As we noted earlier, each application thread can have its own debugger or you can use one debugger window to view various threads one at a time. The command we have seen so far, Application > Debug, debugs only the application's main thread. To debug another thread in the application, choose Go > Threads from the debugger, project window, or editor. From the debugger window you can also use Thread > Select Thread.... To bring up multiple debugger windows, use Window > New Window from an existing debugger.
The Go > Threads command launches a browser on the application itself, treating it as an object consisting of one or more threads whose states are visible in a table. If you browse a particular thread, Functional Developer refreshes the existing debugger window to display the thread or opens a debugger window if none already exists.
You can then debug a thread from the table by double clicking, or by using the right-click popup menu. This action stops the thread if it is running, and opens a debugger window on it.