According to my understanding, one framework may contains several executors, and one executor may include many tasks, one framework is considered completed iff all of its executors are completed, and one executor is considered completed iff all of its tasks are completed, one task is considered completed iff its state equals "TASK_FINISHED", please fix if I am right.
another question: I know that one task may occupy resources, how about an executor? while I am reading the code, it seems that an executor also needs resources? what's the reason? Thank you very much! if you could provide me with some documents that would be much helpful!

