The Ramifications of a Garbage Collected C++

by

Dare Obasanjo

Ever since I read C++ Answers From Bjarne Stroustrop on Slashdot a few months ago I have been struck by this quote "When (not if) automatic garbage collection becomes part of C++, it will be optional". I am drawn by the fact that C++ may become a garbage collected language and have decided to investigate what exists in C++ garbage collection at the current time and also whether this means that maybe more new server applications will start being written in C++ and not Java. My conclusions and speculations are below.

After clicking around Bjarne Stroustrop's site, I came across links to Hans Boehm's site on garbage collection. There he has a well written page that dissects the advantages and disadvantages of garbage collection in C++. From my readings it is clear that there are several third-party garbage collectors for C++, but currently the C++ standard makes no mention of garbage collection (although I heard that a proposal from Bjarne Stroustrop was voted down sometime ago).

Basically the advantages of Garbage Collection are:

• 30 to 40 percent faster development time.
• Less restrictive interfaces and more reusable code.
• Easier implementation of sophisticated data structures.
• Eliminates some premature deallocation errors.
• Uses equivalent or less CPU-time than a program that uses explicit memory deallocation.

While the disadvantages are

• More interaction with the hard disk (virtual memory/paging) due to examining all pointers in the application.
• May not work if programmers use various tricks and hacks while coding (e.g. casting pointers to ints and back)
• May utilize more space than a program that uses explicit memory deallocation.
• Unpredictable nature of collector runs may create unexpected latency and time lags in the system.

In my opinion, the advantages of using garbage collection in C++ greatly outweigh any disadvantages and i may begin to user Boehm's toolkit.