Click here to learn
about this Sponsor:
Home  |  News  |  Articles  |  Polls  |  Forum

Keywords: Match:
Temporal inventory and real-time synchronization in RTLinux
by Victor Yodaiken (Apr. 11, 2003)

Foreword:   In this whitepaper, RTLinux originator Victor Yodaiken gives an overview of synchronization methods for real-time, with special attention to the RTCore (RTLinux) real-time operating system. A glossary, included at the end, provides some useful tutorial material.



Temporal inventory and real-time synchronization in RTLinuxPro
by Victor Yodaiken
Finite State Machine Labs (FSMLabs)


Introduction -- Real-time software is like an automobile factory

Synchronization operations impose temporal order on a software system by forcing some computations to wait until other computations complete. Waiting and negotiating over which computation should take place next can easily absorb significant fractions of processing power and can cause significant delays.

To compensate, engineers can specify more powerful processors and more resources, maybe even multiple processors -- but such things are not free. Even worse, synchronization can easily produce timing failures or deadlocks that may elude testing and this becomes more of a hazard as more complex and sophisticated synchronization operations are employed. It's not uncommon for control system software to spiral in complexity as more hardware is added to provide the compute power needed for synchronization, necessitating more synchronization which requires more resources and also more sophisticated special case software to compensate for hard to find sporadic timing problems and so on.

This paper provides a tutorial on synchronization of real-time software, focused on applications running under the RTCore operating system (RTLinux is RTCore plus Linux). Throughout the design and ongoing development of RTCore, we have tried to solve problems by simplification instead of by adding features.

One of the most brilliant practitioners of this approach to engineering is Taishi Ohno, who helped develop Toyota's manufacturing process. Ohno noticed that large parts inventories in production plants were a significant cost and that they masked ine ciencies. When inventory was reduced and the factory was designed to run, just-in-time problems in quality and reliability were exposed and fixed. The result was greatly increased productivity.

Using up parts inventory and using up slack time "inventory" during synchronization are analogous. If a task is scheduled to start at time t and only starts at time t + w because of delays waiting and negotiating for resources, we have to relax deadlines and build 1 slack time into the system to compensate for w. The slack time is temporal inventory -- time we stockpile in order to compensate for resource conflicts, the overhead of arbitration, and other scheduling ineffciencies. We cannot expect to reduce inventory to zero or to do without any synchronization at all, but we can produce cleaner and more reliable software by working to minimize synchronization time.


Read full whitepaper
(230K PDF file)





About the author:   Victor Yodaiken, CEO and Co-Founder of FSMLabs, came up with the basic RTLinux technology. Yodaiken began his career in 1983 as one of the chief developers of Auragen's distributed fault-tolerant UNIX and he had an active consulting business before starting FSMLabs. He has also worked in academia, as a professor and department chair at New Mexico Tech, and as a research professor and port-doctoral fellow at the University of Massachussetts in Amherst. Currently he is an adjunct faculty member at the University of New Mexico. Yodaiken is a technical advisor to EMBLIX Japan and is on the board of the Embedded Linux Consortium.


(Click here for further information)


FUEL Database on MontaVista Linux
Whether building a mobile handset, a car navigation system, a package tracking device, or a home entertainment console, developers need capable software systems, including an operating system, development tools, and supporting libraries, to gain maximum benefit from their hardware platform and to meet aggressive time-to-market goals.

Breaking New Ground: The Evolution of Linux Clustering
With a platform comprising a complete Linux distribution, enhanced for clustering, and tailored for HPC, Penguin Computing¿s Scyld Software provides the building blocks for organizations from enterprises to workgroups to deploy, manage, and maintain Linux clusters, regardless of their size.

Data Monitoring with NightStar LX
Unlike ordinary debuggers, NightStar LX doesn¿t leave you stranded in the dark. It¿s more than just a debugger, it¿s a whole suite of integrated diagnostic tools designed for time-critical Linux applications to reduce test time, increase productivity and lower costs. You can debug, monitor, analyze and tune with minimal intrusion, so you see real execution behavior. And that¿s positively illuminating.

Virtualizing Service Provider Networks with Vyatta
This paper highlights Vyatta's unique ability to virtualize networking functions using Vyatta's secure routing software in service provider environments.

High Availability Messaging Solution Using AXIGEN, Heartbeat and DRBD
This white paper discusses a high-availability messaging solution relying on the AXIGEN Mail Server, Heartbeat and DRBD. Solution architecture and implementation, as well as benefits of using AXIGEN for this setup are all presented in detail.

Understanding the Financial Benefits of Open Source
Will open source pay off? Open source is becoming standard within enterprises, often because of cost savings. Find out how much of a financial impact it can have on your organization. Get this methodology and calculator now, compliments of JBoss.

Embedded Hardware and OS Technology Empower PC-Based Platforms
The modern embedded computer is the jack of all trades appearing in many forms.

Data Management for Real-Time Distributed Systems
This paper provides an overview of the network-centric computing model, data distribution services, and distributed data management. It then describes how the SkyBoard integration and synchronization service, coupled with an implementation of the OMG¿s Data Distribution Service (DDS) standard, can be used to create an efficient data distribution, storage, and retrieval system.

7 Advantages of D2D Backup
For decades, tape has been the backup medium of choice. But, now, disk-to-disk (D2D) backup is gaining in favor. Learn why you should make the move in this whitepaper.

 


Got a HOT tip?   please tell us!
Free weekly newsletter
Enter your email...
Click here for a profile of each sponsor:
PLATINUM SPONSORS
GOLD SPONSORS
(Become a sponsor)

ADVERTISEMENT
(Advertise here)

Check out the latest Linux powered...

mobile phones!

other cool
gadgets



BREAKING NEWS

• Hacker-friendly karaoke PMP runs Linux
• Maemo gains KOffice port
• OLPC partners with Amazon, ITU
• "cJTAG" debuts
• First $100 laptop runs Linux
• First Linux on Everest
• Dell ships Ubuntu- and Atom-based netbook
• Smallest x86 board ever?
• MontaVista Vision gains focus
• "Olympics" phone runs Linux
• Android Challenge winners push location awareness
• Atmel-based industrial SBC runs Linux
• Atom squeezes onto Pico-ITX board
• Via frees Chrome graphics driver source
• Webinar dissects Linux multicore migration


Most popular stories -- past 90 days:
• Open source phone goes mass-market
• Updated! Linux Mobile Phones Showcase
• World's cheapest Linux-based laptop?
• Garmin Nav devices run Gnome Linux
• First Atom-based notebook runs Linux
• ARM9 board boots Debian in 0.69 seconds
• Open source camera records geotagged video to SATA HDD
• Linux-friendly Beagle fetches $150
• "PDA phone" runs Linux
• Intel offers $80 "Little Falls" Atom mobo
• Netflix Player runs Linux


DesktopLinux headlines:
• OSCON 2008 presentations, videos posted
• Debian distro named for little green man
• Google spins web browser
• Summit debuts for Linux end users
• "UbuntuLite" reviewed
• Linux in the SME
• Linux: not yet photo-friendly
• Linux to gain anti-virus software
• Linux gains backup utility
• Testing Lenny


Also visit our sister site:


Sign up for LinuxDevices.com's...

news feed

Home  |  News  |  Articles  |  Polls  |  Forum  |  About  |  Contact
 

Ziff Davis Enterprise Home | Contact Us | Advertise | Link to Us | Reprints | Magazine Subscriptions | Newsletters
Tech RSS Feeds | White Papers | ROI Calculators | Tech Podcasts | Tech Video | VARs | Channel News

Baseline | Careers | Channel Insider | CIO Insight | DesktopLinux | DeviceForge | DevSource | eSeminars |
eWEEK | Enterprise Network Security | LinuxDevices | Linux Watch | Microsoft Watch | Mid-market | Networking | PDF Zone |
Publish | Security IT Hub | Strategic Partner | Web Buyer's Guide | Windows for Devices

Developer Shed | Dev Shed | ASP Free | Dev Articles | Dev Hardware | SEO Chat | Tutorialized | Scripts |
Code Walkers | Web Hosters | Dev Mechanic | Dev Archives | igrep

Use of this site is governed by our Terms of Service and Privacy Policy. Except where otherwise specified, the contents of this site are copyright © 1999-2008 Ziff Davis Enterprise Holdings Inc. All Rights Reserved. Reproduction in whole or in part in any form or medium without express written permission of Ziff Davis Enterprise is prohibited. Linux is a registered trademark of Linus Torvalds. All other marks are the property of their respective owners.