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

$ gdb high

HP gdb 5.6 for HP Itanium (32 or 64 bit) and target HP-UX 11.2x.

Hewlett-Packard Wildebeest 5.5.8 (based on GDB) is covered

by the GNU General Public License. Type "show copying" to

see the conditions to change it and/or distribute copies.

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(gdb) set heap-check on

(gdb) set heap-check high-mem-count 2

(gdb) r

Starting program: high

warning: High water mark

(address = 0x4044ff00 total memory per call site = 100)

#1 func2() at high.c:15

#2 main() at high.c:40

#3 main_opd_entry() from

warning: Use command backtrace (bt) to see the current context.

Ignore top 4 frames belonging to leak detection library of gdb.

__rtc_event (ecode=RTC_NO_ERROR, pointer=0x0, pclist=0x0, size=0)

at ../../../Src/gnu/gdb/infrtc.c:1236

1236 {

Monitoring De-allocations to Detect Double-Frees

The set heap-check free <on/off> command enables you to detect double-frees

and frees with improper arguments.

When this command is enabled, the free() calls are monitored to verify whether the

parameters address valid heap blocks. If an erroneous free() is detected, the debugger

stops execution and reports the error. You can analyze the stack trace to analyze where

and how the error occurred. Example 19 (page 97) illustrates the use of the set

heap-check free command.

Monitoring Heap Corruption

WDB enables you to detect the presence of heap-corruption in your application. Table 11

lists the commands for monitoring heap corruption

Memory-Debugging Features of WDB 45