Andrew Haley wrote:
> Dave Korn wrote:
>
>> 1) Would this be a reasonable approach, specifically i) in adding a
>> configure
>> option to cause sublibraries to be built, and ii) in using gmake's $(filter)
>> construct to crudely subdivide the libraries like this?
>
> At program startup the first library would be loaded, it would load
> the next, and so on. There are a few parts of libgcj that are truly
> independent, but I suspect that you'd always load almost all of it.
> So, you'd have longer startup time for loading all those files.
Compared to a single DLL that is unusably malformed because it exceeds
system limits, that's still an improvement :)
> With regard to GNU libc platforms:
>
> You'd no longer be able to make so much use of fast calls between
> functions in the same library; you'd have to go via the PLT.
>
> Also, dl_iterate_phdr() is used a great deal (for finding exception
> regions, garbage collection, etc.) and it linearly scans the libraries
> that are loaded. So, the more libraries you have loaded, the slower
> it goes.
>
> Now, I don't know how much of these characteristics are shared by
> Windows, but I imagine some of them are.
Yes, the inter-library calls would have to be dllimports and go through
stubs (one extra indirect branch). I don't know how dl_iterate_phdr works on
win32 but I imagine that it's also linear in the number of libs.
> So, I suspect your best bet would be to split libgcj into core and
> non-core libraries and not slice much more thinly than that. I can
> advise you what is core and what isn't.
Please do, I'll happily try that approach since it might significantly
simplify my inter-dependences problems.
cheers,
DaveK
