Tag Archives : Concurrency


Morning Coffee 146

  • The writers strike is officially over. Everyone goes back to work today. Thomas Cleaver has what I thought was the best post summarizing how the writers won. TV Guide has a rundown of how and when various shows will resume. I can’t wait to see Daily Show and Colbert Report tonight. Lost – aka the best show on TV – looks like it will be getting five more episodes (in addition to the eight shot before the strike).
  • Speaking of TV, Battlestar Galactica Fans: circle April 4th on your calendar.
  • Obama won all three “Potomac Primaries” yesterday, and is now the Democratic front-runner, though there’s a long way to go before the convention. Scott Adams of Dilbert fame has a great take on presidential experience – I’m guessing he’s an Obama fan.
  • In minor acquisition news, Microsoft is acquiringCaligari, makers of 3D modeling tool trueSpace. The Caligari folks are joining the Virtual Earth team, though I wonder what the XNA folks think of the acquisition. This isn’t the first 3D modeling product Microsoft ever acquired – we owned Softimage for four years in the ’90s.
  • Scott Hanselman and Tomas Resprepo both write about PowerShellPlus, which I saw week before last @ Lang.NET. Scott really likes it, for both PS novices and gurus, but Tomas thinks the UI is busy, based on the screenshots. Personally, I’m not doing much PS work lately – occasional one off stuff, but that’s it – so it doesn’t seem worth the effort.
  • Speaking of Scott & Tomas, Scott also has a nice gallery of VS themes. I’m partial to Tomas’ Ragnarok Grey. Is there a VSThemesGallery.com site somewhere?
  • Still speaking of Scott, he points to the new ASP.NET Developer Wiki (beta). I poked around, but didn’t find anything shiny. I was very surprised that searching for “MVC” returned no results.
  • Speaking of MVC, Scott Guthrie has a rundown on what’s coming in the MIX preview release of ASP.NET MVC. Biggest news IMO is that it’s /bin deployable – i.e. you don’t need your hoster to do anything special to support MVC (assuming they already support ASP.NET 3.5). Also big news, they’re releasing the source so you can build and patch (and enhance?) it yourself.
  • Chris Taveres continues is ObjectBuilder series and Tomas continues is DLR Notes series. BTW, my F# based DLR experimentation continues, albeit slowly (frakking day job). Hope to be able to post on this soon.
  • One of the things driving my interest in F# is manycore. An interesting tangent to manycore is general purpose programming on graphics processing units (aka GPGPU). MS Research just released a new version of Accelerator, just such a GPGPU system. I personally haven’t played with it – I’ve been focused on writing parsers, not parallel code.
  • Is XQuery really “a promising technology of the future” as Don Box suggests? I see exactly zero demand or use for it in my day-to-day work. Of course, Don’s paid to build future platform goo, so maybe it is promising and Don’s afore-mentioned goo will leverage it, though I remain skeptical. As for XML being “Done like a well-cooked steak”, I’d say XML is like a great steak cooked perfectly, except it’s done exactly how you don’t like it. You can appreciate its quality, but you don’t really enjoy it as much as you could have.

Morning Eggnog 132

  • My parents are coming into town tomorrow so I’m off for the remaining week or so of the year. Blogging will likely be non-existent, unless I blog something I come up with while geeking out with my dad.
  • Juergen van Gael demonstrates how to use TPL from F#. He wrote this once before using F#’s async workflows feature. I like the TPL version, though the “new Action<int>(RowTask)” is a little wordy. I’m guessing the eventual F# syntax will probably become something compact like “action RowTask”. (via Don Syme)
  • Andrew Peter ported RoR’s Haml view engine to ASP.NET MVC, calling the result NHaml. I haven’t played around with the new MVC stuff much, but I’m guessing ASP.NET’s control-based approach doesn’t work well when you separate out the controller code. If I’m manually authoring view templates, I’d much rather type NHaml’s syntax than the standard ASP.NET <% …%> syntax. On the other hand, there aren’t any design tools out there today handle the NHaml syntax. Also, I wonder if Andrew is working on a Sass port. (via DNK)

Morning Coffee 127


Morning Coffee 120

  • Doing these morning coffee posts is a lot tougher since I cut back my blog reading. Where I used to have no trouble finding 4-5 coffee-worthy items every day, these days I seem to only get 1-2, if that.
  • After starting off 3-0 and 100% on the PK, the Caps dropped four in a row and have been miserable on special teams. The special teams woes continued last night against the Lightning, but they still won. Caps went 0-4 on the powerplay, and coughed up a short handed goal. But they also went 3-3 on the PK, so I guess it wasn’t all bad. Maybe my mother will stop calling for Hanlon’s job now. It’s a long season and as Peerless Prognosticator points out, the rebuild isn’t over.
  • Jomo Fisher, who helped Scott Hanselman auto-merge assemblies, has been digging around in F# of late. As it turns out, he’s joining the F# team so I’m thinking it’s not a huge stretch for him. If you’re a C# developer trying interested in getting a handle on this new F# thing, his blog is a good place to start.
  • Speaking of F#, Don Syme posts about yet another new F# feature: Async Workflows. Workflow is a bad term here IMO since it can be easily confused with WF. Regardless of it’s name, Async Workflows is about making .NET’s Async Programming model a first class citizen in F#. Robert Pickering has a good post explaining how this new feature works.
  • Microsoft sure has a lot of multi-threading / async-programming tools coming out. In addition to F# Async Workflows, there’s the Concurrency and Coordination Runtime, Parallel LINQ and the Task Parallel Library. I would hope all this work eventually coalesces as a coherent product offering.
  • Now that F# is being “producized”, I wonder if the language evolution will slow down. Async workflows were introduced in F# 1.9.2.9. Other recent changes include Computation Expressions (v1.9.2), Use Bindings (v1.9.2) and Active Patterns (v1.9.1). F# seems to churn more in minor releases than C# does in major releases. Of course, that’s because F# was a research project, not a “real” product. Now that it’s going to be a product, will the rate of innovation slow?

Restating the Concurrency Problem

I’ll be honest, I recommended Herb Sutter’s concurrency series in today’s Morning Coffee because it a series on concurrency by Herb Sutter. In other words, I hadn’t actually read it yet, but I know how good Sutter’s stuff is. Now I have read it and I wanted to re-issue my recommendation, even more strongly. Go read it.

Interestingly enough, I like the article because it doesn’t provide an “answer” to the problem of concurrency. Rather, by providing a mental model, it essentially is a concise and precise restatement of the problem. Often, in the rush to find a solution to a problem, this step is skipped and it isn’t until the end that you realize that you misunderstood the original problem and what you built doesn’t match what you need.

I’ve often argued that this is also the key to selling in the enterprise. In my experience, whatever solution you’re selling is usually way too complicated to be understood by the people who have the purchasing power to buy it. So explaining how your solution works or how your solution solves the problem isn’t going to get you very far. However, the buyer does understand the problem at hand. Being able to demonstrate that you understand the fundamental nature of the problem and can communicate it back to them garners you a great deal of trust in the selling process. If you can show that you understand their problem, then you probably know how to fix it – even if the buyer doesn’t understand how your solution works.

One other quick thought on Sutter’s article. In discussing the use of concurrency to keep a GUI responsive (aka Pillar 1), he wrote the following:

Today, we typically express Pillar 1 by running the background work on its own thread or as a work item on a thread pool; the foreground task that wants to stay responsive is typically long-running and is usually a thread; and communication happens through message queues and message-like abstractions like futures (Java Future, .NET IAsyncResult). In coming years, we’ll get new tools and abstractions in this pillar, where potential candidates include active objects/services (objects that conceptually run on their own thread, and calling a method is an asynchronous message); channels of communication between two or more tasks; and contracts that let us explicitly express, enforce, and validate the expected order of messages. [emphasis added]

If we’re going to provide the ability to express, enforce and validate the expected order of messages between concurrent blocks of code, can we also do it for services across the network? WSDL is wholly deficient in this area. SSDL’sCommunicating Sequential Processes (CSP) and Rules-based Protocol Frameworks are a good start.