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Chapter 6 - AppleTalk Transaction Protocol (ATP) / ATP Reference

Routines / Canceling Pending ATP Functions

PRelTCB

The PRelTCB function cancels the pending PSendRequest function that you specify.

FUNCTION PRelTCB (thePBPtr: ATPPBPtr; async: Boolean): OSErr;

thePBPtr

A pointer to an ATP parameter block.

async

A Boolean that indicates whether the function should be executed asynchronously or synchronously. Specify TRUE for asynchronous execution.

-->	ioCompletion	ProcPtr	A pointer to a completion routine.
<--	ioResult	OSErr	The function result.
-->	csCode	Integer	Always relTCB for this function.
-->	addrBlock	AddrBlock	The destination socket address.
-->	transID	Integer	The transaction ID of the request to be canceled.

Field Description

addrBlock

The AppleTalk internet address of the destination socket for which the PSendRequest function that is to be canceled was meant.

transID

The transaction ID of the PSendRequest function to be canceled. You can get the transaction ID from the reqTID field of the PSendRequest parameter block queue entry.

DESCRIPTION

The PRelTCB function releases the queued parameter block for the PSendRequest function whose transaction ID you specify. The PRelTCB function returns a function result of reqAborted for the canceled PSendRequest function.

SPECIAL CONSIDERATIONS

You cannot use this function to cancel a send request that you made using the PNSendRequest function.

ASSEMBLY-LANGUAGE INFORMATION

To execute the PRelTCB function from assembly language, call the _Control trap macro with a value of relTCB in the csCode field of the parameter block. To
execute this function from assembly language, you must also specify the .ATP
driver reference number.

RESULT CODES

noErr	0	No error
cbNotFound	-1102	The ATP control block was not found
noDataArea	-1104	Too many outstanding ATP functions