VideoPortLockBuffer function (video.h)
The VideoPortLockBuffer function probes the specified buffer, makes the buffer's memory pages resident in memory, and locks the physical pages mapped by the virtual address range.
Syntax
VIDEOPORT_DEPRECATED VIDEOPORT_API PVOID VideoPortLockBuffer(
[in] IN PVOID HwDeviceExtension,
[in] IN PVOID BaseAddress,
[in] IN ULONG Length,
[in] IN VP_LOCK_OPERATION Operation
);
Parameters
[in] HwDeviceExtension
Pointer to the miniport driver's device extension.
[in] BaseAddress
Specifies the virtual address of the buffer to be locked.
[in] Length
Specifies the length in bytes of the buffer to be locked.
[in] Operation
Specifies the type of operation for which the caller wants the access rights probed and the pages locked. The operation can be one of the following: VpReadAccess, VpWriteAccess, or VpModifyAccess.
Return value
Returns a pointer to a memory descriptor list (MDL), or a NULL pointer if the MDL for the memory to be locked cannot be allocated.
Remarks
To unlock the buffer, the video miniport driver should call VideoPortUnlockBuffer.
Requirements
Requirement | Value |
---|---|
Minimum supported client | Available in Windows XP and later versions of the Windows operating systems. |
Target Platform | Desktop |
Header | video.h (include Video.h) |
Library | Videoprt.lib |
DLL | Videoprt.sys |
IRQL | PASSIVE_LEVEL |