Can I use the same lock object at two methods, accessed by two different threads? Goal is to make task1 and task2 thread safe.
object lockObject = new object
You can and it works. If you don't use the same object, the blocks could execute at the same time. If you do use the same object, they can't.
Also, you mean lock(lockObject), not using(lockObject).
lock(lockObject)
using(lockObject)