Introduction

Threads are one of several technologies that make it possible to execute multiple code paths concurrently inside a single application. Although newer technologies such as operation objects and Grand Central Dispatch (GCD) provide a more modern and efficient infrastructure for implementing concurrency, OS X and iOS also provide interfaces for creating and managing threads.

This document provides an introduction to the thread packages available in OS X and shows you how to use them. This document also describes the relevant technologies provided to support threading and the synchronization of multithreaded code inside your application.

Organization of This Document

This document has the following chapters and appendixes:

• About Threaded Programming introduces the concept of threads and their role in application design.

• Thread Management provides information about the threading technologies in OS X and how you use them.

• Run Loops provides information about how to manage event-processing loops in secondary threads.

• Synchronization describes synchronization issues and the tools you use to prevent multiple threads from corrupting data or crashing your program.

• Thread Safety Summary provides a high-level summary of the inherent thread safety of OS X and iOS and some of their key frameworks.