Nowadays a lot of projects are opening their source code and letting those who are interested in the development of it edit the code. OpenJDK is no exception, programmers PVS-Studio have found a lot of interesting errors that are worth paying attention to.
OpenJDK (Open Java Development Kit) - a project for the creation and implementation of Java (Java SE) platform, which is now free and open source. The project was started in 2006, by the Sun company. The project uses multiple languages- C, C++, and Java. We are interested in the source code written in C and C++. Let's take the 9th version of OpenJDK. The code of this implementation of Java platform is available at the Mercurial repository.
During verification, the analyzer found different errors in the project including: copy-paste, bugs in the operation precedence, errors in logical expressions and in pointer handling and other bugs, which are described in detail in this article.
It's always amusing to check a project which is used and maintained by a large number of people. The better and more accurate the code is, the more safely and effectively the program will work. Those bugs we found, are another proof of the usefulness of an analyzer, as it allows the detection of such errors which would otherwise be hard to detect doing simple code review.
Here is a small e-Book for your attention: The Ultimate Question of Programming, Refactoring, and Everything. This book is intended for C/C++ programmers, but it could be of interest for developers using other languages as well.
What makes the book peculiar is the descriptions of real, not theoretical cases at the base of it. Each chapter starts with a code fragment taken from a real application, and then the author gives various tips of how this bug could be avoided. The questions touched upon in this book can help the readers improve the personal coding style and the coding standards used in the team.
The authors of the PVS-Studio analyzer invite you to test your attentiveness.
Code analyzers never get tired and can find errors a human's eye cannot easily notice. We have picked a few code fragments with errors revealed by PVS-Studio, all the fragments taken from well-known open-source projects.
We invite you to take part in a competition against code analyzers to test your agility by trying to find the errors by yourself. You will be offered 15 randomly selected tasks. Every correct answer earns you one score if you give it within 60 seconds. The code fragments are short and 60 seconds is a fair limit.
Let's examine a couple of examples with errors for you to understand how to give the answer.
In this article I'm going to discuss a problem few people think of. Computer simulation of various processes becomes more and more widespread. This technology is wonderful because it allows us to save time and materials which would be otherwise spent on senseless chemical, biological, physical and other kinds of experiments. A computer simulation model of a wing section flow may help significantly reduce the number of prototypes to be tested in a real wind tunnel. Numerical experiments are given more and more trust nowadays. However, dazzled by the triumph of computer simulation, nobody notices the problem of software complexity growth behind it. People treat computer and computer programs just as a means to obtain necessary results. I'm worried that very few know and care about the fact that software size growth leads to a non-linear growth of the number of software bugs. It's dangerous to exploit a computer treating it just as a big calculator. So, that's what I think - I need to share this idea with other people.
To be honest, I don't know what the TPP project is intended for. As far as I understand, this is a set of tools to assist in research of proteins and their interaction in living organisms. However, that's not so much important. What is important is that their source codes are open. It means that I can check them with the PVS-Studio static analyzer. Which I'm very much fond of.
So, we have checked the Trans-Proteomic Pipeline (TPP) version 4.5.2 project. To learn more about the project, see the following links:
There are easy and hardly fixable bugs. If the easy bugs could be fixed and forgotten, then the other type of BUGS remains with us forever. I want to share with you 3 such BUGS.
The first bug occurred in 2005 when I worked at the firm of FriendScout24. We had tools for monitoring in which was html tag in every line on the server. If the server responded normally there was green color, if it did not there was red. Usually, it showed all green, and then on one fine day the servers started failing, 4 servers went down for 3 minutes. Then, after 5 minutes everything turned green again, as if nothing had happened.