RtlNumberOfClearBits

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

ULONG
  RtlNumberOfClearBits(
    IN PRTL_BITMAP  BitMapHeader
    ); 

Parameters

BitMapHeader

Pointer to an initialized bitmap header for the caller's bitmap variable.

Return Value

RtlNumberOfClearBits returns the number of bits that are currently clear.

Headers

Declared in ntddk.h. Include ntddk.h.

Comments

Callers of RtlNumberOfClearBits must be running at IRQL < DISPATCH_LEVEL if the memory containing the bitmap variable or at BitMapHeader is pageable. Otherwise, RtlNumberOfClearBits can be called at any IRQL.

See Also

RtlFindClearBits, RtlFindClearRuns, RtlFindFirstRunClear, RtlFindLastBackwardRunClear, RtlFindLongestRunClear, RtlFindNextForwardRunClear, RtlInitializeBitMap, RtlNumberOfSetBits