Debugging Dynamic Memory Usage Errors Using HP WDB (5900-1474; WDB 6.2; January 2011)

Table 16 Commonly Used Commands for Memory Debugging (continued)

Batch ModeInteractive Mode/Attach ModeDescription

Not supported in Batch Modeset heap-check compiler

Enables you to stop whenever

compiler detects corruption in

variables allocated by compiler.

The application should be

compiled with +check=all

option.

check_openfd=[on|off]Not supported in Interactive ModeEnables you to detect open file

descriptors.

Debugging Memory Using WDB GUI

The WDB GUI is a Graphical User Interface (GUI) designed by Hewlett-Packard for WDB.

It can be used to debug native-compiled HP C, HP aC++, and Fortran programs on

Itanium-based systems running HP-UX 11i v2 or HP-UX 11i v3, and PA-RISC systems

running HP-UX 11.0, HP-UX 11i v1, HP-UX 11i v2, or HP-UX 11i v3.

The WDB GUI offers the following capabilities to debug memory–related errors in an

application

• Detects corruption caused by calls to strcpy(), memset(), and memcopy()

• Stops program-execution at free of an unallocated or de-allocated block address

• Stops program-execution when block is freed if bad writes occur before or after

block bounds

• Scrambles previous memory contents on malloc() or free() calls

• Stops if the following block address is allocated or de-allocated

• Stops program execution when an allocation causes heap growth exceeding <num>

bytes

• Collects memory leak data (equivalent to info leak) and memory-usage (equivalent

to info heap) data

WDB GUI supports both interactive and attach mode of memory-debugging. It does not

support the batch mode debugging of applications.

The source window in the WDB GUI displays the source code. The command window

displays the output after debugging the application. It also enables you to use the

command-line interface in WDB. The command window can be used to take advantage

of memory-debugging features that are not directly supported in the GUI.

Using WDB GUI to Debug Memory-Related Problems

To debug an application for memory problems using WDB GUI, complete the following

steps: