This chapter contains preliminary information for the application programmer who writes transaction programs that use the IRIS SNA LU 0-3 Programmable Interface (PI) verbs.
After describing how to set the run-time variables, the chapter identifies the IRIS SNA SERVER verbs used with the LU 0-3 Programmable Interface verbs. When used together, the IRIS SNA SERVER verbs and the LU 0-3 PI verbs make up the Application Program Interface, or API. Information about these verbs is presented in Appendix H, “Man Pages,” of this guide. The programmer needs access to the verb man pages in order to write transaction programs. Appendix G, “API Verb Catalog,”contains a catalog of all verbs and the location of their man pages in the IRIS SNA SERVER manual set.
This chapter introduces the PI verbs, outlines the programmer's responsibilities and describes verb execution and completion, the naustat variable, session management, PU and LU structures, verb-boundary integration, and data types.
If your programs are to be executed on a system that does not have the IRIS SNA SERVER installed, you must set the run-time variable SNAHOST to the system ID of the IRIS SNA SERVER system before your start your SNA API programs.
This section describes functions provided by the IRIS SNA SERVER
that are of interest to the programmer using LU 0-3 Programmable Interface (PI) verbs or programmers using the LU 6.2 API verbs. Outlined below are three categories of IRIS SNA SERVER verbs.
Implementation-specific verbs
Configuration verbs
Node Operator verbs
Implementation-specific verbs, while not a part of the IBM SNA, are required for the IRIS SNA SERVER. These verbs perform specific functions, such as opening and closing the connection between the transaction program and the IRIS SNA Scheduler.
Before a program can issue any conversation, control operator, or node operator function, it must establish a connection with the IRIS SNA Scheduler. Establishing this connection is called “attaching.” For the conversation verbs and the control operator verbs, this is done by specifying the name of the configuration and the local LU that the transaction program wants to use. The names specified in the attach request are called the “context” of the attach. Since a program can issue verbs to more than one configuration or LU, the program can issue multiple attach requests. Each of these “attaches” creates a new logical instance of the program. The setctx verb is used to switch from one instance to the other before issuing verbs to the different LUs.
Transaction Program Connection verbs establish or break the connection between the transaction program and the IRIS SNA Scheduler. Consequently, they are the first and last verbs issued by the program. All applications must use the attach and detach verbs. The setctx verb is optional.
The man pages for these Transaction Program Connection verbs are included in Appendix H. Table 1-1 summarizes these verbs.
Table 1-1. Transaction Program Connection Verbs
Verb | Full Name | Function |
|---|---|---|
attach | Attach | Initiates communication |
|
| between the local program |
|
| and the IRIS SNA |
|
| Scheduler. |
|
|
|
detach | Detach | Detaches the current |
|
| context from the IRIS SNA |
|
| Scheduler. |
|
|
|
setctx | Set Context | Establishes the current |
|
| context under which |
|
| subsequent verbs are |
|
| issued. |
IRIS SNA SERVER Configuration verbs, used to define and display the resources of the node and logical unit, are divided into two groups: define verbs and display verbs. The Define and Display verbs listed in the Table 1-2 are of interest to the programmer using the LU 0-3 Programmable Interface (PI) verbs.
Table 1-2. Configuration Verbs
Verb | Full Name |
|---|---|
dfncp | Define Control Point |
dfnline | Define Line |
dfnllu | Define Local LU |
dfnnode | Define Node |
dfnrlu | Define Remote LU |
dfnslu | Define Secondary Logical Unit |
dfnsta | Define Station |
dfntp | Define Transaction Program |
dspcp | Display Control Point |
dspcph | Display Host Status |
dspline | Display Line |
dspllu | Display Local LU |
dspnode | Display Node |
dsprlu | Display Remote LU |
dspslu | Display Secondary Logical Unit |
dspsta | Display Station |
dsptp | Display Transaction Program |
The Node Operator verbs in Table 1-3 activate, deactivate, and supervise the configured local resources of the IRIS SNA SERVER. These verbs control the links.
Table 1-3. Node Operator Verbs
Verb | Full Name |
|
|---|---|---|
actline | Activate Line |
|
actlu | Activate Logical Unit |
|
actpu | Activate Physical Unit |
|
actsta | Activate Station |
|
chgmsgq | Change Message Queue |
|
dctline | Deactivate Line |
|
dctlu | Deactivate Logical Unit |
|
dctpu | Deactivate Physical Unit |
|
dctsta | Deactivate Station |
|
dspmsgq | Display Message Queue |
|
rtvnmsg | Retrieve Node Message |
|
The PI verbs provide a function-call interface to the services available in a Logical Unit Type 0, 1, 2, or 3, or the Configuration Management Services component of the Physical Unit (PU). This interface is not used for Logical Unit Type 6.2.
Table 1-4 identifies the LU 0-3 PI verbs, provides the full name of the verb, and briefly describes the verbs function. See the man pages in Appendix H for detailed information on the verbs.
Verb | Full Name | Function |
|---|---|---|
initpi | Initialize Verb Data | Initializes the data |
| Structures | structures used |
|
| by the other PI verbs. |
rcvru | Receive Request Unit | Receives data from the |
|
| IRIS SNA SERVER |
|
| Scheduler. Data can be |
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| SNA RUs from the session |
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| or notifications |
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| from the scheduler. |
|
|
|
rejru | Reject Request Unit | Rejects an RU chain or part |
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| of an RU chain received by |
|
| the program. |
|
|
|
sndru | Send Request Unit | Sends an RU chain |
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| according to the |
|
| specifications supplied by |
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| the program. |
|
|
|
ssync | Set Sync Point | Sets the sync-point |
|
| sequence numbers in the |
|
| IRIS SNA Scheduler. |
|
|
These verb functions must be loaded with the LU 0-3 verb library liblu03.a.