Watchpoints
To create a watchpoint expression with the CLI, use the -e argument on the dwatch command, and enter an expression. The expression is compiled into interpreted code that is executed each time the watchpoint triggers.
CLI: dwatch -e expr |
TotalView has two variables used exclusively with watchpoint expressions:
$oldval: The value of the memory locations before a change is made.$newval: The value of the memory locations after a change is made.NOTE: Watchpoints are not available on the Mac OS X platform.
For example:
{if ($newval > 2) $stop}
This watchpoint triggers when the updated value of the variable arg_count equals more than two.
At this point, you can see in the Local Variables view that arg_count equals 1:
The watchpoint is now reflected in the Action Points view with the watchpoint 
icon:
icon:When you advance the program by choosing Go, Next or Step, for instance, TotalView stops at this watchpoint when the value of arg_count has been incremented past 2.
The Processes & Threads view reports the Process State stopped at this watchpoint.The Source view identifies the location of the PC.The Local Variables view reports that arg_count’s value is at 3.The Command Line view reports that watchpoint 2 has been hit.The Action Point view displays a pale yellow background to identify the stopped watchpoint.
