Posix.4 Programmers Guide: Programming for the Real World [Paperback]

Bill Gallmeister (Author)

Book Description

Publication Date: January 8, 1995

What's "real-world programming"?

Real-world programming (typically called real-time programming) is programming that interacts in some way with the "real world" of daily life. At one time, real-time systems were confined to very esoteric applications, like rocket guidance systems. Now, they play a role in almost every aspect of life: they control the brakes on your car, video games, automatic bank tellers -- and the disk drive in your computer. It won't be long before mundane devices like toasters and hair dryers have microprocessors built in, to say nothing of multimedia devices that haven't even been invented yet.

Real-world applications are characterized by deadlines. If the brake processor in your car doesn't meet a deadline, your car doesn't stop; if your video game doesn't meet a deadline, the Klingons don't die when you shoot them; if your ATM doesn't meet a deadline, you may start looking for another bank. When you've just rear-ended another car, it's no consolation that a sudden flurry of input slowed down your brake processor, so it couldn't react quickly enough when you hit the pedal.

This book covers the POSIX.4 standard for portable real-time programming. The POSIX.4 standard itself is a massive document that defines system interfaces for asynchronous I/O, scheduling, communications, and other facilities. However, this book does more than explain the standard. It provides a general introduction to real-time programming and real-time issues: the problems software faces when it needs to interact with the real world and how to solve them. And, unlike most books about standards, this one isn't just readable -- it's enjoyable! If you're at all interested in real-time applications -- which include just about everything from telemetry to transaction processing -- this book will be an essential reference.

Chapters include:

• The Basics of Real-Time: Multiple Tasks
• Better Coordination: Messages, Shared Memory, and Synchronization
• On Time: Scheduling, Time, and Memory Locking
• I/O for the Real World

Includes programming exercises, solutions, and reference manual pages.

Editorial Reviews

From the Publisher

What's "real-world programming"? Real-world programming (typically called real-time programming) is programming that interacts in some way with the "real world" of daily life. At one time, real-time systems were confined to very esoteric applications, like rocket guidance systems. Now, they play a role in almost every aspect of life: they control the brakes on your car, video games, automatic bank tellers -- and the disk drive in your computer. It won't be long before mundane devices like toasters and hair dryers have microprocessors built in, to say nothing of multimedia devices that haven't even been invented yet. Real-world applications are characterized by deadlines. If the brake processor in your car doesn't meet a deadline, your car doesn't stop; if your video game doesn't meet a deadline, the Klingons don't die when you shoot them; if your ATM doesn't meet a deadline, you may start looking for another bank. When you've just rear-ended another car, it's no consolation that a sudden flurry of input slowed down your brake processor, so it couldn't react quickly enough when you hit the pedal. This book covers the POSIX.4 standard for portable real-time programming. The POSIX.4 standard itself is a massive document that defines system interfaces for asynchronous I/O, scheduling, communications, and other facilities. However, this book does more than explain the standard. It provides a general introduction to real-time programming and real-time issues: the problems software faces when it needs to interact with the real world and how to solve them. And, unlike most books about standards, this one isn't just readable -- it's enjoyable! If you're at all interested in real-time applications -- which include just about everything from telemetry to transaction processing -- this book will be an essential reference. Chapters include: The Basics of Real-Time: Multiple Tasks Better Coordination: Messages, Shared Memory, and Synchronization On Time: Scheduling, Time, and Memory Locking I/O for the Real World Measuring Real-Time Performance Includes programming exercises, solutions, and reference manual pages.

From the Back Cover

Real-world programming (more typically called real-time programming) interacts with the "real world" of daily life in some way. Real-world programmers develop the unseen software that runs everything from the brakes in your car to your VCR. This software is typically characterized by deadlines - and harsh penalties if the deadlines aren't met. If the brake processor in your car doesn't meet a deadline, your car doesn't stop; if your ATM doesn't meet a deadline, you may start looking for another bank. When you've just rear-ended another car, it's no consolation that a sudden flurry of input slowed down your brake processor, so it couldn't react quickly enough when you hit the pedal. This book covers the POSIX.4 standard for portable real-time programming. But it goes well beyond a simple replication of the standard. It provides a general introduction to real-time programming and real-time issues: the problems software faces when it needs to interact with the real world, and how to solve them. If you're at all interested in real-time applications - which includes just about everything from telemetry to transaction processing - this book will be an essential reference.

See all Editorial Reviews

Product Details

• Paperback: 570 pages
• Publisher: O'Reilly Media; 1st edition (January 8, 1995)
• Language: English
• ISBN-10: 1565920740
• ISBN-13: 978-1565920743
• Product Dimensions: 9.2 x 7.1 x 1.2 inches
• Shipping Weight: 2 pounds
• Average Customer Review: 4.9 out of 5 stars  See all reviews (8 customer reviews)
• Amazon Best Sellers Rank: #917,929 in Books (See Top 100 in Books)

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Customer Reviews

Most Helpful Customer Reviews

12 of 12 people found the following review helpful:

4.0 out of 5 stars Intro & Reference to Real-Time POSIX S/W Development, March 13, 2001

By 

Elderbear (Loma Linda, Aztlan) - See all my reviews
(VINE VOICE)   

Amazon Verified Purchase

This review is from: Posix.4 Programmers Guide: Programming for the Real World (Paperback)

Gallmeister splits this book into two main sections, an introduction to the material and a reference section, which provides detailed documentation for the various function calls and header files. Somebody new to the material will find the first section indispensable, while the pro will flip to the reference section to answer questions.

Chapter one provides an overview of the problems this book addresses. The second chapter examines POSIX, POSIX options, and POSIX namespaces. Chapters 3 - 6 define real-time problems and POSIX.4 solutions. Chapter 7 considers the issues of real-time performance.

Gallmeister provides many example code fragments to illustrate his points. He would have done better to have annotated his examples, instead of writing a number of descriptive paragraphs after each fragment. A particularly useful feature is his discussion of "current UNIX practice."

Overall, this book provides a reasonable introduction to the concepts of real-time programming, and a number of "recipe" examples for the POSIX environment. Recommended if you'd like to develop real-time skills or need a reference work on the subject. I found it useful learning to develop QNX software, even though QNX implements a number of "optional" features differently.

8 of 8 people found the following review helpful:

5.0 out of 5 stars Excellent guide to real-time POSIX, February 3, 2002

By 

Anatoly Korzun "a_k" - See all my reviews

Amazon Verified Purchase

This review is from: Posix.4 Programmers Guide: Programming for the Real World (Paperback)

The book consists of 2 parts. The 1st part is a detailed guide to the real-time POSIX programming. The 2nd part presents a reference to all POSIX real-time functions. The book also has an appendix with various sample and exercise code.

All explanations in the first part are very clear and complete. Writing style resembles the best programming books (like those from K&R or R.Stevens). At the same time everything is given in a distilled manner without unnecessary water, so that you might handle the stuff surprisingly fast.

The second part is less valuable since all this material can be found in UNIX man. But if to see it as just a free bonus for the 1st part it is not bad at all. In any case having printed manuals is quite useful.

Sample code in the appendix is also interesting to look at.

Actually I didn't notice any considerable drawbacks in the book and recommend it to everyone interested in the subject.

The prerequisites are minimal. You should know C and be familiar with the basic UNIX/POSIX API (like working with files, etc.). The next reading is obvious - some book on POSIX threads (I'd recommend one by Mr. Butenhof).

6 of 6 people found the following review helpful:

5.0 out of 5 stars The Best, January 15, 2003

By A Customer

This review is from: Posix.4 Programmers Guide: Programming for the Real World (Paperback)

If you know C and know UNIX, this book is for you. Simply put, he knows what he's writing about and he presents the material in a logical, methodical manner.
This book was written just before the POSIX4a standard was completed, so no PThreads are covered.
As long as you're not expecting PThreads coverage, you won't be disappointed. Most of the topics you need to know about mutli-threaded programming (besides PThreads) are here.