The Parallel Programming Landscape
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Chapter 1 Issues—The Software Crisis
Chapter 1 Issues—The Software Crisis 1. Introduction to Chapter This chapter describes some of the current issues and problems in system development that are caused The term "software crisis" has been used since the by software—software that is late, is over budget, late 1960s to describe those recurring system devel- and/or does not meet the customers' requirements or opment problems in which software development needs. problems cause the entire system to be late, over Software is the set of instructions that govern the budget, not responsive to the user and/or customer actions of a programmable machine. Software includes requirements, and difficult to use, maintain, and application programs, system software, utility soft- enhance. The late Dr. Winston Royce, in his paper ware, and firmware. Software does not include data, Current Problems [1], emphasized this situation when procedures, people, and documentation. In this tuto- he said in 1991: rial, "software" is synonymous with "computer pro- grams." The construction of new software that is both Because software is invisible, it is difficult to be pleasing to the user/buyer and without latent certain of development progress or of product com- errors is an unexpectedly hard problem. It is pleteness and quality. Software is not governed by the perhaps the most difficult problem in engi- physical laws of nature: there is no equivalent of neering today, and has been recognized as such Ohm's Law, which governs the flow of electricity in a for more than 15 years. It is often referred to as circuit; the laws of aerodynamics, which act to keep an the "software crisis". -
Rational Purifyplus for UNIX
Develop Fast, Reliable Code Rational PurifyPlus for UNIX Customers and end-users demand that your Automatically Pinpoint code works reliably and offers adequate execu- Hard-To-Find Bugs tion performance. But the reality of your deliv- Reliability problems, such as runtime errors and ery schedule often forces you to sacrifice relia- memory leaks in C/C++, can kill a software bility or performance – sometimes both. And company’s reputation. These errors are hard to without adequate time for testing, you may not find, hard to reproduce, and hardest of all, to even know these issues exist. So you reluctant- explain to customers who discover them. No ly deliver your code before it’s ready, knowing one intentionally relies on their customer as good and well that the integrity of your work their "final QA." But without adequate tools, this may be suspect. is the inevitable outcome. Even the best pro- Rational Software has a solution for ensuring grammers make mistakes in their coding. that your code is both fast and reliable. Rational PurifyPlus for UNIX automatically finds HIGHLIGHTS Rational® PurifyPlus for UNIX combines runtime these reliability errors in C/C++ code that can’t error detection, application performance profil- Automatically finds runtime be found in any other way. It finds the errors ing, and code coverage analysis into a single, errors in C/C++ code even before visible symptoms occur (such as a complete package. Together, these functions system crash or other spurious behavior). And help developers ensure the highest reliability Quickly isolates application it shows you exactly where the error originated, and performance of their software from the very performance bottlenecks regardless of how remote from the visible first release. -
Software Engineering and Ethics: When Code Goes Bad
Software Engineering and Ethics: when code goes bad Once upon a time, estimates for the Strategic Defense Initiative (SDI or ``Star Wars'') claimed that there would be 30 million lines of code, all bug free. This is at least three orders of magnitude greater than ever has been achieved. ... What have we learned since then? 2017 TSP (MSc CCN) 1 Lecture Plan It is a bad plan that admits of no modification Publilius Syrus •Software Crisis •Ethics •Software Engineering •Software Engineering and Ethics •The root of the problem - computer science boundaries? •When code goes bad - education through classic examples •Proposals for the future 2017 TSP (MSc CCN) 2 Software Crisis Do you recognise this? 3 When everyone is wrong Software Engineering and “Bugs” everyone is right Nivelle de La Chaussee QUESTION: What’s the difference between hardware and software ?… buy some hardware and you get a warranty, buy some software and you get a disclaimer The software crisis: •always late Does this really exist? •always over-budget •always buggy •always hard to maintain •always better the next time round … but never is! This doesn’t seem right … where are our ethics? 2017 TSP (MSc CCN) 4 Is there really a crisis? … To avoid crisis, just hire the best people … look at the advances we have made Success in software development depends most upon the quality of the people involved. There is more software to be developed than there are capable developers to do it. Demand for engineers will continue to outstrip supply for the foreseeable future. Complacency has already set in … some firms acknowledge that many of their engineers make negative contribution. -
Arxiv:2105.00534V1 [Cs.SE] 2 May 2021 Solutions
Metadata Interpretation Driven Development J´ulioG.S.F. da Costaa,d, Reinaldo A. Pettac,d, Samuel Xavier-de-Souzaa,b,d, aGraduate Program of Electrical and Computer Engineering bDepartamento de Engenharia de Computa¸c~aoe Automa¸c~ao cDepartamento de Geologia dUniversidade Federal do Rio Grande do Norte, Natal, RN, Brazil, 59078-900 Abstract Context: Despite decades of engineering and scientific research efforts, sep- aration of concerns in software development remains not fully achieved. The ultimate goal is to truly allow code reuse without large maintenance and evo- lution costs. The challenge has been to avoid the crosscutting of concerns phe- nomenon, which has no apparent complete solution. Objective: In this paper, we show that business-domain code inscriptions play an even larger role in this challenge than the crosscutting of concerns. We then introduce a new methodology, called Metadata Interpretation Driven Develop- ment (MIDD) that suggests a possible path to realize separation of concerns by removing functional software concerns from the coding phase. Method: We propose a change in the perspective for building software, from being based on object representation at the coding level to being based on ob- ject interpretation, whose definitions are put into layers of representation other than coding. The metadata of the domain data is not implemented at the level of the code. Instead, they are interpreted at run time. Results: As an important consequence, such constructs can be applied across functional requirements, across business domains, with no concerns regarding the need to rewrite or refactor code. We show how this can increase the (re)use of the constructs. -
The Developer's Guide to Debugging
The Developer’s Guide to Debugging Thorsten Grotker¨ · Ulrich Holtmann Holger Keding · Markus Wloka The Developer’s Guide to Debugging 123 Thorsten Gr¨otker Ulrich Holtmann Holger Keding Markus Wloka Internet: http://www.debugging-guide.com Email: [email protected] ISBN: 978-1-4020-5539-3 e-ISBN: 978-1-4020-5540-9 Library of Congress Control Number: 2008929566 c 2008 Springer Science+Business Media B.V. No part of this work may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, microfilming, recording or otherwise, without written permission from the Publisher, with the exception of any material supplied specifically for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work. Printed on acid-free paper 987654321 springer.com Foreword Of all activities in software development, debugging is probably the one that is hated most. It is guilt-ridden because a technical failure suggests personal fail- ure; because it points the finger at us showing us that we have been wrong. It is time-consuming because we have to rethink every single assumption, every single step from requirements to implementation. Its worst feature though may be that it is unpredictable: You never know how much time it will take you to fix a bug - and whether you’ll be able to fix it at all. Ask a developer for the worst moments in life, and many of them will be related to debugging. It may be 11pm, you’re still working on it, you are just stepping through the program, and that’s when your spouse calls you and asks you when you’ll finally, finally get home, and you try to end the call as soon as possible as you’re losing grip on the carefully memorized observations and deductions. -
Heapmon: a Low Overhead, Automatic, and Programmable Memory Bug Detector ∗
Appears in the Proceedings of the First IBM PAC2 Conference HeapMon: a Low Overhead, Automatic, and Programmable Memory Bug Detector ∗ Rithin Shetty, Mazen Kharbutli, Yan Solihin Milos Prvulovic Dept. of Electrical and Computer Engineering College of Computing North Carolina State University Georgia Institute of Technology frkshetty,mmkharbu,[email protected] [email protected] Abstract memory bug detection tool, improves debugging productiv- ity by a factor of ten, and saves $7,000 in development costs Detection of memory-related bugs is a very important aspect of the per programmer per year [10]. Memory bugs are not easy software development cycle, yet there are not many reliable and ef- to find via code inspection because a memory bug may in- ficient tools available for this purpose. Most of the tools and tech- volve several different code fragments which can even be in niques available have either a high performance overhead or require different files or modules. The compiler is also of little help a high degree of human intervention. This paper presents HeapMon, in finding heap-related memory bugs because it often fails to a novel hardware/software approach to detecting memory bugs, such fully disambiguate pointers [18]. As a result, detection and as reads from uninitialized or unallocated memory locations. This new identification of memory bugs must typically be done at run- approach does not require human intervention and has only minor stor- time [1, 2, 3, 4, 6, 7, 8, 9, 11, 13, 14, 18]. Unfortunately, the age and execution time overheads. effects of a memory bug may become apparent long after the HeapMon relies on a helper thread that runs on a separate processor bug has been triggered. -
Edsger Wybe Dijkstra
In Memoriam Edsger Wybe Dijkstra (1930–2002) Contents 0 Early Years 2 1 Mathematical Center, Amsterdam 3 2 Eindhoven University of Technology 6 3 Burroughs Corporation 8 4 Austin and The University of Texas 9 5 Awards and Honors 12 6 Written Works 13 7 Prophet and Sage 14 8 Some Memorable Quotations 16 Edsger Wybe Dijkstra, Professor Emeritus in the Computer Sciences Department at the University of Texas at Austin, died of cancer on 6 August 2002 at his home in Nuenen, the Netherlands. Dijkstra was a towering figure whose scientific contributions permeate major domains of computer science. He was a thinker, scholar, and teacher in renaissance style: working alone or in a close-knit group on problems of long-term importance, writing down his thoughts with exquisite precision, educating students to appreciate the nature of scientific research, and publicly chastising powerful individuals and institutions when he felt scientific integrity was being compromised for economic or political ends. In the words of Professor Sir Tony Hoare, FRS, delivered by him at Dijkstra’s funeral: Edsger is widely recognized as a man who has thought deeply about many deep questions; and among the deepest questions is that of traditional moral philosophy: How is it that a person should live their life? Edsger found his answer to this question early in his life: He decided he would live as an academic scientist, conducting research into a new branch of science, the science of computing. He would lay the foundations that would establish computing as a rigorous scientific discipline; and in his research and in his teaching and in his writing, he would pursue perfection to the exclusion of all other concerns. -
Debugging and Tuning Linux for EDA
Debugging and Tuning Linux for EDA Fabio Somenzi [email protected] University of Colorado at Boulder Outline Compiling gcc icc/ecc Debugging valgrind purify ddd Profiling gcov, gprof quantify vtl valgrind Compiling Compiler options related to static checks debugging optimization Profiling-driven optimization Compiling with GCC gcc -Wall -O3 -g reports most uses of potentially uninitialized variables -O3 (or -O6) necessary to trigger dataflow analysis can be fooled by if (cond) x = VALUE; ... if (cond) y = x; Uninitialized variables not considered for register allocation may escape Achieving -Wall-clean code is not too painful and highly desirable Compiling C code with g++ is more painful, but has its rewards Compiling with GCC gcc -mcpu=pentium4 -malign-double -mcpu=pentium4 optimizes for the Pentium 4, but produces code that runs on any x86 -march=pentium4 uses Pentium 4-specific instructions -malign-double forces alignment of double’s to double-word boundary Use either for all files or for none gcc -mfpmath=sse Controls the use of SSE instructions for floating point For complete listing, check gcc’s info page under Invoking gcc ! Submodel Options Compiling with ICC ICC is the Intel compiler for IA-32 systems. http://www.intel.com/software/products/ icc -O3 -g -ansi -w2 -Wall Aggressive optimization Retain debugging info Strict ANSI conformance Display remarks, warnings, and errors Enable all warnings Remarks tend to be a bit overwhelming Fine grain control over diagnostic: see man page Compiling with ICC icc -tpp7 Optimize instruction scheduling -
IBM Rational Purifyplus for AIX Helps Developers and Testers Deliver Applications Faster and with Fewer Errors
IBM Europe, Middle East, and Africa Software Announcement ZP09-0129, dated May 12, 2009 IBM Rational PurifyPlus for AIX helps developers and testers deliver applications faster and with fewer errors Table of contents 1 At a glance 4 Publications 1 Overview 4 Technical information 2 Key prerequisites 5 Ordering information 2 Planned availability dates 7 Terms and conditions 2 Product positioning 9 IBM Electronic Services 3 Program number 10 Prices 3 Offering Information 10 Announcement countries At a glance tm IBM® Rational® PurifyPlus for AIX® is the newest member of an award-winning family of products that provide a dynamic analysis solution designed to help developers write faster, more reliable code. It includes four basic capabilities: • Memory debugging: Pinpoints hard to find memory errors such as uninitialized memory access, buffer overflow, and improper freeing of memory. • Memory leak detection: Identifies memory blocks that no longer have a valid pointer. • Application performance profiling: Highlights application performance bottlenecks and improves application understanding with a graphical representation of function calls. • Code coverage analysis: Identifies untested code with line-level precision. Overview IBM Rational PurifyPlus for AIX is a set of dynamic analysis tools designed for improving application reliability and performance on the IBM System p® platform. The PurifyPlus software combines the following capabilities into a single, complete package: • Memory debugging • Memory leak detection • Application performance profiling • Code coverage analysis Together, these capabilities help developers and testers to realize high reliability and performance of their software from its very first release. IBM Rational PurifyPlus for AIX allows developers and testers to monitor an entire application or just a subset of an application's modules. -
Unit Structure: 1.1 Software Crisis 1.2 Software Evaluation 1.3 POP (Procedure Oriented Programming) 1.4 OOP (Object Oriented
Unit Structure: 1.1 Software crisis 1.2 Software Evaluation 1.3 POP (Procedure Oriented Programming) 1.4 OOP (Object Oriented Programming) 1.5 Basic concepts of OOP 1.5.1 Objects 1.5.2 Classes 1.5.3 Data Abstraction and Data Encapsulation 1.5.4 Inheritance 1.5.5 Polymorphism 1.5.6 Dynamic Binding 1.5.7 Message Passing 1.6 Benefits of OOP 1.7 Object Oriented Language 1.8 Application of OOP 1.9 Introduction of C++ 1.9.1 Application of C++ 1.10 Simple C++ Program 1.10.1 Program Features 1.10.2 Comments 1.10.3 Output Operators 1.10.4 iostream File 1.10.5 Namespace 1.10.6 Return Type of main () 1.11 More C++ Statements 1.11.1 Variable 1.11.2 Input Operator 1.11.3 Cascading I/O Operator 1.12 Example with Class 1.13 Structure of C++ 1.14 Creating Source File 1.15 Compiling and Linking Page 1 1.1 Software Crisis Developments in software technology continue to be dynamic. New tools and techniques are announced in quick succession. This has forced the software engineers and industry to continuously look for new approaches to software design and development, and they are becoming more and more critical in view of the increasing complexity of software systems as well as the highly competitive nature of the industry. These rapid advances appear to have created a situation of crisis within the industry. The following issued need to be addressed to face the crisis: • How to represent real-life entities of problems in system design? • How to design system with open interfaces? • How to ensure reusability and extensibility of modules? • How to develop modules that are tolerant of any changes in future? • How to improve software productivity and decrease software cost? • How to improve the quality of software? • How to manage time schedules? 1.2 Software Evaluation Ernest Tello, A well known writer in the field of artificial intelligence, compared the evolution of software technology to the growth of the tree. -
Survey of Protections from Buffer-Overflow Attacks
Survey of Protections from Buffer-Overflow Attacks Krerk Piromsopa1,* and Richard J. Enbody2 1 Department of Industrial Engineering, Faculty of Engineering, Chulalongkorn University Bangkok 10330 Thailand 2 Department of Computer Science and Engineering, Michigan State University East Lansing, MI 48824-1226 USA E-mail: [email protected],* and [email protected] Abstract. Buffer-overflow attacks began two decades ago and persist today. Over that time, a number of researchers have proposed many solutions. Their targets were either to prevent or to protect against buffer-overflow attacks. As defenses improved, attacks adapted and became more complicated. Given the maturity of field and the fact that some solutions now exist that can prevent most buffer-overflow attacks, it is time to examine these schemes and their critical issues. In this survey, approaches were categorized into three board categories to provide a basis for understanding buffer- overflow protection schemes. Keywords: Buffer overflow, buffer-overflow attacks, function-pointer attacks, intrusion detection, intrusion prevention. ENGINEERING JOURNAL Volume 15 Issue 2 Received 1 June 2010 Accepted 5 February 2011 Published 1 April 2011 Online at http://www.ej.eng.chula.ac.th/eng/ DOI:10.4186/ej.2011.15.2.31 DOI:10.4186/ej.2011.15.2.31 1. Introduction Though dated back to the 1988 infamous MORRIS worm [1], buffer-overflow attacks are still widely found. In 2007, buffer overflows made up the majority of the vulnerabilities listed by CERT [2] which allowed execution of arbitrary code, i.e. the most serious vulnerabilities. Though skilled programmers should write code that does not allow buffer overflows, current practice does not guarantee programs that are free from vulnerabilities. -
Chapter 3, on Structured Programming
131 on structured programming "In the light of all these difficul- ties the simple approach may be the best." W.F.C. Purser (1976) Software for local multi-mini proc- essor systems. In: 'Multiprocessor Systems', Info- tech State of the Art Report, pg. 408. 132 Contents Chapter Three 1. Introduction pg. 133 1. The origination of structured programming 133 2. The software crisis 135 3. Structured programming and problem solving 136 2. Survey of Structured Programming Techniques 139 1. Restrictions 139 2. Abstraction 141 3. Stepwise refinement 142 4. Notation 143 • Data representation 143 • Flowcharts 145 • Documentation 147 • Programming Languages 148 3. Discussion: Criticisms on Structured Programming 150 1. Pragmatics 150 2. Complexity 150 3. Rigidity 151 4. Methodology 155 4. Conclusion 157 , 5. References Chapter Three 158 Appendix B: Graph Generation and Complexity Measures 161 References Appendix A 167 133 CHAPTER THREE ON STRUCTURED PROGRAMMING 3.1. INTRODUCTION One conclusion we can draw from the discussion in chapter two is that correct- ness proving is by no means a trivial task, neither for sequential programs nor for concurrent programs. The available analysis tools are not powerful enough to allow for the verification of just any program. By necessity one must re- strict oneself to simple and well-structured programs. But, one may ask, what is a well-structured program? Fortunately, there is a wealth of literature on this subject. The larger part of this literature is primarily concerned with sequential programs, but still we should take careful notice of these theories if we want to be able to apply the underlying principles to the multiprocessing cases.