Chapter 1

Life Before Automatic Reference Counting

OSX Lion and iOS5 now offer an application memory management mechanism called Automatic Reference Counting (ARC). In short, ARC makes memory management the job of the compiler rather than the programmer, which quite often increases performance significantly.

In Chapters 2 and 3, you see just how powerful ARC is. But before entering such a dream world, it’s best to review the basics of memory management in a non-ARC environment. In doing so, you’ll form a greater appreciation of all that ARC has to offer and build a stronger foundation for when we delve into ARC in the next two chapters.

We start with an overview of memory management and its concepts followed by the implementation of features such as alloc, dealloc, and autorelease.