원본 http://lunapiece.net/879327

#include < windows.h >
#include < cstdio >
#include < cstdlib >

bool isThreadWaiting(HANDLE ThreadHandle)
{
	bool Result = false;

	SuspendThread(ThreadHandle);
	CONTEXT ThreadContext;
	ThreadContext.ContextFlags = CONTEXT_CONTROL;
	BOOL a = GetThreadContext(ThreadHandle, &ThreadContext);
	INT_PTR* StackPointer = reinterpret_cast< INT_PTR* > ( ThreadContext.Esp);

	HMODULE DLLHandle = LoadLibraryA("Ntdll.dll");
	INT_PTR WaitFunctionPtr = reinterpret_cast< INT_PTR >( GetProcAddress(DLLHandle, "NtWaitForSingleObject")); 
	//WaitForSingleObject의 종착점이 되는 함수가 NtWaitForSingleObject
	
	if ( (*StackPointer >= WaitFunctionPtr)  &&  (*StackPointer <= WaitFunctionPtr + 50) )
	{
		//대충 +50을 해 주는 이유는 실제 복귀주소로 저장된 곳이 NtWaitForSingleObject의 시작주소가 아니라 조금 실행된 뒤이기 때문
		Result = true;		
	}

	FreeLibrary(DLLHandle);
	ResumeThread(ThreadHandle);

	return Result;
}

DWORD PASCAL ThreadFun1(PVOID Param)
{
	WaitForSingleObject(HANDLE(Param), INFINITE);

	return 0;
}

DWORD PASCAL ThreadFun2(PVOID Param)
{
	while(true)
	{
		Sleep(100000);
	}

	return 0;
}
void main()
{	
	HANDLE Event = CreateEvent(nullptr, TRUE, FALSE, nullptr);

	HANDLE Thread1 = CreateThread(nullptr, 0, &ThreadFun1, reinterpret_cast< LPDWORD >(Event), 0, nullptr);
	HANDLE Thread2 = CreateThread(nullptr, 0, &ThreadFun2, nullptr, 0, nullptr);

	Sleep(1000); //Thread 돌 시간좀 주고 ...

	printf("Is Thread1 Waiting? %s\n", isThreadWaiting(Thread1) ? "Yes" : "No");
	printf("Is Thread2 Waiting? %s\n", isThreadWaiting(Thread2) ? "Yes" : "No");

	system("pause");
}

Wait계열 함수가 몇종류 더 있는데 그것도 그냥 각자 처리해 주면 간단...