HARI MAHADEVAN (何瑞理)

One of the fundamental differences between C++ and the more modern and if I dare say popular programming languages such as Java and C#, is the lack of a garbage collector in C++. Often this is used as an example to portray how C++ has not kept up with the times and how code written with the language is a potential minefield for memory leaks. While the debate about the merits of one language over the other continues (and in all possibility would continue for many more years), there are a few steps one can take, as a programmer, that can pretty much minimize, if not eliminate, the chances of a memory leak. I would like to list some of the techniques that I have employed over the years and have worked for me pretty well. Use RAII Use objects to abstract concepts Use std::auto_ptr Turn on memory tagging Use std::vector<> to allocate memory Declare base class destructor as virtual Use RAII Use RAII (Resoure Acquisition Is Initialization) programming paradigm: Per...

Problem One of the common sources of runtime errors in C++ comes from using the good old vararg function types -- printf() or its variants. The problem stems from type mismatch between the type specifier in the format string and the actual arguments supplied to match this format string. Though most of the present-day software do not employ the printf function for user interaction, a variant of it is quite heavily used -- sprintf()  for outputting log messages. Often log messages are written in response to an error condition and formal testing does not always simulate all the possible error conditions which means some code goes untested. Also, log messages typically have an associated logging level which is usually set to a medium value by default. Testers often do not set the logging level to the lowest possible level before embarking on the testing process meaning that messages at the lowest level are also not exercised during testing.  Another real-world situ...

In the last two days, I have been twice bitten by the loose nature of legacy C++ language. I had developed a base class that abstracts the core features of a module a year back. The class itself was a great success. Since developing it for a specific module, I successfully refactored another module to use this and was able to do so in a relatively short window of 1 week. This is the background. Recently, I had an opportunity to re-use this class for another module and having been successful earlier twice, I guess I was a little callous in using it without referring to the accompanied documentation. The design requires that I override a bunch of methods and admittedly I was as little cocky -- if I had designed and implemented it earlier, it should be a snap for me to re-use it. So I wrote the code, compiled it, removed a few syntax errors and dropped it into test. All good, except that couple of overridden methods were not being invoked! WTF? It also so happened that the call...