IOMBufDBDMAMemoryCursor



Member Functions

getPhysicalSegments

Abstract: Generate a DBDMA descriptor list from a given mbuf.
public:

UInt getPhysicalSegments(struct mbuf * packet, struct IODBDMADescriptor *vector, UInt numVectorSegments = 0);

Parameters

NameDescription
packetThe mbuf packet.
vectorPointer to an array of IODBDMADescriptor for the output list.
numVectorSegmentsMaximum number of IODBDMADescriptors accepted.
Result: The number of segments that were filled in is returned, or 0 if an error occurred.

getPhysicalSegmentsWithCoalesce

Abstract: Generate a DBDMA descriptor list from a given mbuf.
public:

UInt getPhysicalSegmentsWithCoalesce(struct mbuf * packet, struct IODBDMADescriptor * vector, UInt numVectorSegments = 0);

Generate a DBDMA descriptor list from a given mbuf. Coalesce mbuf chain when the number of elements in the list exceeds numVectorSegments.

Parameters

NameDescription
packetThe mbuf packet.
vectorPointer to an array of IODBDMADescriptor for the output list.
numVectorSegmentsMaximum number of IODBDMADescriptors accepted.
Result: The number of segments that were filled in is returned, or 0 if an error occurred.

withSpecification

Abstract: Factory function to create and initialize an IOMBufDBDMAMemoryCursor in one operation, see IOMBufMemoryCursor::initWithSpecification.
public:

static IOMBufDBDMAMemoryCursor * withSpecification(UInt maxSegmentSize, UInt maxNumSegments);

Parameters

NameDescription
maxSegmentSizeMaximum allowable size for one segment.
maxNumSegmentsMaximum number of segments.
Result: A new mbuf cursor if successfully created and initialized, 0 otherwise.

© 2000 Apple Computer, Inc. — (Last Updated 2/23/2000)