Application Threads and Thread Identifiers
When you start an application, you open the first thread. Each time thereafter that your application issues an openframe statement, it begins a new thread in the application.
Generally, the user remains unaware of these individual threads in an application. However, when you use the OpenROAD Debugger, you must be aware of which thread you are working on, especially if your application uses the openframe statement to open several instances of the same frame.
To keep track of the various threads, the Debugger displays a thread identifier when appropriate. This identifier has the format:
framename:integer_number
framename
Identifies the starting frame of the thread
integer_number
Specifies a value that identifies the thread's relative position in the sequence of threads in the application.
For example, if a thread identifier is framename:6, this thread is the sixth thread opened in the application. The integer_number also makes it possible to distinguish between threads originating from multiple openframe statements that open the same frame.
The threads are numbered consecutively from the start of the application, beginning with number 1. If you close a thread, its number disappears and is not reused. This behavior results in breaks in the sequence of thread identifier numbers as you step through your application.