QP (framework)

QP (Quantum Platform) is a family of open source real-time embedded frameworks (RTEFs) and runtime environments based on active objects (actors) and hierarchical state machines (UML statecharts). The QP family consists of the lightweight QP/C and QP/C++ frameworks, written in C (C99) and C++ (C++11), respectively. The QP RTEFs are an implementation of the Active Object (Actor) model of computation, specifically tailored for real-time embedded (RTE) systems. Active Objects (Actors) can be combined with a wide variety of threading models, including real-time kernels (RTOS kernels). In the latter case, the combination, designed for deterministic performance, is called the Real-Time Embedded Framework (RTEF). This framework uses higher level abstractions than Real-Time Operating System (RTOS) in graphical modelling and code generation to embedded systems, which create safer, and more responsive applications. Compared to a (real-time) framework, when using an RTOS, the main part of each individual thread can be written in the application itself and the various RTOS services can be called from there (e.g. a time delay or a semaphore). When you use a framework, you reuse the overall architecture (such as the event loop for all private threads of Active Objects) and you only write the code that the RTEF calls. This leads to inversion of control, which allows the RTEF to automatically enforce the best practices of concurrent programming. The behavior of active objects (actors) is specified in QP by means of hierarchical state machines (UML statecharts).