Linus Kvarnhammar's Weblog

Øredev 2009 Day 1

2009-11-04T08:40:00.001-08:00

The talks by Dan North, Eric Ries and Neal Ford in the Agile Ways track were definitely the highlights for me this first day at Øredev. They all touch on the same subject of being effective in development by using quick feedback in the form of TDD, pair programming, iterative development and releasing software continuously. Another point made clear (which is obvious when you think about it) is that you get the results for which you measure, so measure the stuff you really want. Is high test coverage what you really want? Probably not. You probably want high quality software, so measure that.

And another point made over and over in agile and lean talks is to eliminate waste and being effective by looking at what hinders you from producing quality software. Stop and fix your issues and then continue working. This is “obvious” but we see it over and over again. People doing repetitive or unnecessary tasks instead of pausing, having a retrospection to find a way to automate or fix the things that take time away from developers.

This first day of the best conference in the world has been great and two more great days awaits. :)

Linus Roslund becomes Linus Kvarnhammar

2009-05-27T03:45:00.001-07:00

I have changed my surname from Roslund to Kvarnhammar. Roslund is my father's side of my family and Kvarnhammar is my mother's side. Me and my girlfriend are having a baby in August/September and we decided that Kvarnhammar was the name we'd like our future children to have so that's the main reason for the name change. Another reason is that Kvarnhammar is unique for my family, it was taken by my grandfather. And yet another reason is of course that I own the domain kvarnhammar.com :)

FAQ

Are you getting married?
No

Øredev videos - viddler tryout

2008-12-17T09:23:00.001-08:00

We're about ready to publish the videos from Øredev last month. We will try to use external free services as we have limited time to get the videos out. I uploaded a couple of videos from last year's Øredev to viddler.com and it looks nice. I'll try embed one here to see how it turns out.

Øredev 2007 - No best practices? Methodology for thinkers - Dan North, ThoughtWorks

Viddler is like YouTube but with some additional cool features. Among other things you can add comments and tags in the timeline of the video clip. And an absolutely crucial thing for the Øredev videos is that the maximum size of a video is 500MB when YouTube has a maximum video length of 10 minutes.

Another .NET Rocks interview from Øredev

2008-12-17T09:08:00.001-08:00

The interview with Oren Eini (aka Ayende Rahien) from Øredev has been published. You can find it here.

.NET Rocks interviewing Glenn Block at Øredev

2008-12-05T13:13:00.001-08:00

A week ago the first .NET Rocks interview at Øredev was published. It's an interview with Glenn Block from Microsoft talking about the Managed Extensibility Framework (MEF) and you can find it here. As always Richard and Carl are a lot of fun to listen to.

Interviews still to be published are Ayende Rahien, Ted Neward, Tim Heuer, Scott Bellware and Robert C. Martin.

System.Windows.Forms.Timer and Garbage Collection

2008-12-03T13:02:00.001-08:00

When you create a .NET object you count on the garbage collector to clean it up when there's no rooted reference left to your object. That's the beauty of the garbage collector, it cleans up whatever objects are no longer in use. Well, when you use the Timer class in the System.Windows.Forms namespace you should be aware that it doesn't behave as you would think and it can give you a memory leak if you don't use it correctly. Suppose you do this :

    class Foo
   {
       public Foo()
       {
           Timer timer = new Timer();
           timer.Tick += timer_Tick;
           timer.Enabled = true;
       }

       void timer_Tick(object sender, EventArgs e)
       {
          
       }
   }

Your class Foo is interested in the Tick events from the timer as long as Foo is used. When Foo is no longer used you would assume that there is no longer a rooted reference to Foo and also no rooted reference to the timer as the only object that has a reference to the timer is Foo. All should be good. But what is happening behind the scenes is something else and this might be hard to figure out until you're sitting there debugging a memory leak.

When setting the Timer's Enabled property to true it calls GCHandle.Alloc(this) which creates "A new GCHandle that protects the object from garbage collection. This GCHandle must be released with Free when it is no longer needed." Setting the Enabled property to false will call GCHandle.Free() and the timer object is again available for garbage collection.

The result of the mistake in the code above is not only that the timer object is not garbage collected but also that the Foo object stays in memory forever. As you probably know, hooking up the event handler timer_Tick will create a reference from the timer object to the Foo object, i.e. the event source keeps the event subscriber in memory. So if you have a heavy object Foo and you add a timer like in this case you get yourself a nasty memory leak.

So bottom line : somewhere in Foo you need to set Enabled to false to get rid of the memory leak. Note : Calling Start() is the same thing as setting Enabled to true and calling Stop() is the same thing as ... you guessed it, setting Enabled to false.

Memory leaks often take hours or days to track down and often just minutes to fix, we found this one out in our project a couple of days ago and by searching the code for usage of the Timer class we found at least one more place were it was used in the wrong way.

Øredev 2008 Feedback

2008-11-25T12:39:00.001-08:00

This year's Øredev is over and it has been a blast! We have worked almost a year with the conference, putting our utmost into making it even better than last year. And judging by the feedback we have gotten I can say quite sure that we have succeeded.

I have spent an hour or so reading through the response Øredev got in the blogosphere this far and it's very honoring indeed and I feel great to be part of organizing such an event. I have collected some of the most valuable feedback here below, and it's just the tip of the iceberg.

Øredev is different - Glenn Block, Microsoft, USA
I wanted to let everyone know that Øredev is one awesome conference, and I am having a real blast! If you know me, then you know I am usually really bad about blogging about conferences I attend. I already have a backlog that includes PDC, Kaizen and the p&p summit. Why this one? Well I am really feeling inspired, and thus it's became a moral imperative. :-)

Thank you Malmö and Øredev for a wonderful conference so far. I'll definitely be coming back if you'll have me :)

A good conference and Why Øredev rocks - Ayende Rahien, We!, Israel
One indication of a good conference is that it completely swallow the entire time that you have.

Oredev excel by this criteria. I am busy all the time, and having fun while doing so.

Øredev 2008 Summary - Tim Heuer, Microsoft, USA
I’ve attended Microsoft’s PDC, TechEd, VSLive, DevConnections, etc. I’ve got most of them all under my belt (as an attendee). They are all good in their own regard. The ones that are most interesting, however, are those that have an intensity about them and a collaboration among the other attendees who may or may not know each other. That is what I felt at Øredev this past week. This was the ultimate “code camp” which brought together a ton of different technology conversations in the setting of a large conference. There was representation from both technology and practices: .NET, Java, project management, user experience, Agile/Scrum methodologies, mobile development, etc., etc. You name it, it was there.
...
What made Øredev special to me was the sincerity of learning and diversity in attendees. Generally, even at the local code camps I’ve attended, there always seems to be this animosity between technology experts. Not here.

JavaBlackBelt@Øredev908 - Nicolas Brasseur, JavaBlackBelt
Unlike most of the other conferences I attend, Øredev is cross-technology, mixing tracks such as classic Java, .NET, Agile and Mobile tracks with more exotic subjects such as Domain-Driven Design, Aspects of Leadership, PM in Practice, User Experience and more. I like conferences where you have the opportunity to meet people active outside Java: it's always enriching to share ideas and vision with someone from a different viewpoint.
...
I can't end this article without warmly thanking Emilie and Michael, the core organizers, for the amazing event they have successfully set up. Thank you very much and I hope to see you next year at Øredev09.

Apache ActiveMQ and ServiceMix at Øredev Conference - Bruce Snyder, Apache, USA
One unique feature of this conference is the keynote talk each morning to start off the day and each one has been very good in topic and delivered by some very entertaining speakers including Ted Neward, James Bach and Robert C. Martin. Another unique offering here has been a track dedicated to development processes, and, as I mentioned, very slanted toward Scrum.

And some comments in Swedish from two of the developer evangelists at Microsoft Sweden.

Øredev gör mig lycklig i själen - Mikael Deurell, Microsoft, Sweden
Øredev fångar många av de aspekter jag älskar med den här branschen. Passion, kompetens, nyfikenhet och öppenhet för att nämna några... I vilken annan miljö har man lyxen att gå från en skön dragning om MEF för att sedan gå på en lysande dragning om aspektorienterad programmering där jag inte ens bryr mig att det ligger i ett java-spår utan bara njuter av innehållet...

Från detta till att få höra Scott Bellware spy galla över varför det finns miljoner olika versioner av Windows, Office och Visual Studio och inte kunna bemöta detta med annat än... "Ehmmm... Jag håller med, kan vi inte ta en grymt god Oracle kaffe och snacka mer?". Underbart! Uppfriskande och magiskt!

Öredev-konferensen - Robert Folkesson, Microsoft, Sweden
Det som är en smula speciellt med Öredev är att konferensen samlar så många olika typer av besökare: från .NET- och Java-utvecklare till utvecklare som håller på med mobila/inbäddade system till testare, projektledare, agilförespråkare och ALT.NET-possen till User Experience/interaktionsdesigners, DDD-folk och arkitekter i en salig skön blandning.

Will it be possible to do it all over again next year? We'll definitely try and the work will start pretty soon :)

If you have ideas or suggestions that will help us create another great conference, feel free to contact us at the Øredev website.

Underground@PDC

2008-10-30T13:51:00.001-07:00

Yesterday was another totally awesome party. On Sunday was a party called "Party with Palermo" which was basically a party at a scabby bar arranged by a guy called Jeff Palermo. There you got a couple of free drinks in the beginning of the night and the party died quite quickly. Yesterday was another party called Underground@PDC and I expected something similar. But hell no, it was at a really fancy place and there were a bunch of "famous" people speaking. People like Scott Guthrie, Don Box, Chris Anderson and Scott Hanselman. The latter gave an excellent and funny presentation.

They also had gave away a bunch of stuff and Björn won $100 and Truls a Zune :). And drinks and food was free all night (until 02.00). There were also free shoe shine and free cigars. I don't smoke but I have very nice shoes now :)

Late at night we met some guys working on the Windows 7 team. One guy that was working on the Windows Explorer was really friendly and me and Björn was nice nice enough to tell him what we thought about it and why Total Commander totally rocks :) .. But what really surprised us was that he didn't know what Total Commander was. That feels like working on IE and not knowing what Firefox is. Anyway, we promised him a demo on Total Commander today but I haven't found him yet.

PDC Halloween party at Universal Studios

2008-10-29T15:42:00.001-07:00

Yesterday was the PDC official party at Universal Studios. I have been to two different TechEd parties before that has been very cool with no expenses spared but yesterday was something else! The entire Universal Studios area had a Halloween theme and not in a childish way but quite scary (not for me though ;) ). Zombies with chainsaws (that actually seemed to work) and 3 meter high skeletons were walking around scaring people .

Note: The photos below are taken with my cheap party camera, not my DSLR.

Street performer

Chainsaw zombie

Except for all the zombies, free food and drinks on the premises there are also a bunch of different shows and rides to enjoy. One show was called Bill & Ted's Halloween Show and it was probably one of the most intense and fun shows I have ever seen. It started off with a "battle" between McCain/Palin and Obama where it ended with all the performers taking there clothes off (not completely of course) while dancing.

Bill & Ted's Halloween show

It was an awesome performance with professional show artists! It continued with different famous people and movie characters fighting and singing. Basically it was a lot of fun and continued for about 20-30 minutes.

Another crazy chainsaw character

And then after having a bite to eat and a few drinks (all free of course :) ) we went for yet another show, the Waterworld. It wasn't as good as the Bill & Ted's show but there was a lot of stunts, fire, explosions and water. So it was entertainment Hollywood style :)

Waterworld show

Wednesday keynote - Microsoft Research

2008-10-29T14:46:00.001-07:00

Today's keynote was all about Microsoft Research and it was an intense showcase of different new and cool projects MSR is working on.

MSR has over 800 PhDs around the world and they expand by the size of a Berkeley Computer Science faculty every year! An interesting side note to all the demos was that Rick said that a lot of researchers have started to question the research sponsored by the current administration (which means Bush & Co and their political agenda).

They showed a cool demo of SensorMap - how they had put sensors all over the keynote hall that record data on the environment like temperature etc. They then played a graphic visualization on top of Virtual Earth on how the temperature changed in the keynote hall during the course of one of the previous days. This maybe sounds quite basic but what this software enables them to do is for example to place sensors in data centers (I think he said they have placed 100.000 sensors in Microsoft data centers already) and then monitor the temperature to understand where in the racks it's cool and then move computing intense processes to that part, either physically or virtually. That sounds really cool and it helps reducing energy consumption as air condition can be optimized. They also use the sensors and software outdoor to help climate researchers finding out what is happening in the world.

MSR are also doing research in data analysis that helps other researchers that are trying to find a cure for HIV. They also showed the newest version of the World Wide Telescope and how you can create virtual tours of the universe. Apparently amateur astronomers have used WWT to find phenomenon's in space that was previously unknown to the scientific community.

But one of the coolest things they showed (at least for us developers) was the Boku programming language for kids. Check out this video. It's targeted to young kids and you could do some amazing stuff with it. The user can create their own world with rules and actions. You can have user characters and you can place AI characters in your world. All the "programming" is done by the XBox control so no keyboard is used. And as the presenter said "We asked the kids and they said shooting was an absolutely mandatory feature" :)

They finished off with showing SecondLight - which is basically Surface on steroids. In addition to the regular surface table they could hold a piece of paper or plastic above the surface and have a second image reflected on the paper. The paper could be tilted and still have show non-distorted image. You can use this to show additional information in an extra layer over the image on the surface. I.e. if you have a satellite view you can display street names or text about the place you're hovering over. It's hard to explain but it was really cool. It's got to be seen, but there don't seem to be much information on the internet about it at this time.

Monday/Tuesday PDC keynotes on Windows Azure, Windows 7, VS 2010 and more

2008-10-28T17:13:00.001-07:00

Yesterday's keynote was a boring 1.5 hour introduction of Windows Azure - which itself I think will be really cool but Ray Ozzie is not the most interesting person to listen to and the demo did unfortunately not show much.

Ray Ozzie

Today the keynotes lasted from 8.30 to 12.30 and were great, much better than yesterday. A lot of demos on Windows 7, Visual Studio 2010 / NET Framework 4.0 and Windows Azure.

Windows 7 looks promising but nothing miraculous. As far as I understand they haven't changed the kernel or any major parts so compatibility will not be a problem. In short it feels like they just fixed Vista by removing annoying stuff, increasing performance and reducing memory usage. They have also added several minor things that will be nice for sure but nothing that one haven't seen elsewhere before. Some new features are :

New design of the taskbar. Instinctively it looks like Microsoft moves one step closer to OS X here. You can decide which programs you want to have in the taskbar and they will be there if they are started or not. There is also a nice full-size mouse-over-preview of open applications.
The window manager has been improved and you can dock windows in different ways and the support for multi-monitor has been improved. Reminds me of WinSplit Revolution.
Like they said in the keynote : sharing folders in your home network has been around since Windows for Workgroups but it has never been easy for regular people. Now it will be, a lot of work have been done to improve the experience when sharing documents, videos and music on your home network. And you can play music from your computer to another device in your network, just like with iTunes :)
You can mount virtual hard disks in the Computer Management tool. You are even supposed to be able to boot your computer from a VHD. That is cool and Don Box says this is his favorite feature.
Built-in zoom support in Windows with ctrl +/-, I hear OS X has this feature already.
System tray customization. You will be able to customize the system tray more than today and for example disable notifications from the windows firewall.
Multi-touch support. This is cool and there is probably a lot of potential here.
With a slider you will be able to set the level you want UAC to bother you, i.e. annoyance minimized.
You will be able to customize how the Shutdown button will behave. This is nice, maybe I will not have to see the 7 shutdown options every time I want to shut down Windows in the future.

No major things but at least Windows 7 looks more appealing than Vista :)

Interesting music in the Windows 7 demo

Then Scott Guthrie showed a lot of new stuff in Visual Studio 2010 and .NET Framework 4.0. Among other things the new Managed Extensibility Framework, new WPF controls, better TDD support.

ScottGu

After a short break another keynote followed with Don Box and Chris Anderson. These guys are a lot of fun and they know how to entertain developers. They showed how powerful the Windows Azure services are and how easily you can build, test and deploy your own web sites or services in Microsoft's hosted environment and have them communicate with services hosted in your own location. Communication is done by web standards and identity management seems to be working really smooth. Very impressive stuff and I and I feel like taking some time to play with it right now, unfortunately there is no time - the schedule is packed! :)

Don Box

We also saw some demos on Live Mesh and how you synchronize files and integrate with Live Messenger in your applications.

I hear you can go ahead and download Visual Studio 2010/.NET Framework 4.0 CTP right now and you can also sign up for tech previews of Azure and Live Mesh. You might need to use an Live account with country set to USA.

A lot of stuff has happened and I've been to some other sessions but time and battery power is running out so I've got to finish. Tonight is the PDC party at the Universal Studios with Halloween theme and apparently a lot of fright! :O

Over and out...

My cousin and colleague on Android

2008-10-26T16:32:00.001-07:00

I own an Iphone 3G and I love it! As far as I am concerned it's the best phone out there right now.

But at least according to my cousin and colleague at Realway Android is even better. He was interviewed (for the second time) by Computer Sweden, read it here (in Swedish).

Microsoft PDC 2008 in Los Angeles

2008-10-26T15:43:00.001-07:00

This week it's time for the biggest event of the year for Microsoft developers, the Professional Developer's Conference (PDC) in Los Angeles. With five people attending, my company Dotway hopes to take in most of what's new and upcoming in the Microsoft world.

PDC is the conference where Microsoft launches new technologies and only occurs in the years where there are new things to talk about. The previous PDC was in 2005 and then everyone from Dotway attended.

At this year's PDC we expect to hear a lot about the new version of Windows, Windows 7. There will also be a lot of talk about services in the cloud. Attendees will get a USB hard drive loaded with new betas and CTPs. That's cool :)

Today is pre-conference day and tomorrow the conference kicks off for real. The keynotes on Monday and Tuesday will be streamed live so check out www.microsoftpdc.com.

On the flight here and later in the hotel bar we had some interesting discussions with Miguel de Icaza, speaker at PDC and working for the mono project. Tonight Jeffrey Palermo organizes an official party for PDC attendees and hopefully we'll meet more interesting people for interesting discussions there.