Month: August 2009

Effective Concurrency: Design for Manycore Systems

This month’s Effective Concurrency column, Design for Manycore Systems, is now live on DDJ’s website.

From the article:

Why worry about “manycore” today?

Dual- and quad-core computers are obviously here to stay for mainstream desktops and notebooks. But do we really need to think about "many-core" systems if we’re building a typical mainstream application right now? I find that, to many developers, "many-core" systems still feel fairly remote, and not an immediate issue to think about as they’re working on their current product.

This column is about why it’s time right now for most of us to think about systems with lots of cores. In short: Software is the (only) gating factor; as that gate falls, hardware parallelism is coming more and sooner than many people yet believe. …

I hope you enjoy it. Finally, here are links to previous Effective Concurrency columns:

The Pillars of Concurrency (Aug 2007)

How Much Scalability Do You Have or Need? (Sep 2007)

Use Critical Sections (Preferably Locks) to Eliminate Races (Oct 2007)

Apply Critical Sections Consistently (Nov 2007)

Avoid Calling Unknown Code While Inside a Critical Section (Dec 2007)

Use Lock Hierarchies to Avoid Deadlock (Jan 2008)

Break Amdahl’s Law! (Feb 2008)

Going Superlinear (Mar 2008)

Super Linearity and the Bigger Machine (Apr 2008)

Interrupt Politely (May 2008)

Maximize Locality, Minimize Contention (Jun 2008)

Choose Concurrency-Friendly Data Structures (Jul 2008)

The Many Faces of Deadlock (Aug 2008)

Lock-Free Code: A False Sense of Security (Sep 2008)

Writing Lock-Free Code: A Corrected Queue (Oct 2008)

Writing a Generalized Concurrent Queue (Nov 2008)

Understanding Parallel Performance (Dec 2008)

Measuring Parallel Performance: Optimizing a Concurrent Queue (Jan 2009)

volatile vs. volatile (Feb 2009)

Sharing Is the Root of All Contention (Mar 2009)

Use Threads Correctly = Isolation + Asynchronous Messages (Apr 2009)

Use Thread Pools Correctly: Keep Tasks Short and Nonblocking (Apr 2009)

Eliminate False Sharing (May 2009)

Break Up and Interleave Work to Keep Threads Responsive (Jun 2009)

The Power of “In Progress” (Jul 2009)

Design for Manycore Systems (Aug 2009)

Suggestions on improving C++ skills

Someone just asked me about getting more proficient in C++, and with their permission I thought I’d share the question and my answer in case it’s of broader interest to folks wanting to improve their C++ skills.

Here’s the question:

I need to take my C++ knowledge up a notch – or two. On a scale of 1-10 I’d consider my C++ knowledge a 5 and would like to get to 7-8 in the next 4, or so, months. As C++ is a large language my quandary is what subject areas, using what study materials, should I focus on to get myself to this next level.

Questions (assuming that I’m going to study approx 2 hrs/day for 4 months):

1. How would you suggest I structure such a course of study (subject areas, 5 of time for each) ?
1.1 If you were in my shoes, how would you proceed?
2. If I was going to study and hopefully know cold one of your books, which do you think I should select?

Here’s my response, which I didn’t limit to my own books. These are the first two “next books” books I would recommend to anyone who already knew the basics of the language and wanted to improve their proficiency with using C++ in production code:

If you’re not already familiar with Scott Meyers’ Effective C++, the current third edition is the plate to start (it’s substantially reworked since the first and second editions).

After that, I’d say the most important is C++ Coding Standards which I wrote with Andrei Alexandrescu. Not only does it cover the top 100 things we felt were important to say about using C++ in production code, and had its guidance peer-reviewed in advance by a who’s-who of the C++ community more than any other C++ book I’ve ever heard of, but it also includes references in each Item for where to find more in-depth treatment. Most Items are just one or two pages, so if you know that Item already you can use it as a refresher; and if you discover ones that you’re less familiar with or rusty on the details, it tells you where to go to find out more.

I’d say those are the two most important that I can suggest. Best wishes with your studies!