Towards a Java Virtual Machine for pervasive computing – Infra-JVM

Pervasive computing is now a reality with the massive deployment of mobile appliances, particularly smart phones. Despite the increasing importance of pervasive applications, providing adequate support for them within a computing environment remains a challenge. Pervasive applications vary greatly in their resource requirements (processors, memory bandwidth, and disks): for critical applications, such as surveillance systems, a known bounded amount of resources must be guaranteed for the application to run properly; for multimedia applications, the amount of resources needed may change over time and dynamic adaption is often required. To manage these differing and possibly varying resource requirements, a system of resource reservations is required. Because the availability of resources is global to a computing environment, such reservations have to be managed at the middleware level.

Modern pervasive middleware is typically implemented using Java, for example with OSGi or Android, because of its safety, flexibility, and mature development environment. However, the Java virtual machine specification has not been revised since 1999, at the time when the idea of pervasive computing was first introduced. It was designed to execute only a single application at a time, and thus it does not provide resource accounting or per-application resource reservations. Current pervasive middlewares are thus unable to reserve resources for critical applications, which may cause these applications to crash or hang when insufficient resources are available, and are unable to provide resource accounting, making it impossible to balance the load on the devices and to optimize resource use.

The Infra-JVM project will investigate how to enhance the design of Java virtual machines with new functionalities to better manage resources. As a result of the project, we will propose a new Java virtual machine prototype based on our prototype of Java virtual machine VMKit that will integrate functionalities for resource accounting and reservation, for application-driven scheduling, and for effective memory management. We will evaluate this prototype on a pervasive end-to-end experimental use-case provided by one of the partners. This use-case is an information system that allows real time communication and coordination between firefighters and various command positions.