On Distributed Computing: A View, Physical Versus Logical Objects, and a Look at Fully Anonymous Systems
摘要
This article presents a short (and partial) history of synchronization in systems made up of asynchronous sequential processes (automata). Among other points, it shows that synchronization (which consists in ordering operations issued by processes on shared objects) has a different flavor according to the fact that the objects are physical objects (such as a printer or a disk) or logical objects (immaterial objects represented by sequences of bits). It then follows from this physical/logical nature of computing objects that mutual exclusion is to physical objects what consensus is to logical objects. The article also addresses recent results on process synchronization in fully anonymous systems (systems in which processes cannot be distinguished one from the other, and where there is a disagreement on the addresses of the memory registers.