Solution of a Problem in Concurrent Programming Control

Assume there are N computers which engage in a cyclic activity.

The computers engage with a common store where they can write or read to (but not at the same time).

The Problem

1. The solution must be symmetrical. There is no static ordering of the computers (i.e. if 1 and 2 are trying to use the store, there is no previous ordering that says 1 should beat out 2 in case of ties. If there is, this problem is trivial).
2. The speeds of the computers are unknown.
3. If a computer is stopped outside of its critical section, this should not block other computers.
4. There should be no deadlock, where two computers spin forever, each waiting for the other.

The Solution

The solution proposes a common store where

The Proof