Implementing Application Specific RTOS Policies using Reflection

Abstract

Conventionally, a Real-time Operating System (RTOS) is built without knowing which specific applications will be executed upon it. The RTOS is built for the general case, rather than to meet the specific requirements of an application. This paper proposes a generic module-based reflective framework to implement an RTOS that allows applications to dynamically adapt the policies within the RTOS to better meet applicationspecific requirements.The specific approach taken is to augment a conventional µkernel with a module-based reflective mechanism that allows applications to dynamically change the behaviour of themselves, and the policies of the underlying RTOS. Reflection is used to allow applications and system modules to access key OS data structures to obtain information pertaining to the current system performance and resource management policies (eg. scheduling). An application is then able to modify or introduce new policies into the RTOS to satisfy its demands. Evaluation of our approach shows a considerable performance gain.

Predictable Interrupt Management and Scheduling in the Composite Component-Based System

“…Both of these techniques are complementary to our work, and can be used to refine or verify a given hierarchy of user-level schedulers. Application-specific scheduling methods that take into account application constraints, and alter behavior based on system dynamics [23,25] promise to lessen the semantic gap by offering a tighter coupling between application and scheduler.…”

An Efficient Page Lock/Release OS Mechanism for Out-of-Core Embedded Applications

“…Many proposed extensible memory management solutions use a µkernel based approach, extending the existing paging mechanism [1]. VINO [13] enables applications to override some or all operations within MemoryResource objects to specialise their behaviour.…”

POSIX Trace Based Behavioural Reflection

“…A more recent approach has been done in DAMROS [5] which augments a µ-kernel with a reflection mechanism. This approach allows the application to install user-defined policies in the form of executable source code under certain restrictions.…”

“…Research in the field has already addressed the problem of adapting a reflective approach to an RTOS kernel. Systems like ApertOS [3]; the Spring kernel [4] and more recently DAMROS [5] are attempts to provide reflective capabilities to operating systems. Our approach differs from previous works, since it is intended to be used in general purpose RTOS.…”