Implementation of new Ada 2005 real-time services in MaRTE OS and GNAT

The paper presents the implementation of some of the new Ada 2005 real-time services ("Execution Time Clocks", "Execution Time Timers", "Timing Events" and "Dynamic Priorities for Protected Objects") in the MaRTE OS/ GNAT run-time library for GNU/Linux. For each these new services we discuss different implementation alternatives and evaluate they performance. As a consequence of the results obtained, our view is that the new services can be implemented in an efficient way in a existing run-time system without requiring major changes. To illustrate the usefulness of the new Ada services, the implementation of a complex scheduling policy is described.