Storage Change/Watch Breakpoint/Watchpoint dialog box

The name of this dialog box changes depending on what you are debugging. Select the dialog box that has opened on your system:

Storage Change Breakpoint dialog box

Use the Storage Change Breakpoint dialog box to set a new breakpoint that causes execution to stop whenever storage at a specific address changes. Execution stops only if the value changes; if the same data is moved into a storage area, the breakpoint does not trigger a stop. On Windows, you also use this dialog box to redefine an existing breakpoint.

Usage tip: If you set a storage change breakpoint for an address that is on the call stack, be sure to remove the breakpoint before leaving the routine associated with it. Otherwise, when you return from the routine, the routine's stack frame will be removed from the stack, but the breakpoint will still be active for that address. Any other routine that gets loaded on the stack will then contain the breakpoint.

Controls and control groupings are described below. Group and subgroup names appear in italics, and control names appear in bold.

Required Parameters Use controls in this group to define where the breakpoint is placed in the program being debugged.
Address or Expression Use this field to enter an address, or an expression that evaluates to a valid address.

ng390.gif (283 bytes)ngcobol.gif (330 bytes) When debugging COBOL on OS/390, use this field to enter a variable name.

Bytes to Monitor Use this field to specify a value to tell the Debugger the number of bytes you want it to monitor.

The valid range depends on the operating system where you are debugging your program.
Optional Parameters Provide additional control over when breakpoints are triggered.
Thread This selection list lets you choose what threads to set the breakpoint in. To select a thread ID from the list, highlight the thread where you want to set the breakpoint. This list is available only on platforms that support multithreaded programs.
Frequency Use the Frequency controls to tell the Debugger when to stop on a breakpoint and when to skip it. The Debugger keeps track of how many times each breakpoint is encountered. The fields in this section tell the Debugger on which encounter of a breakpoint the Debugger should first stop, how often it should stop, and on which encounter the Debugger should no longer stop.
From Enter the first breakpoint encounter you want the Debugger to stop on. For example, if you want the Debugger to skip over the breakpoint the first five times it is encountered, enter "6".
To Enter the last breakpoint encounter you want the Debugger to stop on. For example, if you want it to start ignoring the breakpoint after the 20th encounter, enter "20". To have it always stop on the breakpoint, enter "Infinity".
Every Enter the frequency with which you want the Debugger to stop on this breakpoint. For example, if you want it to stop on only one out of every four it encounters, enter "4".
Push buttons
OK Creates the storage change breakpoint using the settings you specified, then closes the Storage Change Breakpoint dialog box.
Set Creates the storage change breakpoint using the settings you specified, but keeps the Storage Change Breakpoint dialog box open so you can create more breakpoints.
Default Saves the settings in the Optional Parameters group for use as default settings when you next set a new breakpoint.
Cancel Closes the Storage Change Breakpoint dialog box without creating a new breakpoint.
Help Displays this help panel.

Watch Breakpoint dialog box

Use the Watch Breakpoint dialog box to set a watch breakpoint. Use this type of breakpoint when you want to see where and how a variable is being changed in your program.

Controls and control groupings are described below. Group and subgroup names appear in italics, and control names appear in bold.

Required Parameters Define where the breakpoint is placed in the program being debugged.
Expression Enter a variable or expression to be watched. The maximum length of the expression is 256 characters.

For CL, COBOL, and RPG, an expression is always the name of a variable.

For C/C++, an expression is the name of a variable or any other expression that resolves to a storage address. For example, a dereferenced pointer is an expression.

Bytes to Monitor Select the number of bytes of a variable or expression you want to watch, up to 128.

The default value of 0 means that the declared type length of the variable is watched.

Optional Parameters Provide added control over when a breakpoint will stop program execution.
Thread This selection list lets you choose which threads to set the breakpoint in. To select a thread ID from the list, highlight the thread in which you want to set the breakpoint. This list is available only on platforms that support multithreaded programs.

The Debugger uses this information to correctly qualify the watched expression. A watch breakpoint is set such that it may be hit in any thread, no matter what thread it is set for.

Frequency Use the Frequency controls to tell the Debugger when to stop on a breakpoint and when to skip it. The Debugger keeps track of how many times each breakpoint is encountered. The fields in this section tell the Debugger on which encounter of a breakpoint the Debugger should first stop, how often it should stop, and on which encounter the Debugger should no longer stop.
From Enter the first breakpoint encounter you want the Debugger to stop on. For example, if you want the Debugger to skip over the breakpoint the first five times it is encountered, enter "6".
To Enter the last breakpoint encounter you want the Debugger to stop on. For example, if you want it to start ignoring the breakpoint after the 20th encounter, enter "20". To have it always stop on the breakpoint, enter "Infinity".
Every Enter the frequency with which you want the Debugger to stop on the breakpoint. For example, if you want it to stop on only one out of every four it encounters, enter "4".
Push buttons
OK Creates the watch breakpoint using the settings you specified, then closes the Watch Breakpoint dialog box.
Set Creates the line breakpoint using the settings you specified, but keeps the Watch Breakpoint dialog box open so you can create more breakpoints.
Default Resets the values in the Optional Parameters group to system-supplied defaults.
Cancel Closes the Watch Breakpoint dialog box without creating a new breakpoint.
Help Displays this help panel.

Watchpoint dialog box

Use the Watchpoint dialog box to set a new watchpoint, which causes execution to stop whenever the class field being watched is modified. Program execution stops even if the new value for the field is the same as the old value.

Controls and control groupings are described below. Group and subgroup names appear in italics and control names appear in bold.

Required Parameters Use controls in this group to define where the watchpoint is placed in the program.
Address or Expression Use this field to enter an expression that evaluates to a class field.
Optional Parameters Provide added control over when a watchpoint will stop program execution. Optional parameters are not available when debugging interpreted Java programs.
Thread This selection list lets you choose which threads to set the watchpoint in. To select a thread ID from the list, highlight the thread in which you want to set the watchpoint. This list is available only on platforms that support multithreaded programs.

The Debugger uses this information to correctly qualify the watched expression. A watchpoint is set so that it may be hit in any thread, no matter what thread it is set for.

Frequency Use the Frequency controls to tell the Debugger when to stop on a watchpoint and when to skip it. The Debugger keeps track of how many times each watchpoint is encountered. The fields in this section tell the Debugger on which encounter of a watchpoint the Debugger should first stop, how often it should stop, and on which encounter the Debugger should no longer stop.
From Enter the first watchpoint encounter you want the Debugger to stop on. For example, if you want the Debugger to skip over the watchpoint the first five times it is encountered, enter "6".
To Enter the last watchpoint encounter you want the Debugger to stop on. For example, if you want it to start ignoring the watchpoint after the 20th encounter, enter "20". To have it always stop on the watchpoint, enter "Infinity".
Every Enter the frequency with which you want the Debugger to stop on the watchpoint. For example, if you want it to stop on only one out of every four it encounters, enter "4".
Push buttons
OK Creates the watchpoint using the settings you specified, then closes the Watchpoint dialog box.
Set Creates the watchpoint using the settings you specified, but keeps the Watchpoint dialog box open so you can create more watchpoints.
Default Saves the settings in the Optional Parameters group for use as default settings when you next set a new watchpoint.
Cancel Closes the Watchpoint dialog box without creating a new watchpoint.
Help Displays this help panel.