Re: [xml] [PATCH] DSO/Module Support

[Joel Reed <joelwreed comcast net>]

On Tue, Dec 21, 2004 at 04:03:35AM -0500, Daniel Veillard wrote:
> On Mon, Dec 20, 2004 at 05:37:14PM -0500, Joel Reed wrote:
> > The following patch implements a basic API for dynamically loading
> > shared objects (.so/.dll files).
> >
> > The API is as follows:
> >
> > XMLPUBFUN xmlModulePtr XMLCALL xmlModuleOpen (const char *filename);       
> > XMLPUBFUN void* XMLCALL xmlModuleSymbol (xmlModulePtr module, const char* name);
> > XMLPUBFUN int XMLCALL xmlModuleClose(xmlModulePtr module);                
> > XMLPUBFUN int XMLCALL xmlModuleFree (xmlModulePtr module);
>
>
>   Okay I read the patch, this looks clean I have just a few comments:
>      1/ why different close() and free() operations ? Can you call
>         free() without calling close() first ? I don't see a way to
>       "reopen" a module.

you can see how ModuleFree is used in libxslt patch. basically used to
load the DSO into memory & leave it there, but free libxml related module
buffers. we could get rid of struct xmlModule.name if you like, i put it
there to make debugging easier. i put xmlModuleClose in there for the
load a module/DSO, use it, and close it use case.

>      2/ XML_FROM_MODULE must be moved at the end of the enum list to
>         not break ABI compatibility.
>      3/ xmllint --version should be extended to display whether module
>         support was compiled in.

ok, will do.

>      4/ I don't see support for "sharing" loaded modules, I wonder how often
>         multiple pieces of code will rely on the same extensions and how
>       this is best handled. Maybe the system interface take care of that
>       maybe not, maybe it would be usefule at the libxml2 layer, maybe not.
>       That can probably be added later if deemed needed.

sounds reasonable.

<snip>

thanks for reviewing the patch Daniel.

jr