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RtlIsGenericTableEmpty routine

The RtlIsGenericTableEmpty routine determines if a generic table is empty.

Syntax


BOOLEAN RtlIsGenericTableEmpty(
  _In_  PRTL_GENERIC_TABLE Table
);

Parameters

Table [in]

Pointer to the generic table (RTL_GENERIC_TABLE). The table must have been initialized by calling RtlInitializeGenericTable.

Return value

RtlIsGenericTableEmpty returns FALSE if the table contains one or more elements, TRUE otherwise.

Remarks

By default, the operating system uses splay trees to implement generic tables. Under some circumstances, operations on a splay tree will make the tree deep and narrow and might even turn it into a straight line. Very deep trees degrade the performance of searches. You can ensure a more balanced, shallower tree implementation of generic tables by using Adelson-Velsky/Landis (AVL) trees. If you want 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 RtlIsGenericTableEmptyAvl Structure routine instead of RtlIsGenericTableEmpty. In the call to RtlIsGenericTableEmptyAvl, the caller must pass a RTL_AVL_TABLE table structure rather than RTL_GENERIC_TABLE.

Callers of RtlIsGenericTableEmpty must be running at ≤ APC_LEVEL if the caller-allocated memory at Table is pageable.

Requirements

Version

This routine is available on Microsoft Windows 2000 and later.

Header

Ntddk.h (include Ntddk.h or Ntifs.h)

Library

Ntoskrnl.lib

IRQL

<= APC_LEVEL (see Remarks section)

See also

RtlInitializeGenericTable

 

 

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