RtlLookupElementGenericTableFullAvl function (ntddk.h)

Article
10/21/2021

The RtlLookupElementGenericTableFullAvl routine searches a generic table for an element that matches the specified data.

Syntax

NTSYSAPI PVOID RtlLookupElementGenericTableFullAvl(
  [in]  PRTL_AVL_TABLE      Table,
  [in]  PVOID               Buffer,
  [out] PVOID               *NodeOrParent,
  [out] TABLE_SEARCH_RESULT *SearchResult
);

Parameters

[in] Table

Pointer to the generic Adelson-Velsky/Landis (AVL) table (RTL_AVL_TABLE). The table must have been initialized by calling RtlInitializeGenericTableAvl.

[in] Buffer

A buffer of search data to pass to the CompareRoutine that was registered when RtlInitializeGenericTableAvl initialized the generic table. For more information, see the description of RtlInitializeGenericTableAvl.

[out] NodeOrParent

On output, a value that describes the relationship of the NodeOrParent with the table entry (node) that RtlLookupElementGenericTableFullAvl is searching for. The SearchResult parameter can have any of the following values:

TableEmptyTree

The tree was empty. The contents of NodeOrParent has not been altered.

TableFoundNode

The RtlLookupElementGenericTableFullAvl routine found a table entry whose key matches the data in Buffer. NodeOrParent contains a pointer to the matched entry.

TableInsertAsLeft

The RtlLookupElementGenericTableFullAvl routine did notfind a table entry whose key matches the data in Buffer. Inotf the entry that RtlLookupElementGenericTableFullAvl searched for were in the table, it would be the left child of the entry that NodeOrParent points to.

TableInsertAsRight

The RtlLookupElementGenericTableFullAvl routine did notfind a table entry whose key matches the data in Buffer. If the entry that RtlLookupElementGenericTableFullAvl searched for were in the table, it would be the right child of the entry that NodeOrParent points to.

[out] SearchResult

A pointer to a table entry. If the RtlLookupElementGenericTableFullAvl routine matches an entry, NodeOrParentpoints to the matched entry. If the RtlLookupElementGenericTableFullAvl routine fails to find a match, NodeOrParent points to the entry that would be the parent of the entry that RtlLookupElementGenericTableFullAvl routine was searching for.

Return value

RtlLookupElementGenericTableFullAvl returns a pointer to the user data that is associated with the matching element in the generic table, or NULL if the generic table currently has no elements or if no matching element is found.

Remarks

By default, the operating system uses splay trees to implement generic tables, but the RtlLookupElementGenericTableFullAvl routine only works with Adelson-Velsky/Landis (AVL) trees. To configure the generic table routines to use AVL trees instead of splay trees in your driver, insert the following define statement in a common header file before including Ntddk.h:

#define RTL_USE_AVL_TABLES 0

If RTL_USE_AVL_TABLES is not defined, you must use the AVL form of the generic table routines. For example, use the RtlLookupElementGenericTableFullAvl routine instead of RtlLookupElementGenericTable. In the call to RtlLookupElementGenericTableFullAvl, the caller must pass a RTL_AVL_TABLE table structure rather than RTL_GENERIC_TABLE.

Callers of the Rtl..GenericTableAvl routines are responsible for exclusively synchronizing access to the generic table. An exclusive fast mutex is the most efficient synchronization mechanism to use for this purpose.

Callers of RtlLookupElementGenericTableFullAvl must be running at IRQL < DISPATCH_LEVEL if either of the following conditions holds:

The caller-allocated memory at Table or at Buffer is pageable.
The caller-supplied CompareRoutine contains pageable code.

Requirements

Requirement	Value
Minimum supported client	Available starting with Windows XP.
Target Platform	Universal
Header	ntddk.h (include Ntddk.h, Ntifs.h)
Library	NtosKrnl.lib
DLL	NtosKrnl.exe
IRQL	< DISPATCH_LEVEL (see Remarks section)