HP UX SoftBench Software manual Verifying Correct Data Structures, Viewing btree

Using SoftBench Debugger Data Graph Window

Sample Use Models

Sample Use Models

This section introduces you to several Data Graph Window concepts useful in verifying the correct or expected operation of your program's data structures. By setting strategic breakpoints and selecting the pointer dereferencing commands, you can quickly visualize what happens to your data structures during program execution. Using the Data Graph Window increases your program understanding and decrease your defect isolation time.

The following scenario assumes you have a defect in your program, which contains binary trees implemented with pointers. These use models provide scenarios for:

•Visually picturing the data structures, by graphing the overall connections within a large interconnected data structure.

•Displaying values of data members within the structures represented by nodes on the Data Graph Window.

The source for the example used in this section is found in /opt/softbench/examples/bintree/bintree.C.

Verifying Correct Data Structures

Suppose that your program has a binary tree defined by the variable btree. At some breakpoint during execution of the program, assume you want to see the state of the binary tree.

Viewing btree

To see the binary tree in the Data Graph Window, you would enter btree in the "()" input box and choose "Show: Data Graph ( )". The Data Graph Window opens, displaying a single node representing the btree variable. The node is labeled (btree) with the type class \\BinaryTree.

To follow all the pointers in btree, you would select the node and select "Follow All" from the "Selected" menu. SoftBench Debugger dereferences all non-NULL pointers in btree and adds new nodes to the Data Graph Window for each pointer. In this model, one node is added of type class TreeNode.

Chapter 8 245