Can a windows DLL have more than one process attached?

In reviewing some recent patches I notice the following code added to
src/interfaces/libpq/libpqdll.c:

BOOL WINAPI
DllMain(HINSTANCE hinstDLL, DWORD fdwReason,
LPVOID lpReserved)
{
switch (fdwReason)
{
case DLL_PROCESS_ATTACH:
...
if (netmsgModule == NULL)
netmsgModule = LoadLibraryEx("netmsg.dll", NULL, LOAD_LIBRARY_AS_DATAFILE);
break;
case DLL_PROCESS_DETACH:
if (netmsgModule != NULL)
FreeLibrary(netmsgModule);
...
break;
}
}

where netmsgModule is

static HINSTANCE netmsgModule = NULL;

This sure looks to me like it will fail miserably if more than one
process can attach to the DLL concurrently: won't the first one to
detach release the netmsg library, breaking access to it for all the
remaining processes?

I don't know enough about Windows to know if there's really a problem
here, but the code looks fishy to me. I'd expect to need a reference
count. Comments anyone?

regards, tom lane