The traditional Distributed Shared Memory (DSM) model provides atomicity
at levels of read and write on single objects. Therefore, multi-object
operations such as double compare and swap, and atomic m-register assignment
cannot be efficiently expressed in this model. We extend the traditional
DSM model to allow operations to span multiple objects. We show that memory
consistency conditions such as sequential consistency and linearizability
can be extended to this general model. We also provide algorithms to implement
these consistency conditions in a distributed system.