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Inside Macintosh: Networking /

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

Routines / Notifying Routines When Your Application-Defined Transition Occurs

ATEvent

The ATEvent procedure calls the routines specified by each of the entries in the AppleTalk Transition Queue with notification of a transition event that you have defined.

PROCEDURE ATEvent (event: LongInt; infoPtr: Ptr);

event

The AppleTalk transition event code for your application-defined transition. This can be any four-character string that starts with an uppercase letter--that is, any value in the range $41 00 00 00 through
$5A FF FF FF.

infoPtr

A pointer to information that you make available to the AppleTalk Transition Queue entry routines. If you do not want to pass any information to these routines, set the infoPtr parameter to NIL.

DESCRIPTION

The ATEvent procedure calls the routines in the queue with the AppleTalk transition event code you specify in the event parameter. You can use the infoPtr parameter to point to any information that you want to make available to the transition event handler routines; for an ADSP-open transition, for example, you might pass a pointer to the parameter block used by the dspOpen routine.

You use the ATEvent procedure to send notification of an ATTransSpeedChange transition to time-dependent processes. You must send this transition event notification if your application changes the CPU speed. Note that you must issue this transition event at system task time only.

For transition events that you define, you can issue the ATEvent procedure at interrupt time provided that the transition event handler routines follow the standard rules for interrupt operation.

SPECIAL CONSIDERATIONS

You can call the ATEvent procedure only at virtual-memory safe time.

AppleTalk transitions defined by developers might return other result codes.

RESULT CODES

noErr

0

No error, or unrecognized event code

SEE ALSO

For more information about the ATTransSpeedChange event, see "CPU-Speed-Change Transition" on page 10-20.

For more information about developer-defined transition events, see "Developer-Defined Transitions" on page 10-21 and "Defining Your Own AppleTalk Transition" on page 10-21.

For information on virtual memory, see Inside Macintosh: Memory.