A Model for Updating Real-Time Applications

Updating application software is a common occurrence for modern computing systems. Software updates stem from the need to correct coding errors or to enhance the functionality of an application. Updating an application typically requires taking the current application offline and restarting a new application. This method of updating an application is perfectly acceptable for many general purpose-computing environments. However, in real-time environments that require high availability and have stringent timing constraints, taking a process offline for updates may be unacceptable or pose unnecessary risks. Some examples of these environments include telecommunications, air traffic control, railway control and medical patient monitoring. We present a new method to dynamically update a real-time application without having to take it offline. Our new method, which we call dynamic update for real-time systems, can be used to update real-time applications using rate-monotonic scheduling, while preserving the original deadline guarantees.