About an Action Point’s Width: Group, Process or Thread
For a single-process, single-threaded program, an action point’s width is irrelevant: when the thread hits the breakpoint, it stops. For a multi-process, multi-threaded program, it is useful to finely control what to stop. You can stop all the threads in a group, all the threads in a process, or just that single thread.
• Group: All the processes a program creates are placed into a control group.
When an action point is set to Stop Group, and a thread reaches the breakpoint, all running threads in all processes in the group stop.
• Process: A process can contain any number of threads.
The default setting for action points is Stop Process, which stops all the running threads in the process containing the thread that hit the breakpoint. This is useful in a multi-process program in which you might want to let the other processes continue running.
• Thread: A thread is a single unit of execution created by your program.
When an action point is set to Stop Thread, the thread that first executes to this breakpoint stops. The other threads retain their current states, running or stopped.