typedef struct _DPH_HEAP_ROOT
{
     ULONG Signature;
     ULONG HeapFlags;
     PRTL_CRITICAL_SECTION HeapCritSect;
     ULONG nRemoteLockAcquired;
     PDPH_HEAP_BLOCK pVirtualStorageListHead;
     PDPH_HEAP_BLOCK pVirtualStorageListTail;
     ULONG nVirtualStorageRanges;
     ULONG nVirtualStorageBytes;
     RTL_AVL_TABLE BusyNodesTable;
     PDPH_HEAP_BLOCK NodeToAllocate;
     ULONG nBusyAllocations;
     ULONG nBusyAllocationBytesCommitted;
     PDPH_HEAP_BLOCK pFreeAllocationListHead;
     PDPH_HEAP_BLOCK pFreeAllocationListTail;
     ULONG nFreeAllocations;
     ULONG nFreeAllocationBytesCommitted;
     LIST_ENTRY AvailableAllocationHead;
     ULONG nAvailableAllocations;
     ULONG nAvailableAllocationBytesCommitted;
     PDPH_HEAP_BLOCK pUnusedNodeListHead;
     PDPH_HEAP_BLOCK pUnusedNodeListTail;
     ULONG nUnusedNodes;
     ULONG nBusyAllocationBytesAccessible;
     PDPH_HEAP_BLOCK pNodePoolListHead;
     PDPH_HEAP_BLOCK pNodePoolListTail;
     ULONG nNodePools;
     ULONG nNodePoolBytes;
     LIST_ENTRY NextHeap;
     ULONG ExtraFlags;
     ULONG Seed;
     PVOID NormalHeap;
     PRTL_TRACE_BLOCK CreateStackTrace;
     PVOID FirstThread;
} DPH_HEAP_ROOT, *PDPH_HEAP_ROOT;

Windows Vista Kernel Structures