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Inside Macintosh: Networking /

Chapter 5 - AppleTalk Data Stream Protocol (ADSP) / ADSP Reference

Routines / Establishing and Terminating an ADSP Connection Listener

dspCLInit

The dspCLInit routine establishes and initializes a connection listener. You use the PBControl function to call the dspCLInit routine. See "Routines" on page 5-43 for a description of the PBControl function.

-->	ioCompletion	ProcPtr	A pointer to a completion routine.
<--	ioResult	OSErr	The function result.
-->	ioCRefNum	Integer	The driver reference number.
-->	csCode	Integer	Always dspCLInit for this function.
<--	ccbRefNum	Integer	The CCB reference number.
-->	ccbPtr	TPCCB	A pointer to CCB.
<->	localSocket	Byte	The local DDP socket number.

Field Description

csCode

The routine selector, always equal to dspCLInit for this routine.

ccbRefNum

The connection control block (CCB) reference number. The dspCLInit routine returns this value.You must provide this number in all subsequent dspCLListen and dspCLRemove
calls to this connection listener.

ccbPtr

A pointer to the CCB that you allocated. The CCB is 242 bytes
in size.

localSocket

The number of the DDP socket that you want ADSP to use for this connection end. Specify 0 for this parameter to cause ADSP to assign the socket; in this case, ADSP returns the socket number when the dspCLInit routine completes execution.

DESCRIPTION

The dspCLInit routine establishes a connection listener; that is, it assigns a specific socket for use by ADSP and initializes the variables that ADSP uses to maintain a connection listener. The dspCLInit routine does not cause the connection listener
to listen for connection requests; you must follow the dspCLInit routine with the dspCLListen routine to activate the connection listener.

You must allocate a block of nonrelocatable memory for a CCB before you call the dspCLInit routine and pass a pointer to that CCB as the value of the ccbPtr parameter. See the section "Creating and Using a Connection Control Block" on page 5-12 and the section "The ADSP Connection Control Block Record" on page 5-35 for more information.

SPECIAL CONSIDERATIONS

The connection control block for which you allocate memory belongs to ADSP until you explicitly remove the connection listener. You cannot release the memory for the CCB until after you eliminate the connection listener.

ASSEMBLY-LANGUAGE INFORMATION

To execute the dspCLInit routine from assembly language, call the _Control trap macro with a value of dspCLInit in the csCode field of the parameter block.

RESULT CODES

noErr	0	No error
ddpSktErr	-91	Error opening socket

SEE ALSO

To establish a connection end that is not a connection listener, use the dspInit routine described on page 5-45.

To eliminate a connection listener, use the dspCLRemove routine, described on page 5-68.