Intended audience
This book assumes that you are an experienced programmer, familiar with developing code
for an operating system in "the UNIX family" using the ANSI C language. I have tried not to
assume that you have any experience with threads or other forms of asynchronous programming.
The Introduction chapter provides a general overview of the terms and concepts you'll need for the
rest of the book. If you don't want to read the Introduction first, that's fine, but if you ever feel like
you're "missing something" you might try skipping back to get introduced.
Along the way you'll find examples and simple analogies for everything. In the end I hope
that you'll be able to continue comfortably threading along on your own. Have fun, and "happy
threading."
About the author
I have been involved in the Pthreads standard since it began, although I stayed at home for
the first few meetings. I was finally forced to spend a grueling week in the avalanche-proof
concrete bunker at the base of Snowbird ski resort in Utah; watching hard-working standards
representatives from around the world wax their skis. This was very distracting, because I had
expected a standards meeting to be a formal and stuffy environment. As a result of this
misunderstanding, I was forced to rent ski equipment instead of using my own.
After the Pthreads standard went into balloting, I worked on additional thread
synchronization interfaces and multiprocessor issues with several POSIX working groups. I also
helped to define the Aspen threads extensions, which were fast tracked into X/Open XSH5.
I have worked at Digital Equipment Corporation for (mumble, mumble) years, in various
locations throughout Massachusetts and New Hampshire. I was one of the creators of Digital’s
own threading architecture, and I designed (and implemented much of) the Pthreads interfaces on
Digital UNIX 4.0. I have been helping people develop and debug threaded code for more than
eight years.
My unofficial motto is "Better Living Through Concurrency." Threads are not sliced bread,
but then, we're programmers, not bakers, so we do what we can.
Acknowledgments
This is the part where I write the stuff that I'd like to see printed, and that my friends and
coworkers want to see. You probably don't care, and I promise not to be annoyed if you skip over
it but if you're curious, by all means read on.
No project such as this book can truly be accomplished by a single person, despite the fact
that only one name appears on the cover. I could have written a book about threads without any
help--I know a great deal about threads, and I am at least reasonably competent at written
communication. However, the result would not have been this book, and this book is better than
that hypothetical work could possibly have been.
Thanks first and foremost to my manager Jean Fullerton, who gave me the time and
encouragement to write this book on the job--and thanks to the rest of the DECthreads team who
kept things going while I wrote, including Brian Keane, Webb Scales, Jacqueline Berg, Richard
Love, Peter Portante, Brian Silver, Mark Simons, and Steve Johnson.
Thanks to Garret Swart who, while he was with Digital at the Systems Research Center, got
us involved with POSIX. Thanks to Nawaf Bitar who worked with Garret to create, literally
overnight, the first draft of what became Pthreads, and who became POSIX thread evangelist
through the difficult period of getting everyone to understand just what the heck this threading
