This paper focuses on scheduling different hard real-time applications on a uniprocessor when the earliest deadline first algorithm is used as the local scheduler, and the global scheduler of the...
Tiina Niklander, Real-time Computer, Alan Burns, Andy Wellings
� Real-time application � Communication environment � Properties of real-time communication � Disciplines to guarantee real-time properties in packet-switched networks � Real-time transfer...
Efficient Exact Schedulability Tests for Fixed Priority Real-time Systems (2008)
Robert Davis, Attila Zabos, Alan Burns
Efficient exact schedulability tests are required both for on-line admission of applications to dynamic systems and as an integral part of design tools for complex distributed real-time systems. This...
A Priority-Based Consensus Protocol (2008)
Abstract. Consensus is a basic agreement problem whose solutions are fundamental for building fault-tolerant distributed systems. Consensus for real-time systems is usually designed under strong...
Guaranteed Message Latencies For Distributed (2008)
Analysis is presented that enables the worst case latencies for Controller Area Network (CAN) messages to be predicted. The analysis is illustrated in terms of the Intel 82527 controller and applied...
This paper investigates the problem of server parameter selection in hierarchical fixed priority preemptive systems. A set of algorithms are provided that determine the optimal values for a single...
This paper investigates the problem of server parameter selection in hierarchical fixed priority preemptive systems. A set of algorithms are provided that determine the optimal values for a single...
Exact Scheduling Analysis of Non-Accumulatively Monotonic Multiframe Tasks (2008)
In this paper, we present the exact analysis of the worst case response time of the general multiframe (MF) task model executing on a uniprocessor according to the fixed priority scheduling scheme....
Quantifying the sub-optimality of uniprocessor fixed-priority scheduling (2008)
There are sporadic task systems schedulable by EDF, which no fixed-priority (FP) algorithm can schedule successfully. For instance, it is known that while all implicit-deadline sporadic task systems...
Exact Scheduling Analysis of Non-Accumulatively Monotonic Multiframe Tasks (2008)
In this paper, we present the exact analysis of the worst case response time of the general multiframe (MF) task model executing on a uniprocessor according to the fixed priority scheduling scheme....
Quantifying the sub-optimality of uniprocessor fixed-priority scheduling (2008)
There are sporadic task systems schedulable by EDF, which no fixed-priority (FP) algorithm can schedule successfully. For instance, it is known that while all implicit-deadline sporadic task systems...
Davis, Robert, Rothvoss, Thomas, Baruah, Sanjoy, Burns, Alan
This paper examines the relative effectiveness of fixed priority pre-emptive scheduling in a uniprocessor system, compared to an optimal algorithm. The quantitative metric used in this comparison is...
Eduardo Tovar, Francisco Vasques, Alan Burns
Abstract: P-NET is a multi-master fieldbus standard based on a virtual token passing scheme. In P-NET each master is allowed to transmit only one message per token visit. In the worst-case, the...
Combining (n choose m)-Hard deadlines and Dual Priority Scheduling (2007)
The problem of effectively scheduling soft tasks whilst guaranteeing the behaviour of hard tasks has been addressed in many papers and a large number of techniques have been proposed. The dual...
Emergence of an Architectural Topology for Safety-Critical Real-Time Systems (2007)
Mark Nicholson, Alan Burns, Yo Dd
Constructing a system architecture for a distributed safety-critical real-time control system is a complex task. This complexity results from non-functional as well as functional requirements. One...
A Worst-Case Behaviour Analysis for Hard Real-Time Transactions (2007)
Jeongyong Byun, Alan Burns, Andy Wellings
Most hard real-time systems that incorporate database components assume that the data is resident in main memory. For these systems, priority ceiling protocols can be used to limit priority...
Message Latencies, Ken Tindell, Alan Burns
Analysis is presented that enables the worst case latencies for Controller Area Network (CAN) messages to be predicted. The analysis is illustrated in terms of the Intel 82527 controller and applied...
Alan Burns, Brian Dobbing, Tullio Vardanega, Rod Chapman, ...
Guide for the use of the
j-Hard deadlines and Dual Priority Scheduling (2007)
The problem of effectively scheduling soft tasks whilst guaranteeing the behaviour of hard tasks has been addressed in many papers and a large number of techniques have been proposed. The dual...
Analysis of checkpointing for schedulability of real-time systems (2007)
Sasikumar Punnekkat, Alan Burns
Checkpointing is a relatively cost effective method for achieving fault tolerance in real-time systems. Since checkpointing schemes depend on time redundancy, they could affect the correctness of the...
Controller area network (can) schedulability analysis: Refuted, revisited and revised (2007)
Controller Area Network (CAN) is used extensively in automotive applications, with in excess of 400 million CAN enabled microcontrollers manufactured each year. In 1994 schedulability analysis was...
List of Potential Supervisors (2007)
Neil Audsley, Jim Austin, Iain Bate, Ian Benest, Sam Braunstein, Alan Burns, ...
This document outlines some of the present research interests of most members of the Department who are in a position to supervise the research of students entering in October 2007. The sections are...
Hierarchical fixed priority pre-emptive scheduling (2005)
This report focuses on the hierarchical scheduling of systems where a number of separate applications reside on a single processor. It addresses the particular case where fixed priority pre-emptive...
Real-Time Scheduling Theory: A Historical Perspective (2004)
Sha, Lui, Abdelzaher, Tarek, Årzén, Karl-Erik, Cervin, Anton, Baker, Theodore, Burns, Alan, ...
In this 25th year anniversary paper for the IEEE Real Time Systems Symposium, we review the key results in real-time scheduling theory and the historical events that led to the establishment of the...
Comparing real-time communication under electromagnetic interference (2004)
The contribution of this paper is threefold. First, an improvement to a previously published paper on the timing analysis of Controller Area Network (CAN) in the presence of transient network faults...
Alan Burns, Brian Dobbing, Tullio Vardanega, Rod Chapman, Stephen Michell, ...
Guide for the use of the
Probabilistic analysis of CAN with faults (2002)
As CAN (Controller Area Network) is increasingly used in safety-critical applications, there is a need for accurate predictions of failure probability. In this paper we provide a general...
Timing-Independent Safety on Top of CAN (2002)
We describe an approach to designing CAN-based distributed real-time systems so that safety is preserved regardless of timeliness. Our approach offers gains with respect to both fault tolerance and...
Implementing a flexible scheduler in Ada (2001)
Much of the research on flexible scheduling schemes is prevented from being used in practice by the lack of implementations that provide the necessary abstractions. In this paper we show how...
A Timely Distributed Consensus Solution in a Crash/Omission-Fault Environment (2001)
A timely protocol to solve the distributed consensus problem that tolerates process crashes and message omissions is described. The protocol is optimal in terms of the number of communication steps...
An Effective Schedulability Analysis for FaultTolerant Hard Real-Time Systems (2001)
We propose worst-case response time schedulability analysis for fault-tolerant hard real-time systems which takes into account the effects of temporary faults. The major contribution of our approach...
Jorvik: A Framework for Effective Scheduling (2001)
This paper presents a collection of mechanisms that together form a framework for the support of flexible scheduling. By choosing a mixture of established and novel techniques, a robust scheme is...
Jorvik: A Framework for Effective Scheduling (2001)
Alan Burns And, Alan Burns, Guillem Bernat
This paper presents a collection of mechanisms that together form a framework for the support of flexible scheduling. By choosing a mixture of established and novel techniques, a robust scheme is...
Weakly hard real-time systems (2001)
Guillem Bernat, Alan Burns, Senior Member, Albert Llamosõâ
AbstractÐIn a hard real-time system, it is assumed that no deadline is missed, whereas, in a soft or firm real-time system, deadlines can be missed, although this usually happens in a nonpredictable...
Determining the Worst-case Synchronous Message Response Time in FDDI Networks (2001)
Zhang, Sijing, Lee, E. Stewart, Burns, Alan
Finding the worst-case message response time is important for guaranteeing message deadlines in any hard real-time communication environment. This paper proposes an $O(n)$-time algorithm for exactly...
Replica Determinism and Flexible Scheduling in Hard Real-Time Dependable Systems (2000)
Stefan Poledna, Alan Burns, Andy Wellings, Peter Barrett
AbstractÐFault-tolerant real-time systems are typically based on active replication where replicated entities are required to deliver their outputs in an identical order within a given time...
An approach to symbolic worst-case execution time analysis (2000)
Abstract: Using the constant value for the worst case execution time for all calls to a subprogram is safe but pessimistic. We address the problem of tailoring the WCET of each call to a subprogram...
Portable Worst-Case Execution Time Analysis using Java Byte Code (2000)
Guillem Bernat, Alan Burns, Andy Wellings
In this paper we address the problem of performing worst case execution time (WCET) analysis of Java Byte Code (JBC) which may be generated from different compilers and from different source...
Scheduling Optional Computations for Adaptive Real-Time Systems (2000)
At present, the critical computations of real-time systems are guaranteed before runtime by performing a worst-case analysis of the system's timing and resource requirements. The result is that...
Dynamic CPU Scheduling with Imprecise Knowledge of Computation -Time (1999)
Abstract: The majority of the studies conducted in scheduling real-time transactions mostly concentrate on concurrency control protocols, while overlooking the CPU as being the primary resource....
New results on fixed priority aperiodic servers (1999)
The issue of using the Sporadic Server (SS) for scheduling aperiodic tasks has received new attention under the POSIX standard as it has been proposed in P1003.1d, the additional real-time extensions...
Dynamic Value-Density for Scheduling Real-Time Systems (1999)
Scheduling decisions in time-critical systems are very dif-ficult, due to the vast number of systems ' parameters and tasks ' attributes involved in such decisions. Value-based scheduling...
The Ravenscar profile is described. All its features and restrictions are noted. Also, the means of designating the profile is presented. Derailed motivations for the profile are not given. The aim...
Eduardo Tovar, Francisco Vasques, Alan Burns
In this paper we address the real-time capabilities of P-NET, which is a multi-master fieldbus standard based on a virtual token passing scheme. We show how P-NET's medium access control (MAC)...
Dynamic CPU Scheduling with Imprecise Knowledge of Computation-Time (1999)
The majority of the studies conducted in scheduling real-time transactions mostly concentrate on concurrency control protocols, while overlooking the CPU as being the primary resource. Consequently,...
Dynamic CPU Scheduling with (1999)
Imprecise Knowledge Of, Saud A. Aldarmi, Alan Burns
The majority of the studies conducted in scheduling real-time transactions mostly concentrate on concurrency control protocols, while overlooking the CPU as being the primary resource. Consequently,...
Scheduling decisions in time-critical systems are very difficult, due to the vast number of systems' parameters and tasks' attributes involved in such decisions. Due to the intractability...
Eduardo Tovar, Francisco Vasques, Alan Burns
. Fieldbus networks aim at the interconnection of field devices such as sensors, actuators and small controllers. Therefore, they are an effective technology upon which Distributed Computer...
: In future real-time systems such as those required for intelligent autonomous vehicle control, we need flexibility in choosing the set of services to support under varying environmental conditions...
Time-Cognizant Value Functions for Scheduling Real-Time Systems (1998)
There has been an intensive amount of research conducted in scheduling real-time systems. Different scheduling policies use different attributes of the tasks within the system in deriving their...
Asynchronous Data Sharing in Multiprocessor Real-Time Systems Using Process Consensus (1998)
This report presents an approach to implementing fully asynchronous reader/writer mechanisms which addresses the problems of priority inversion and blocking among tasks within multiprocessor...
Time-Cognizant Value Functions for (1998)
There has been an intensive amount of research conducted in scheduling real-time systems. Different scheduling policies use different attributes of the tasks within the system in deriving their...
The Ravenscar Tasking Profile for High Integrity Real-Time Programs (1998)
Alan Burns, Brian Dobbing, George Romanski
Abstract: The Ravenscar Profile defines a simple subset of the tasking features of Ada in order to support efficient, high integrity applications that need to be analysed for their timing properties....
A Three-Slot Asynchronous Reader/Writer Mechanism for Multiprocessor Real-Time Systems (1997)
This report presents an approach to realizing a three-slot asynchronous reader/writer mechanism in multiprocessor real-time systems. The mechanism allows both the reader and the writer to access the...
Structuring Architectural Topologies for Real-Time Safety-Critical Systems (1997)
This report describes an integrated approach to solving a particular system architecture design issue. Constructing architectures for safety-critical realtime control systems is a complex task. This...
Efficient Transient Overload Tests for Real-Time Systems (1997)
Guillem Bernat, Alan Burns, Albert Llamos
. Timing requirements of real-time systems are usually specified in terms of deadlines which are often classified as being either hard, firm or soft. A hard task must always meet its deadline while a...
A Fully Asynchronous Reader/Writer Mechanism for Multiprocessor Real-Time Systems (1997)
Data sharing among tasks within multiprocessor real-time systems is a crucial issue. This report presents a fully asynchronous mechanism of sharing data between a single writer and multiple readers....
Using Modecharts to define terminal HRT-HOOD object structure (1997)
Method integration is a term used to describe the combining of two methods to optimize their strengths and to minimize their weaknesses. This report looks at the first stage in integrating HRT-HOOD...
Analysis of Checkpointing for Schedulability of Real-time Systems (1997)
Sasikumar Punnekkat, Alan Burns
Checkpointing is a relatively cost effective method for achieving fault tolerance in real-time systems. Since checkpointing schemes depend on time redundancy, they could affect the correctness of the...
Genericity and Upgradability in Ultra-Dependable Real-Time Architectures (1996)
Andy Wellings, Ljerka Beus-Dukic, Alan Burns, David Powell
We report on the ideas currently being developed within the European GUARDS project to develop a generic upgradable architecture for real-time dependable systems. After a brief introduction and...
Preemptive priority-based scheduling: An appropriate engineering approach (1995)
Scheduling theories for fixed-priority scheduling are now sufficiently mature that a genuine engineering approach to the construction of hard real-time systems is possible. In this chapter we review...
The Design and Analysis of a Close-In Weapons System Simulator Using HRT-HOOD (1995)
Pete Cornwell, Alan Burns, Andy Wellings
This paper examines the architectural design and analysis of a naval close-in weapons system simulator. Using the TARDIS development framework we trace the emergence of a design solution using...
Optimal Priority Assignment for Aperiodic Tasks with Firm Deadlines (1995)
In Fixed Priority, Robert Davis, Alan Burns
An optimal priority assignment policy is presented for independent aperiodic tasks with arbitrary ready times and firm deadlines, scheduled on a uniprocessor along with a set of hard...
Timing Properties of the Timed Token Protocol (1994)
We investigate the inherent timing properties of the timed token protocol which is necessary to guarantee synchronous message deadlines in a timed token ring network such as FDDI (Fibre Distributed...
Guaranteeing Message Latencies On Control Network (CAN) (1994)
A generally perceived problem with CAN is that it is unable to guarantee the timing performance of lower priority messages. Recent work has developed analysis to bound message latencies under...
Integrated program proof and worst-case timing analysis of SPARK Ada. (1994)
Roderick Chapman, Alan Burns, Andy Wellings
. This paper describes work in progress at the University of York on worst-case timing analysis of software for hard real-time and safety-critical systems. We are pursuing a programming environment...
Guaranteed Message Latencies For Distributed Safety-Critical Hard Real-Time Control Networks (1994)
Analysis is presented that enables the worst case latencies for Controller Area Network (CAN) messages to be predicted. The analysis is illustrated in terms of the Intel 82527 controller and applied...
A Study of Timing Properties with the Timed Token Protocol (1994)
We investigate the timing properties necessary to guarantee synchronous message deadlines in a token ring network such as FDDI (Fibre Distributed Data Interface) where the timed token medium access...
Preemptive Priority Based Scheduling: An Appropriate Engineering Approach (1994)
Scheduling theories for fixed priority scheduling are now sufficiently mature that a genuine engineering approach to the construction of hard real-time systems is possible. In this paper we review...
Preemptive Priority Based Scheduling: An Appropriate Engineering Approach (1994)
Scheduling theories for fixed priority scheduling are now sufficiently mature that a genuine engineering approach to the construction of hard real-time systems is possible. In this paper we review...
A Study of Timing Properties with the Timed Token Protocol (1994)
We investigate the timing properties necessary to guarantee synchronous message deadlines in a token ring network such as FDDI (Fibre Distributed Data Interface) where the timed token medium access...
Preemptive Priority Based Scheduling: An Appropriate Engineering Approach (1994)
Scheduling theories for fixed priority scheduling are now sufficiently mature that a genuine engineering approach to the construction of hard real-time systems is possible. In this paper we review...
Worst-case timing analysis of exception handling in Ada (1993)
Roderick Chapman, Alan Burns, Andy Wellings
. This paper describes a method for analysing the timing properties of exception handling in Ada. The paper first describes how exceptions are implemented and considers the use of exceptions in the...
Allocating Hard Real Time Tasks + (An NP-Hard Problem Made Easy) (1992)
Ken Tindell, Alan Burns, Andy Wellings
A distributed hard real time system can be composed from a number of communicating tasks. One of the difficulties with building such systems is the problem of where to place the tasks. In general...
Thesis (M.S.)--Drexel Institute of Technology, 1956.
We investigate the inherent timing properties of the timed token protocol which is necessary to guarantee synchronous message deadlines in a timed token ring network such as FDDI (Fibre Distributed...
We investigate the inherent timing properties of the timed token protocol which is necessary to guarantee synchronous message deadlines in a timed token ring network such as FDDI (Fibre Distributed...
An optimal priority assignment policy is presented for independent aperiodic tasks with arbitrary ready times and firm deadlines, scheduled on a uniprocessor along with a set of hard...