RtlTestBit function (wdm.h)
The RtlTestBit routine returns the value of a bit in a bitmap.
Syntax
NTSYSAPI BOOLEAN RtlTestBit(
[in] PRTL_BITMAP BitMapHeader,
[in] ULONG BitNumber
);
Parameters
[in] BitMapHeader
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 returns the value of this bit.
Return value
RtlTestBit returns the value of the bit that the BitNumber parameter points to.
Remarks
Callers of RtlTestBit 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, RtlTestBit 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) |