RtlAreBitsClear function

Description

The RtlAreBitsClear routine determines whether a given range of bits within a bitmap variable is clear.

Parameters

BitMapHeader [in]

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

StartingIndex [in]

Specifies the start of the bit range to be tested. This is a zero-based value indicating the position of the first bit in the range.

Length [in]

Specifies how many bits to test.

Return value

RtlAreBitsClear returns TRUE if Length consecutive bits beginning at StartingIndex are clear (that is, all the bits from StartingIndex to (StartingIndex + Length) -1). It returns FALSE if any bit in the given range is set, if the given range is not a proper subset of the bitmap, or if the given Length is zero.

Remarks

Callers of RtlAreBitsClear 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, RtlAreBitsClear can be called at any IRQL.

See also

RTL_BITMAP

RtlAreBitsSet

RtlCheckBit

RtlClearAllBits

RtlFindClearBits

RtlFindFirstRunClear

RtlFindLastBackwardRunClear

RtlFindLongestRunClear

RtlFindNextForwardRunClear

RtlInitializeBitMap