Analysis of guaranteed service times of distributed real-time objects

As the demands for real time distributed systems increase, the need for programming tools useful in development of such application systems is becoming increasingly acute. An issue that the research community has long recognized as an important technological challenge but has not shown much progress in meeting the challenge is to guarantee response times of real time distributed systems. Two basic problems must be solved to effectively meet this challenge: (1) to establish the distributed real time program structure and the system infrastructure structure, i.e., the structure of the operating system (OS) and the communication infrastructure, that enable systematic analysis of the worst case time behavior of the application systems; and (2) to establish a tool which performs automated analysis of the worst case time behavior while leaving only minimal work to the designers. The problem area (1) has been recognized as a research area for a long time, but only in recent years has the skeleton of a usable technical foundation started emerging. In other words, there has long been a lack of fully general and yet easily analyzable distributed real time program structures and also a lack of useful OS timing models. However, on the basis of the skeleton emerged, rapid progress is expected in the future toward establishment of a full technical foundation. Therefore, the time seems ripe for launching new larger scale attacks on problem (2) on the basis of those recent developments in handling problem (1)