Figure 234 illustrates the relationship between the CLI, the GUI, the TotalView core, and your program:

The CLI and GUI are components that communicate with the TotalView core, which is what actually does the work. In this figure, the dotted arrow between the GUI and the CLI indicates that you can invoke the CLI from the GUI. The reverse is not true: you can’t invoke the GUI from the CLI.

In turn, the TotalView core communicates with the processes that make up your program, receives information back from these processes, and passes information back to the component that sent the request. If the GUI is also active, the core also updates the GUI’s windows. For example, stepping your program from within the CLI changes the PC in the Process Window, updates data values, and so on.