TotalView compiles, links, and patches expressions into the target process. Because the target thread executes this code, eval points and conditional breakpoints execute very quickly. (Conditional watchpoints are always interpreted.) Also, this code doesn’t communicate with the TotalView host process until it needs to.

If the expression executes a $stop function, TotalView stops executing the compiled expression. At this time, you can single-step through it and continue executing the expression as you would the rest of your code.

If you plan to use many compiled expressions or your expressions are long, you may need to think about allocating patch space. For more information, see he section Allocating Patch Space for Compiled Expressions.