K. Altisen, G. Gossler, and J. Sifakis. A methodology for the construction of scheduled systems. In M. Joseph, editor, proc. FTRTFT 2000.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....tasks by considering them as periodic with the minimal inter arrival time as the task periods. Our work is more related to work on automata theoretic approach to solving scheduling problems. A nice work on relating classic scheduling theory to timed systems is the controller synthesis approach [2, 3]. The idea is to achieve schedulability by construction. A general framework to characterize scheduling contstraints as invariants and synthesize scheduled systems by decomposition of constraints is presented in [3] Timed automata has been used to solve non preemptive scheduling problems mainly ....

....classic scheduling theory to timed systems is the controller synthesis approach [2, 3] The idea is to achieve schedulability by construction. A general framework to characterize scheduling contstraints as invariants and synthesize scheduled systems by decomposition of constraints is presented in [3]. Timed automata has been used to solve non preemptive scheduling problems mainly for job shop scheduling[1, 12, 15] These techniques specify pre de ned locations of an automaton as goals to achieve by scheduling and use reachability analysis to construct traces leading to the goal states. The ....

K. Altisen, G. Goler, and J. Sifakis. A methodology for the construction of scheduled systems. In Proceedings of FTRTFT 2000, Pune, India, September 2000, LNCS 1926, pp.106-120, 2000.

....processes are quite simple: once created, they work (calling an external C procedure) and when nished they send a done message back to the server. These messages are delayed through a unique signalroute cs (which is passed as a parameter when creating a thread process) signalroute cs(1) #delay[1,2] from thread to server with done; process server(1) var thc integer; state idle #start ; provided thc N; input request( fork thread(self, cs0) task thc : thc 1; deadline eager; input done( task thc : thc 1; endprocess; process thread(0) fpar parent pid, route ....

....IF 2.0. In particular, slicing and abstraction techniques are mandatory to keep tractable the state space exploration. However, due to the dynamic features of IF 2.0, some of these techniques have to be revisited. Another perspective is the integration of the scheduling framework of [1] in order to improve the standard execution modes provided by the exploration engine (e.g, asynchronous or synchronous) Based on dynamic priorities, this scheduling framework is exible and general enough to ensure a ne grained control of execution of real time systems, depending on various ....

K. Altisen, G. Goler, and J. Sifakis. A Methodology for the Construction of Scheduled Systems. In Mathai Joseph, editor, Proceedings of FTRTFT 2000, number 1926 in LNCS, pages 106-120. Springer-Verlag, September 2000.

....formats. 1 Introduction On the background of the growing complexity of real time systems, it is a crucial, but more and more complex task to guarantee the absence of unwanted interference between the processes, which make the system behavior hard or impossible to predict. Priority functions [3, 1] are an intuitive and powerful means of modeling coordination between processes. Their composability allows a modular speci cation of di erent aspects of coordination for example, functional aspects such as mutual exclusion, as well as non functional aspects such as scheduling algorithms. These ....

....P waits for resource r, respectively. Moreover, integer expressions occurring in blocking may use the pre de ned expressions prio(P) for the xed priority of some process P , and ceiling(r) for the priority ceiling [10] of some resource r. A priority function de ning the con ict resolution policy [1], can be given as a list of priority rules of the form aid 1 0 aid 2 [ IF state constraint ] 7 where aid 1 , aid 2 are action identi ers, or of the form [FORALL pid 1 : PROCESS] FORALL pid 2 : PROCESS] pid 1 0 pid 2 [ IF state constraint ] In the rst case, the priority is assigned ....

K. Altisen, G. Goler, and J. Sifakis. A methodology for the construction of scheduled systems. In M. Joseph, editor, proc. FTRTFT

....and in MetaH tools. The verification examines several scenarios, each consisting of one or two tasks with different timing characteristics and synchronization constraints. Each of these simple scenarios is analyzed using state exploration algorithms. Using the same type of automata, Altisen et al. [1] propose a general methodology for examining scheduling issues. Tasks are modeled by timed automata with controllable and uncontrollable transitions. Controllable transitions represent scheduler actions, such as activation or preemption of tasks, and resource allocations. Uncontrollable ....

....model checking, they discovered a serious flaw in the kernel code, that prevents a thread from receiving its alloted CPU time. As these examples illustrate, fully automatic verification of real time schedulers is out of the reach of current modelchecking technology. The models used in [12] and [1] are timed automata with integrators, for which reachability and controller computation are only semi decidable (i.e. computations may fail to converge) Even when computations terminate, the practical complexity of the algorithms is very high and only small automata can be analyzed. More ....

K. Altisen, G. Gler, and J. Sifakis. A Methodology for the Construction of Scheduled Systems. In Formal Techniques in Real-Time and Fault-Tolerant Systems, Pune, India, September 2000. To appear.

....in systems of the form CkC obtained by further integration. For example, if C is deadlock free then it remains deadlock free by integration. Composability is essential for building models which are by construction correct. Unfortunately, time dependent properties are non composable, in general [AGS00,AGS01,Lee00] By re nement, that is by getting from an abstract description C a more concrete (restricted) one C in the sense that the behaviors of C are contained in the behaviors of C. Re nement relations are captured as simulation relations modulo some observability criterion ....

....of system activities so that requirements about their timed behavior are met, especially QoS requirements. We have shown that schedulers can be considered as controllers of the system model composed of its timed tasks with their synchronization and of a timed model of the external environment [AGS00,AGS01] They apply execution strategies which satisfy, on the one hand timing constraints resulting from the underlying implementation, essentially execution times, and on the other hand QoS requirements represented by a timed model of the environment. Under some conditions, correct scheduling ....

[Article contains additional citation context not shown here]

K. Altisen, G. Goler, and J. Sifakis. A methodology for the construction of scheduled systems. In M. Joseph, editor, proc. FTRTFT 2000, volume 1926 of LNCS, pages 106-120. Springer-Verlag, 2000.

No context found.

K. Altisen, G. Gossler, and J. Sifakis. A methodology for the construction of scheduled systems. In M. Joseph, editor, proc. FTRTFT 2000.

No context found.

K. Altisen, G. Gssler, and J. Sifakis. A methodology for the construction of scheduled systems. In proc. FTRTFT 2000, LNCS 1926, 2000.

No context found.

K. Altisen, G. Gler, and J. Sifakis. A methodology for the construction of scheduled systems. In Proc. of FTRTFT'2000, LNCS 1926, pp.106120, 2000.

No context found.

K. Altisen, G. Goler, and J. Sifakis. A Methodology for the Construction of Scheduled Systems. In Formal Techniques in Real-Time and Fault-Tolerant Systems, Pune, India, September 2000. To appear.

No context found.

K. Altisen, G. Gossler, and J. Sifakis. A methodology for the construction of scheduled systems. In M. Joseph, editor, proc. FTRTFT 2000.

No context found.

K. Altisen, G. Gssler, and J. Sifakis. A methodology for the construction of scheduled systems. In proc. FTRTFT 2000, LNCS 1926, 2000.

Online articles have much greater impact   More about CiteSeer.IST   Add search form to your site   Submit documents   Feedback  

CiteSeer.IST - Copyright Penn State and NEC