Inside Macintosh: Open Transport /

Chapter 3 - Endpoints / Endpoints Reference

Functions / Functions for Connectionless Transactionless Endpoints

OTRcvUDErr

Clears an error condition indicated by a T_UDERR event and returns the reason for the error.

C INTERFACE

OSStatus OTRcvUDErr (EndpointRef ref, TUDErr* uderr);

C++ INTERFACE

OSStatus TEndpoint::RcvUDErr(TUDErr* uderr);

PARAMETERS

ref

The endpoint reference of the endpoint that has attempted to send the data.

uderr

A pointer to a TUDErr structure (page 3-57) that specifies the reason for the error.

DESCRIPTION

You use the OTRcvUDErr function if you have called the OTSndUData function and the endpoint provider has issued the T_UDERR event to indicate that the send operation did not succeed. This usually happens when the endpoint provider cannot determine immediately that you have specified a bad address or option value. For example, assume that you are using AppleTalk and you specify an NBP address. If Open Transport cannot resolve the address, it sends a T_UDERR event to your notifier function. To clear the error condition and determine the cause of the failure, you must call the OTRcvUDErr function.

If the size of the option or error data returned exceeds the size of the allocated buffers, the OTRcvUDErr function returns with the result kOTBufferOverflowErr, but the error indication is cleared anyway.

If you do not need to identify the cause of the failure, you can set the uderr pointer to nil. In this case, the OTRcvUDErr function clears the error indication without reporting any information to you. It is important, nevertheless, that you actually call the OTRcvUDErr function to clear the error condition. If you don't call this function, the endpoint remains in an invalid state for doing other send operations, and the endpoint provider is unable to deallocate memory reserved for internal buffers associated with the send operation.

VALID STATES

T_IDLE

SEE ALSO

Open Transport uses the TUDErr structure (page 3-57) to return information about why the OTSndUData function (page 3-101) failed.