The ever-increasing functional and nonfunctional requirements in real-time safety-critical embedded systems call for new design flows that solve the specification, validation, and synthesis problems. Ensuring key properties, such as functional determinism and temporal predictability, has been the main objective of many embedded system design models. Dataflow models of computation (such as KPN, SDF, CSDF, etc.) are widely used to model stream-based embedded systems due to their inherent functional determinism. Since the introduction of the (C)SDF model, a considerable effort has been made to solve the static-periodic scheduling problem. Ensuring boundedness and liveness is the essence of the proposed algorithms in addition to optimizing some nonfunctional performance metrics (e.g. buffer minimization, throughput maximization, etc.). However, nowadays real-time embedded systems are so complex that real-time operating systems are used to manage hardware resources and host real-time tasks. Most of real-time operating systems rely on priority-driven scheduling algorithms (e.g. RM, EDF, etc.) instead of static schedules which are inflexible and difficult to maintain. This thesis addresses the real-time scheduling problem of dataflow graph specifications; i.e. transformation of the dataflow specification to a set of independent real-time tasks w.r.t. a given priority-driven scheduling policy such that the following properties are satisfied: (1) channels are bounded and overflow/underflow-free; (2) the task set is schedulable on a given uniprocessor (or multiprocessor) architecture. This problem requires the synthesis of scheduling parameters (e.g. periods, priorities, processor allocation, etc.) and channel capacities. Furthermore, the thesis considers two performance optimization problems: buffer minimization and throughput maximization.

Les systèmes temps-réel critiques sont de plus en plus complexes, et les exigences fonctionnelles et non-fonctionnelles ne cessent plus de croître. Le flot de conception de tels systèmes doit assurer, parmi d’autres propriétés, le déterminisme fonctionnel et la prévisibilité temporelle. Le déterminisme fonctionnel est inhérent aux modèles de calcul flot de données (ex. KPN, SDF, etc.) ; c’est pour cela qu’ils sont largement utilisés pour modéliser les systèmes embarqués de traitement de flux. Un effort considérable a été accompli pour résoudre le problème d’ordonnancement statique périodique et à mémoire de communication bornée des graphes flot de données. Cependant, les systèmes embarqués temps-réel optent de plus en plus pour l’utilisation de systèmes d’exploitation temps-réel et de stratégies d’ordonnancement dynamique pour gérer les tâches et les ressources critiques. Cette thèse aborde le problème d’ordonnancement temps-réel dynamique des graphes flot de données ; ce problème consiste à assigner chaque acteur dans un graphe à une tâche temps-réel périodique (i.e. calcul des périodes, des phases, etc.) de façon à : (1) assurer l’ordonnançabilité des tâches sur une architecture et pour une stratégie d’ordonnancement (ex. RM, EDF) données ; (2) exclure statiquement les exceptions d’overflow et d’underflow sur les buffers de communication ; et (3) optimiser les performances du système (ex. maximisation du débit, minimisation des tailles des buffers). / The ever-increasing functional and nonfunctional requirements in real-time safety-critical embedded systems call for new design flows that solve the specification, validation, and synthesis problems. Ensuring key properties, such as functional determinism and temporal predictability, has been the main objective of many embedded system design models. Dataflow models of computation (such as KPN, SDF, CSDF, etc.) are widely used to model stream-based embedded systems due to their inherent functional determinism. Since the introduction of the (C)SDF model, a considerable effort has been made to solve the static-periodic scheduling problem. Ensuring boundedness and liveness is the essence of the proposed algorithms in addition to optimizing some nonfunctional performance metrics (e.g. buffer minimization, throughput maximization, etc.). However, nowadays real-time embedded systems are so complex that real-time operating systems are used to manage hardware resources and host real-time tasks. Most of real-time operating systems rely on priority-driven scheduling algorithms (e.g. RM, EDF, etc.) instead of static schedules which are inflexible and difficult to maintain. This thesis addresses the real-time scheduling problem of dataflow graph specifications; i.e. transformation of the dataflow specification to a set of independent real-time tasks w.r.t. a given priority-driven scheduling policy such that the following properties are satisfied: (1) channels are bounded and overflow/underflow-free; (2) the task set is schedulable on a given uniprocessor (or multiprocessor) architecture. This problem requires the synthesis of scheduling parameters (e.g. periods, priorities, processor allocation, etc.) and channel capacities. Furthermore, the thesis considers two performance optimization problems: buffer minimization and throughput maximization.