Introduction

Guidelines for improving the performance of memory-related code.

Organization of This Document

This programming topic includes the following articles:

About the Virtual Memory System introduces the terminology and provides a high-level overview of the virtual memory systems of OS X and iOS.

Tips for Allocating Memory describes the best techniques for allocating, initializing, and copying memory. It also describes the proper ways to respond to low-memory notifications in iOS.

Caching and Purgeable Memory discusses the benefits of caching, and how to avoid some of the problems that can arise from implementing caches. It also details the advantages of implementing purgeable memory into a caching system and how to successfully implement this beneficial technology.

Tracking Memory Usage describes the tools and techniques for analyzing your application’s memory usage.

Finding Memory Leaks describes the tools and techniques for finding memory leaks in your application.

Enabling the Malloc Debugging Features describes the environment variables used to enable malloc history logging. You must set some of these variables before using some of the memory analysis tools.

Viewing Virtual Memory Usage describes the tools and techniques for analyzing your application’s in-memory footprint.