CICS Applications

Editing a BMS Mapset

Chapter 18: Running with Multi-tasking

Use the support that CICS Option provides for CICS multi-tasking to take advantage of CICS features that are allowed only within a multitasking environment.

You need to have read the chapter Start Here for the Tutorials and worked through the first session, Using Mainframe Express, and the session CICS Applications, before you do this session.

You need to have installed CICS Option to do this session. We assume you are familiar with CICS on a mainframe.

18.1 Overview

You must use a multi-tasking environment if you want to use any of the following:

• 3270 printer support.
• Inbound communications such as:
  • Function shipping.
  • Distributed program linking (DPL).
  • Distributed transaction processing (DTP).
  • Transaction routing.
• External CICS Interface (ECI), External Presentation Interface (EPI), or other client technologies.
• Interval control (asynchronous START rather than single threaded in single-tasking).
• INQUIRE commands that refer to a multi-tasking environment.
• Resource contention - record locks, syncpoints, or ENQs.
• MRO region modeling.

This session uses the same demo application as the chapter CICS Applications. To use multi-tasking, you start a CICS region and associated 3270 terminals.

18.2 Preparation

This demo uses the project cicsdemo.mvp that you created and built in the chapter CICS Applications.

1. If you have closed Mainframe Express, open it as before. Close any project windows and any other windows that are open.

2. Open the project cicsdemo.mvp in any of the ways described in the chapter Start Here for the Tutorials.

   The full path is \mfuser\projects\gsdemo\cicsdemo\cicsdemo.mvp. If you use Open on the File menu, you need the Files of Type field on the Open dialog box set to Project Files (*.mvp) to see this file.

18.3 Sample Session

In this session you:

• Start a CICS region
• Start a 3270 terminal
• Run the application
• Debug the application

18.3.1 Starting a CICS Region

To start a CICS region:

1. Click CICS on the Tools menu, then click Start Region.

   In the Output window, a Console tab appears. The Console view appears in front of the other views in the Output window, and you can see messages showing the region starting up.

   When the region has started (no more messages are coming), let's take a quick look, before continuing, at how you can monitor regions you have running.

2. Click CICS on the Tools menu, then click Region Management, then click Monitor Region.

   The monitor window appears, showing the active region and its status - in our case, cicsdemo. If it hasn't appeared after a moment, press Enter.

   Across the bottom of the window are listed the keys you can use in the monitor. We will just close the monitor and continue.

3. Press Esc to close the monitor window.

18.3.2 Starting a 3270 Terminal

To start a 3270 terminal:

1. Click CICS on the Tools menu, then click Start 3270 Terminal.

   A terminal emulator window opens , and the transaction CESN, for CICS sign-on, is automatically run and invites you to sign on. As no security is set, you don't need to do this.

2. Press CICS Clear (Esc).

   The emulator window goes blank, and you can now run a transaction in the normal CICS way.

18.3.3 Running the Application

To run the application:

1. Type ACCT, then press 3270 Enter (right-hand Ctrl).

   As before, the application displays its first map.

2. Press CICS Clear (Esc).

3. Type EXIT, then press 3270 Enter (right-hand Ctrl). Click OK on the "Application completed" message that appears.

   The emulator window closes.

4. Click CICS on the Tools menu, then click Stop Region.

18.3.4 Debugging the Application

To debug in a multi-tasking environment:

1. Click CICS on the Tools menu, then click Start Region.

2. When the region has started, click CICS on the Tools menu, then click Start 3270 Terminal.

3. Press CICS Clear (Esc).

4. Click Start Debugging on the Debug menu.

5. Click the CICS tab, make sure Generic is selected in the Multi-tasking Debug Options box, then click OK.

   An Application Output window opens. Messages in it show the debugger starting up. If it is undocked, you may have to drag it to one side to see the emulator window.

6. In the terminal emulator window, type ACCT, then press 3270 Enter (right-hand Ctrl).

   A source view window opens, with the source of Acct00, ready to execute the first statement.

7. Click a few times, until the first map is displayed.

8. In the terminal emulator window, press CICS Clear (Esc). .

9. Click .

   The transaction completes without debugging, and exits. The terminal emulator window shows a blank screen.

10. In the emulator window, type EXIT and press 3270 Enter (right-hand Ctrl). Click OK on the "Application completed" message that appears.

    The emulator window closes.

11. Click CICS on the Tools menu, then click Stop Region.

18.4 Before Continuing

Close both source view windows and hide the Application Output window.

The Cicsdemo project is used in a related session, Editing a BMS Mapset. If you're planning to go onto that session, you can keep the project open.

If you want to take a break before going on to the next session, you can close Mainframe Express.

Return to the Tutorials Map in the chapter Start Here for the Tutorials and choose which session to go on to next, depending on your interests.

CICS Applications

Editing a BMS Mapset