Symbian OS Explained Effective C++ Programming for Smartphones phần 1 doc

Simpo PDF Merge and Split Unregistered Version - http://www.simpopdf.com Symbian OS Explained Effective C++ Programming for Smartphones Jo Stichbury Reviewed by David Batchelor, Andy Cloke, Reem EI Ghazzawi, Martin Hardman, Morgan Henry, John Pagonis, William Roberts, Keith Robertson, Phil Spencer, Colin Turfus Managing editor Phil Northam Project editor Freddie Gjertsen Simpo PDF Merge and Split Unregistered Version - http://www.simpopdf.com Simpo PDF Merge and Split Unregistered Version - http://www.simpopdf.com Symbian OS Explained Simpo PDF Merge and Split Unregistered Version - http://www.simpopdf.com TITLES PUBLISHED BY SYMBIAN PRESS • Symbian OS Explained Jo Stichbury 0470 021306 416pp 2004 Paperback • Symbian OS C++ for Mobile Phones, Volume 2 Richard Harrison 0470 871083 448pp 2004 Paperback • Programming Java 2 Micro Edition on Symbian OS Martin de Jode 0470 092238 498pp 2004 Paperback • Symbian OS C++ for Mobile Phones, Volume 1 Richard Harrison 0470 856114 826pp 2003 Paperback • Programming for the Series 60 Platform and Symbian OS Digia 0470 849487 550pp 2002 Paperback • Symbian OS Communications Programming Michael J Jipping 0470 844302 418pp 2002 Paperback • Wireless Java for Symbian Devices Jonathan Allin 0471 486841 512pp 2001 Paperback Simpo PDF Merge and Split Unregistered Version - http://www.simpopdf.com Symbian OS Explained Effective C++ Programming for Smartphones Jo Stichbury Reviewed by David Batchelor, Andy Cloke, Reem EI Ghazzawi, Martin Hardman, Morgan Henry, John Pagonis, William Roberts, Keith Robertson, Phil Spencer, Colin Turfus Managing editor Phil Northam Project editor Freddie Gjertsen Simpo PDF Merge and Split Unregistered Version - http://www.simpopdf.com Copyright  2005 by John Wiley & Sons, Ltd The Atrium, Southern Gate, Chichester, West Sussex PO19 8SQ, England Telephone (+44) 1243 779777 Email (for orders and customer service enquiries): cs-books@wiley.co.uk Visit our Home Page on www.wileyeurope.com or www.wiley.com All Rights Reserved. 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All brand names and product names used in this book are trade names, service marks, trademarks or registered trademarks of their respective owners. The Publisher is not associated with any product or vendor mentioned in this book. This publication is designed to provide accurate and authoritative information in regard to the subject matter covered. It is sold on the understanding that the Publisher is not engaged in rendering professional services. If professional advice or other expert assistance is required, the services of a competent professional should be sought. Other Wiley Editorial Offices John Wiley & Sons Inc., 111 River Street, Hoboken, NJ 07030, USA Jossey-Bass, 989 Market Street, San Francisco, CA 94103-1741, USA Wiley-VCH Verlag GmbH, Boschstr. 12, D-69469 Weinheim, Germany John Wiley & Sons Australia Ltd, 33 Park Road, Milton, Queensland 4064, Australia John Wiley & Sons (Asia) Pte Ltd, 2 Clementi Loop #02-01, Jin Xing Distripark, Singapore 129809 John Wiley & Sons Canada Ltd, 22 Worcester Road, Etobicoke, Ontario, Canada M9W 1L1 Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic books. Library of Congress Cataloging-in-Publication Data Stichbury, Jo. Symbian OS explained effective C++ programming for smartphones / By Jo Stichbury. p. cm. Includes bibliographical references and index. ISBN 0-470-02130-6 (pbk. alk. paper) 1. Mobile communication systems–Computer programs. 2. Operating systems (Computers) 3. C++ (Computer program language) I. Title. TK6570.M6S745 2004 005.265–dc22 2004015414 British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library ISBN 0-470-02130-6 Typeset in 10/12pt Optima by Laserwords Private Limited, Chennai, India Printed and bound in Great Britain by Biddles Ltd, King’s Lynn This book is printed on acid-free paper responsibly manufactured from sustainable forestry in which at least two trees are planted for each one used for paper production. Simpo PDF Merge and Split Unregistered Version - http://www.simpopdf.com Contents Foreword xi About This Book xiii Who Is It For? xiv How to Use This Book xiv Notation and Code Conventions Used in This Book xv Introduction to Symbian OS xvii Author Biography xxi Author’s Acknowledgments xxiii Symbian Press Acknowledgments xxv 1 Class Name Conventions on Symbian OS 1 1.1 Fundamental Types 1 1.2 T Classes 3 1.3 C Classes 4 1.4 R Classes 6 1.5 M Classes 7 1.6 Static Classes 11 1.7 Buyer Beware 11 1.8 Summary 12 2 Leaves: Symbian OS Exceptions 13 2.1 Leaving Functions 13 2.2 Heap Allocation Using new (ELeave) 16 2.3 Constructors and Destructors 17 Simpo PDF Merge and Split Unregistered Version - http://www.simpopdf.com vi CONTENTS 2.4 Working with Leaving Functions 18 2.5 Trapping a Leave Using TRAP and TRAPD 20 2.6 LeaveScan 26 2.7 Summary 27 3 The Cleanup Stack 29 3.1 Using the Cleanup Stack 31 3.2 How Does the Cleanup Stack Work? 35 3.3 Using the Cleanup Stack with Non-CBase Classes 38 3.4 Using TCleanupItem for Customized Cleanup 44 3.5 Portability 46 3.6 An Incidental Note on the Use of Casts 46 3.7 Summary 47 4 Two-Phase Construction 49 5 Descriptors: Symbian OS Strings 55 5.1 Non-Modifiable Descriptors 56 5.2 Modifiable Descriptors 58 5.3 Pointer Descriptors 60 5.4 Stack-Based Buffer Descriptors 63 5.5 Heap-Based Buffer Descriptors 65 5.6 Literal Descriptors 69 5.7 Summary 72 6 Good Descriptor Style 75 6.1 Descriptors as Parameters and Return Types 75 6.2 Common Descriptor Methods 78 6.3 The Use of HBufC Heap Descriptors 82 6.4 Externalizing and Internalizing Descriptors 84 6.5 The Overuse of TFileName 86 6.6 Useful Classes for Descriptor Manipulation 87 6.7 Summary 88 7 Dynamic Arrays and Buffers 91 7.1 CArrayX Classes 92 7.2 RArray<class T> and RPointerArray<class T> 97 7.3 Why Use RArray Instead of CArrayX? 102 7.4 Dynamic Descriptor Arrays 103 7.5 Fixed-Length Arrays 104 7.6 Dynamic Buffers 106 7.7 Summary 109 8 Event-Driven Multitasking Using Active Objects 111 8.1 Multitasking Basics 111 Simpo PDF Merge and Split Unregistered Version - http://www.simpopdf.com CONTENTS vii 8.2 Event-Driven Multitasking 112 8.3 Working with Active Objects 115 8.4 Example Code 120 8.5 Threads Without an Active Scheduler 123 8.6 Application Code and Active Objects 123 8.7 Summary 124 9 Active Objects under the Hood 127 9.1 Active Object Basics 128 9.2 Responsibilities of an Active Object 131 9.3 Responsibilities of an Asynchronous Service Provider 133 9.4 Responsibilities of the Active Scheduler 134 9.5 Starting the Active Scheduler 135 9.6 Nesting the Active Scheduler 135 9.7 Extending the Active Scheduler 136 9.8 Cancellation 137 9.9 Request Completion 138 9.10 State Machines 138 9.11 Long-Running Tasks 143 9.12 Class CIdle 146 9.13 Class CPeriodic 148 9.14 Common Mistakes 149 9.15 Summary 150 10 Symbian OS Threads and Processes 151 10.1 Class RThread 152 10.2 Thread Priorities 155 10.3 Stopping a Running Thread 157 10.4 Inter-Thread Data Transfer 162 10.5 Exception Handling 163 10.6 Processes 164 10.7 Summary 166 11 The Client–Server Framework in Theory 167 11.1 Why Have a Client–Server Framework? 168 11.2 How Do the Client and Server Fit Together? 168 11.3 How Do the Client and Server Communicate? 170 11.4 What Classes Does the Client–Server Framework Use? 170 11.5 How Do Synchronous and Asynchronous Requests Differ? 179 11.6 How Is a Server Started? 179 11.7 How Many Connections Can a Client Have? 180 11.8 What Happens When a Client Disconnects? 180 11.9 What Happens If a Client Dies? 181 11.10 What Happens If a Server Dies? 181 Simpo PDF Merge and Split Unregistered Version - http://www.simpopdf.com [...]... The targettype Specifier Summary 18 1 18 2 18 2 18 3 18 6 18 6 18 6 18 7 18 9 19 0 19 1 19 8 203 205 213 214 214 217 217 218 220 223 226 226 228 230 14 ECOM 233 14 .1 14.2 14 .3 14 .4 14 .5 14 .6 14 .7 233 236 237 240 242 245 246 ECOM Architecture Features of an ECOM Interface Factory Methods Implementing an ECOM Interface Resource Files Example Client Code Summary 15 Panics 247 15 .1 15.2 248 249 Just-In-Time Debugging... http://www.simpopdf.com 15 .3 15 .4 15 .5 15 .6 Symbian OS Panic Categories Panicking Another Thread Faults, Leaves and Panics Summary 16 Bug Detection Using Assertions 16 .1 16.2 16 .3 ix 250 2 51 253 253 255 ASSERT_DEBUG ASSERT_ALWAYS Summary 256 2 61 263 17 Debug Macros and Test Classes 265 17 .1 17.2 17 .3 17 .4 Heap-Checking Macros Object Invariance Macros Console Tests Using RTest Summary 18 Compatibility 18 .1 18.2 18 .3 18 .4... http://www.simpopdf.com 11 .11 How Does Client–Server Communication Use Threads? 11 .12 What Are the Implications of Server-Side Active Objects? 11 .13 What Are the Advantages of a Local (Same-Process) Server? 11 .14 What Are the Overheads of Client–Server Communication? 11 .15 How Many Outstanding Requests Can a Client Make to a Server? 11 .16 Can Server Functionality Be Extended? 11 .17 Example Code 11 .18 Summary 12 The... Summary 12 The Client–Server Framework in Practice 12 .1 12.2 12 .3 12 .4 12 .5 12 .6 12 .7 12 .8 Client–Server Request Codes Client Boilerplate Code Starting the Server and Connecting to It from the Client Server Startup Code Server Classes Server Shutdown Accessing the Server Summary 13 Binary Types 13 .1 13.2 13 .3 13 .4 13 .5 13 .6 13 .7 13 .8 Symbian OS EXEs Symbian OS DLLs Writable Static Data Thread-Local Storage... 18 .1 18.2 18 .3 18 .4 18 .5 18 .6 18 .7 18 .8 Forward and Backward Compatibility Source Compatibility Binary Compatibility Preventing Compatibility Breaks What Can I Change Without Breaking Binary Compatibility? Best Practice: Planning for Future Changes Compatibility and the Symbian OS Class Types Summary 265 270 273 276 277 278 279 280 2 81 287 289 2 91 292 19 Thin Templates 293 20 Expose a Comprehensive... 300 3 01 303 309 312 314 315 317 317 320 325 328 x CONTENTS Simpo PDF Merge and Split Unregistered Version - http://www.simpopdf.com 21. 5 21. 6 Optimize Late Summary Appendix Code Checklist 330 3 31 333 Glossary 339 Bibliography and Online Resources 347 Index 3 51 Simpo PDF Merge and Split Unregistered Version - http://www.simpopdf.com Foreword Charles Davies, Chief Technical Officer, Symbian Software engineers... http://www.simpopdf.com Who Is It For? The book assumes a reasonable understanding of programming in C++ It does not assume in-depth knowledge of Symbian OS and covers the basics such as descriptors (Chapters 5 and 6) and active objects (Chapters 8 and 9) as well as more complex features such as the Symbian OS client–server architecture (Chapters 11 and 12 ) and ECOM (Chapter 14 ) The book focuses upon the... the central concepts and key features of Symbian OS and good techniques in C++ To quote from Scott Meyers ,1 whose book inspired me to write this one, ”In this book you’ll find advice on what you should do, and why, and what you should not do, and why not” 1 Scott Meyers, Effective C++: 50 specific ways to improve your programs and designs, 19 97 See the Bibliography for further details xiv ABOUT THIS BOOK... essential Symbian OS concepts Simpo PDF Merge and Split Unregistered Version - http://www.simpopdf.com About this Book Developing good C++ code on Symbian OS requires a clear understanding of the underlying concepts and the nature of the operating system This book explains the key features of Symbian OS and shows how you can use this knowledge most effectively It also focuses on some aspects of good C++. .. follows on Symbian OS: void TypicalFunction(TAny* aPointerParameter); This is the one exception to the rule of replacing a native type with a Symbian OS typedef; it occurs because void is effectively compiler-independent when referring to ”nothing” • TBool should be used for boolean types For historical reasons TBool is equivalent to int and you should use the Symbian OS typedef’d values of ETrue ( =1) and . xxv 1 Class Name Conventions on Symbian OS 1 1 .1 Fundamental Types 1 1.2 T Classes 3 1. 3 C Classes 4 1. 4 R Classes 6 1. 5 M Classes 7 1. 6 Static Classes 11 1. 7 Buyer Beware 11 1. 8 Summary 12 2. Server? 18 6 11 .16 Can Server Functionality Be Extended? 18 6 11 .17 Example Code 18 6 11 .18 Summary 18 7 12 The Client–Server Framework in Practice 18 9 12 .1 Client–Server Request Codes 19 0 12 .2 Client. 14 3 9 .12 Class CIdle 14 6 9 .13 Class CPeriodic 14 8 9 .14 Common Mistakes 14 9 9 .15 Summary 15 0 10 Symbian OS Threads and Processes 15 1 10 .1 Class RThread 15 2 10 .2 Thread Priorities 15 5 10 .3 Stopping a