HP WDB GUI Reference Manual (August 2006)

Debugging with WDB GUI
Saving and Restoring Debug Sessions
Chapter 368
• Stop when freeing unallocated or deallocated blocks.
• Stop when freeing a block if bad writes have occurred outside block boundary.
• Stop if a specified block address is allocated or deallocated.
• Scramble previous memory contents at malloc and free calls.
• Stop when allocation causes heap growth.
• Collect memory leak data.
• Stop if the specified block is allocated or deallocated.
Stop when freeing unallocated or deallocated blocks :
WDB inspects the parameters to free() and realloc() to verify that they are pointing to
valid currently allocated heap blocks, when freeing unallocated and deallocated blocks.
Stop when freeing a block if bad writes have occurred outside block boundary
When bounds checking is turned on, WDB allocates extra space at the beginning and end of a
block during allocation and fills it up with a specific pattern. When blocks are freed, WDB
verifies whether these patterns are intact. If they are corrupted, it indicates an underflow or
and WDB reports the problem.
Stop if a specified block address is allocated or deallocated
This option can be turned on to stop a program whenever a block at a specified address is
allocated or deallocated.
Scramble previous memory contents at malloc or free calls
When this setting is turned on, any time a memory block is allocated or deallocated, WDB
scrambles the space and overwrites it with a specific pattern. This change to the memory
content, increases the chance that erroneous behaviors will cause the program to fail.