VENDORS

Students' Testimonials



Killexams.com 000-834 Dumps and Real Questions 2019

Latest and 100% real exam Questions - Memorize Questions and Answers - Guaranteed Success in exam



000-834 exam Dumps Source : Object Oriented Analysis and Design - Part 2 (Design)

Test Code : 000-834
Test Name : Object Oriented Analysis and Design - Part 2 (Design)
Vendor Name : IBM
Q&A : 180 Real Questions

What do you mean with the aid of 000-834 exam?
I was trying to get ready for my 000-834 test that was around the corner, I found myself to be lost in the books and wandering far away from the real point. I didnt understand a single word and that was really concerning because I had to prepare as soon as possible. Giving up on my books I decided to register myself on this killexams.com and that was the best decision. I cruised through my 000-834 test and was able to get a decent score so thank you very much.


Do you want actual test questions modern day 000-834 exam to prepare?
It is a captains job to influence the deliver much like it is a pilots process to influence the aircraft. This killexams.com can be known as my captain or my pilot as it advised me in to the right direction before my 000-834 test and it become their guidelines and guidance that were given me to observe the right direction that ultimately lead me to achievement. I was very successful in my 000-834 test and it turned into a moment of glory for which I will forever continue to be obliged to this on-line test center.


discovered an accurate source for actual 000-834 present day dumps.
Earlier than I walk to the attempting out center, i was so confident about my preparation for the 000-834 exam because of the truth I knew i was going to ace it and this self perception came to me after using this killexams.com for my help. Its farsuperb at helping university college students similar to it assisted me and i used for you to get acceptable rankings in my 000-834 test.


Did you tried these 000-834 real examination financial institution and take a look at guide.
Are you able to scent the sweet fragrance of victory I understand i am capable of and it is clearly a very stunning smell. You may scent it too in case you pass surfing to this killexams.com as a way to put together for your 000-834 check. I did the same aspect right in advance than my test and became very satisfied with the provider provided to me. The facilitiesright right here are impeccable and whilst you are in it you wouldnt be worried about failing in any respect. I didnt fail and did quite nicely and so can you. Strive it!


test out those real 000-834 questions and have a look at help.
I wound up the exam with a fulfilling 84% marks in stipulated time. Thanks very plenty killexams. Through and by means of, it grow to be difficult to do top to bottom observe proceeding with a full-time work. At that factor, I became to the Q&A of killexams. Its concise solutions helped me to see a few complicated subjects. I selected to sit for the exam 000-834 to attain in addition development in my career.


000-834 questions and answers that works in the actual test.
Me and my roommate have been living together for a long time and we have a lot of disagreements and arguments regarding various things but if there is one thing that both of us agree on it is the fact that this killexams.com is the best one on the internet to use if you want to pass your 000-834 . Both of us used it and were very satisfied with the outcome that we got. I was able to perform well in my 000-834 test and my marks were actually terrific. Thank you for the guidance.


Great source of great Latest dumps, accurate answers.
Im very satisfied with the 000-834 QAs, it helped me lot in exam center. I can really come for specific IBM certifications additionally.


these 000-834 ultra-modern dumps works terrific within the actual test.
Very very good 000-834 exam preparation questions answers, I passed 000-834 exam this month. killexams.com is very reliable. I didnt think that braindumps could get you this high, but now that i have passed my 000-834 exam, I know that killexams.com is more than a dump. killexams.com gives you what you need to pass your 000-834 exam, and also helps you learn things you might need. Yet, it gives you only what you REALLY need to know, saving your time and energy. I have passed 000-834 exam and now recommend killexams.com to everyone out there.


i've located a superb source of 000-834 fabric.
Like many others, i have presently passed the 000-834 exam. In my case, huge majority of 000-834 exam questions got here exactly from this manual. The solutions are accurate, too, so if you are making ready to take your 000-834 exam, you may completely rely upon this website.


All actual take a look at questions of 000-834 exam! Are you kidding?
yes, very beneficial and i was capable of score eighty two% in the 000-834 exam with 5 days coaching. particularly the facility of downloading as PDF documents for your package gave me an amazing room for effective practice coupled with on line tests - no constrained tries limit. solutions given to each question by way of you is a hundred% accurate. thanksloads.


IBM Object Oriented Analysis and

Object-Oriented analysis and Design | killexams.com Real Questions and Pass4sure dumps

This chapter is from the booklet 

evaluation emphasizes an investigation of the difficulty and necessities, in preference to a solution. as an example, if a new on-line trading system is preferred, how will or not it's used? What are its services?

"analysis" is a huge time period, foremost certified, as in requirements evaluation (an investigation of the requirements) or object-oriented evaluation (an investigation of the area objects).

Design emphasizes a conceptual answer (in application and hardware) that fulfills the necessities, rather than its implementation. for example, an outline of a database schema and software objects. Design ideas frequently exclude low-level or "obvious" details—evident to the supposed buyers. in the end, designs will also be carried out, and the implementation (similar to code) expresses the actual and comprehensive realized design.

As with evaluation, the term is most fulfilling qualified, as in object-oriented design or database design.

constructive analysis and design were summarized in the phrase do the right thing (evaluation), and do the factor correct (design).


Python GUI Programming tasks using Tkinter and Python three - Simpliv | killexams.com Real Questions and Pass4sure dumps

Python GUI Programming tasks the use of Tkinter and Python 3 - SimplivFebruary 6, 2019 - August 1, 2023 - Albama CA AS

simpliv

simplivllc@gmail.comPhone: 5108496155

About this path be taught palms-On Python Programming by growing initiatives, GUIs and portraits Python is a dynamic up to date object -oriented programming language it is effortless to be trained and might be used to do a lot of issues each huge and small Python is what's referred to as a excessive stage language Python is used within the industry for issues like embedded application, net building, computer purposes, and even mobile apps! SQL-Lite makes it possible for your applications to turn into even more effective by using storing, retrieving, and filtering through giant statistics units quite simply if you wish to be trained to code, Python GUIs are the top-rated option to beginning! I designed this programming direction to be quite simply understood via absolute freshmen and younger people. We beginning with primary Python programming ideas. enhance the identical by using establishing mission and GUIs. Why Python? The Python coding language integrates neatly with different systems – and runs on virtually all contemporary gadgets. if you’re new to coding, that you can quite simply be taught the basics in this speedy and strong coding ambiance. in case you have event with other computing device languages, you’ll locate Python standard and straightforward. This OSI-accepted open-supply language allows for free use and distribution – even business distribution. When and the way do I delivery a profession as a Python programmer? In an independent third celebration survey, it has been printed that the Python programming language is at present probably the most normal language for data scientists international. This claim is substantiated with the aid of the Institute of Electrical and digital Engineers, which tracks programming languages by popularity. in line with them, Python is the 2d most standard programming language this year for development on the web after Java. Python Job Profiles software Engineer analysis Analyst statistics Analyst facts Scientist software Developer Python salary The median complete pay for Python jobs in California, united states is $seventy four,410, for an expert with 12 months of experience under are graphs depicting common Python salary by means of metropolis the primary chart depicts average profits for a Python professional with one year of journey and the second chart depicts the general salaries by way of years of event Who uses Python? This route gives you a superior set of potential in one of nowadays’s proper programming languages. today’s greatest corporations (and smartest startups) use Python, together with Google, fb, Instagram, Amazon, IBM, and NASA. Python is more and more getting used for scientific computations and data analysis Take this route these days and study the skills you need to rub shoulders with these days’s tech industry giants. have a good time, create and control fascinating and interactive Python GUIs, and revel in a vivid future! best of success who is the target viewers? any person who desires to study to code For finished Programming freshmen For americans New to Python This route became designed for college students with little to no programming adventure individuals interested in constructing initiatives any individual seeking to start with Python GUI development Contact Us: simplivllc@gmail.com mobile: 76760-08458 electronic mail: sudheer@simpliv.com mobilephone: 9538055093 To read greater and register: https://www.simpliv.com/python/python-gui-programming-tasks-the usage of-tkinter-and-python-3

extra suggestions


Object-Oriented analysis And Design — Introduction (part 1) | killexams.com Real Questions and Pass4sure dumps

The idea Of Object-Orientation

Object-orientation is what’s referred to as a programming paradigm. It’s not a language itself but a set of ideas that's supported by way of many languages.

if you aren’t regular with the ideas of object-orientation, you might also take a glance at the Story of Object-Oriented Programming.

If every little thing we do in these languages is object-oriented, it skill, we are oriented or focused around objects.

Now in an object-oriented language, this one huge application will as an alternative be split apart into self contained objects, very nearly like having several mini-classes, each object representing a different a part of the software.

and every object carries its own records and its own common sense, and they communicate between themselves.

These objects aren’t random. They represent the way you speak and suppose about the difficulty you try to clear up for your real existence.

They characterize issues like employees, photographs, bank money owed, spaceships, asteroids, video phase, audio files, or whatever exists in your program.

Object-Oriented analysis And Design (OOAD)

It’s a structured system for inspecting, designing a equipment via making use of the thing-oriented ideas, and improve a collection of graphical gadget fashions all through the building life cycle of the software.

OOAD within the SDLC

The application life cycle is customarily divided up into levels going from summary descriptions of the difficulty to designs then to code and trying out and at last to deployment.

The earliest levels of this system are evaluation (requirements) and design.

The difference between evaluation and design is frequently described as “what Vs how”.

In analysis developers work with clients and domain consultants to outline what the equipment is supposed to do. Implementation particulars are presupposed to be by and large or completely omitted at this phase.

The aim of the evaluation section is to create a model of the device even with constraints equivalent to acceptable expertise. this is customarily finished by the use of use cases and summary definition of essentially the most critical objects using conceptual mannequin.

The design section refines the analysis mannequin and applies the vital technology and different implementation constrains.

It specializes in describing the objects, their attributes, habits, and interactions. The design model may still have all the particulars required so that programmers can enforce the design in code.

They’re most excellent carried out in an iterative and incremental application methodologies. So, the actions of OOAD and the developed fashions aren’t accomplished as soon as, we will revisit and refine these steps consistently.

Object-Oriented analysis

within the object-oriented analysis, we …

  • Elicit necessities: define what does the application deserve to do, and what’s the difficulty the software making an attempt to clear up.
  • Specify requirements: Describe the necessities, continually, the usage of use instances (and eventualities) or consumer stories.
  • Conceptual model: determine the critical objects, refine them, and define their relationships and conduct and draw them in an easy diagram.
  • We’re now not going to cowl the first two activities, just the ultimate one. These are already defined in aspect in requirements Engineering.

    Object-Oriented Design

    The analysis phase identifies the objects, their relationship, and behavior using the conceptual model (an summary definition for the objects).

    while in design part, we describe these objects (by means of creating type diagram from conceptual diagram — usually mapping conceptual mannequin to classification diagram), their attributes, behavior, and interactions.

    in addition to making use of the application design concepts and patterns which should be lined in later tutorials.

    The input for object-oriented design is provided by using the output of object-oriented evaluation. however, evaluation and design might also turn up in parallel, and the consequences of one activity can be used by using the different.

    in the object-oriented design, we …

  • Describe the classes and their relationships the usage of class diagram.
  • Describe the interplay between the objects using sequence diagram.
  • follow software design ideas and design patterns.
  • a class diagram gives a visible illustration of the classes you want. And right here is where you get to be definitely particular about object-oriented principles like inheritance and polymorphism.

    Describing the interactions between those objects permits you to more advantageous be mindful the obligations of the distinct objects, the behaviors they should have.

    — other diagrams

    there are many other diagrams we can use to model the gadget from distinctive views; interactions between objects, structure of the equipment, or the conduct of the system and how it responds to pursuits.

    It’s at all times about deciding upon the appropriate diagram for the appropriate want. you should realize which diagrams can be effective when pondering or discussing a situation that isn’t clear.

    gadget modeling and the diverse fashions we will use can be mentioned next.

    gadget Modeling

    gadget modeling is the process of setting up models of the system, with every model representing a unique perspectives of that system.

    essentially the most essential element a few system mannequin is that it leaves out aspect; It’s an summary representation of the device.

    The fashions are continually in keeping with graphical notation, which is almost always according to the notations in the Unified Modeling Language (UML). other fashions of the gadget like mathematical model; an in depth equipment description.

    fashions are used right through the analysis procedure to support to elicit the requirements, all the way through the design process to explain the device to engineers, and after implementation to doc the device constitution and operation.

    distinctive perspectives

    We may additionally boost a mannequin to symbolize the equipment from different perspectives.

  • external, where you model the context or the atmosphere of the gadget.
  • interplay, where you model the interaction between accessories of a system, or between a equipment and other programs.
  • Structural, the place you mannequin the corporation of the system, or the structure of the statistics being processed by way of the gadget.
  • Behavioral, the place you mannequin the dynamic conduct of the equipment and how it reply to hobbies.
  • Unified Modeling Language (UML)

    The unified modeling language turn into the typical modeling language for object-oriented modeling. It has many diagrams, although, the most diagrams that are conventional are:

  • Use case diagram: It shows the interplay between a equipment and it’s ambiance (users or programs) within a selected condition.
  • category diagram: It suggests the distinctive objects, their relationship, their behaviors, and attributes.
  • Sequence diagram: It indicates the interactions between the different objects within the equipment, and between actors and the objects in a gadget.
  • State machine diagram: It shows how the equipment reply to exterior and internal routine.
  • exercise diagram: It indicates the movement of the statistics between the procedures in the device.
  • you can do diagramming work on paper or on a whiteboard, at least within the initial degrees of a task. but there are some diagramming equipment with a view to help you to draw these UML diagrams.


    Whilst it is very hard task to choose reliable exam questions / answers resources regarding review, reputation and validity because people get ripoff due to choosing incorrect service. Killexams. com make it certain to provide its clients far better to their resources with respect to exam dumps update and validity. Most of other peoples ripoff report complaint clients come to us for the brain dumps and pass their exams enjoyably and easily. We never compromise on our review, reputation and quality because killexams review, killexams reputation and killexams client self confidence is important to all of us. Specially we manage killexams.com review, killexams.com reputation, killexams.com ripoff report complaint, killexams.com trust, killexams.com validity, killexams.com report and killexams.com scam. If perhaps you see any bogus report posted by our competitor with the name killexams ripoff report complaint internet, killexams.com ripoff report, killexams.com scam, killexams.com complaint or something like this, just keep in mind that there are always bad people damaging reputation of good services due to their benefits. There are a large number of satisfied customers that pass their exams using killexams.com brain dumps, killexams PDF questions, killexams practice questions, killexams exam simulator. Visit Killexams.com, our test questions and sample brain dumps, our exam simulator and you will definitely know that killexams.com is the best brain dumps site.

    [OPTIONAL-CONTENTS-2]


    000-258 brain dumps | CCM dump | 000-890 test questions | M2090-234 practice questions | 000-M76 questions answers | HP2-B40 practice test | MOS-O2K questions and answers | HP2-Z21 test prep | 250-530 exam prep | 922-097 mock exam | 000-Z04 practice exam | 9A0-901 pdf download | 310-880 free pdf | P2080-088 dumps questions | MB7-255 real questions | 2B0-015 braindumps | E20-594 sample test | ICYB practice test | 700-001 examcollection | HP0-Y12 free pdf |


    Guarantee your prosperity with this 000-834 question bank
    killexams.com offer you to attempt its free demo, you will see the common UI and besides you will surmise that its easy to change the prep mode. Our investigation direct questions contain finish brain dump examcollection. killexams.com offers you three months free updates of 000-834 Object Oriented Analysis and Design - Part 2 (Design) exam brain dump questions. Our affirmation group is always available at back end who refreshes the material as and when required.

    You should get the recently updated IBM 000-834 Braindumps with the actual answers, which are prepared via killexams.com experts, allowing the candidates to comprehend expertise about their 000-834 exam path in the maximum, you will not find 000-834 merchandise of such nice anywhere in the marketplace. Our IBM 000-834 Practice Dumps are given to applicants at acting a hundred% of their exam. Our IBM 000-834 exam dumps are cutting-edge in the marketplace, giving you a chance to put together in your 000-834 exam inside the proper manner.

    If you are interested in effectively Passing the IBM 000-834 exam to start earning? killexams.com has leading side developed Object Oriented Analysis and Design - Part 2 (Design) exam questions so one can make sure you pass this 000-834 exam! killexams.com offers you the maximum correct, recent and updated 000-834 exam questions and available with a 100% money back assure guarantee. There are many organizations that provide 000-834 brain dumps but those arent correct and modern ones. Preparation with killexams.com 000-834 new questions is a first-class manner to pass this certificationexam in high marks.

    killexams.com Huge Discount Coupons and Promo Codes are as underneath;
    WC2017 : 60% Discount Coupon for all tests on website
    PROF17 : 10% Discount Coupon for Orders greater than $69
    DEAL17 : 15% Discount Coupon for Orders more than $99
    DECSPECIAL : 10% Special Discount Coupon for All Orders


    We are all well aware that a main hassle in the IT industry is that there is a loss of excellent braindumps. Our exam preparation material provides you everything you will want to take a certification exam. Our IBM 000-834 Exam will provide you with exam questions with established answers that reflect the real exam. These questions and answers offer you with the enjoy of taking the real test. High best and price for the 000-834 Exam. 100% assure to pass your IBM 000-834 exam and get your IBM certification. We at killexams.com are devoted that will help you pass your 000-834 exam with high rankings. The probabilities of you failing your 000-834 exam, after going through our comprehensive exam dumps are very little.

    killexams.com enables a huge number of contender to finish the tests and get their certifications. We have a huge number of a hit tributes. Our dumps are solid, moderate, updated and of genuinely best pleasant to vanquish the challenges of any IT certifications. killexams.com exam dumps are front line updated in detectably bulldoze route on normal premise and material is discharged intermittently. Most recent killexams.com dumps are accessible in experimenting with focuses with whom we are safeguarding our pursuing to get advanced fabric.

    The killexams.com exam inquiries for 000-834 Object Oriented Analysis and Design - Part 2 (Design) exam is especially considering two convenient formats, PDF and Practice questions. PDF record conveys the majority of the exam questions, answers which makes your training less confounded. While the Practice questions are the correlative capacity inside the exam item. Which empowers to self-decide your improvement. The appraisal instrument furthermore addresses your helpless territories, inyou have to put more endeavors with the goal that you can improve the majority of your worries.

    killexams.com advocate you to should attempt its free demo, you will watch the natural UI and furthermore you will find it extremely go to customize the direction mode. In any case, ensure that, the genuine 000-834 item has additional capacities than the preliminary form. if, you are mollified with its demo then you should buy the genuine 000-834 exam item. Profit 3 months Free endless supply of 000-834 Object Oriented Analysis and Design - Part 2 (Design) Exam questions. killexams.com allows you three months free endless supply of 000-834 Object Oriented Analysis and Design - Part 2 (Design) exam questions. Our master group is always accessible at back stopped who updates the substance as and keeping thinking that required.

    killexams.com Huge Discount Coupons and Promo Codes are as under;
    WC2017: 60% Discount Coupon for all exams on website
    PROF17: 10% Discount Coupon for Orders greater than $69
    DEAL17: 15% Discount Coupon for Orders greater than $99
    DECSPECIAL: 10% Special Discount Coupon for All Orders



    Killexams C9530-404 exam prep | Killexams 000-431 questions answers | Killexams COG-635 sample test | Killexams 1Z0-070 test prep | Killexams WPT-R real questions | Killexams 000-955 real questions | Killexams JK0-019 practice exam | Killexams 1D0-538 brain dumps | Killexams 190-956 brain dumps | Killexams 250-504 test prep | Killexams 640-461 Practice test | Killexams E20-307 exam questions | Killexams 000-992 cheat sheets | Killexams BCP-421 test questions | Killexams 650-032 exam prep | Killexams COG-612 braindumps | Killexams C2070-981 free pdf | Killexams 650-377 Practice Test | Killexams ST0-095 braindumps | Killexams 9A0-063 free pdf download |


    [OPTIONAL-CONTENTS-5]

    View Complete list of Killexams.com Brain dumps


    Killexams HP0-A03 cheat sheets | Killexams LOT-825 real questions | Killexams A2090-312 exam prep | Killexams HP2-E53 braindumps | Killexams 190-621 Practice test | Killexams 9A0-164 test prep | Killexams CAT-220 practice test | Killexams 1Z0-533 cram | Killexams 9A0-901 dumps questions | Killexams C9560-568 VCE | Killexams SD0-302 sample test | Killexams 9L0-353 test prep | Killexams HP3-X04 practice exam | Killexams 000-703 questions and answers | Killexams HPE2-K43 study guide | Killexams 000-301 study guide | Killexams 000-M224 dump | Killexams CWSP-205 brain dumps | Killexams 000-053 practice questions | Killexams C9060-518 braindumps |


    Object Oriented Analysis and Design - Part 2 (Design)

    Pass 4 sure 000-834 dumps | Killexams.com 000-834 real questions | [HOSTED-SITE]

    Object-Oriented Analysis & Design | killexams.com real questions and Pass4sure dumps

    Object-Oriented Analysis & DesignJune 2, 3, 9, 10Worcester State CollegeTaught by Jan Bergandy, Computer Science, UMass, Dartmouth

    Seminar Objectives:

  • To develop an in-depth understanding of object-oriented paradigm
  • To obtain a working knowledge of object-oriented analysis & design techniques
  • To learn object-oriented modeling using Unified Modeling Language (UML)
  • To learn about basic design patterns and the role of patterns is software development
  • To understand the impact of object paradigm on software development activities
  • To explore synergy between object-oriented design and object-oriented programming
  • To learn about key object technologies
  • Who should attend:This workshop is addressed to faculty involved in teaching programming, software design, and other courses related to software development. It is addressed to those who face a transition to object technology and want to learn about challenges and benefits of this transition. The workshop does not require any prior knowledge of object-oriented programming or knowledge of object paradigm. General computer fluency and general knowledge of issues associated with software and software development are expected.

    Seminar Organization:The course will be conducted as a project with instructor giving short presentations pertaining to a specific stage of the analysis and design process. During this course the participants will construct an analysis model for a selected problem. This model will be refined in to the detailed design level providing an opportunity for discussion about the relationship between object-oriented design and object-oriented programming. Each student will receive a copy of the course materials and the textbook.

    Tools & Platforms:Rational-Rose CASE toolThe CASE tool is used exclusively to expedite the process of model construction. The students spend no more than half an hour of their time during the entire class on learning how to use the tool. Not using the CASE toll will make it almost impossible to experience hands-on all the elements of the object-oriented analysis and design process.

    Textbooks:M. Fowler, ÒUML DistilledÓ, Addison-Wesley, ISBN 0-201-32563-2 (additional/optional )

    E. Gamma, R. Helm, R. Johnson, J. Vlissides, ÒDesign PatternÓ, Addison-Wesley, ISBN 0-201-63361-2

    Outline:

    June 2, 2001, 9:00 - 5:00Topics to be addressed:Object paradigm top-down - analysis & design perspectiveObject paradigm bottom-up - programming perspectiveBasic concepts: abstraction, encapsulation, information hiding, modularityResponsibility view of the requirementsClasses and objects emerging from responsibilitiesComparison of procedural and object-oriented paradigmsClasses and relationships as the building blocks of software architectureCriteria of class qualityIntroduction to Unified Modeling Language (UML)Static & dynamic modelActors and use casesTransitioning from functional requirements to objects - introduction

    Project:Analysis of the requirements for the selected projectIdentifying actors and use casesConstructing use case diagrams

    June 3, 2001, 9:00 - 2:00Topics to be addressed:Transitioning from functional requirements to objectsIdentifying the first group of classesClass specificationClass as an encapsulation of a responsibilityClass, Utility Class, Parameterized Class and its instantiationClass diagram - introductionIdentifying relationships between classesAssociation relationshipsAssociation classesRepresenting relationships with cardinalityAggregation versus compositionRepresenting aggregation and composition relationshipsRepresenting generalization/ specialization (inheritance)PolymorphismAbstract classes and interfacesSpecification of relationshipsImplementing classes & relationships (bottom-up view of relationships)Class diagram

    Project:Identifying first group of classes based on responsibilitiesPreliminary class diagramIdentifying relationships between classesDefining cardinalitiesClass diagram

    June 10, 2001, 9:00 - 5:00 (part I)Topics to be addressed:Static versus dynamic modelIdentifying scenarios through refinement of use casesModeling scenarios using object-interaction and sequence diagrams

    Project:Refining use casesDeveloping and modeling scenariosIdentifying methodsRefining class specifications

    June 10, 2001 (part II)Topics to be addressed:Events, states and actionsState diagramCriteria for using state diagramsConcurrency, active objectsMutual exclusion problemSequential, guarded, and synchronous objectsModeling concurrencyConcurrent state diagramsActivity diagrams

    Project:Evaluating classes for the need of state diagramsConstructing state diagrams for selected classes(Constructing activity diagrams)Refining class specifications

    June 10, 2001, 9:00 - 2:00Topics to be addressed:Introduction to design patterns: Creational patterns, Abstract Factory, Builder, Prototype, Singleton, Virtual Constructor

    Structural Patterns: Adapter, Bridge, Composite, Decorator, Façade, Proxy

    Behavioral Patterns: Chain of Responsibility, Command, Iterator, Mediator, Memento

    Other important topics to be covered in this course:What to expect from an object-oriented languageDynamic nature of object-oriented systems and the issues of garbage collectionEffective use of inheritance and polymorphism and their impact on software qualitySingle versus multiple inheritancePolymorphism versus genericsClass design and data normalization (attribute dependence issues)


    Object-Oriented Analysis And Design — Introduction (Part 1) | killexams.com real questions and Pass4sure dumps

    The Concept Of Object-Orientation

    Object-orientation is what’s referred to as a programming paradigm. It’s not a language itself but a set of concepts that is supported by many languages.

    If you aren’t familiar with the concepts of object-orientation, you may take a look at The Story of Object-Oriented Programming.

    If everything we do in these languages is object-oriented, it means, we are oriented or focused around objects.

    Now in an object-oriented language, this one large program will instead be split apart into self contained objects, almost like having several mini-programs, each object representing a different part of the application.

    And each object contains its own data and its own logic, and they communicate between themselves.

    These objects aren’t random. They represent the way you talk and think about the problem you are trying to solve in your real life.

    They represent things like employees, images, bank accounts, spaceships, asteroids, video segment, audio files, or whatever exists in your program.

    Object-Oriented Analysis And Design (OOAD)

    It’s a structured method for analyzing, designing a system by applying the object-orientated concepts, and develop a set of graphical system models during the development life cycle of the software.

    OOAD In The SDLC

    The software life cycle is typically divided up into stages going from abstract descriptions of the problem to designs then to code and testing and finally to deployment.

    The earliest stages of this process are analysis (requirements) and design.

    The distinction between analysis and design is often described as “what Vs how”.

    In analysis developers work with users and domain experts to define what the system is supposed to do. Implementation details are supposed to be mostly or totally ignored at this phase.

    The goal of the analysis phase is to create a model of the system regardless of constraints such as appropriate technology. This is typically done via use cases and abstract definition of the most important objects using conceptual model.

    The design phase refines the analysis model and applies the needed technology and other implementation constrains.

    It focuses on describing the objects, their attributes, behavior, and interactions. The design model should have all the details required so that programmers can implement the design in code.

    They’re best conducted in an iterative and incremental software methodologies. So, the activities of OOAD and the developed models aren’t done once, we will revisit and refine these steps continually.

    Object-Oriented Analysis

    In the object-oriented analysis, we …

  • Elicit requirements: Define what does the software need to do, and what’s the problem the software trying to solve.
  • Specify requirements: Describe the requirements, usually, using use cases (and scenarios) or user stories.
  • Conceptual model: Identify the important objects, refine them, and define their relationships and behavior and draw them in a simple diagram.
  • We’re not going to cover the first two activities, just the last one. These are already explained in detail in Requirements Engineering.

    Object-Oriented Design

    The analysis phase identifies the objects, their relationship, and behavior using the conceptual model (an abstract definition for the objects).

    While in design phase, we describe these objects (by creating class diagram from conceptual diagram — usually mapping conceptual model to class diagram), their attributes, behavior, and interactions.

    In addition to applying the software design principles and patterns which will be covered in later tutorials.

    The input for object-oriented design is provided by the output of object-oriented analysis. But, analysis and design may occur in parallel, and the results of one activity can be used by the other.

    In the object-oriented design, we …

  • Describe the classes and their relationships using class diagram.
  • Describe the interaction between the objects using sequence diagram.
  • Apply software design principles and design patterns.
  • A class diagram gives a visual representation of the classes you need. And here is where you get to be really specific about object-oriented principles like inheritance and polymorphism.

    Describing the interactions between those objects lets you better understand the responsibilities of the different objects, the behaviors they need to have.

    — Other diagrams

    There are many other diagrams we can use to model the system from different perspectives; interactions between objects, structure of the system, or the behavior of the system and how it responds to events.

    It’s always about selecting the right diagram for the right need. You should realize which diagrams will be useful when thinking about or discussing a situation that isn’t clear.

    System modeling and the different models we can use will be discussed next.

    System Modeling

    System modeling is the process of developing models of the system, with each model representing a different perspectives of that system.

    The most important aspect about a system model is that it leaves out detail; It’s an abstract representation of the system.

    The models are usually based on graphical notation, which is almost always based on the notations in the Unified Modeling Language (UML). Other models of the system like mathematical model; a detailed system description.

    Models are used during the analysis process to help to elicit the requirements, during the design process to describe the system to engineers, and after implementation to document the system structure and operation.

    Different Perspectives

    We may develop a model to represent the system from different perspectives.

  • External, where you model the context or the environment of the system.
  • Interaction, where you model the interaction between components of a system, or between a system and other systems.
  • Structural, where you model the organization of the system, or the structure of the data being processed by the system.
  • Behavioral, where you model the dynamic behavior of the system and how it respond to events.
  • Unified Modeling Language (UML)

    The unified modeling language become the standard modeling language for object-oriented modeling. It has many diagrams, however, the most diagrams that are commonly used are:

  • Use case diagram: It shows the interaction between a system and it’s environment (users or systems) within a particular situation.
  • Class diagram: It shows the different objects, their relationship, their behaviors, and attributes.
  • Sequence diagram: It shows the interactions between the different objects in the system, and between actors and the objects in a system.
  • State machine diagram: It shows how the system respond to external and internal events.
  • Activity diagram: It shows the flow of the data between the processes in the system.
  • You can do diagramming work on paper or on a whiteboard, at least in the initial stages of a project. But there are some diagramming tools that will help you to draw these UML diagrams.


    Object-oriented design patterns in the kernel, part 2 | killexams.com real questions and Pass4sure dumps

    Did you know...?

    LWN.net is a subscriber-supported publication; we rely on subscribers to keep the entire operation going. Please help out by buying a subscription and keeping LWN on the net.

    June 7, 2011

    This article was contributed by Neil Brown

    In the first part of this analysis we looked at how the polymorphic side of object-oriented programming was implemented in the Linux kernel using regular C constructs. In particular we examined method dispatch, looked at the different forms that vtables could take, and the circumstances where separate vtables were eschewed in preference for storing function pointers directly in objects. In this conclusion we will explore a second important aspect of object-oriented programming - inheritance, and in particular data inheritance.

    Data inheritance

    Inheritance is a core concept of object-oriented programming, though it comes in many forms, whether prototype inheritance, mixin inheritance, subtype inheritance, interface inheritance etc., some of which overlap. The form that is of interest when exploring the Linux kernel is most like subtype inheritance, where a concrete or "final" type inherits some data fields from a "virtual" parent type. We will call this "data inheritance" to emphasize the fact that it is the data rather than the behavior that is being inherited.

    Put another way, a number of different implementations of a particular interface share, and separately extend, a common data structure. They can be said to inherit from that data structure. There are three different approaches to this sharing and extending that can be found in the Linux kernel, and all can be seen by exploring the struct inode structure and its history, though they are widely used elsewhere.

    Extension through unions

    The first approach, which is probably the most obvious but also the least flexible, is to declare a union as one element of the common structure and, for each implementation, to declare an entry in that union with extra fields that the particular implementation needs. This approach was introduced to struct inode in Linux-0.97.2 (August 1992) when

    union { struct minix_inode_info minix_i; struct ext_inode_info ext_i; struct msdos_inode_info msdos_i; } u;

    was added to struct inode. Each of these structures remained empty until 0.97.5 when i_data was moved from struct inode to struct ext_inode_info. Over the years several more "inode_info" fields were added for different filesystems, peaking at 28 different "inode_info" structures in 2.4.14.2 when ext3 was added.

    This approach to data inheritance is simple and straightforward, but is also somewhat clumsy. There are two obvious problems. Firstly, every new filesystem implementation needs to add an extra field to the union "u". With 3 fields this may not seem like a problem, with 28 it was well past "ugly". Requiring every filesystem to update this one structure is a barrier to adding filesystems that is unnecessary. Secondly, every inode allocated will be the same size and will be large enough to store the data for any filesystem. So a filesystem that wants lots of space in its "inode_info" structure will impose that space cost on every other filesystem.

    The first of these issues is not an impenetrable barrier as we will see shortly. The second is a real problem and the general ugliness of the design encouraged change. Early in the 2.5 development series this change began; it was completed by 2.5.7 when there were no "inode_info" structures left in union u (though the union itself remained until 2.6.19).

    Embedded structures

    The change that happened to inodes in early 2.5 was effectively an inversion. The change which removed ext3_i from struct inode.u also added a struct inode, called vfs_inode, to struct ext3_inode_info. So instead of the private structure being embedded in the common data structure, the common data structure is now embedded in the private one. This neatly avoids the two problems with unions; now each filesystem needs to only allocate memory to store its own structure without any need to know anything about what other filesystems might need. Of course nothing ever comes for free and this change brought with it other issues that needed to be solved, but the solutions were not costly.

    The first difficulty is the fact that when the common filesystem code - the VFS layer - calls into a specific filesystem it passes a pointer to the common data structure, the struct inode. Using this pointer, the filesystem needs to find a pointer to its own private data structure. An obvious approach is to always place the struct inode at the top of the private inode structure and simply cast a pointer to one into a pointer to the other. While this can work, it lacks any semblance of type safety and makes it harder to arrange fields in the inode to get optimal performance - as some kernel developers are wont to do.

    The solution was to use the list_entry() macro to perform the necessary pointer arithmetic, subtracting from the address of the struct inode its offset in the private data structure and then casting this appropriately. The macro for this was called list_entry() simply because the "list.h lists" implementation was the first to use this pattern of data structure embedding. The list_entry() macro did exactly what was needed and so it was used despite the strange name. This practice lasted until 2.5.28 when a new container_of() macro was added which implemented the same functionality as list_entry(), though with slightly more type safety and a more meaningful name. With container_of() it is a simple matter to map from an embedded data structure to the structure in which it is embedded.

    The second difficulty was that the filesystem had to be responsible for allocating the inode - it could no longer be allocated by common code as the common code did not have enough information to allocate the correct amount of space. This simply involved adding alloc_inode() and destroy_inode() methods to the super_operations structure and calling them as appropriate.

    Void pointers

    As noted earlier, the union pattern was not an impenetrable barrier to adding new filesystems independently. This is because the union u had one more field that was not an "inode_info" structure. A generic pointer field called generic_ip was added in Linux-1.0.5, but it was not used until 1.3.7. Any file system that does not own a structure in struct inode itself could define and allocate a separate structure and link it to the inode through u.generic_ip. This approach addressed both of the problems with unions as no changes are needed to shared declarations and each filesystem only uses the space that it needs. However it again introduced new problems of its own.

    Using generic_ip, each filesystem required two allocations for each inode instead of one and this could lead to more wastage depending on how the structure size was rounded up for allocation; it also required writing more error-handling code. Also there was memory used for the generic_ip pointer and often for a back pointer from the private structure to the common struct inode. Both of these are wasted space compared with the union approach or the embedding approach.

    Worse than this though, an extra memory dereference was needed to access the private structure from the common structure; such dereferences are best avoided. Filesystem code will often need to access both the common and the private structures. This either requires lots of extra memory dereferences, or it requires holding the address of the private structure in a register which increases register pressure. It was largely these concerns that stopped struct inode from ever migrating to broad use of the generic_ip pointer. It was certainly used, but not by the major, high-performance filesystems.

    Though this pattern has problems it is still in wide use. struct super_block has an s_fs_info pointer which serves the same purpose as u.generic_ip (which has since been renamed to i_private when the u union was finally removed - why it was not completely removed is left as an exercise for the reader). This is the only way to store filesystem-private data in a super_block. A simple search in the Linux include files shows quite a collection of fields which are void pointers named "private" or something similar. Many of these are examples of the pattern of extending a data type by using a pointer to a private extension, and most of these could be converted to using the embedded-structure pattern.

    Beyond inodes

    While inodes serve as an effective vehicle to introduce these three patterns they do not display the full scope of any of them so it is useful to look further afield and see what else we can learn.

    A survey of the use of unions elsewhere in the kernel shows that they are widely used though in very different circumstances than in struct inode. The particular aspect of inodes that is missing elsewhere is that a wide range of different modules (different filesystems) each wanted to extend an inode in different ways. In most places where unions are used there are a small fixed number of subtypes of the base type and there is little expectation of more being added. A simple example of this is struct nfs_fattr which stores file attribute information decoded out of an NFS reply. The details of these attributes are slightly different for NFSv2 and NFSv3 so there are effectively two subtypes of this structure with the difference encoded in a union. As NFSv4 uses the same information as NFSv3 this is very unlikely to ever be extended further.

    A very common pattern in other uses of unions in Linux is for encoding messages that are passed around, typically between the kernel and user-space. struct siginfo is used to convey extra information with a signal delivery. Each signal type has a different type of ancillary information, so struct siginfo has a union to encode six different subtypes. union inputArgs appears to be the largest current union with 22 different subtypes. It is used by the "coda" network file system to pass requests between the kernel module and a user-space daemon which handles the network communication.

    It is not clear whether these examples should be considered as the same pattern as the original struct inode. Do they really represent different subtypes of a base type, or is it just one type with internal variants? The Eiffel object-oriented programming language does not support variant types at all except through subtype inheritance so there is clearly a school of thought that would want to treat all usages of union as a form of subtyping. Many other languages, such as C++, provide both inheritance and unions allowing the programmer to make a choice. So the answer is not clear.

    For our purposes it doesn't really matter what we call it as long as we know where to use each pattern. The examples in the kernel fairly clearly show that when all of the variants are understood by a single module, then a union is a very appropriate mechanism for variants structures, whether you want to refer to them as using data inheritance or not. When different subtypes are managed by different modules, or at least widely separate pieces of code, then one of the other mechanisms is preferred. The use of unions for this case has almost completely disappeared with only struct cycx_device remaining as an example of a deprecated pattern.

    Problems with void pointers

    Void pointers are not quite so easy to classify. It would probably be fair to say that void pointers are the modern equivalent of "goto" statements. They can be very useful but they can also lead to very convoluted designs. A particular problem is that when you look at a void pointer, like looking at a goto, you don't really know what it is pointing at. A void pointer called private is even worse - it is like a "goto destination" command - almost meaningless without reading lots of context.

    Examining all the different uses that void pointers can be put to would be well beyond the scope of this article. Instead we will restrict our attention to just one new usage which relates to data inheritance and illustrates how the untamed nature of void pointers makes it hard to recognize their use in data inheritance. The example we will use to explain this usage is struct seq_file used by the seq_file library which makes it easy to synthesize simple text files like some of those in /proc. The "seq" part of seq_file simply indicates that the file contains a sequence of lines corresponding to a sequence of items of information in the kernel, so /proc/mounts is a seq_file which walks through the mount table reporting each mount on a single line.

    When seq_open() is used to create a new seq_file it allocates a struct seq_file and assigns it to the private_data field of the struct file which is being opened. This is a straightforward example of void pointer based data inheritance where the struct file is the base type and the struct seq_file is a simple extension to that type. It is a structure that never exists by itself but is always the private_data for some file. struct seq_file itself has a private field which is a void pointer and it can be used by clients of seq_file to add extra state to the file. For example md_seq_open() allocates a struct mdstat_info structure and attaches it via this private field, using it to meet md's internal needs. Again, this is simple data inheritance following the described pattern.

    However the private field of struct seq_file is used by svc_pool_stats_open() in a subtly but importantly different way. In this case the extra data needed is just a single pointer. So rather than allocating a local data structure to refer to from the private field, svc_pool_stats_open simply stores that pointer directly in the private field itself. This certainly seems like a sensible optimization - performing an allocation to store a single pointer would be a waste - but it highlights exactly the source of confusion that was suggested earlier: that when you look at a void pointer you don't really know what is it pointing at, or why.

    To make it a bit clearer what is happening here, it is helpful to imagine "void *private" as being like a union of every different possible pointer type. If the value that needs to be stored is a pointer, it can be stored in this union following the "unions for data inheritance" pattern. If the value is not a single pointer, then it gets stored in allocated space following the "void pointers for data inheritance" pattern. Thus when we see a void pointer being used it may not be obvious whether it is being used to point to an extension structure for data inheritance, or being used as an extension for data inheritance (or being used as something else altogether).

    To highlight this issue from a slightly different perspective it is instructive to examine struct v4l2_subdev which represents a sub-device in a video4linux device, such as a sensor or camera controller within a webcam. According to the (rather helpful) documentation it is expected that this structure will normally be embedded in a larger structure which contains extra state. However this structure still has not just one but two void pointers, both with names suggesting that they are for private use by subtypes:

    /* pointer to private data */ void *dev_priv; void *host_priv;

    It is common that a v4l sub-device (a sensor, usually) will be realized by, for example, an I2C device (much as a block device which stores your filesystem might be realized by an ATA or SCSI device). To allow for this common occurrence, struct v4l2_subdev provides a void pointer (dev_priv), so that the driver itself doesn't need to define a more specific pointer in the larger structure which struct v4l2_subdev would be embedded in. host_priv is intended to point back to a "parent" device such as a controller which acquires video data from the sensor. Of the three drivers which use this field, one appears to follow that intention while the other two use it to point to an allocated extension structure. So both of these pointers are intended to be used following the "unions for data inheritance" pattern, where a void pointer is playing the role of a union of many other pointer types, but they are not always used that way.

    It is not immediately clear that defining this void pointer in case it is useful is actually a valuable service to provide given that the device driver could easily enough define its own (type safe) pointer in its extension structure. What is clear is that an apparently "private" void pointer can be intended for various qualitatively different uses and, as we have seen in two different circumstances, they may not be used exactly as expected.

    In short, recognizing the "data inheritance through void pointers" pattern is not easy. A fairly deep examination of the code is needed to determine the exact purpose and usage of void pointers.

    A diversion into struct page

    Before we leave unions and void pointers behind a look at struct page may be interesting. This structure uses both of these patterns, though they are hidden somewhat due to historical baggage. This example is particularly instructive because it is one case where struct embedding simply is not an option.

    In Linux memory is divided into pages, and these pages are put to a variety of different uses. Some are in the "page cache" used to store the contents of files. Some are "anonymous pages" holding data used by applications. Some are used as "slabs" and divided into pieces to answer kmalloc() requests. Others are simply part of a multi-page allocation or maybe are on a free list waiting to be used. Each of these different use cases could be seen as a subtype of the general class of "page", and in most cases need some dedicated fields in struct page, such as a struct address_space pointer and index when used in the page cache, or struct kmem_cache and freelist pointers when used as a slab.

    Each page always has the same struct page describing it, so if the effective type of the page is to change - as it must as the demands for different uses of memory change over time - the type of the struct page must change within the lifetime of that structure. While many type systems are designed assuming that the type of an object is immutable, we find here that the kernel has a very real need for type mutability. Both unions and void pointers allow types to change and as noted, struct page uses both.

    At the first level of subtyping there are only a small number of different subtypes as listed above; these are all known to the core memory management code, so a union would be ideal here. Unfortunately struct page has three unions with fields for some subtypes spread over all three, thus hiding the real structure somewhat.

    When the primary subtype in use has the page being used in the page cache, the particular address_space that it belongs to may want to extend the data structure further. For this purpose there is a private field that can be used. However it is not a void pointer but is an unsigned long. Many places in the kernel assume an unsigned long and a void * are the same size and this is one of them. Most users of this field actually store a pointer here and have to cast it back and forth. The "buffer_head" library provides macros attach_page_buffers and page_buffers to set and get this field.

    So while struct page is not the most elegant example, it is an informative example of a case where unions and void pointers are the only option for providing data inheritance.

    The details of structure embedding

    Where structure embedding can be used, and where the list of possible subtypes is not known in advance, it seems to be increasingly the preferred choice. To gain a full understanding of it we will again need to explore a little bit further than inodes and contrast data inheritance with other uses of structure embedding.

    There are essentially three uses for structure embedding - three reasons for including a structure within another structure. Sometimes there is nothing particularly interesting going on. Data items are collected together into structures and structures within structures simply to highlight the closeness of the relationships between the different items. In this case the address of the embedded structure is rarely taken, and it is never mapped back to the containing structure using container_of().

    The second use is the data inheritance embedding that we have already discussed. The third is like it but importantly different. This third use is typified by struct list_head and other structs used as an embedded anchor when creating abstract data types.

    The use of an embedded anchor like struct list_head can be seen as a style of inheritance as the structure containing it "is-a" member of a list by virtue of inheriting from struct list_head. However it is not a strict subtype as a single object can have several struct list_heads embedded - struct inode has six (if we include the similar hlist_node). So it is probably best to think of this sort of embedding more like a "mixin" style of inheritance. The struct list_head provides a service - that of being included in a list - that can be mixed-in to other objects, an arbitrary number of times.

    A key aspect of data inheritance structure embedding that differentiates it from each of the other two is the existence of a reference counter in the inner-most structure. This is an observation that is tied directly to the fact that the Linux kernel uses reference counting as the primary means of lifetime management and so would not be shared by systems that used, for example, garbage collection to manage lifetimes.

    In Linux, every object with an independent existence will have a reference counter, sometimes a simple atomic_t or even an int, though often a more explicit struct kref. When an object is created using several levels of inheritance the reference counter could be buried quite deeply. For example a struct usb_device embeds a struct device which embeds struct kobject which has a struct kref. So usb_device (which might in turn be embedded in a structure for some specific device) does have a reference counter, but it is contained several levels down in the nest of structure embedding. This contrasts quite nicely with a list_head and similar structures. These have no reference counter, have no independent existence and simply provide a service to other data structures.

    Though it seems obvious when put this way, it is useful to remember that a single object cannot have two reference counters - at least not two lifetime reference counters (It is fine to have two counters like s_active and s_count in struct super_block which count different things). This means that multiple inheritance in the "data inheritance" style is not possible. The only form of multiple inheritance that can work is the mixin style used by list_head as mentioned above.

    It also means that, when designing a data structure, it is important to think about lifetime issues and whether this data structure should have its own reference counter or whether it should depend on something else for its lifetime management. That is, whether it is an object in its own right, or simply a service provided to other objects. These issues are not really new and apply equally to void pointer inheritance. However an important difference with void pointers is that it is relatively easy to change your mind later and switch an extension structure to be a fully independent object. Structure embedding requires the discipline of thinking clearly about the problem up front and making the right decision early - a discipline that is worth encouraging.

    The other key telltale for data inheritance structure embedding is the set of rules for allocating and initializing new instances of a structure, as has already been hinted at. When union or void pointer inheritance is used the main structure is usually allocated and initialized by common code (the mid-layer) and then a device specific open() or create() function is called which can optionally allocate and initialize any extension object. By contrast when structure embedding is used the structure needs to be allocated by the lowest level device driver which then initializes its own fields and calls in to common code to initialize the common fields.

    Continuing the struct inode example from above which has an alloc_inode() method in the super_block to request allocation, we find that initialization is provided for with inode_init_once() and inode_init_always() support functions. The first of these is used when the previous use of a piece of memory is unknown, the second is sufficient by itself when we know that the memory was previously used for some other inode. We see this same pattern of an initializer function separate from allocation in kobject_init(), kref_init(), and device_initialize().

    So apart from the obvious embedding of structures, the pattern of "data inheritance through structure embedding" can be recognized by the presence of a reference counter in the innermost structure, by the delegation of structure allocation to the final user of the structure, and by the provision of initializing functions which initialize a previously allocated structure.

    Conclusion

    In exploring the use of method dispatch (last week) and data inheritance (this week) in the Linux kernel we find that while some patterns seem to dominate they are by no means universal. While almost all data inheritance could be implemented using structure embedding, unions provide real value in a few specific cases. Similarly while simple vtables are common, mixin vtables are very important and the ability to delegate methods to a related object can be valuable.

    We also find that there are patterns in use with little to recommend them. Using void pointers for inheritance may have an initial simplicity, but causes longer term wastage, can cause confusion, and could nearly always be replaced by embedded inheritance. Using NULL pointers to indicate default behavior is similarly a poor choice - when the default is important there are better ways to provide for it.

    But maybe the most valuable lesson is that the Linux kernel is not only a useful program to run, it is also a useful document to study. Such study can find elegant practical solutions to real problems, and some less elegant solutions. The willing student can pursue the former to help improve their mind, and pursue the latter to help improve the kernel itself. With that in mind, the following exercises might be of interest to some.

    Exercises
  • As inodes now use structure embedding for inheritance, void pointers should not be necessary. Examine the consequences and wisdom of removing "i_private" from "struct inode".

  • Rearrange the three unions in struct page to just one union so that the enumeration of different subtypes is more explicit.

  • As was noted in the text, struct seq_file can be extended both through "void pointer" and a limited form of "union" data inheritance. Explain how seq_open_private() allows this structure to also be extended through "embedded structure" data inheritance and give an example by converting one usage in the kernel from "void pointer" to "embedded structure". Consider submitting a patch if this appears to be an improvement. Contrast this implementation of embedded structure inheritance with the mechanism used for inodes.

  • Though subtyping is widely used in the kernel, it is not uncommon for a object to contain fields that not all users are interested in. This can indicate that more fine grained subtyping is possible. As very many completely different things can be represented by a "file descriptor", it is likely that struct file could be a candidate for further subtyping.

    Identify the smallest set of fields that could serve as a generic struct file and explore the implications of embedding that in different structures to implement regular files, socket files, event files, and other file types. Exploring more general use of the proposed open() method for inodes might help here.

  • Identify an "object-oriented" language which has an object model that would meet all the needs of the Linux kernel as identified in these two articles.

  • (Log in to post comments)


    Direct Download of over 5500 Certification Exams

    3COM [8 Certification Exam(s) ]
    AccessData [1 Certification Exam(s) ]
    ACFE [1 Certification Exam(s) ]
    ACI [3 Certification Exam(s) ]
    Acme-Packet [1 Certification Exam(s) ]
    ACSM [4 Certification Exam(s) ]
    ACT [1 Certification Exam(s) ]
    Admission-Tests [13 Certification Exam(s) ]
    ADOBE [93 Certification Exam(s) ]
    AFP [1 Certification Exam(s) ]
    AICPA [2 Certification Exam(s) ]
    AIIM [1 Certification Exam(s) ]
    Alcatel-Lucent [13 Certification Exam(s) ]
    Alfresco [1 Certification Exam(s) ]
    Altiris [3 Certification Exam(s) ]
    Amazon [2 Certification Exam(s) ]
    American-College [2 Certification Exam(s) ]
    Android [4 Certification Exam(s) ]
    APA [1 Certification Exam(s) ]
    APC [2 Certification Exam(s) ]
    APICS [2 Certification Exam(s) ]
    Apple [69 Certification Exam(s) ]
    AppSense [1 Certification Exam(s) ]
    APTUSC [1 Certification Exam(s) ]
    Arizona-Education [1 Certification Exam(s) ]
    ARM [1 Certification Exam(s) ]
    Aruba [6 Certification Exam(s) ]
    ASIS [2 Certification Exam(s) ]
    ASQ [3 Certification Exam(s) ]
    ASTQB [8 Certification Exam(s) ]
    Autodesk [2 Certification Exam(s) ]
    Avaya [96 Certification Exam(s) ]
    AXELOS [1 Certification Exam(s) ]
    Axis [1 Certification Exam(s) ]
    Banking [1 Certification Exam(s) ]
    BEA [5 Certification Exam(s) ]
    BICSI [2 Certification Exam(s) ]
    BlackBerry [17 Certification Exam(s) ]
    BlueCoat [2 Certification Exam(s) ]
    Brocade [4 Certification Exam(s) ]
    Business-Objects [11 Certification Exam(s) ]
    Business-Tests [4 Certification Exam(s) ]
    CA-Technologies [21 Certification Exam(s) ]
    Certification-Board [10 Certification Exam(s) ]
    Certiport [3 Certification Exam(s) ]
    CheckPoint [41 Certification Exam(s) ]
    CIDQ [1 Certification Exam(s) ]
    CIPS [4 Certification Exam(s) ]
    Cisco [318 Certification Exam(s) ]
    Citrix [48 Certification Exam(s) ]
    CIW [18 Certification Exam(s) ]
    Cloudera [10 Certification Exam(s) ]
    Cognos [19 Certification Exam(s) ]
    College-Board [2 Certification Exam(s) ]
    CompTIA [76 Certification Exam(s) ]
    ComputerAssociates [6 Certification Exam(s) ]
    Consultant [2 Certification Exam(s) ]
    Counselor [4 Certification Exam(s) ]
    CPP-Institue [2 Certification Exam(s) ]
    CPP-Institute [1 Certification Exam(s) ]
    CSP [1 Certification Exam(s) ]
    CWNA [1 Certification Exam(s) ]
    CWNP [13 Certification Exam(s) ]
    Dassault [2 Certification Exam(s) ]
    DELL [9 Certification Exam(s) ]
    DMI [1 Certification Exam(s) ]
    DRI [1 Certification Exam(s) ]
    ECCouncil [21 Certification Exam(s) ]
    ECDL [1 Certification Exam(s) ]
    EMC [129 Certification Exam(s) ]
    Enterasys [13 Certification Exam(s) ]
    Ericsson [5 Certification Exam(s) ]
    ESPA [1 Certification Exam(s) ]
    Esri [2 Certification Exam(s) ]
    ExamExpress [15 Certification Exam(s) ]
    Exin [40 Certification Exam(s) ]
    ExtremeNetworks [3 Certification Exam(s) ]
    F5-Networks [20 Certification Exam(s) ]
    FCTC [2 Certification Exam(s) ]
    Filemaker [9 Certification Exam(s) ]
    Financial [36 Certification Exam(s) ]
    Food [4 Certification Exam(s) ]
    Fortinet [13 Certification Exam(s) ]
    Foundry [6 Certification Exam(s) ]
    FSMTB [1 Certification Exam(s) ]
    Fujitsu [2 Certification Exam(s) ]
    GAQM [9 Certification Exam(s) ]
    Genesys [4 Certification Exam(s) ]
    GIAC [15 Certification Exam(s) ]
    Google [4 Certification Exam(s) ]
    GuidanceSoftware [2 Certification Exam(s) ]
    H3C [1 Certification Exam(s) ]
    HDI [9 Certification Exam(s) ]
    Healthcare [3 Certification Exam(s) ]
    HIPAA [2 Certification Exam(s) ]
    Hitachi [30 Certification Exam(s) ]
    Hortonworks [4 Certification Exam(s) ]
    Hospitality [2 Certification Exam(s) ]
    HP [750 Certification Exam(s) ]
    HR [4 Certification Exam(s) ]
    HRCI [1 Certification Exam(s) ]
    Huawei [21 Certification Exam(s) ]
    Hyperion [10 Certification Exam(s) ]
    IAAP [1 Certification Exam(s) ]
    IAHCSMM [1 Certification Exam(s) ]
    IBM [1532 Certification Exam(s) ]
    IBQH [1 Certification Exam(s) ]
    ICAI [1 Certification Exam(s) ]
    ICDL [6 Certification Exam(s) ]
    IEEE [1 Certification Exam(s) ]
    IELTS [1 Certification Exam(s) ]
    IFPUG [1 Certification Exam(s) ]
    IIA [3 Certification Exam(s) ]
    IIBA [2 Certification Exam(s) ]
    IISFA [1 Certification Exam(s) ]
    Intel [2 Certification Exam(s) ]
    IQN [1 Certification Exam(s) ]
    IRS [1 Certification Exam(s) ]
    ISA [1 Certification Exam(s) ]
    ISACA [4 Certification Exam(s) ]
    ISC2 [6 Certification Exam(s) ]
    ISEB [24 Certification Exam(s) ]
    Isilon [4 Certification Exam(s) ]
    ISM [6 Certification Exam(s) ]
    iSQI [7 Certification Exam(s) ]
    ITEC [1 Certification Exam(s) ]
    Juniper [64 Certification Exam(s) ]
    LEED [1 Certification Exam(s) ]
    Legato [5 Certification Exam(s) ]
    Liferay [1 Certification Exam(s) ]
    Logical-Operations [1 Certification Exam(s) ]
    Lotus [66 Certification Exam(s) ]
    LPI [24 Certification Exam(s) ]
    LSI [3 Certification Exam(s) ]
    Magento [3 Certification Exam(s) ]
    Maintenance [2 Certification Exam(s) ]
    McAfee [8 Certification Exam(s) ]
    McData [3 Certification Exam(s) ]
    Medical [69 Certification Exam(s) ]
    Microsoft [374 Certification Exam(s) ]
    Mile2 [3 Certification Exam(s) ]
    Military [1 Certification Exam(s) ]
    Misc [1 Certification Exam(s) ]
    Motorola [7 Certification Exam(s) ]
    mySQL [4 Certification Exam(s) ]
    NBSTSA [1 Certification Exam(s) ]
    NCEES [2 Certification Exam(s) ]
    NCIDQ [1 Certification Exam(s) ]
    NCLEX [2 Certification Exam(s) ]
    Network-General [12 Certification Exam(s) ]
    NetworkAppliance [39 Certification Exam(s) ]
    NI [1 Certification Exam(s) ]
    NIELIT [1 Certification Exam(s) ]
    Nokia [6 Certification Exam(s) ]
    Nortel [130 Certification Exam(s) ]
    Novell [37 Certification Exam(s) ]
    OMG [10 Certification Exam(s) ]
    Oracle [279 Certification Exam(s) ]
    P&C [2 Certification Exam(s) ]
    Palo-Alto [4 Certification Exam(s) ]
    PARCC [1 Certification Exam(s) ]
    PayPal [1 Certification Exam(s) ]
    Pegasystems [12 Certification Exam(s) ]
    PEOPLECERT [4 Certification Exam(s) ]
    PMI [15 Certification Exam(s) ]
    Polycom [2 Certification Exam(s) ]
    PostgreSQL-CE [1 Certification Exam(s) ]
    Prince2 [6 Certification Exam(s) ]
    PRMIA [1 Certification Exam(s) ]
    PsychCorp [1 Certification Exam(s) ]
    PTCB [2 Certification Exam(s) ]
    QAI [1 Certification Exam(s) ]
    QlikView [1 Certification Exam(s) ]
    Quality-Assurance [7 Certification Exam(s) ]
    RACC [1 Certification Exam(s) ]
    Real-Estate [1 Certification Exam(s) ]
    RedHat [8 Certification Exam(s) ]
    RES [5 Certification Exam(s) ]
    Riverbed [8 Certification Exam(s) ]
    RSA [15 Certification Exam(s) ]
    Sair [8 Certification Exam(s) ]
    Salesforce [5 Certification Exam(s) ]
    SANS [1 Certification Exam(s) ]
    SAP [98 Certification Exam(s) ]
    SASInstitute [15 Certification Exam(s) ]
    SAT [1 Certification Exam(s) ]
    SCO [10 Certification Exam(s) ]
    SCP [6 Certification Exam(s) ]
    SDI [3 Certification Exam(s) ]
    See-Beyond [1 Certification Exam(s) ]
    Siemens [1 Certification Exam(s) ]
    Snia [7 Certification Exam(s) ]
    SOA [15 Certification Exam(s) ]
    Social-Work-Board [4 Certification Exam(s) ]
    SpringSource [1 Certification Exam(s) ]
    SUN [63 Certification Exam(s) ]
    SUSE [1 Certification Exam(s) ]
    Sybase [17 Certification Exam(s) ]
    Symantec [134 Certification Exam(s) ]
    Teacher-Certification [4 Certification Exam(s) ]
    The-Open-Group [8 Certification Exam(s) ]
    TIA [3 Certification Exam(s) ]
    Tibco [18 Certification Exam(s) ]
    Trainers [3 Certification Exam(s) ]
    Trend [1 Certification Exam(s) ]
    TruSecure [1 Certification Exam(s) ]
    USMLE [1 Certification Exam(s) ]
    VCE [6 Certification Exam(s) ]
    Veeam [2 Certification Exam(s) ]
    Veritas [33 Certification Exam(s) ]
    Vmware [58 Certification Exam(s) ]
    Wonderlic [2 Certification Exam(s) ]
    Worldatwork [2 Certification Exam(s) ]
    XML-Master [3 Certification Exam(s) ]
    Zend [6 Certification Exam(s) ]





    References :


    Dropmark : http://killexams.dropmark.com/367904/11772769
    Wordpress : http://wp.me/p7SJ6L-1vT
    Dropmark-Text : http://killexams.dropmark.com/367904/12337091
    Issu : https://issuu.com/trutrainers/docs/000-834
    Blogspot : http://killexamsbraindump.blogspot.com/2017/11/pass4sure-000-834-practice-tests-with.html
    RSS Feed : http://feeds.feedburner.com/JustMemorizeThese000-834QuestionsBeforeYouGoForTest
    Box.net : https://app.box.com/s/fkkjfgucwbnj1gw7f9wfff5j2dw19nsh
    zoho.com : https://docs.zoho.com/file/64ypub2c738a9eb44443a80bd723ebf70dac0






    Back to Main Page

    You really have to study hard. These questions are a big help and worth the price. Test Engine has specific steps which you need to follow in order to install it. But is a nice piece of software.

    Rajesh | INDIA



    I ordered this exam prep. The content is well formatted and pretty clean. I was able to use the PDF and the Test Engine to prepare. Quite helpful.

    Lisa | UNITED STATES



    Great Black Friday deal and good content. I am impressed

    Mike | Anonymous



    fast and easy order. No issues. I can't wait to pass this test!

    teechee | UNITED STATES



    Wouldn't have passed if I had not studied from this dump. Good job guys.

    Mitul | INDIA



    I did get about 80-85% of the questions in my exam. So it is a valid one.

    James | UNITED STATES



    What joy!
    I passed my exam today.

    Zan | UNITED KINGDOM



    Good Content

    Raj | UNITED STATES



    Trying to download the updates. Pretty solid braindumps.

    cpinkney | UNITED STATES



    Excellent!

    elixir | UNITED STATES



    Good, Definitely worth the investment.

    Tom | UNITED STATES



    I just completed the test and got a 96%. missed only 2 questions.

    Sahil | Franfurt



    I thought i should thank you for assisting me to obtain my ITIL qualification. I received the exam on Thursday and i studied the moment i received it. I must say i was very nervous before the exam. Well I wrote and passed. The pass mark was 65% and I scored 92%.
    Thank you so much guys.

    Nahid | Bremen



    I just completed my exam today and wanted to share the great news. Your study guide in combination with self study have helped me to achieve another certification. After the conclusion to this upcoming fall semester I plan to pursue my other goals... I hav

    John | koln



    Great Job. I passed my exam with score of 868. I got 100 questions and could finish the exam within 20 minutes, ofcourse after my two weeks of hard work.

    Anon | Anon



    I took my exam today and passed with a score of 87%. After taking the practise exam with all the 200+ questions included with your material and reading the student manual once I felt that I had no problem passing this exam. Great material!

    JK | Dortmund



    Today, I passed my Exam and I have to say that the your materials for the Exam helped get me into the right frame of mind for taking the exam. The Help button for each question is an invaluable feature. Great job getting this together!

    Munchi | Rotterdam



    I just had to say thank you so much for such a fantastic product ! I just completed my exam in 30 minutes with a score of 95%.

    Angili | Emmen



    I just took my Certification testing for Apple exam and passed it with full score. Your questions covered the essence of the exam material.

    Madu | Nederland




    I truely appreciate your prompt response. It has been nice doing business with you. I have already registered for the exam (taking it this weekend) and it went smooth as you assured. I plan to come back to your site in future for my other certification.

    Priyanka | Ireland



    Thanks a lot for your help. I have successfully completed my exams studying your materials. It was a great help by you.
    "It was an excellent total immersion exams material."

    Peter | Leeds UK





    I just passed the exam with 90%. Thanks for your help.

    Audreena | Norwich




    hello again. First of all i'd like to inform you'll that i passed my oracle 1zo-042 exam with the help of your questions. I owe it all to you'll so thank you. Thank you so much. You really changed my life!

    Viki | Belfast



    Yesterday I cleared Solaris 9 Administration Certification Paper Part 1 ( CX 310-014). Your Cheat-Test paper is really very helpful. My test result was 91%.

    Josef | Dundee



    Hey Guys. I wanna thank you for helping me through providing 310-012 exam and Training Material. It is so good that I will recommend all my friends to use.

    Josh | Cardiff



    I just passed my Exam using your QA product. Thanks!

    Reddy | Glasgow



    Warm greetings and let me thank you so very much for the great stuff you are doing. I am now a 000-207 Certified. I passed all with flying colors.

    Jessica | SD



    I passed the written exam with 920. Thank you very much for your services. It was worth every penny of it.

    Bella | VA



    I just wanted you all to know that you have really changed my life. Recently I passed the CCSA exam and now just passed the CCSE exam. My employer is so delighted with my integrity that I just received a 12% pay increase. This is too good to be true. Thank

    Mike | Victoria



    I was feeling helpless for my exam and then find material at your website and passed with 90. thank you guys.

    Racheal | colima



    I purchased your products, it was great, really helped me pass the exam. thank you

    Lisa | Mexico



    I just bought the exam prep two days before writing my exam. I studied the guide inside out and wrote the exam in under 45 minutes! The most amazing part is that I passed with a score of 1000!! WOW, you are the greatest and I will always use your products.

    Vishal | Lahor



    Tried many websites for my 70-500 Exam Preparation but no vain and finally i tried your study material for my exam and it was impressive and I was able to clear Exam with confidence. thanks you very much!

    Aalia | Deli



    I will, you guys have always been really good whenever i buy stuff from u and need questions answering....keep up the good work
    THANK YOU !

    Jacob | Piaui



    I passed the the NSO-111 with flying colors. Thank your for your help.

    Mark | Para



    You gusy Rock!
    killexams.com provided everything you could want and made things very comfortable.

    Tanisha | Sinop



    Great products!! I passed the CCIE written exam on my first attempt!

    Neesha | India



    I have already given up...but your exam and study packs finally made me pass this CCNA exam!

    Angus | Kansas



    My company needed me to pass the CCIP exams, as we are a Service Provider offering more and more Voice Services. Great exam materials you provide!

    Terah | San Angelo



    I was lucky enough to use killexams.com for my 000-630 Certification Exam Training. The difference is clear. I passed the exam without a problem. Have you done it yet or not?

    Kim | Lubbock



    I am very happy with the performance of your 000-094 QA from you. It is no doubt the best.

    Martin | Calgary



    I just made it in the 000-215 Exam. Your 000-215 QA is outclass. Made it so easy for me to succeed.

    Shila M. | Montana



    I have passed all the 7 Windows 2000 MCSE tests with the help of your great guides. Those questions I met in my tests are very very similar, if not the same, with the ones in your guides. 70-220 and 70-221 are so difficult. I can't imagine how I could pass

    Rosa | Monitoba



    Hi, I passed today!!! I passed both my exams within ONE WEEK!!! THANK YOU VERY MUCH!!!

    Aaron G. | vancouver



    I just passed (310-025) SCJP test yesterday. Your guide is right on the money and almost covers every question word for word. Great work !

    seagal | Edmonton



    I passed my exam today with a score of 964. This was a difficult test but the preparation guide was very good. I would not have passed without the materials. Thank you very much for giving me the opportunity to better my life.

    Illya | Alberta



    Exam syo-101 Exam
    I passed my exam today with no problem whatsoever. I just wanted to say a sincere thank you for the outstanding study guide. You guys are a phenomenal help when it comes to study assistance. Thanks and definitely expect to see me again.

    Jackson | MJ



    Exam 1Z0-040: 1Z0-040 passed!!!
    I have passed my exam 59/60. You people are the boom. Thanks for the exam questions. They were so real!!

    CJ | DC



    Dear Support,
    I passed (as you expected) the Sun Solaris Admin I (310-011) at first trial. Thank you so much.

    Oshrit | Israel



    Just thought I would let you know I took the CCDA test on Tuesday, like I planned and scored a 902!"

    Lee W. | China



    I have used your Exams for preparation for 70-290, 70-291, 70-292, 70-296, 70-298, 70- 299, 70-300, 70-305, 70-310, 70-315, 70-316,70-320. I also passed all those on the first round. I'm currently preparing for the CCNA.

    Micheal C. | ON



    Now my dream has come true. I thank you a million times for the best study guides that you provided to a poor kid like me....I got it. Finally MCSE.

    Best regards,

    kris J. | GTA



    I passed my CCNA exam yesterday. I would like to make some comments. "Excellent Study Guide, Excellent Support Service, Excellent Examination Web Site"
    Best Regards

    Jason | California



    Thanks for your study guides, i have passed it. All questions in your material, we study this only 2 days. Thanks very very much!!!!!

    Micheal | US



    Thanks very much for your study guides, with your help i only use 3 weeks to take the MCSE. Your study guides are very very good.

    L. Woo | China



    I passed the CCIE Written exam 350-001 last Friday, Thanks very much for your study guide and your help.

    Mick H. | US



    i ust wanted to thank you folks at braindumgalaxy.com for your assistance. I used your CCNP exams for practice and to identify my weak areas. Passed the CCNP recert on Tuesday without any big problems.

    Hagit | Israel



    I have found that your resources are probably the best on the market...and I work at Cisco.

    Cisco Engineer | USA



    A well Good morning Dear killexams.com Team I wanna say that I passed the 000-888 yesterday and i am happy

    Koshani | NYC



    I took the A+ hardware exam yesterday and thanks to your excellent and helping preparation material. I got a nice score.

    Aized | Pakistan



    I passed the exam with great distinction!

    Nazanin | Toronto



    Great Price....Great Product. Keep up the good work!

    Xiwan W | China



    So far your practice exams are extremely helpful. My test scores keep on going up every time I do them and I feel very confident now.

    Ashwin | India



    The exams was excellent and helped me pass without any doubt.Very helpful! Thank you! I passed!

    Mike M | Dubai