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Active Object Systems Redacted for Privacy Abstract Approved
AN ABSTRACT OF THE THESIS OF Sungwoon Choi for the degree of Doctor of Philosophyin Computer Science presented on February 6, 1992. Title: Active Object Systems Redacted for Privacy Abstract approved. v '" Toshimi Minoura An active object system isa transition-based object-oriented system suitable for the design of various concurrentsystems. An AOS consists of a collection of interacting objects, where the behavior of eachobject is determined by the transition statements provided in the class of that object.A transition statement is a condition-action pair, an equational assignmentstatement, or an event routine. The transition statements provided for eachobject can access, besides the state of that object, the states of the other objectsknown to it through its interface variables. Interface variablesare bound to objects when objects are instantiated so that desired connections among objects are established. The major benefit of the AOS approach is thatan active system can be hierarchically composed from its active software componentsas if it were a hardware system. An AOS provides better encapsulation andmore flexible communication protocols than ordinary object oriented systems, since control withinan AOS is localized. ©Copyright by Sungwoon Choi February 6, 1992 All Rights Reserved Active Object Systems by Sungwoon Choi A THESIS submitted to Oregon State University in partial fulfillment of the requirements for the degree of Doctor of Philosophy Completed February 6, 1992 Commencement June 1992 APPROVED: Redacted for Privacy Professor of Computer Science in charge ofmajor Redacted for Privacy Head of Department of Computer Science Redacted for Privacy Dean of Gradu to School Or Date thesis presented February 6, 1992 Typed by Sungwoon Choi for Sungwoon Choi To my wife Yejung ACKNOWLEDGEMENTS I would like to express my sincere gratitude tomy major professor, Dr. -
Leader/Followers
Leader/Followers Douglas C. Schmidt, Carlos O’Ryan, Michael Kircher, Irfan Pyarali, and Frank Buschmann {schmidt, coryan}@uci.edu, {Michael.Kircher, Frank.Buschmann}@mchp.siemens.de, [email protected] University of California at Irvine, Siemens AG, and Washington University in Saint Louis The Leader/Followers architectural pattern provides an efficient concurrency model where multiple threads take turns sharing a set of event sources in order to detect, de- multiplex, dispatch, and process service requests that occur on these event sources. Example Consider the design of a multi-tier, high-volume, on-line transaction processing (OLTP) system. In this design, front-end communication servers route transaction requests from remote clients, such as travel agents, claims processing centers, or point-of-sales terminals, to back-end database servers that process the requests transactionally. After a transaction commits, the database server returns its results to the associated communication server, which then forwards the results back to the originating remote client. This multi-tier architecture is used to improve overall system throughput and reliability via load balancing and redundancy, respectively.It LAN WAN Front-End Back-End Clients Communication Servers Database Servers also relieves back-end servers from the burden of managing different communication protocols with clients. © Douglas C. Schmidt 1998 - 2000, all rights reserved, © Siemens AG 1998 - 2000, all rights reserved 19.06.2000 lf.doc 2 Front-end communication servers are actually ``hybrid'' client/server applications that perform two primary tasks: 1 They receive requests arriving simultaneously from hundreds or thousands of remote clients over wide area communication links, such as X.25 or TCP/IP. -
A Survey of Architectural Styles.V4
Survey of Architectural Styles Alexander Bird, Bianca Esguerra, Jack Li Liu, Vergil Marana, Jack Kha Nguyen, Neil Oluwagbeminiyi Okikiolu, Navid Pourmantaz Department of Software Engineering University of Calgary Calgary, Canada Abstract— In software engineering, an architectural style is a and implementation; the capabilities and experience of highest-level description of an accepted solution to a common developers; and the infrastructure and organizational software problem. This paper describes and compares a selection constraints [30]. These styles are not presented as out-of-the- of nine accepted architectural styles selected by the authors and box solutions, but rather a framework within which a specific applicable in various domains. Each pattern is presented in a software design may be made. If one were to say “that cannot general sense and with a domain example, and then evaluated in be called a layered architecture because the such and such a terms of benefits and drawbacks. Then, the styles are compared layer must communicate with an object other than the layer in a condensed table of advantages and disadvantages which is above and below it” then one would have missed the point of useful both as a summary of the architectural styles as well as a architectural styles and design patterns. They are not intended tool for selecting a style to apply to a particular project. The to be definitive and final, but rather suggestive and a starting paper is written to accomplish the following purposes: (1) to give readers a general sense of several architectural styles and when point, not to be used as a rule book but rather a source of and when not to apply them, (2) to facilitate software system inspiration. -
An Efficient Implementation of Guard-Based Synchronization for an Object-Oriented Programming Language an Efficient Implementation of Guard-Based
AN EFFICIENT IMPLEMENTATION OF GUARD-BASED SYNCHRONIZATION FOR AN OBJECT-ORIENTED PROGRAMMING LANGUAGE AN EFFICIENT IMPLEMENTATION OF GUARD-BASED SYNCHRONIZATION FOR AN OBJECT-ORIENTED PROGRAMMING LANGUAGE By SHUCAI YAO, M.Sc., B.Sc. A Thesis Submitted to the Department of Computing and Software and the School of Graduate Studies of McMaster University in Partial Fulfilment of the Requirements for the Degree of Doctor of Philosophy McMaster University c Copyright by Shucai Yao, July 2020 Doctor of Philosophy (2020) McMaster University (Computing and Software) Hamilton, Ontario, Canada TITLE: An Efficient Implementation of Guard-Based Synchro- nization for an Object-Oriented Programming Language AUTHOR: Shucai Yao M.Sc., (Computer Science) University of Science and Technology Beijing B.Sc., (Computer Science) University of Science and Technology Beijing SUPERVISOR: Dr. Emil Sekerinski, Dr. William M. Farmer NUMBER OF PAGES: xvii,167 ii To my beloved family Abstract Object-oriented programming has had a significant impact on software development because it provides programmers with a clear structure of a large system. It encap- sulates data and operations into objects, groups objects into classes and dynamically binds operations to program code. With the emergence of multi-core processors, application developers have to explore concurrent programming to take full advan- tage of multi-core technology. However, when it comes to concurrent programming, object-oriented programming remains elusive as a useful programming tool. Most object-oriented programming languages do have some extensions for con- currency, but concurrency is implemented independently of objects: for example, concurrency in Java is managed separately with the Thread object. We employ a programming model called Lime that combines action systems tightly with object- oriented programming and implements concurrency by extending classes with actions and guarded methods. -
University of Vaasa
UNIVERSITY OF VAASA FACULTY OF TECHNOLOGY DEPARTMENT OF COMPUTER SCIENCE Arvi Lehesvuo A SOFTWARE FRAMEWORK FOR STORING USER WORKSPACES OF DESKTOP APPLICATIONS Master’s thesis in Technology for the degree of Master of Science in Technology submitted for inspection, Vaasa, June 30, 2012. Supervisor Prof. Jouni Lampinen Instructor M.Sc. Pasi Pelkkikangas 1 TABLE OF CONTENTS page ABBREVIATIONS 3 LIST OF FIGURES 4 TIIVISTELMÄ 5 ABSTRACT 6 1. INTRODUCTION 7 1.1. Company Introduction: Wapice Ltd 8 1.2. Professional Background Statement 9 1.3. The Scope of the Research 9 1.4. Research Questions 10 2. RESEARCH METHODOLOGY 12 2.1. Constructive Research Approach 12 2.2. Research Process as Applied in This Research 13 3. THEORY AND BACKGROUND OF THE STUDY 17 3.1. Introduction to the Subject 17 3.2. History of Object Oriented Programming 17 3.3. Most Central Elements in Object Oriented Programming 19 3.4. More Advanced Features of Object Oriented Programming 25 3.5. Software Design Patterns 27 3.6. Graphical User Interface Programming 34 4. DEVELOPING THE SOLUTION 39 4.1. Identifying the Solution Requirements 39 4.2. Designing Basic Structure for the Solution 43 4.3. Building the Solution as an External Software Component 47 4.4. Storing the User Data 48 4.5. Optimizing Construction for C# 51 2 5. EVALUATING PRACTICAL RELEVANCE OF THE DESIGN 54 5.1. Testing Design by applying it to Different GUI Design Models 54 5.2. Analyzing Results of the User Questionnaire 57 6. CONCLUSIONS AND FUTURE 61 6.1. Practical Contribution 62 6.2. -
The Need for Hardware/Software Codesign Patterns - a Toolbox for the New Digital Designer
The need for Hardware/Software CoDesign Patterns - a toolbox for the new Digital Designer By Senior Consultant Carsten Siggaard, Danish Technological Institute May 30. 2008 Abstract Between hardware and software the level of abstraction has always differed a lot, this is not a surprise, hardware is an abstraction for software and the topics which is considered important by either a hardware developer or a software developer are quite different, making the communication between software and hardware developers (or even departments) difficult. In this report the software concept of design patterns is expanded into hardware, and the need for a new kind of design pattern, The Digital Design Pattern, is announced. Copyright © 2008 Danish Technological Institute Page 1 of 20 Contents Contents ............................................................................................................................................... 2 Background .......................................................................................................................................... 4 What is a design pattern ....................................................................................................................... 4 Three Disciplines when using Design Patterns ................................................................................ 5 Pattern Hatching ........................................................................................................................... 6 Pattern Mining............................................................................................................................. -
A Framework to Support Behavioral Design Pattern Detection from Software Execution Data
A Framework to Support Behavioral Design Pattern Detection from Software Execution Data Cong Liu1, Boudewijn van Dongen1, Nour Assy1 and Wil M. P. van der Aalst2;1 1Department of Mathematics and Computer Science, Eindhoven University of Technology, 5600MB Eindhoven, The Netherlands 2Department of Computer Science, RWTH Aachen University, 52056 Aachen, Germany Keywords: Pattern Instance Detection, Behavioral Design Pattern, Software Execution Data, General Framework. Abstract: The detection of design patterns provides useful insights to help understanding not only the code but also the design and architecture of the underlying software system. Most existing design pattern detection approaches and tools rely on source code as input. However, if the source code is not available (e.g., in case of legacy software systems) these approaches are not applicable anymore. During the execution of software, tremendous amounts of data can be recorded. This provides rich information on the runtime behavior analysis of software. This paper presents a general framework to detect behavioral design patterns by analyzing sequences of the method calls and interactions of the objects that are collected in software execution data. To demonstrate the applicability, the framework is instantiated for three well-known behavioral design patterns, i.e., observer, state and strategy patterns. Using the open-source process mining toolkit ProM, we have developed a tool that supports the whole detection process. We applied and validated the framework using software execution data containing around 1000.000 method calls generated from both synthetic and open-source software systems. 1 INTRODUCTION latter specifies how classes and objects interact. Many techniques have been proposed to detect design pat- As a common design practice, design patterns have tern instances. -
Sample Chapter
SAMPLE CHAPTER C# in Depth by Jon Skeet Chapter 6 Copyright 2008 Manning Publications brief contents PART 1PREPARING FOR THE JOURNEY ......................................1 1 ■ The changing face of C# development 3 2 ■ Core foundations: building on C# 1 32 PART 2C#2: SOLVING THE ISSUES OF C# 1........................... 61 3 ■ Parameterized typing with generics 63 4 ■ Saying nothing with nullable types 112 5 ■ Fast-tracked delegates 137 6 ■ Implementing iterators the easy way 161 7 ■ Concluding C# 2: the final features 183 PART 3C# 3—REVOLUTIONIZING HOW WE CODE ..................205 8 ■ Cutting fluff with a smart compiler 207 9 ■ Lambda expressions and expression trees 230 10 ■ Extension methods 255 11 ■ Query expressions and LINQ to Objects 275 12 ■ LINQ beyond collections 314 13 ■ Elegant code in the new era 352 vii Implementing iterators the easy way This chapter covers ■ Implementing iterators in C# 1 ■ Iterator blocks in C# 2 ■ A simple Range type ■ Iterators as coroutines The iterator pattern is an example of a behavioral pattern—a design pattern that simplifies communication between objects. It’s one of the simplest patterns to understand, and incredibly easy to use. In essence, it allows you to access all the elements in a sequence of items without caring about what kind of sequence it is— an array, a list, a linked list, or none of the above. This can be very effective for building a data pipeline, where an item of data enters the pipeline and goes through a number of different transformations or filters before coming out at the other end. Indeed, this is one of the core patterns of LINQ, as we’ll see in part 3. -
Performance Analysis of the Reactor Pattern in Network Services
Performance Analysis of the Reactor Pattern in Network Services Swapna Gokhale1, Aniruddha Gokhale2, Jeff Gray3, Paul Vandal1, Upsorn Praphamontripong1 1University of Connecticut 2Vanderbilt University Dept. of Computer Science Dept. of Electrical Engineering and Engineering and Computer Science Storrs, CT 06269 USA Nashville, TN 37235 USA [email protected] [email protected] 3University of Alabama at Birmingham Dept of Computer and Information Science Birmingham, AL USA [email protected] Abstract 1. Introduction Service oriented computing (SoC), which is made feasi- ble by middleware-based distributed systems, is an emerg- ing technology to provide the next-generation services to meet societal needs ranging from basic necessities, such as The growing reliance on services provided by software education, energy, communications and healthcare to emer- applications places a high premium on the reliable and ef- gency and disaster management. For SOC to be successful ficient operation of these applications. A number of these in meeting the demands of society, assurance on the perfor- applications follow the event-driven software architecture mance of these services is necessary. Since these services style since this style fosters evolvability by separating event are primarily built using communication middleware, the handling from event demultiplexing and dispatching func- problem reduces to the issue of performance assurance of tionality. The event demultiplexing capability, which ap- the middleware platforms. pears repeatedly across a class of event-driven applica- Middleware typically comprises a number of building tions, can be codified into a reusable pattern, such as the blocks, which are essentially patterns-based reusable soft- Reactor pattern. In order to enable performance analysis of ware frameworks. -
The Design and Use of the ACE Reactor an Object-Oriented Framework for Event Demultiplexing
The Design and Use of the ACE Reactor An Object-Oriented Framework for Event Demultiplexing Douglas C. Schmidt and Irfan Pyarali g fschmidt,irfan @cs.wustl.edu Department of Computer Science Washington University, St. Louis 631301 1 Introduction create concrete event handlers by inheriting from the ACE Event Handler base class. This class specifies vir- This article describes the design and implementation of the tual methods that handle various types of events, such as Reactor pattern [1] contained in the ACE framework [2]. The I/O events, timer events, signals, and synchronization events. Reactor pattern handles service requests that are delivered Applications that use the Reactor framework create concrete concurrently to an application by one or more clients. Each event handlers and register them with the ACE Reactor. service of the application is implemented by a separate event Figure 1 shows the key components in the ACE Reactor. handler that contains one or more methods responsible for This figure depicts concrete event handlers that implement processing service-specific requests. In the implementation of the Reactor pattern described in this paper, event handler dispatching is performed REGISTERED 2: accept() by an ACE Reactor.TheACE Reactor combines OBJECTS 5: recv(request) 3: make_handler() the demultiplexing of input and output (I/O) events with 6: process(request) other types of events, such as timers and signals. At Logging Logging Logging Logging Handler Acceptor LEVEL thecoreoftheACE Reactor implementation is a syn- LEVEL Handler Handler chronous event demultiplexer, such as select [3] or APPLICATION APPLICATION Event Event WaitForMultipleObjects [4]. When the demulti- Event Event Handler Handler Handler plexer indicates the occurrence of designated events, the Handler ACE Reactor automatically dispatches the method(s) of 4: handle_input() 1: handle_input() pre-registered event handlers, which perform application- specified services in response to the events. -
Skin Vs. Guts: Introducing Design Patterns in the MIS Curriculum Elizabeth Towell and John Towell Carroll College, Waukesha, WI, USA
Journal of Information Technology Education Volume 1 No. 4, 2002 Skin vs. Guts: Introducing Design Patterns in the MIS Curriculum Elizabeth Towell and John Towell Carroll College, Waukesha, WI, USA [email protected] [email protected] Executive Summary Significant evidence suggests that there is increasing demand for information technology oriented stu- dents who have exposure to Object-Oriented (OO) methodologies and who have knowledge of the Uni- fied Modeling Language (UML). Object-oriented development has moved into the mainstream as the value of reusable program modules is becoming more evident. Building blocks such as software com- ponents and application frameworks allow organizations to bring products to market faster and to adapt to changes more quickly. When only one analysis and design course is required, the study of object-oriented analysis and design is often minimal or left out of the Management Information Systems curriculum. This paper argues for an increased emphasis on object-oriented techniques in the introductory Systems Analysis and Design course. Specifically, it provides guidance for faculty who are considering adding object-orientation to a systems analysis and design course where existing content leaves little time for new topics. In particular, the authors recommend the introduction of two successful, generalized design patterns in the context of adaptation of a software development framework. Where time is limited, coverage of such recurring software problems cannot be comprehensive so it is proposed that students explore two design patterns in depth as opposed to a cursory review of more patterns. Students must first learn or review the OO vocabulary including terms such as classes, inheritance, and aggregation so that the ap- propriate term can be used to discuss the UML relationships among the object model components. -
1. Difference Between Factory Pattern and Abstract Factory Pattern S.No
1. Difference between Factory Pattern and Abstract Factory Pattern S.No Factory Pattern Abstract Factory Pattern 1 Create object through inheritance Create object through composition 2 Produce only one product Produce families of products 3 Implements code in the abstract creator Concrete factories implements factory that make use of the concrete type that method to create product sub class produces 2.Difference between Abstract Factory Pattern And Builder Pattern S.No Builder Pattern Abstract Factory Pattern 1 In Builder Pattern, there will be one Abstract Factory Pattern will return the Director class which will instruct Builder instance directly. class to build the different parts/properties of our object and finally retrieve the object. 2 It will have reference to the created It does not keep the track of it's created object. object. 3.Difference between Builder Pattern And Composite Pattern S.No Builder Pattern Composite Pattern 1 It is used to create group of objects of It creates Parent - Child relations between predefined types. our objects. 4.Difference between MVC and MVP S.No MVP MVC 1 MVP is a bit more complex to MVC is easier to implement than MVP. implement than MVC .Also, it has additional layer for view interfaces. 2 The request is always received by the The request is received by the controller View and delegated to the presenter which in turn gets the required data and which in turn gets the data does the loads up the appropriate view processing 3 The presentation and view logic an be The controller logic can be unit tested.