A method, apparatus, system, and signal-bearing medium that in an
embodiment determine whether to stop execution of a program at a
breakpoint based on a previous value of a variable. In another
embodiment, an attribute is applied to all breakpoints in a breakpoint
group. The attribute includes data that is used to decide whether to halt
the program upon encountering the breakpoints or allow the program to
continue to execute. In another embodiment, breakpoints are excluded or
included on the basis of the thread in which the breakpoint is
encountered by the program.