Concurrency Programming Models in Mobile Real-Time Platforms

To support real-time properties, mobile real-time operating system (RTOS) platforms have added to their classical cyclic executive model more flexible concurrency paradigms based on threads and preemptive priority-based scheduling algorithms. However, in newer mobile RTOS, the concurrency model is also going back to prior cooperative multi-tasking models similar to cyclic executives (based on active objects). This paper presents the concurrency model of a very popular mobile RTOS platform, as Symbian, that contains both concurrency models. This OS has been chosen for its popularity in the market and due to the fact that it includes both concurrency models with real-time support. The traditional AOM (Active Object Model) paradigm is taken in the personal embedded device´s community as a means to simplify the interface given to programmers; no usage of synchronization primitives is required. This paper discusses how a combined pattern would take advantage of both worlds: AOM and thread based execution models; it allows using AOM-based programming inside threads in real-time environments.