EMS FastStart Manual

EMS FastStart Manual–133701

6-1

Building Your Application for Event

Generation

To use EMSFS, you must modify your application to use the EGEN module generated

by EMS FastStart. These modifications will enable you to generate the event messages

needed for your application. This section includes information on defining, modifying,

and compiling an application (EGEN Operating Modes). It details the specific steps a

programmer must take to use EGEN with a specific application and shows how to use

EGEN with a COBOL85 program (Mode 1

). For a description of TAL and C examples

using EGEN, see the ATM example in the EMS FastStart Distribution subvolume.

How EGEN Works

EGEN is the TAL module which links the application process and the EMS system.

Your application interfaces with EGEN by moving values to the event record structure

(called egen-record in this section) defined by the ACF. The ENTER TAL constructs

pass these parameters to EGEN. EGEN then generates the tokenized event by

performing a WRITE-READ of the event buffer to the collector $0 or to an alternate

location.

EGEN Operating Modes

EGEN is designed to be used by a number of different application types such as

COBOL85 batch programs, COBOL85, C or TAL servers, or multi-threaded TAL

programs. Each type of application has specific requirements (for example, a simple

interface or full control of all I/O operations) which can be addressed by choosing one of

the four operating modes supported by EGEN. Before any modifications can be made,

you must select the correct EGEN operating mode. Each mode has a pre-defined set of

procedures and parameters provided within the EGEN module. Table 6-1

and Table 6-2

summarize the procedures and parameters required for each mode of operation.

Mode 1

This is the simplest operating mode and is used mainly by COBOL85 applications. In

mode 1, EGEN sends approximately three messages to the collector for each event

generated. Each of the other operating modes sends only one message per event.

Because of the heavy use of CPU resources, it is recommended that mode 1 be used only

by applications which generate few events.

For each event generated, EGEN opens the defined collector, writes the event, completes

the write operation and then closes the defined collector.