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Inside Macintosh: Interapplication Communication /

Chapter 11 - Program-to-Program Communications Toolbox / PPC Toolbox Reference

PPC Toolbox Routines / Starting and Ending a Session

PPCEnd

Use the PPCEnd function to end a session. This function completes all outstanding asynchronous calls associated with the session reference number.

FUNCTION PPCEnd (pb: PPCEndPBPtr; async: Boolean): OSErr; 

pb

A pointer to a PPCEnd parameter block.

async

A value that specifies whether the function is to be executed asynchronously (TRUE) or synchronously (FALSE).

-->	ioCompletion	PPCCompProcPtr	Address of a completion routine
<--	ioResult	OSErr	Result code
-->	sessRefNum	PPCSessRefNum	Session reference number of session to end

DESCRIPTION

If your application calls the PPCEnd function asynchronously, you must specify in the ioCompletion field either the address of a completion routine or NIL. If you set ioCompletion to NIL, you should poll the ioResult field of the PPC parameter block (from your application's main event loop) to determine whether the PPC Toolbox has completed the requested operation. A value in the ioResult field other than 1 indicates that the call is complete. Note that it is unsafe to poll the ioResult field at interrupt time since the PPC Toolbox may be in the process of completing a call. See "PPC Toolbox Calling Conventions" beginning on page 11-14 for detailed information.

You provide a session identifier in the sessRefNum field to identify the session that you are terminating. The PPCStart, StartSecureSession, or PPCInform function returns the session reference number.

ASSEMBLY-LANGUAGE INFORMATION

The trap macro and routine selector for the PPCEnd function are

Trap macro	Selector
_PPC	$0008

The registers on entry and exit for this routine are

Registers on entry
A0	Pointer to a parameter block
D0	Selector code

Registers on exit
D0	Result code

RESULT CODES

noErr	0	No error
notInitErr	-900	PPC Toolbox has not been initialized yet
noGlobalsErr	-904	System unable to allocate memory, critical error
noSessionErr	-908	Invalid session reference number

SEE ALSO

For an example of the use of the PPCEnd function, see Listing 11-18 on page 11-43.