The watchpoint — another type of action point — is yet another way to look at data. A TotalView watchpoint can stop execution when a variable’s data changes, no matter the cause. That is, you could change data from within 30 different statements, triggering the watchpoint to stop execution after each of these 30 statements make a change. Or, if data is being overwritten, you could set a watchpoint at that location in memory and then wait until TotalView stops execution because of an overwrite.

If you associate an expression with a watchpoint (by selecting the Conditional button in the Watchpoint Properties dialog box to enter an expression), TotalView evaluates the expression after the watchpoint triggers.