RIO_BUF structure (mswsockdef.h)

The RIO_BUF structure specifies a portion of a registered buffer used for sending or receiving network data with the Winsock registered I/O extensions.

Syntax

typedef struct _RIO_BUF {
  RIO_BUFFERID BufferId;
  ULONG        Offset;
  ULONG        Length;
} RIO_BUF, *PRIO_BUF;

Members

BufferId

The registered buffer descriptor for a Winsock registered I/O buffer used with send and receive requests.

Offset

The offset, in bytes, into the buffer specified by the BufferId member. An Offset value of zero points to the beginning of the buffer

Length

A length, in bytes, of the buffer to use from the Offset member.

Remarks

The Winsock registered I/O extensions often operate on portions of registered buffers sometimes called buffer slices. The RIO_BUF structure is used by an application that needs to use a small amount of registered memory for sending or receiving network data. The application can often increase performance by registering one large buffer and then using small chunks of the buffer as needed. The RIO_BUF structure may describe any contiguous segment of memory contained in a single buffer registration.

A pointer to a RIO_BUF structure is passed as the pData parameter to the RIOSend, RIOSendEx, RIOReceive, and RIOReceiveEx functions to send or receive network data.

An application cannot resize a registered buffer simply by using a buffer slice with values larger than the original buffer that was registered using the RIORegisterBuffer function.

The RIO_BUF structure is defined in the Mswsockdef.h header file which is automatically included in the Mswsock.h header file. The Mswsockdef.h header file should never be used directly.

Requirements

Requirement	Value
Minimum supported client	Windows 8 [desktop apps only]
Minimum supported server	Windows Server 2012 [desktop apps only]
Header	mswsockdef.h (include Mswsock.h)

See also

RIODeregisterBuffer

RIOReceive

RIOReceiveEx

RIORegisterBuffer

RIOSend

RIOSendEx

RIO_BUFFERID