Legacy Document

Inside Macintosh: Networking /

Chapter 10 - Link-Access Protocol (LAP) Manager / LAP Manager Reference

Routines / Adding and Removing AppleTalk Transition Queue Entries

LAPRmvATQ

The LAPRmvATQ function removes an entry from the AppleTalk Transition Queue.

FUNCTION LAPRmvATQ (theATQEntry: ATQEntryPtr): OSErr;

theATQEntry

A pointer to the ATQEntry record to be removed from the AppleTalk Transition Queue.

DESCRIPTION

You use the LAPRmvATQ function to remove your application's entry from the AppleTalk Transition Queue. To identify the entry to be removed, you pass the LAPRmvATQ function the same pointer to the AppleTalk Transition Queue entry record that you provided as the value of the theATQEntry parameter when you called the LAPAddATQ function to place the entry in the queue.

SPECIAL CONSIDERATIONS

You must not call the LAPRmvATQ function at interrupt time or through a callback routine. This restriction is to prevent any routine from removing an entry from the AppleTalk Transition Queue while another routine is in the process of adding or removing an entry.

ASSEMBLY-LANGUAGE INFORMATION

From assembly language, you remove an AppleTalk Transition Queue entry by placing a routine selector in the D0 register, placing a pointer to your AppleTalk Transition Queue entry in the A0 register, and executing a JSR instruction to an offset past the start of the LAP Manager. The start of the LAP Manager is contained in the global variable LAPMgrPtr ($B18). The offset to the LAP Manager routines is given by the constant LAPMgrCall (2).

Registers on entry
D0	24
A0	Pointer to AppleTalk Transition Queue entry

Registers on exit
D0	Result code

RESULT CODES

noErr	0	No error
qErr	-1	Queue element not found