core.runtime.Runtime.loadLibrary & unloadLibrary missing

[Rambutan001]

https://dlang.org/phobos/core_runtime.html#.Runtime.loadLibrary
If these are used so as to reconcile D runtime with dynamic loading there's a linkage error with dmd. (Works with gdc.)
This is a bug, right? Is this unimplemented?
Any information about what's going on gratefully received.
R.

[adamdruppe]

that function is only available of using the shared lib druntime.

[Rambutan001]

So this is a bug, possibly in the documentation rather than the static libphobos, right? Do you know if the function in the shared lib druntime does anything that dlopen doesn't do?

[kinke]

For Posix targets, this is only available with the shared druntime, otherwise you get the pretty ugly/unclear undefined rt_loadLibrary symbol at link-time that you've reported in the forum (https://forum.dlang.org/post/fsjfnoktvhzynifzyalg@forum.dlang.org).

On Windows however (where DMD still doesn't ship a shared lib AFAIK), this function is available with static druntime. And makes the GC in the loaded DLL's druntime be a proxy to the main application's, so as to have a single GC. So I guess the (incomplete) documentation comes from that angle.

I can only discourage using multiple statically linked druntimes in a single process though. It can work if you know exactly what you are doing and avoid all potential pitfalls (like each druntime only knowing about the threads it spawned, for GC scanning, GC pausing etc. etc.), but that's usually hard. Linking every D binary to a single shared druntime/Phobos as documented in https://dlang.org/articles/dll-linux.html#dso10 (-defaultlib=libphobos2.so) prevents all of these problems.

[Rambutan001]

I took the documentation for Runtime.loadLibrary to mean those issues would be taken care of for me.

[Rambutan001]

Can I be confident that Runtime.loadLibrary works as documented when I link with a shared druntime, but dynamically load a shared object that has a static druntime?

[Rambutan001]

Well, it seems this omission from the static library is a bug.