ORDER VIOLATION IN MULTITHREADED APPLICATIONS AND ITS DETECTION IN STATIC CODE ANALYSIS PROCESS

The subject presented in the paper concerns resource conflicts, which are the cause of order violation in multithreaded applications. The work focuses on developing conditions that can be implemented as a tool for allowing to detect these conflicts in the process of static code analysis. The research is based on known errors reported to developers of large applications such as Mozilla Firefox browser and MySQL relational database system. These errors could have been avoided by appropriate monitoring of the source code

GRAPHICAL REPRESENTATIONS OF MULTITHREADED APPLICATIONS

This article contains a brief description of existing graphical methods for presenting multithreaded applications, i.e. Control Flow Graph and Petri nets. These methods will be discussed, and then a way to represent multithreaded applications using the concurrent process system model will be presented. All these methods will be used to present the idea of a multithreaded application that includes the race condition phenomenon. In the summary, all three methods will be compared and subjected to the evaluation, which will depend on whether the given representation will allow to find the mentioned phenomenon

THE MODEL AND FUNCTION OF QUALITY ASSESSMENT OF IMPLEMENTATION OF DESIGN PATTERNS

One of the ways of providing high internal software quality (that is a source code) is using design patterns. The article aims at presenting a suggested model which enables one to assess the quality of implementation of design patterns. The model assumes verification of different aspects of the patterns and a numeric expression of the obtained results. The analysis of the obtained results may show the occurrence of certain problems which are difficult to be identified during code review or testing

VERIFICATION OF ACCURACY AND COST OF USE METHOS OF QUALITY ASSESSMENT OF IMPLEMENTATION OF DESIGN PATTERNS

Professional programmers use many additional tools over the Integrated Development Environment during their work. Very often they are looking for new solutions, while expecting that the new tool will provide accurate results, and the cost of use will fit within the planned budget. The aim of the article is to present the results of two comparative analyzes carried out in terms of accuracy and the cost of using the quality assessment method of implementation of design patterns

The model and the method of quality assessment of design pattern implementation

Design patterns are very popular in programmers. It allow you to solve choosen problems in the object-oriented languages, and also provide some benefits, for example: lower cost of program upgrades. Implementations of patterns (even the same kind) can vary considerably from one another and do not provide the expected benefits. The paper presents a solution for measuring the implementation of patterns, and then provides a verification of this solution in practice and on the space of a joint formal representation

Atomicity Violation in Multithreaded Applications and Its Detection in Static Code Analysis Process

This paper is a contribution to the field of research dealing with the parallel computing, which is used in multithreaded applications. The paper discusses the characteristics of atomicity violation in multithreaded applications and develops a new definition of atomicity violation based on previously defined relationships between operations, that can be used to atomicity violation detection. A method of detection of conflicts causing atomicity violation was also developed using the source code model of multithreaded applications that predicts errors in the software

Order violation in multithreaded applications and its detection in static code analysis process

The subject presented in the paper concerns resource conflicts, which are the cause of order violation in multithreaded applications. The work focuses on developing conditions that can be implemented as a tool for allowing to detect these conflicts in the process of static code analysis. The research is based on known errors reported to developers of large applications such as Mozilla Firefox browser and MySQL relational database system. These errors could have been avoided by appropriate monitoring of the source code

Difficulties in implementation of design pattern in small developers team

There are many small businesses create their own, original software or performing services for third parties, in IT market. Small teams often work by the so-called. agile methodologies, which are limited by the amount of project documentation, and most of the procedures considerably simplified. However, small teams not reject good practice, including design patterns. The aim of the article is to present some difficulties faced by small development teams in the implementation of design patterns, and to present the author’s method of supporting an increase in the quality of implementation of design patterns.Na rynku IT występuje wiele małych przedsiębiorstw tworzących własne, autorskie oprogramowanie lub wykonujące usługi dla firm trzecich. Małe zespoły często pracują według tzw. zwinnych metodyk wytwórczych, w których ograniczona jest ilość dokumentacji projektowej, a większość procedur znacznie uproszczona. Jednakże małe zespoły nie rezygnują ze stosowania dobrych praktyk, w tym wzorców projektowych. Celem artykułu jest przybliżenie wybranych trudności, z którymi borykają się małe zespoły programistyczne przy implementacji wzorców projektowych, oraz przedstawienie autorskiej metody wspomagającej wzrost jakości implementacji wzorców projektowych

Weryfikacja użycia metody oceny jakości implementacji wzorców projektowych w zastosowaniu produkcyjnym

Programiści pracujący zgodnie z metodykami zwinnymi bardzo chętnie implementują wzorce projektowe w trakcie swojej pracy. Często robią to bazując wyłącznie na własnym doświadczeniu, co nie uwzględnia dodatkowych korzyści, których można oczekiwać po implementacji wzorców. Celem artykułu jest przedstawienie przebiegu i wyników z weryfikacji metody oceny wzorców projektowych w zastosowaniu produkcyjnym. Eksperyment przeprowadzono wspólnie z zewnętrzną firmą, pracującą według zwinnej metodyki wytwórczej.Developers working according to agile methodologies are very happy to implement design patterns in their work. They often do so based solely on their own experience, which does not take into account the additional benefits that can be expected from implementing patterns. The purpose of the article is to present the mileage and results of verification of the method of assesment design patterns in production. The experiment was conducted jointly with an external company, working according to a agile manufacturing methodology

Przewidywanie ataków DDoS w środowisku symulacyjnym przy użyciu technik eksploracji danych

The notion of Internet attacks has been well-known in the area of computer networks for a long time now. The effects of these actions can be difficult to rectify and also very expensive.  Therefore, these harmful attacks should be detected in the shortest time possible when the effects are still quite easily reversible. The article presented the results of the research on predicting the occurrence of DoS attacks on the selected network resources by using data mining techniques.Pojęcie związane z atakami sieciowymi jest znane w tematyce sieci komputerowych już od dawna. Efekty ataków sieciowych są trudne do naprawienia i bardzo drogie.  Dlatego też wskazane jest jak najszybsze wykrywanie ataków, tak aby ich skutki były jak najmniej dotkliwe. Artykuł przedstawia wyniki badań dotyczących przewidywania wystąpienia ataku DDoS na wybranych zasobach sieciowych przy użyciu technik eksploracji danych