RtlClearBit function (wdm.h)

The RtlClearBit routine sets the specified bit in a bitmap to zero.

Syntax

NTSYSAPI VOID RtlClearBit(
  [in] PRTL_BITMAP BitMapHeader,
  [in] ULONG       BitNumber
);

Parameters

[in] BitMapHeader

A pointer to the RTL_BITMAP structure that describes the bitmap. This structure must have been initialized by the RtlInitializeBitMap routine.

[in] BitNumber

Specifies the zero-based index of the bit within the bitmap. The routine sets this bit to zero.

Return value

None

Remarks

Callers of RtlClearBit must be running at IRQL <= APC_LEVEL if the memory that contains the bitmap variable is pageable or the memory at BitMapHeader is pageable. Otherwise, RtlClearBit can be called at any IRQL.

Requirements

Requirement	Value
Minimum supported client	Available in Windows XP and later versions of Windows.
Target Platform	Universal
Header	wdm.h (include Wdm.h, Ntddk.h, Ntifs.h)
Library	NtosKrnl.lib
DLL	NtosKrnl.exe
IRQL	<= APC_LEVEL (See Remarks section)

See also

RTL_BITMAP

RtlInitializeBitMap