is accepted form of an address in memory. getProcAddress returns >> address of a symbol in the dynamic library and it (the underlying >> implementation) doesn't care how exported symbol looks like (i.e. >> types), nor knows what will that address be used for. There may be >> implementations around (IIRC, with boost::function and boost::bind) >> but it may be too complicated and doesn't simplify your job anyway. >> >> Ismail >> _______________________________________________ >> osg-users mailing list >> [email protected] >> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >> > >
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