Index

A

Android

benchmarking, 244, 245

data caching, 250

emulator, 242–243

ListViews performance, 246–248

memory management, 259–260

multitasking, 261–262

multithreading, 255–257

programming language, 242

Automatic reference counting (ARC)

coding, 180

qualifiers

autoreleasing, 183

object property, 183

strong reference, 182

unsafe_unretained reference, 183

variable declarations, 183

weak reference, 182

rules, 182

Xcode, 181

B

Belady's algorithm, 65

Big-O notation

computation logics, 90, 91

CPU Sampler, 93, 94

general performance analysis, 93

insertion sort performance, 92

myFirstArray and mySecondArray elements, 90

myFirstCount and mySecondCount variables, 90

Time Profiler, 93–95

Binary tree, 106

insert/delete mechanism, 121

left and right child, 121

node and edge, 120

O(log(n)) performance, 119

search strategy, 117–118

search tree, 121, 123

sorting algorithms, 116

uses, 119

Bottleneck

file activity instrument, 60, 61

file/network loading test, 60

system usage instrument, 61

C

C programming

advanced data types

array, 224–225

bitwise operators, 229–230

function pointers, 228

linked list, 227–228

memory management mechanism, 226–227

string, 225

struct, 225

benefits and costs, 220

data types and functions, 221–222

pointer, 222–224

C programming, 262

C++ programming, 231, 262

.h and .cpp files, 238

benefits and costs, 220

class, 231–232, 238

inheritance, 233–234

memory management, 232

multiple inheritance, 234–235

MyObject.h and MyObject.m files, 238

pointers, 232

template, 235–236

TestC_CPlus, 238

Caching

Belady's algorithm, 65

cache hit, 62

cache invalidation, 64

cache miss, 62

data caching. See Data caching

definition, 62

FIFO, 66–67

image storage

application bundle, 76

cache directory, 73

documents directory, 74–75

photo album, 75–76

temporary directory, 73

least frequently used algorithm, 70–71

least recently used algorithm, 68, 70

measuring cache, 71–72

memory caching. See Memory caching

random replacement, 66

replacement policy, 64–65

retrieval cost, 63

simple time-based algorithm, 67–68

storage cost, 63

UIWebView, 72

Cocoa Touch data structures

hashing, 98

isEqual and Hash methods, 98, 100

NSMutableArray, 95

access, 97

API, 97

array illustration, 96

insert/delete, 96

search, 96

sorting, 97

NSMutableSet

access, 102

API, 102–103

hash method, 100, 101

insert/delete, 101

khang, 101

NSMutableDictionary, 104–105

search, 101

sorting, 102

Core animation, 25–27

D, E

Data caching

checking and deleting, 81

CoreData storing, 78–80

plist/xml/json storing, 77–78

SQLite, 80–81

Data encapsulation, 83

Data structure and algorithm, 253–254

benchmark testing, 88, 89

Big-O notation. See Big-O notation

binary tree, 106, Seealso Binary tree

Cocoa Touch data structures. See Cocoa Touch data structures

graph, 106

breadth-first search algorithm, 128, 130

connected graph, 124

depth-first search algorithm, 125–128

directed graph, 125

path, 124

vertex and edge, 124

weighted graph, 125

intersect method, 89

linked list, 106–110

Add Object method, 110–111

Count method, 112

Get Object method, 112

Init method, 110

ListNode, 107–108

Node and List object, 107

performance analysis, 113

Remove Object method, 113

vs. array, 106

NSLog and NSDate, 89

NSSet API, 88, 89

recursion, 131–132

SAX/DOM Parser, 132–133

source coding, 88

stack and queue, 106, 113–116

F, G

Facebook, 41

First In First Out (FIFO) algorithm, 66–67

H

Hashing, 98

I, J, K

iOS performance optimization

Android and Windows Phone environment, 2

Cocoa Touch Framework, 2

Java development, 2

Mac OS, Xcode, 3

network data transfers, 2

smartphone, 1

Stack Overflow, 2

iPhone, 242

L

Legacy code

memory garbage, 16–18

memory leaks

leaks instrument, 15–16

static analyzer, 13–14

M, N

Memory caching

Global Access vs. Strict Access, 82

image preloading, 83–85

memory allocations and usage, 82

memory warnings, 82

Memory management

advanced autorelease pool, 191–192

advanced memory issues, 184–185

ARC. See Automatic reference counting (ARC)

autorelease method, 178–179

autorelease pool, 179–180

instruments

leak instrument, 193

memory warning levels, 195

object allocation, 194–195

static analyzer, 193

Zombie, 194

object copy, 188–190

old object ownership policy, 178

UIViewController. SeeUIViewController

Multitasking apps performance

application life cycle events, 214

audio service, 206–207

background execution technique, 211–213

benefits and costs, 204–205

guidelines, 213

handler methods, 202–204

iOS 3.2, 198

iOS 4.0, 199

iOS versions, 216

life cycle

application:didEnterBackground method, 200, 201

application:didFinishLaunchingWithOptions method, 199

applicationWillTerminate method, 199

background and suspend states, 201

phone interruption and home button, 202

location notification, 211

location service, 207

continuous background location update mechanism, 210

significant location change mechanism, 209–210

standard location services, 208–209

memory, 213–214

shared resources, 214

show splash screen, 207

system changes notification, 215–216

user interface update, 214–215

VOIP, 211

Multithreading

advantages, 139, 142–143, 152

asynchronous functions, 172–173

autorelease pool, 153

Core Animation instrument, 140

disadvantages, 152

exception handler, 153

Idle-Time Notifications, 173–174

image loading process, 140

instrument, iPhone, 174

liveness

deadlock, 164–166

NSCondition solution, 163–164

NSLock solution, 162

push and pop threads, 161

multi-processor system, 138

NSObject, 145

NSOperationQueue, 146

code snippet, 147

NSBlockOperation, 148

NSInvocationOperation, 147

NSOperation, 148–150

NSThread, 144

NSTimer, 171

odd/even integer code, 156

performance, 166–168

POSIX Threads, 144–145

priorities, 151

run loop, 154

safety

application crash, 157

lock mechanism, 159–161

thread safety code, 157–158

single-processor system, 138

stack size, 150–151

stacks, 151

synchronization, 169–170

terminology, 139–140

thread-local storage, 151

UIImageView, 141–142

UITableViewDataSource's Method, 141

O

Old object ownership policy, 178

OpenGL ES driver, 27–28

P, Q, R

Performance tools, 18

battery power measurement, 31–32

blank template, 33

CPU measurement

activity monitor, 23

advantages, 22

CPU sampler panel, 21

disadvantages, 22–23

Hide System Libraries, 21

running count, function call, 22

running time, function call, 22

sample and stack trace, 20

system load and user load, 21

usages, 23

file and network access measurement

file activity, 29–30

system usage, 28–29

file I/O and network access, 19

instrument applications, 19–20

instrument tools, 34–36

library list, 33

measure thread performance, 30

time measurement, 23–24

user interface response time measurement

core animation, 25–26

OpenGL ES driver, 27–28

S

Simulators and real device test

basic tools, 9–10

iPhone simulator environment and real iPhone environment, 8

memory and runtime performance, 8, 9

memory tools

automatic reference counting, 10

convert tool, 10

legacy code. See Legacy code

memory allocation, 11–13

performance tools. See Performance tools

SlowPerformanceTableView project, 41

Smartphone, 1

SQLite, 236–238

Stack and queue, 114–116

T

Thread-safe, 169

U

UITableView performance

cell preparation process, 54

CoreAnimation tool, 40–41

custom cell drawing

custom drawing code, 51

drawInRect method, 53

drawRect method, 53

images reusing, 51

source code, 52

TableViewCell, 52

user interface, 50

editing/reordering performance, 56

Facebook, 41

graphical effects, 55–56

height caching, 54

images reusing, 48–49

initial benchmark, 43

NSLog, 40

opaque, 55

preparation time reduction, 49

ReuseIdentifier, 54

SlowPerformanceTableView project, 41

standard benchmark, 42–43

tableView dequeues, 39

UITableViewCell reusing

benchmarks, 47

CPU-intensive process, 43

custom class ReuseTableViewCell, 45

custom code, 46

interface builder, 44–45

Nib file, 46

standard TableView Cell, 44

UIViewController

life cycle, 185

load view process, 185–186

unload view process, 186–187

viewDidAppear method, 188

viewDidDisappear method, 188

viewWillAppear method, 187

viewWillDisappear method, 188

V

Voice Over IP (VOIP), 211

W, X, Y, Z

Windows phone

automatic binding mechanism, 246

benchmarking, 245

C# programming language, 242

data caching, 251–253

emulator, 243

ListViews performance, 248–249

memory management, 260–261

multithreading, 257–258

user interface framework, 242