Real Time Task Scheduling Download Seminar Report: When rigid time requirements is placed on a processor or the flow of data than a real time task scheduling is utilized. Hence it is used as a control device in a dedicated application.
The aim of real time scheduling is to execute its critical control tasks with the appropriate deadlines. The allocation/scheduling problem: Given a set of tasks, resource requirements, task precedence constraints, task characteristics, and deadlines and to devise allocation/schedule on a system.
A task requires one or more resources and requires some execution time on a processor. Tasks may have precedence constraints and may require some amount of memory or access to a bus. The physical resource may be exclusive or non-exclusive depending on the operation to be performed.
The total time which all the data required to begin executing are available is the release time of a task and the time taken to complete its execution is the deadline time. The deadline time may be hard or soft depending on the nature of the task. The absolute deadline minus the release time is the relative deadline of a task.
There are three types of tasks. They are periodic, sporadic or aperiodic. If task Ti is released periodically then it is a periodic task. If the task is not periodic then it is a sporadic task but invoked at irregular intervals. Sporadic tasks are sometimes also called a periodic task.
The process of deciding which task to execute next is called dispatching. Simple priority assignment policies regard with time constraints associated with a task. Priority assignment is scheduling of tasks with precedence constraints, timing constraints resource constraints and arbitrary values on multi-processors.
There two main considerations are schedule construction and feasibility checking. Hence the complexity of the algorithm is not dependent on a number of tasks but depends only on the number of processors.