Inside Macintosh: Interapplication Communication /

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

PPC Toolbox Routines / Opening and Closing a Port

PPCClose

You use the PPCClose function to close the port specified by the port reference number.

FUNCTION PPCClose (pb: PPCClosePBPtr; async: Boolean): OSErr; 

pb

A pointer to a PPCClose 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
-->	portRefNum	PPCPortRefNum	Port reference number of port to close

DESCRIPTION

If your application calls this 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.

The portRefNum field specifies the PPC port identifier of the port to close. The port reference number must be a valid port reference number returned from a previous call to the PPCOpen function.

ASSEMBLY-LANGUAGE INFORMATION

The trap macro and routine selector for the PPCClose function are

Trap macro	Selector
_PPC	$0009

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
noPortErr	-903	Bad port reference number
noGlobalsErr	-904	System unable to allocate memory, critical error

SEE ALSO

For an example of the use of the PPCClose function, see Listing 11-19 on page 11-44.

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