typedef struct _HANDLE_TRACE_DEBUG_INFO
{
     LONG RefCount;
     ULONG TableSize;
     ULONG BitMaskFlags;
     FAST_MUTEX CloseCompactionLock;
     ULONG CurrentStackIndex;
     HANDLE_TRACE_DB_ENTRY TraceDb[1];
} HANDLE_TRACE_DEBUG_INFO, *PHANDLE_TRACE_DEBUG_INFO;

Windows Vista Kernel Structures