UML 2.0 Notation for Modeling Real Time Task Scheduling.

Abstract

UML is the standard visual object modeling language which may be very useful as a system design communication language. However, UML as a real-time modeling language has limitations. It basically provides a lot of syntax, but not enough semantics. The UML Profile for Schedulability, Performance and Time, extends the notation and semantics for the real-time domain. It is supposed to overcome the limitations which are related to and provide suitability for modeling real-time systems. Since we are mainly concerned with the problem of real-time operating system scheduling, the article discusses the ability of UML and its profile to determine the schedulability of a planned piece of software.

Comparative analysis of real time resource access control protocols using UML 2.0

“… C a : task duration before entering the critical section  C b : task duration within the critical section  C c : task duration after the critical section Then, the computation time becomes C= C a + C b + C c In [18] the Priority Inheritance Protocol is used for sharing a critical resource but this protocol does not prevent deadlock. In this paper the occurrence of deadlock is first highlighted by considering the following task set which is described by the classical parameters given in Table1.…”

“…These were generalized by Sha, Rajkumar and Lehoczky [15] and incorporated into the rate-monotonic (RM) scheduling framework [17]. Maria et al [18] consider the Priority Inheritance Protocol to share critical resources though the Priority Inheritance Protocol does not prevent deadlock.…”

“…Therefore, it is not required to use notes indicating when a task awakes (when the state of a task changes to "Ready") [18].…”

Systems Analysis and Design for Advanced Modeling Methods

“…They have a simple representation as a diagram with the time along the horizontal axis and object states or attribute value along the vertical axis. Its usefulness for modeling of the real time systems is presented by Valiente, Genova and Cerretero (2005).…”

Assessment of Response Time for New Multi Level Feedback Queue Scheduler

“…As it is DynamicPriorityQueue, we have to use HashTable for storing both priority and processes. Processes will be added based on the priority to the Queue and will removed from the end or again, based on priority form [24] A job is a function of many tasks or processes. Division of jobs into task modules is performed from analysis of jobs.…”