In iOS and macOS (TM) Performance Tuning, Marcel Weiher drills down to the code level to help you systematically optimize CPU, memory, I/O, graphics, and program responsiveness in any Objective-C, Cocoa, or CocoaTouch program. This guide focuses entirely on performance optimization for macOS and iOS. Drawing on more than 25 years of experience optimizing Apple device software, Weiher identifies concrete performance problems that can be discovered empirically via measurement. Then, based on a deep understanding of fundamental principles, he presents specific techniques for solving them. Weiher presents insights you won't find anywhere else, most of them applying to both macOS and iOS development. Throughout, he reveals common pitfalls and misconceptions about Apple device performance, explains the realities, and helps you reflect those realities in code that performs beautifully. Understand optimization principles, measurement, tools, pitfalls, and techniques Recognize when to carefully optimize, and when it isn't worth your time Balance performance and encapsulation to create efficient object representations, communication, data access, and computation Avoid mistakes that slow down Objective-C programs and hinder later optimization Fix leaks and other problems with memory and resource management Address I/O issues associated with drives, networking, serialization, and SQLite Code graphics and UIs that don't overwhelm limited iOS device resources Learn what all developers need to know about Swift performance This book's source code can be downloaded at github.com/mpw/iOS-macOS-performance. Register your product at informit.com/register for convenient access to downloads, updates, and corrections as they become available.