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Introduction to Memory Management Programming Guide for Cocoa

Contents:

Who Should Read This Document
Organization of This Document

Memory management, especially as it concerns Objective-C programs, is an important subject. Some of the more common problems encountered by novice application developers derive from poor memory management. Cocoa provides mechanisms and a policy to assist you in the proper creation, retention, and disposal of objects.

Memory management in Cocoa is largely object-oriented. This programming topic addresses the object-ownership policy and related techniques for creating, copying, retaining, and disposing of objects using “managed memory”.

Who Should Read This Document

The material in this programming topic relates to Objective-C objects and is of interest primarily to Objective-C programmers. If you are starting a new project targeted at Mac OS X v10.5 and later, you should typically use garbage collection unless you have good reason to use the techniques described here.

Organization of This Document

This document contains the following articles:

• “Object Ownership and Disposal” describes the primary policy.

• “Allocating and Initializing Objects” explains techniques for allocating and initializing Objective-C objects.

• “Autorelease Pools” describes the use of autorelease pools—a mechanism for deferred deallocation—in Cocoa programs.

• “Accessor Methods” describes how to implement accessor methods.

• “Implementing Object Copy” discusses issues related to object copying, such as deciding whether to implement a deep or shallow copy and approaches for implementing object copy in your subclasses.

• “Memory Management of Core Foundation Objects in Cocoa” gives guidelines and techniques for memory management of Core Foundation objects in Cocoa code.

• “Using Memory Zones” discusses the use of memory zones.

• “Memory Management Rules” summarizes the rules for object ownership and disposal.

Additional information about memory management and nib files can be found in Resource Programming Guide > Nib Files and Cocoa > “The Nib Object Life Cycle.”

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