[shanxS]

> ... sound great until you need to SHARE data ...

If by "share" you mean one writer and others with read-only access, then staleness of data is a question. In java we have volatile for that, I think there is a similar keyword in C++. However, you'll have to maintain the invariant of "one writer and others with read-only access". If you don't need absolute latest version, you can do message passing/pubsub etc.

If by "share" you mean multiple writers, I'll have to question your design decision. Why do multiple threads have to write to same memory location? Most of the time, you can get away with partitioning/sharding.

If you disagree, I'd like to know why?

[smallstepforman]

Unfortunately, our objects are not isolated, they interact with the world, and often need to be shared when we cannot copy the resource (performance). Eg. a (partitioned) rendering surface may be written simultaneously, a physics engine needs to know what objects are in the game world, multiple bank accounts need to be updated simultaneously, etc. By design is not always possible to sequence, some transactions must be atomic across multiple objects.

[ahasani]

Yes they are, atom is in isolation, cell has membrane, we have a body we have isolation and encapsulation in physics/chemistry/biology. In actor model message passing is interaction. Since you mentioned game, check out https://github.com/aeplay/kay, which is the isolation "objects" for https://github.com/citybound/citybound "physics engine". On multiple bank accounts, well an account is an actor, so there is no problem there, please have a look at http://proto.actor/blog/2017/06/24/money-transfer-saga.html