2—variable traces

The Variable Traces option on the Traces panel is used to establish criteria for recording variable usage. A variable's usage is recorded if an ISPF service is directly asked to operate on the variable (such as VGET, VPUT, and VCOPY), or if an ISPF service is indirectly asked to operate on the variable (such as DISPLAY). Variables changed under the Variables option (7.3) are also recorded if the trace specifications are met.

When you select the Variable Traces option, you are shown a display that you can scroll (Figure 1). The pop-up window can also be resized using the RESIZE command. The display lists all currently defined variable traces. You can add, delete, and change variable trace definitions at a breakpoint, or by using this panel before calling a function.

Figure 1. Variable traces panel (ISPYRVP)

 ┌────────────────────────────── Variable Traces ──────────────────────────────┐
 │   Menu  Utilities  Help                                                     │
 │ ──────────────────────────────────────────────────────────────────────────  │
 │                                                            Row 1 to 8 of 13 │
 │                                                                             │
 │ Add, delete, and change traces.  Underscores need not be blanked.           │
 │ Enter END command to finalize changes.                                      │
 │                                                                             │
 │          Variable       Pool        Operation      Function     Active      │
 │         (Required) (No entry=all) (GET,PUT,CHG) (No entry=all) (YES,NO)     │
 │                                 (No entry=all)              (No entry=YES)  │
 │         ALL                                                      NO         │
 │                                                                             │
 │                                                                             │
 │                                                                             │
 │                                                                             │
 │                                                                             │
 │                                                                             │
 │                                                                             │
 │                                                                             │
 │ Command ===>                                             Scroll ===> PAGE   │
 │  F1=Help        F2=Split       F3=Exit        F4=Expand      F5=Rfind       │
 │  F6=Resize      F7=Backward    F8=Forward     F9=Swap       F10=Actions     │
 └─────────────────────────────────────────────────────────────────────────────┘

Each line defines a variable trace, showing a line command area and these fields:

Variable

Name of the variable to be traced, or ALL to show tracing of all variables. Initially, ALL is presented on the display but is not started. Change the NO in the Active column to YES to start such a trace. If you want to trace a variable whose name is ALL, enclose that name in single quotes to distinguish it; that is, type 'ALL', not ALL.

Pool

Pool of interest for variable tracing:

F: Function variable pool.
S: Shared variable pool.
P: Profile variable pool.
Blank: All pools.

Operation

Type of variable reference to trace:

GET: Accesses to the variable's value.
PUT: Stores to the variable's value.
CHG: Changes to the variable's value.
Blank: All references to variable are traced.

Function

If there is no entry, this variable is traced for all functions.

Active

Indication of whether the trace is to be active:

YES: The trace is currently active.
NO: The trace is currently not active.
Blank: The trace is currently active.

All variable trace definitions exist until you leave Dialog Test, or until you delete them from this panel. Enter new information by typing over the existing data. The underscores are pad characters to show the start and end of each field; you do not need to blank them out. You can create several variable traces before you press the Enter key.

During dialog processing, to determine whether the criteria for a variable trace have been met, Dialog Test processes a logical AND of the Variable, Pool, Operation, Function, and Active fields specified for that variable trace. Therefore, if you want more than one trace for a variable, you should create multiple rows.