Building Cocoa Applications: A Step by Step Guide

Chapter 9. Darwin and the Window Server

If your only previous exposure to computing is to previous versions of the Macintosh operating system (Mac OS) or Microsoft Windows, you’ve probably noticed that Mac OS X is very different indeed. If you’re familiar with the “classic” Mac OS, you’ve probably noticed that with Mac OS X you don’t need to preallocate how much memory a program uses, and that programs in the background run without any noticeable degradation in performance. If you have used either Mac OS or Windows, you’ve surely noticed that Mac OS X does not crash as much as these other operating systems — in fact, for most users it doesn’t crash at all! In this chapter, we’ll see why Mac OS X is so different.

Unix, Mach, and the Mac OS X Environment

The Mac OS X environment is built on top of the Unix operating system and the Mach kernel. Together, they form a powerful computing infrastructure that is part of what Apple calls Darwin . In addition to the Mach and Unix services, Darwin includes the Mac OS X networking and (multiple integrated) filesystems.

Operating Systems

An operating system is the master control program that loads and runs other programs and controls a computer’s input and output systems, such as the keyboard, display, and disk drives. Multitasking operating systems such as Mach allow more than one program to run at the same time on the same computer; the operating system automatically arbitrates between the various programs that are waiting to run, letting one ...