Issott_Common Design Patterns for Symbian OS-The Foundations of Smartphone Software_0470516356 (Symbian Books)

Common Design Patternsfor Symbian OSThe Foundations of SmartphoneSoftwareLead AuthorAdrian IssottWithNicholas Addo, Toby Gray, David Harper, Craig Heath,Guruprasad Kini, Ian McDowall, Ben Morris, John Roe,Dale Self, James Steele, Jo Stichbury, Oliver Stuart, Viki Turner,Hamish WilleeReviewed bySandip Ahluwalia, Matthew Allen, Sorin Basca, David Caabiero,Iain Campbell, Douglas Feather, Ryan Gilmour,Martin Hardman, Richard Harrison, Tim Howes, Mark Jacobs,Martin Jakl, Sian James, Antti Juustila, Simon Mellor,Sihem Merah, Will Palmer, Subhasis Panigrahi, Lucian Piros,Mark Shackman, Adrian Taylor, Paul Todd, Gabor Torok,Charles Weir, Alex Wilbur, Tim WilliamsHead of Symbian PressFreddie GjertsenManaging EditorSatu McNabbA John Wiley and Sons, Ltd., PublicationCommon Design Patternsfor Symbian OSThe Foundations of Smartphone SoftwareCommon Design Patternsfor Symbian OSThe Foundations of SmartphoneSoftwareLead AuthorAdrian IssottWithNicholas Addo, Toby Gray, David Harper, Craig Heath,Guruprasad Kini, Ian McDowall, Ben Morris, John Roe,Dale Self, James Steele, Jo Stichbury, Oliver Stuart, Viki Turner,Hamish WilleeReviewed bySandip Ahluwalia, Matthew Allen, Sorin Basca, David Caabiero,Iain Campbell, Douglas Feather, Ryan Gilmour,Martin Hardman, Richard Harrison, Tim Howes, Mark Jacobs,Martin Jakl, Sian James, Antti Juustila, Simon Mellor,Sihem Merah, Will Palmer, Subhasis Panigrahi, Lucian Piros,Mark Shackman, Adrian Taylor, Paul Todd, Gabor Torok,Charles Weir, Alex Wilbur, Tim WilliamsHead of Symbian PressFreddie GjertsenManaging EditorSatu McNabbA John Wiley and Sons, Ltd., PublicationCopyright  2008John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester,West Sussex PO19 8SQ, EnglandTelephone (+44) 1243 779777Email (for orders and customer service enquiries): cs-books@wiley.co.ukVisit our Home Page on www.wileyeurope.com or www.wiley.comAll Rights Reserved.

No part of this publication may be reproduced, stored in a retrieval system ortransmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning orotherwise, except under the terms of the Copyright, Designs and Patents Act 1988 or under the terms ofa licence issued by the Copyright Licensing Agency Ltd, 90 Tottenham Court Road, London W1T 4LP,UK, without the permission in writing of the Publisher. Requests to the Publisher should be addressed tothe Permissions Department, John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, WestSussex PO19 8SQ, England, or emailed to permreq@wiley.co.uk, or faxed to (+44) 1243 770620.Designations used by companies to distinguish their products are often claimed as trademarks. Allbrand names and product names used in this book are trade names, service marks, trademarks orregistered trademarks of their respective owners.

The Publisher is not associated with any product orvendor mentioned in this book.This publication is designed to provide accurate and authoritative information in regard to the subjectmatter covered. It is sold on the understanding that the Publisher is not engaged in renderingprofessional services. If professional advice or other expert assistance is required, the services of acompetent professional should be sought.Other Wiley Editorial OfficesJohn Wiley & Sons Inc., 111 River Street, Hoboken, NJ 07030, USAJossey-Bass, 989 Market Street, San Francisco, CA 94103-1741, USAWiley-VCH Verlag GmbH, Boschstr.

12, D-69469 Weinheim, GermanyJohn Wiley & Sons Australia Ltd, 42 McDougall Street, Milton, Queensland 4064, AustraliaJohn Wiley & Sons (Asia) Pte Ltd, 2 Clementi Loop #02-01, Jin Xing Distripark, Singapore 129809John Wiley & Sons Canada Ltd, 6045 Freemont Blvd, Mississauga, Ontario, L5R 4J3, CanadaWiley also publishes its books in a variety of electronic formats. Some content that appearsin print may not be available in electronic books.British Library Cataloguing in Publication DataA catalogue record for this book is available from the British LibraryISBN 978-0-470-51635-5Typeset in 10/12 Optima by Laserwords Private Limited, Chennai, IndiaPrinted and bound in Great Britain by Bell & Bain, GlasgowThis book is printed on acid-free paper responsibly manufactured from sustainable forestryin which at least two trees are planted for each one used for paper production.Dedicated to Kat and to MikeContentsAuthor BiographiesixAuthors’ AcknowledgmentsxvForewordxviiGlossaryxix1 Introduction1.11.21.31.41.51.61.71.81.9About this BookWho this Book Is ForWhich Version of Symbian OS this Book Is ForGeneral Design PatternsSymbian OS PatternsDesign Pattern TemplateStructure of this BookConventionsOther Sources of Information2 Error-Handling StrategiesFail FastEscalate Errors3 Resource LifetimesImmortal111224101213131517324953viiiCONTENTSLazy AllocationLazy De-allocation4 Event-Driven ProgrammingEvent MixinRequest CompletionPublish and Subscribe5 Cooperative MultitaskingActive ObjectsAsynchronous Controller6 Providing ServicesClient-Thread ServiceClient–ServerCoordinator7 SecuritySecure AgentBuckleQuarantineCradle8 Optimizing Execution TimeEpisodesData Press9 Mapping Well-Known Patterns onto Symbian OSModel–View–ControllerSingletonAdapterHandle–Body63738793104114131133148165171182211233240252260273287289309331332346372385Appendix: Impact Analysis of RecurringConsequences397References403Index407Author BiographiesNicholas AddoNicholas has worked on Symbian OS for six years.

He first joined theBrowser Technology group in Symbian, developing a generic frameworkfor content handling. He then moved to the Personal Information Management group to work on Enterprise Group Scheduling technology.From there, he joined the Multi-technology development group to workon cross-technology and process-improvement projects.

This included astint in product management defining a Component Technology productstrategy for Symbian OS and an ongoing involvement in improvementinitiatives for Symbian OS core idioms.Nicholas started his career as an apprentice Electronics Engineer in the1980s, developing semiconductor devices for telecommunications. Hemoved into a solely software development career in the 1990s. This wasinitially in real-time embedded systems and later Windows-based userinterfaces for image scanners, writers, and print register and color controldevices for the printing and pre-press industry.Toby GrayToby has worked with Symbian OS since joining the System Managementgroup of Symbian in 2005.

Since then, he has worked on topics rangingfrom optimizing system characteristics (e.g. speed, RAM usage and ROMusage) to management of system start-up and from development ofdiagnostic tools to ARM assembler optimization. He holds a BA inComputer Science from the University of Cambridge.xAUTHOR BIOGRAPHIESDavid HarperDavid has worked at Psion Software and Symbian for over 10 years.During that time he has developed an in-depth knowledge of HTTP,Internet technologies, ECom and Platform Security.

He now works inIntegration Management, specializing in Technology Integration. Davidholds an MSc in Artificial Intelligence from Queen Mary and WestfieldCollege.Craig HeathCraig has been working in IT security since 1988, with The Santa CruzOperation as security architect for SCO UNIX, then at Lutris Technologiesas security architect for their Java Enterprise Application Server. Hejoined Symbian in 2002, working in product management and strategy.He has contributed to several published industry standards and hasa long association with The Open Group Security Forum, includingco-authorship of the Open Group Technical Guide to Security DesignPatterns.

Craig is lead author of Symbian OS Platform Security.Adrian IssottAdrian joined Symbian’s Shortlink team in 2004 working first on developing support for Bluetooth stereo headsets and then on enhancing theBluetooth HAI. In 2006, he moved on to become an architect focusingon system characteristics such as performance, RAM usage, reliabilityand security. His time is currently spent either working on long-termarchitectural improvements in areas such as system start-up and trace oron urgent projects helping device manufacturers optimize their devicesand get the best out of Symbian OS.