PAM Programming Manual

File-System Procedures

PAM Programming Manual—142482

2-2

Using the PORT Interface

PORTs are programmatic interfaces that provide link-level service access points

(LSAPs) to level-2 services available in PAM. The L2S and L2TR programmatic

interfaces allow application programs running on a Himalaya S-series server to use PAM

as a link-level service provider for LANs attached to adapter such as the Ethernet 4

ServerNet adapter (E4SA) and the Token Ring ServerNet adapter (TRSA).

The link-level interfaces use a FILE_OPEN_ or OPEN call to open a dedicated port

named, for example, $PAM1.#ENET01, where $PAM1 is the configured name of the

line and #ENET01 is the configured name of the PORT.

LLC1-type ports provide IEEE 802.2 Logical Link Control, Type 1 (LLC1). The service

accessed through a port is determined by the Distributed System Management (DSM)

object subtype specified when the port is added. See the programming examples in

Appendix B, Link-Level Programming Examples

for more information.

File-System Error Codes

On completion of each procedure call, your program should test the hardware condition

code. This code identifies error conditions associated with execution of a particular

procedure call. If it is less than (<) or greater than (>) zero, then an error has occurred.

You can obtain the specific file-system error code by using the FILE_GETINFO_ or

FILEINFO procedure described in the Guardian Procedure Calls Reference Manual.

Appendix A, File-System Error Codes

summarizes the Guardian file-system error codes.

These messages are described fully, including probable cause, system action, and

suggested recovery actions, in the Guardian Procedure Calls Reference Manual.

SETMODENOWAIT is identical to SETMODE except that the procedure call itself

is performed as a nowait operation (that is, the

SETMODENOWAIT call must be completed by a subsequent

AWAITIO call).

AWAITIO waits for completion of an outstanding nowait I/O operation

FILE_GETINFO_ obtains error information pertaining to the most recently

completed file-system procedure call.

FILE_GETINFOBY

NAME_

obtains the configured subdevice type and physical record

length of the line.

CANCELREQ cancels a specified outstanding nowait I/O request.

Note. The procedure calls OPEN, CLOSE, WRITE, READ, FILEINFO, and DEVICEINFO are

superseded by FILE_OPEN_, FILE_CLOSE, WRITEX, READX, FILE_GETINFO_, and

FILE_GETINFOBYNAME; however, if your TLAM application used the older file-system calls

the older calls will still function in PAM applications.