Shared Library: Why doesn't this work?

[Benji Smith]

I'm trying to read the total amount of memory on a Windows system (using 
D 1.35 and Tango 0.99.7 on WinXP SP3) using tango.sys.SharedLib to load 
kerner32.dll.

Here's the code...

---------------------------------------------------------------------
module SystemMemoryTest;

import tango.io.Stdout;
import tango.sys.SharedLib;

alias uint DWORD;
alias ulong DWORDLONG;

struct MEMORYSTATUSEX
{
    DWORD dwLength;
    DWORD dwMemoryLoad;
    DWORDLONG ullTotalPhys;
    DWORDLONG ullAvailPhys;
    DWORDLONG ullTotalPageFile;
    DWORDLONG ullAvailPageFile;
    DWORDLONG ullTotalVirtual;
    DWORDLONG ullAvailVirtual;
    DWORDLONG ullAvailExtendedVirtual;
}

typedef void function(MEMORYSTATUSEX*) func_type;
func_type myFunction;

void main() {

    if (auto lib = SharedLib.load(`c:\windows\system32\kernel32.dll`)) {
       Stdout("Loaded library").newline;

       if (void* symbolAddress = lib.getSymbol("GlobalMemoryStatusEx")) {
          Stdout.formatln("Found symbol at 0x{:x}", symbolAddress);

          void** pMyFunction = cast(void**) &myFunction;
          *pMyFunction = symbolAddress;

          MEMORYSTATUSEX mem;
          myFunction(&mem);

          Stdout.formatln("total physical mem: {0}", mem.ullTotalPhys);
          Stdout.formatln("avail physical mem: {0}", mem.ullAvailPhys);
       }
       lib.unload();
    }
}
---------------------------------------------------------------------

I have no problem compiling or running that example, it just doesn't 
produce the correct results:

    Loaded library
    Found symbol at 0x7c81f97a
    total physical mem: 0
    avail physical mem: 0

On the other hand, I can use a function from the UserGdi module, and it 
works correctly...

---------------------------------------------------------------------
module SystemMemoryTest;

import tango.io.Stdout;
import tango.sys.win32.UserGdi : GlobalMemoryStatus;
import tango.sys.win32.Types : MEMORYSTATUS;

void main() {

    MEMORYSTATUS mem;
    GlobalMemoryStatus(&mem);

    Stdout.formatln("total physical mem: {0}", mem.dwTotalPhys);
    Stdout.formatln("avail physical mem: {0}", mem.dwAvailPhys);
}
---------------------------------------------------------------------

Works like a charm!

    total physical mem: 2078838784
    avail physical mem: 1008336896

The reason I don't just use this code (despite it being much more clean 
and nice looking :) is that it doesn't work for systems with more than 
2GB of RAM. The "GlobalMemoryStatusEx", which will work for systems with 
effectively limitless RAM, function isn't in the UserGdi module 
(evidently, it doesn't exist on earlier win32 platforms like Windows 98).

I'd like to use the "GlobalMemoryStatusEx" where it exists, and fallback 
to using the "GlobalMemoryStatus" function in cases where it doesn't.

But I can't figure out how to get the shared lib functionality to work.

Any suggestions?

Thanks!

--benji