During experiment preparation, JCoz samples threads, collects topmost stack trace frames that are in user-defined scope, and then randomly selects one of collected frames. So, the "hotter" the line, the more often it will be selected.
There are some cases when we do not want some lines to be selected, even if they are executed very often. For example, we've already profiled our program and now want to take a closer look only at a subset of lines. Or some user threads can do work that we're not interested in. Profiling takes a very long time, and we do not want to spend it at something that is out of our concern right now.
So, having several scopes to search might be useful, especially in large projects with deep and branchy packaging, and having several scopes to ignore makes it more flexible. This will help easily tune profiler to search lines for experiments only where we want.
During experiment preparation, JCoz samples threads, collects topmost stack trace frames that are in user-defined scope, and then randomly selects one of collected frames. So, the "hotter" the line, the more often it will be selected.
There are some cases when we do not want some lines to be selected, even if they are executed very often. For example, we've already profiled our program and now want to take a closer look only at a subset of lines. Or some user threads can do work that we're not interested in. Profiling takes a very long time, and we do not want to spend it at something that is out of our concern right now.
So, having several scopes to search might be useful, especially in large projects with deep and branchy packaging, and having several scopes to ignore makes it more flexible. This will help easily tune profiler to search lines for experiments only where we want.