The security method with deterministic real time - embodiment of a multi task - applications - of the control and command type with fault location

摘要

The invention concerns a method implemented with a time synchronised architecture type management system connected to a central computing unit having a privileged execution mode whereto access is protected by an instruction of the call to the system layer type. The only authorised call to the system layer from an application task in question to the layer system consists in taking into account the change of node in the graph controlling the task concerned. When the layer system has verified that the call is legal with respect to the control graph execution path which is described in the constant tables of the application, all the operations to be performed on the node in question, by the layer system, are predetermined by the constant tables of the layer system associated application. A pre-ordering of the lists of tasks of an application in question is carried out before real time execution at a micro-kernel which, when called by the layer system, during real time execution, will update the lists of tasks in ordered fashion based on the new time characteristics of the tasks, that is their starting date d(i) at the earliest and the end date f(i) at latest calculated by the layer system.