struct KWAIT_BLOCK

typedef struct _KWAIT_BLOCK
{
     LIST_ENTRY WaitListEntry;
     PKTHREAD Thread;
     PVOID Object;
     PKWAIT_BLOCK NextWaitBlock;
     WORD WaitKey;
     UCHAR WaitType;
     UCHAR SpareByte;
} KWAIT_BLOCK, *PKWAIT_BLOCK;

Windows Vista Kernel Structures