Turing machine approach to runtime software adaptation

In this paper, the problem of applying changes to software at runtime is considered. The computability theory is used in order to develop a more general and programming-language-independent model of computation with support for runtime changes. Various types of runtime changes were defined in terms of computable functions and Turing machines. The properties of such functions and machines were used to prove that arbitrary runtime changes on Turing machines are impossible in general cases. A method of Turing machine decomposition into subtasks was presented and runtime changes were defined through transformations of the subtask graph. Requirements for the possible changes were considered with regard to the possibility of subtask execution during such changes. Finally, a runtime change model of computation was defined by extension of the Universal Turing Machine

A componentbased approach to online software evolution:

SUMMARY Many software systems need to provide services continuously and uninterruptedly. Meanwhile, these software systems need to keep evolving continuously to fix bugs, add functions, improve algorithms, adapt to new running environments and platforms, or prevent potential problems. This situation makes online evolution an important issue in the field of software maintenance and evolution. This paper proposes a component-based approach to online software evolution. Nowadays component technology has been widely adopted. Component technology facilitates software evolution, but also introduces some new issues. In our approach, an application server is used to evolve the application, without special support from the compiler or operating system. The implementation and performance analysis of our approach are also covered