Programming with POSIX® Threads

Programming with POSIX® Threads

Addison-Wesley Professional Computing Series

Brian W. Kernighan, Consulting Editor

Ken Arnold/John Peyton, A C User's Guide to ANSI C David R. Butenhof, Programming with POSIX® Threads Tom Cargill, C++ Programming Style

William R. Cheswick/Steven M. Bellovin, Firewalls and Internet Security: Repelling the Wily Hacker David A. Curry, UNIX® System Security: A Guide for Users and System Administrators Erich Gamma/Richard Helm/Ralph Johnson/John Vlissides, Design Patterns: Elements of

Reusable Object-Oriented Software Erich Gamma/Richard Helm/RalphJohnson/John Vlissides, Design Patterns CD: Elements of

Reusable Object-Oriented Software David R. Hanson, C Interfaces and Implementations: Techniques for Creating Reusable Software S. Keshav, An Engineering Approach to Computer Networking: ATM Networks, The Internet, and

the Telephone Network John Lakos, Large-Scale C++ Software Design

Scott Meyers, Effective C++, Second Edition: 50 Specific Ways to Improve Your Programs and Designs Scott Meyers, More Effective C++: 35 New Ways to Improve Your Programs and Designs Robert B. Murray, C++ Strategies and Tactics

David R. Musser/Atul Saini, STL Tutorial and Reference Guide: C++ Programming with the

Standard Template Library John K. Ousterhout, Tcl and the Tk Toolkit Craig Partridge, Gigabit Networking

J. Stephen Pendergrast Jr., Desktop KornShell Graphical Programming Radia Perlman, Interconnections: Bridges and Routers

David M. Piscitello/A. Lyman Chapin, Open Systems Networking: TCP/IP and OSI Stephen A. Rago, UNIX® System V Network Programming

Curt Schimmel, UNIX® Systemsfor Modern Architectures: Symmetric Multiprocessing and

Cachingfor Kernel Programmers W. Richard Stevens, Advanced Programming in the UNIX® Environment W. Richard Stevens, TCP/IP Illustrated, Volume 1: The Protocols

W. Richard Stevens, TCP/IP Illustrated, Volume 3: TCP for Transactions, HTTP, NNTP and the

UNIX® Domain Protocols Gary R. Wright/W. Richard Stevens, TCP/IP Illustrated, Volume 2: The Implementation

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Trademark acknowledgments:

UNIX is a registered trademark in the United States and other countries, licensed exclusively through X/Open Company Ltd. Digital, DEC, Digital UNIX, DECthreads, VMS, and OpenVMS are trademarks of Digital Equipment Corporation. Solaris, SPARC, SunOS, and Sun are trademarks of Sun Microsystems Incorporated. SGI and IRIX are trademarks of Silicon Graphics, Incorporated. HP-UX is a trademark of Hewlett-Packard Company. ALX, lBM, and OS/2 are trademarks or registered trademarks of the IBM Corporation. X/Open is a trademark of X/Open Company Ltd. POSIX is a registered trademark of the Institute of Electrical and Electronics Engineers, Inc.

Many of the designations used by manufacturers and sellers to distinguish their products are claimed as trademarks. Where those designations appear in this book and Addison-Wesley was aware of a trademark claim, the designations have been printed in initial caps or all caps.

The authors and publishers have taken care in the preparation of this book, but make no expressed or implied warranty of any kind and assume no responsibility for errors or omissions. No liability is assumed for incidental or consequential damages in connection with or arising out of the use of the information or programs contained herein.

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Library of Congress Cataloging-in-Publication Data

Butenhof, David R., 1956-

Programming with POSIX threads / David R. Butenhof.

p. cm. — (Addison-Wesley professional computing series) Includes bibliographical references and index. ISBN 0-201-63392-2 (pbk.)

l.Threads(Computerprograms) 2. POSIX(Computersoftware standard) 3. Electronic digital computers— Programming. I. Title. II. Series.

QA76.76.T55B88 1997

005.4'32-dc21 97-6635

CIP

Copyright © 1997 by Addison Wesley Longman, Inc.

All rights reserved. No part ofthis publication may be reproduced, stored in a retrieval system, or transmitted, in any form, or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior consent of the publisher. Printed in the United States of America. Published simultaneously in Canada.

Text printed on recycled and acid-free paper.

2 3 4 5 6 7 8 9 MA 00 99 98 97

2nd Printing October, 1997

To Anne, Amy, and Alyssa.

Quote acknowledgments:

American Heritage Dictionary of the English Language: page 1. ISO/IEC 9945-1:1996, © 1996 by IEEE: page 29.

Lewis Carroll, Alice's Adventures in Wonderland: pages xv, 47, 70, 88, 97, 98, 106, 131, 142, 161, 189, 197.Reproduced by permission of Macmillan Children's Books.

Lewis Carroll, Through the Looking-Glass: pages 1, 4, 8, 20, 25, 29, 35, 45, 172, 214, 241, 283, 290, 302. Reproduced by permission of Macmillan Children's Books.