I'm not sure if this is something unique to D or not, but I've
having a minor issue where stdout output from a DLL (either via
printf or phobos std.stdio write) is not displayed until after
the main process has completed. I'm making a project based
around the example at https://wiki.dlang.org/Win32_DLLs_in_D
which I've heard is a little out of date but I've gotten it
working nonetheless. I have the following project files:
```d
// mydll.d
module mydll;
import core.runtime;
import core.stdc.stdio;
import core.stdc.stdlib;
import core.sys.windows.windows;
extern(Windows) BOOL DllMain(HINSTANCE hInstance, ULONG ulReason,
LPVOID pvReserved) {
switch (ulReason) {
case DLL_PROCESS_ATTACH:
printf("[dll] DLL_PROCESS_ATTACH\n");
Runtime.initialize();
break;
case DLL_PROCESS_DETACH:
printf("[dll] DLL_PROCESS_DETACH\n");
Runtime.terminate();
break;
case DLL_THREAD_ATTACH:
printf("[dll] DLL_THREAD_ATTACH\n");
return false;
case DLL_THREAD_DETACH:
printf("[dll] DLL_THREAD_DETACH\n");
return false;
default:
}
return true;
}
export int MyDLL_Test() {
printf("[dll] MyDLL_Test\n");
return 5;
}
static this() {
printf("[dll] static this for mydll\n");
}
static ~this() {
printf("[dll] static ~this for mydll\n");
}
```
```d
// mydll.di
module mydll;
export int MyDLL_Test();
```
```d
// main.d
import mydll;
pragma(lib, "mydll.lib");
import core.sys.windows.windows;
void main() {
printf("[Main] Start\n");
scope(exit) printf("[Main] END\n");
int x = MyDLL_Test();
printf("[Main] x: %d\n", x);
printf("[Main] Finished\n");
}
```
DLL compilation command line: `dmd -m64 -ofmydll.dll -L/DLL
mydll.d mydll.def`
Main command line: `rdmd -m64 main.d`
And upon running, the output I receive is:
```
[Main] Start
[Main] x: 5
[Main] Finished
[Main] END
[dll] DLL_PROCESS_ATTACH
[dll] static this for mydll
[dll] MyDLL_Test
[dll] DLL_PROCESS_DETACH
[dll] static ~this for mydll
```
I would expect the first three lines of dll output to precede the
"[Main] x:" line at least. Is there something I'm doing wrong?
Do I need to somehow pass a reference to the main stdio to the
DLL's D runtime similar to how the GC can be shared?
