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POO - A hybrid OO method for real time SW
200 030
Abstracts P O O . A Hybrid OO Method for Real Time SW V. Cortes, pp 19%201
A new method/platform specially suited to develop hard real-time software products, so as to reuse any non-specific feature (both high-level and HW-clependent), has been devised and intensively used. The mefluxl is language- and OS- (Operating System-) independent and uses OO (Object-Oriented) techniques, adapted to allow the usage of traditional languages like C, and to assure concurrent execution of classes. The fifteen concurrent, generalpmpo.se (configurable) classes are the main reusable result of the experience, but an interesting side-effect is the increase of knowledge and confidence in the necessary steps to pure OO in real-time SW. 031
Applying Object-orientod Principles in Control.system Design M. Tittus, B. Egardt, pp 203-208
To date there exist no general framework with adequate tools for the designing of large control systems that contain, besides feedback loops, logic and other more-advanced control functions. Object-orientation suppoRs a highly structured approach to this design task and provides powerful features like reusability and inheritance. The .plant is modeled by objects that may reside in a number of generalized states and that are transferred between these states by state transitions and can serve as an interface to a faultdiagnosis system. Two examples show the approach's ability to model feedback loops and other control functions. One example has been implemented in G2, a real-time expert system. 032
Real Time Toolbox for PC.MATLAB J. Hon]ka, B. SILidek, pp 213-217
A real-time toolbox for MATLAB has been created as a tool for data acquisition and control of real-time systems or their scale models directly from the MATLAB environment. The paper presents the main features of the read-time toolbox and its use m real systems control. Controllers can either be programmed in MATLAB language or pre-programmed polynomial (possibly multivariable) controllers running in background can be used. Adaptive polynomial controllers are also supported. 033
Long Term, Real-time Generating Unit Simulator (GUS) On Personal Computer B. Malfliet, J.P. Piret, pp 219-224
Laborelec developed a real-~ne simulator on a personal computer to study the long-term dynamic behaviour of the Belgian grid, interconnecled with the European grid. The simulator can be used to test the interactions between generating units and between countries. It includes the elements necessary for the tuning of an automatic generation controller (AGC-system). GUS can also be used to test the long-term behaviour in frequency and activepower of a large set of generating units. The models used in GUS are briefly described and a number of applications are included. 034
Graphical Programming for Real Time Systems. An Experience from the World of Education* J.-J. Schwarz, M. Miquel, J.-J. Skubich, pp 225-230
This paper first presents the graphical method we have developed in our University in order to improve the teaching efficiency in a multitasking real-time programming and industrial computation application design. This method is based upon the LACATRE graphical language (Language d'Aide ~ la Conception d'Application Temps REel) which acts as an overlayer to industrial standard real-time executives (RTXs). Then, we expose what has been our lecturing experience for 5 years now.
of real-time programming. Three different approaches are considered: using routines from software libraries, following an object-oriented approach or connecting programs in a UNiX-like style.
036
Developers of real-time systems are often faced with the problem of having to selec~ an operating system without being able to assess its ability to rum a specific real-time application. We developed a system which helps in assessing the performance of a real-time operating system running any user-defined application. 037
How to ensure Software Quality for Real Time Systems* B. Hindel, pp 231-236
This paper discusses several definitions of software quality, and tries to answer the following questions: What are the suggestions ef Case tools for real-time programming to improve software quality? Which test strategies are suited to meet the requinanents of a quality standard for real-time software? In addition, we consider different methodologies for software engineering which try to speed up software development and meet a high quality standard. Here we talk about reusmg software modules in the field
Monitoring the Development of Real Time Systems: The COSMOS Project N. Fuchs, R. Lockhart, S. Stainer, R. Whitty, pp 241-246
We describe the theory and use of the COSMOS static analysing tool. which has been developed under the CEC Esprit programme. The tool can be used to analyse a wide range of program languages and formal spe.c/fication notations. It produces common-ground structural accounts of these documents which are then, in turn, analysed for metrication purposes. The result is a range of wellknown structural product metrics, which may be used to monitor and control software development projects. We have placed particular emphasis on re,-time telecom applications and our paper concludes with an account of the preliminary results from our validation studies. 038
Real-time UNIX: What Performance can we Expect?* H. Rzehak, pp 247-252
The paper deals with necessary enhancements of traditional UN]X systems to meet requirements for real-time applications and gives an insight into sources of delays for application processes caused by the operating system. A survey of the real-time extensions for POSIX, the ISO/IEC standard operating system, is given. Some key parameters and basic concepts for implementing good realtime performance are discussed. Figures for commonly used metrics are reported. Application of Formal Description Techniques to Realtime Scheduling A. Garcie Lirola, F. Fourn6n y Gonzilez-Barcla, F. G6mez Molinero, pp 253-258
039
This paper describes a study about the applicability of formal descripuon techniques like LOTOS to analyse and validate realtime subsystems. The basic priority inheritance scheduling algorithm has been specified using the formal description technique LOTOS. With the help of the specification, validation tests have been derived and applied to an independent VLSI implementation of the mentioned algorithm embedded in an Ada tasking co-processor. With this experience it has been shown that LOTOS can be applied to specify real-time subsystems and therefore to develop and validate them. 040
Some Results on Hard Real.time Scheduling N. Litoiu, M. Litoiu, pp 259-262
A single-processor real-time system and n independent tasks T 1, T2, T n an: considered. The tasks are described by the periods I:jP by the execution times e:; ' and by the deadlines d:.t . The tasks . . . have prionues and are preemptive. The paper offers msmnnents for optimal assignment of priorities so that deadlines can be observed. ...,
041 035
Analysis and Prototyping of Real-time Systems H. Basham, E. Koch, pp 237-239
A Statecharts-based Specification and Verification of Real-time Job Scheduling Systems* A. Sowmya, pp 263.268
Real-tune job scheduling is a difficult problem. The jobscheduling system receives jobs from the environment, each job with its own real-time deadline. Queueing and scheduling may still be necessary, in order to maximise the processor usage and also to impose job priorities. In order to compare different scheduling algorithms, we need formal methods to specify the real-time job-scheduling system, so that properties of the algorithms may be tested against the specified model, prior to
Abstracts P O O . A Hybrid OO Method for Real Time SW V. Cortes, pp 19%201
A new method/platform specially suited to develop hard real-time software products, so as to reuse any non-specific feature (both high-level and HW-clependent), has been devised and intensively used. The mefluxl is language- and OS- (Operating System-) independent and uses OO (Object-Oriented) techniques, adapted to allow the usage of traditional languages like C, and to assure concurrent execution of classes. The fifteen concurrent, generalpmpo.se (configurable) classes are the main reusable result of the experience, but an interesting side-effect is the increase of knowledge and confidence in the necessary steps to pure OO in real-time SW. 031
Applying Object-orientod Principles in Control.system Design M. Tittus, B. Egardt, pp 203-208
To date there exist no general framework with adequate tools for the designing of large control systems that contain, besides feedback loops, logic and other more-advanced control functions. Object-orientation suppoRs a highly structured approach to this design task and provides powerful features like reusability and inheritance. The .plant is modeled by objects that may reside in a number of generalized states and that are transferred between these states by state transitions and can serve as an interface to a faultdiagnosis system. Two examples show the approach's ability to model feedback loops and other control functions. One example has been implemented in G2, a real-time expert system. 032
Real Time Toolbox for PC.MATLAB J. Hon]ka, B. SILidek, pp 213-217
A real-time toolbox for MATLAB has been created as a tool for data acquisition and control of real-time systems or their scale models directly from the MATLAB environment. The paper presents the main features of the read-time toolbox and its use m real systems control. Controllers can either be programmed in MATLAB language or pre-programmed polynomial (possibly multivariable) controllers running in background can be used. Adaptive polynomial controllers are also supported. 033
Long Term, Real-time Generating Unit Simulator (GUS) On Personal Computer B. Malfliet, J.P. Piret, pp 219-224
Laborelec developed a real-~ne simulator on a personal computer to study the long-term dynamic behaviour of the Belgian grid, interconnecled with the European grid. The simulator can be used to test the interactions between generating units and between countries. It includes the elements necessary for the tuning of an automatic generation controller (AGC-system). GUS can also be used to test the long-term behaviour in frequency and activepower of a large set of generating units. The models used in GUS are briefly described and a number of applications are included. 034
Graphical Programming for Real Time Systems. An Experience from the World of Education* J.-J. Schwarz, M. Miquel, J.-J. Skubich, pp 225-230
This paper first presents the graphical method we have developed in our University in order to improve the teaching efficiency in a multitasking real-time programming and industrial computation application design. This method is based upon the LACATRE graphical language (Language d'Aide ~ la Conception d'Application Temps REel) which acts as an overlayer to industrial standard real-time executives (RTXs). Then, we expose what has been our lecturing experience for 5 years now.
of real-time programming. Three different approaches are considered: using routines from software libraries, following an object-oriented approach or connecting programs in a UNiX-like style.
036
Developers of real-time systems are often faced with the problem of having to selec~ an operating system without being able to assess its ability to rum a specific real-time application. We developed a system which helps in assessing the performance of a real-time operating system running any user-defined application. 037
How to ensure Software Quality for Real Time Systems* B. Hindel, pp 231-236
This paper discusses several definitions of software quality, and tries to answer the following questions: What are the suggestions ef Case tools for real-time programming to improve software quality? Which test strategies are suited to meet the requinanents of a quality standard for real-time software? In addition, we consider different methodologies for software engineering which try to speed up software development and meet a high quality standard. Here we talk about reusmg software modules in the field
Monitoring the Development of Real Time Systems: The COSMOS Project N. Fuchs, R. Lockhart, S. Stainer, R. Whitty, pp 241-246
We describe the theory and use of the COSMOS static analysing tool. which has been developed under the CEC Esprit programme. The tool can be used to analyse a wide range of program languages and formal spe.c/fication notations. It produces common-ground structural accounts of these documents which are then, in turn, analysed for metrication purposes. The result is a range of wellknown structural product metrics, which may be used to monitor and control software development projects. We have placed particular emphasis on re,-time telecom applications and our paper concludes with an account of the preliminary results from our validation studies. 038
Real-time UNIX: What Performance can we Expect?* H. Rzehak, pp 247-252
The paper deals with necessary enhancements of traditional UN]X systems to meet requirements for real-time applications and gives an insight into sources of delays for application processes caused by the operating system. A survey of the real-time extensions for POSIX, the ISO/IEC standard operating system, is given. Some key parameters and basic concepts for implementing good realtime performance are discussed. Figures for commonly used metrics are reported. Application of Formal Description Techniques to Realtime Scheduling A. Garcie Lirola, F. Fourn6n y Gonzilez-Barcla, F. G6mez Molinero, pp 253-258
039
This paper describes a study about the applicability of formal descripuon techniques like LOTOS to analyse and validate realtime subsystems. The basic priority inheritance scheduling algorithm has been specified using the formal description technique LOTOS. With the help of the specification, validation tests have been derived and applied to an independent VLSI implementation of the mentioned algorithm embedded in an Ada tasking co-processor. With this experience it has been shown that LOTOS can be applied to specify real-time subsystems and therefore to develop and validate them. 040
Some Results on Hard Real.time Scheduling N. Litoiu, M. Litoiu, pp 259-262
A single-processor real-time system and n independent tasks T 1, T2, T n an: considered. The tasks are described by the periods I:jP by the execution times e:; ' and by the deadlines d:.t . The tasks . . . have prionues and are preemptive. The paper offers msmnnents for optimal assignment of priorities so that deadlines can be observed. ...,
041 035
Analysis and Prototyping of Real-time Systems H. Basham, E. Koch, pp 237-239
A Statecharts-based Specification and Verification of Real-time Job Scheduling Systems* A. Sowmya, pp 263.268
Real-tune job scheduling is a difficult problem. The jobscheduling system receives jobs from the environment, each job with its own real-time deadline. Queueing and scheduling may still be necessary, in order to maximise the processor usage and also to impose job priorities. In order to compare different scheduling algorithms, we need formal methods to specify the real-time job-scheduling system, so that properties of the algorithms may be tested against the specified model, prior to