KsStreamPointerLock - NtDoc
Native API online documentation, based on the System Informer
(formerly Process Hacker) phnt
headers
// ks.h
KSDDKAPI NTSTATUS KsStreamPointerLock(
[in] PKSSTREAM_POINTER StreamPointer
);
View the official Windows Driver Kit DDI referenceNo description available.
The KsStreamPointerLock function attempts to lock the specified stream pointer.
StreamPointer [in]A pointer to a KSSTREAM_POINTER structure representing the stream pointer to attempt to lock.
KsStreamPointerLock returns either STATUS_SUCCESS, indicating that the stream pointer has been locked, or an appropriate error code. STATUS_DEVICE_NOT_READY is the usual error code indicating that the frame could not be locked. This error code frequently means that the frame to which StreamPointer was pointing was canceled.
A locked stream pointer guarantees that there is a data frame associated with the stream pointer and that this frame is not canceled as long as the lock is maintained. The minidriver should lock a stream pointer before attempting to access the data to which the stream pointer points.
If the pin that the stream pointer references specifies that DMA scatter/gather mappings should be generated using KSPIN_FLAG_GENERATE_MAPPINGS, AVStream generates the mappings when the stream pointer is locked.
Also see Stream Pointers.