DYMOS

Abstract

Programs are frequently modified during their lifetime. Furthermore, modifications to some systems have to be made on the fly; that is, without stopping their execution. For example, changes to airline reservation systems, telephone switching systems, and on-line banking systems have to performed dynamically. Other continuously running systems, such as operating systems, may be modified on the fly to increase their availability. DYMOS is a programming system that supports a programmer modifying a StarMod program dynamically. StarMod [2] is an extension of Modula [3]. To modify procedures dynamically, the programmer modifies and recompiles the source code of the procedures to be replaced and then requests the system to change the current core image to incorporate new code and data.