Method to Execute Time-Triggered Tasks in a Computer System with Flexible Execution Intervals

A method to execute jobs of a set of tasks in a computer system according to a global time-triggered schedule,

• wherein the computer system comprises one or more cores on one or more central processing units of the computer system,
• wherein said global time-triggered schedule comprises one time-triggered schedule, “core schedule”, for each of said cores, wherein the tasks of the set of tasks to be executed on a specific core are executed on said core according to the core schedule of said core,
• wherein the global time-triggered schedule specifies a cycle with a cycle length for the set of tasks,
• wherein the core schedule of a core specifies for each task of the set of tasks, which is to be executed on said core:
• an execution interval for each task instance, “job”, of the task, during which execution interval the job can be executed, wherein each execution interval comprises a release point, at which the execution interval starts, and a completion point, at which the execution interval ends, wherein the duration of an execution interval is the duration of the time span between the release point and the completion point of the execution interval, wherein the execution interval of a job defines a time interval during which the job has a guarantee to be executed on the core, and
• a period according to which period the jobs of said task are executed on the core,
• wherein the execution interval of each job of the task is iterated cyclically according to the cycle, and
• wherein the execution intervals of any two jobs of the same and of different tasks do not overlap, and
• wherein the cycle is a common multiple of all periods of all tasks in the set of tasks,
• wherein:
• the core schedule specifies for each job a flexibility interval, wherein the duration of the flexibility interval of a job is equal or longer than the execution interval of said job,
• at least the flexibility interval of one job is longer than the execution interval of said job,
• the flexibility interval of a job starts no later than the release point of the execution interval of said job, and the flexibility interval of a job ends no sooner than the completion point of the execution interval of said job,
• the flexibility of a job defines a time interval during which said job can be executed, and
• runtime dispatching means are provided, which select and launch jobs for execution according to the global time-triggered schedule, taking into account for each core all flexibility intervals as specified in the core schedule.