[peheje]

Can someone explain to me how it makes sense that you want to define a locking mechanism using.. locking mechanism (the "atomic"). Does this mean that in an actual implementation you would have to drop down to some hardware-level-atomic operation, and is that even practical?

Also won't fencing token require some kind of token manager, that ensures you must present the highest token to do the action, and that you have to ask to get a new token, and that when you fail because your token is too old you must re-request one, is this modelled?

[OJFord]

Well it's not a general purpose programming language defining the actual lock this way, it's checking a locking algorithm; so the atomic in the specification of the algorithm is just saying given that these steps do occur atomically, how will it behave.

The algorithm we're checking is using Redis, and the atomic read/write in the example is a behaviour Redis gives you.