synchronized thread execution

Question

my task is to create thread in this order: if A start->start B and C, if B start->start D. And destroy them in reverse order If D then B. If B and C then A. I hope you get it.

Answer 1

In my opinion, it is quite strange to use synchronized (lock) in your run method to lock your object. The reason is that in each Thread object has the different lock attribute, which is belong to each object. It means you are trying to lock the different objects. Actually, it doesn't make sense.

Basically, the object that you should apply the synchronized are any shared objects. For example, you need to count something and then you create a class object to share it in your class. In this case, it should be locked while being read or written.