typedef struct _RTL_CRITICAL_SECTION_DEBUG
{
     WORD Type;
     WORD CreatorBackTraceIndex;
     PRTL_CRITICAL_SECTION CriticalSection;
     LIST_ENTRY ProcessLocksList;
     ULONG EntryCount;
     ULONG ContentionCount;
     ULONG Flags;
     WORD CreatorBackTraceIndexHigh;
     WORD SpareUSHORT;
} RTL_CRITICAL_SECTION_DEBUG, *PRTL_CRITICAL_SECTION_DEBUG;

Windows Vista Kernel Structures