Legacy Document

Inside Macintosh: Networking With Open Transport / Part 2 - Open Transport Reference

Chapter 22 - Endpoints Reference / Functions

Functions for Connection-Oriented Transaction-Based Endpoints /

OTCancelReply

Cancels an outstanding call to the OTRcvRequest function.

C INTERFACE

OSStatus OTCancelReply(EndpointRef ref,
                     OTSequence sequence);

C++ INTERFACE

OSStatus TEndpoint::CancelReply(OTSequence sequence);

PARAMETERS

ref

The endpoint reference of the endpoint that has sent the request being canceled.

sequence

A 32-bit value, specifying the transaction ID of the request being canceled. You must specify the same value that was passed to you in the seq field of the req parameter to the OTRcvRequest function. If you specify 0 for this parameter, the provider cancels all outstanding incoming requests for the endpoint. If you specify an invalid sequence number, the provider does nothing.

function result

An error code. See Appendix B.

DISCUSSION

When you make a call to the OTRcvRequest function, the provider allocates memory for internal buffers and assigns a sequence value to identify this transaction. If you are no longer interested in a transaction, you must explicitly cancel the transaction by calling the OTCancelReply function. Calling this function allows the provider to free up the memory it has reserved and to reuse the sequence number associated with the canceled transaction. If the endpoint is acknowledging sends, the provider generates a T_MEMORYRELEASED event for each freed buffer.

If the function completes successfully, it returns the kOTNoErr result; it does not return any other kind of acknowledgment. It is your responsibility to deallocate memory that you have reserved for the address, options, and data buffers associated with the cancelled OTRcvRequest function.

Use the OTCancelReply function to cancel an incoming request; use the OTCancelRequest function to cancel an outgoing request.

SEE ALSO

The OTSndRequest function.

"AppleTalk Reference".

Table 4-4.