When to use recursive mutex?

Question

I understand recursive mutex allows mutex to be locked more than once without getting to a deadlock and should be unlocked the same number of times. But in what specific sit

Answer 1

If you want to be able to call public methods from different threads inside other public methods of a class and many of these public methods change the state of the object, you should use a recursive mutex. In fact, I make it a habit of using by default a recursive mutex unless there is a good reason (e.g. special performance considerations) not to use it.

It leads to better interfaces, because you don't have to split your implementation among non-locked and locked parts and you are free to use your public methods with peace of mind inside all methods as well.

It leads also in my experience to interfaces that are easier to get right in terms of locking.