Tarmac: a language system substrate based on mobile memory

Tarmac, a language system substrate on which systems for distributed parallel programming can be built, is described. A model of shared global state, called mobile memory, which is provided by Tarmac, is discussed. The basic unit of state in this model can be viewed both (1) as a block of memory that can be directly accessed by machine instructions and (2) as a logical entity with a globally unique name that may be efficiently located, copied, and moved. To support higher level synchronization models, the movements of a memory unit may optionally enable computations. The implementation and performance of Tarmac are discussed. Tarmac is contrasted with other systems for parallel distributed programming