RtlNumberOfClearBits function

The RtlNumberOfClearBits routine returns a count of the clear bits in a given bitmap variable.

Syntax

NTSYSAPI ULONG RtlNumberOfClearBits(
  PRTL_BITMAP BitMapHeader
);

Parameters

BitMapHeader

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

Return Value

RtlNumberOfClearBits returns the number of bits that are currently clear.

Remarks

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

Requirements

   
Windows version Available starting with Windows 2000.
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

RtlFindClearBits

RtlFindClearRuns

RtlFindFirstRunClear

RtlFindLastBackwardRunClear

RtlFindLongestRunClear

RtlFindNextForwardRunClear

RtlInitializeBitMap

RtlNumberOfSetBits