Techwiki:Win32k/BASEOBJECT

For Windows XP and Windows 2003

struct _BASEOBJECT
{
   HANDLE hHmgr; // Handle for this object
   ULONG ulShareCount;  
   LONG cExclusiveLock; // lock with InterlockedIncrement or not
   ULONG BaseFlags;     
   PW32THREAD Tid;   // contain which thread it belong to, PsGetCurrentThread()
};