Naming Anonymous Processes with Test-and-Set Registers

Abstract

A system of anonymous processes that have no names assigned to them is considered in both synchronous and asynchronous communication models. The processes are fault free and can only communicate using test-and-set (TAS) registers. The aim of the paper is to assign unique names to all processes using a distributed algorithm. The naming of anonymous processes is studied in eight new problem models based on two categories; the number of TAS registers available, and the knowledge of the number of processes. In this paper, two distributed naming algorithms are developed that can assign unique names to anonymous processes. One is deterministic and the other is randomized. The developed algorithms are optimal in time complexity and namespace size. The Sequential Lookup algorithm, which is a deterministic algorithm, has a time complexity of 0(n2) steps, whereas the Random Lookup algorithm, which is a randomized algorithm, has a time complexity of 0(n log n) steps. Proof of the correctness of each naming algorithm is presented for all categories of the problem model where the number of processes is known. The Random Lookup algorithm has a better time complexity compared to the Sequential Lookup algorithm due to the use of randomness in accessing TAS registers.