MSDN Blogs

Wir erklären das Internet und geben Tipps und Tricks im Umgang mit dem Browser

OliverS — Sat, 04 Jul 2009 08:38:50 GMT

Wir erklären, wie das Internet funktioniert, was ein Browser ist, was man bei der Benutzung beachten muss, was es mit Webseiten und deren Darstellung auf sich hat und geben Tipps und Tricks im Umgang mit einem Webbrowser… und beantworten auch die wichtigste aller Fragen: Warum die Oma von Lukas ihm den Laptop wegnimmt, obwohl er richtig brav und artig war.

Coding4Fun выходит на экрaны

Ujane — Sat, 04 Jul 2009 08:32:00 GMT

Опубликовано 30 июня 2009 в 19:27:00 | Coding4Fun

Coding4Fun начинает показы на канале Channel9 (EN) MSDN. Мы долго к этому готовились, так что держитесь! Джефф Сэндквист (Jeff Sandquist (EN)) и Дэн Фернандес (Dan Fernandez (EN)) рассказывают о том, что вас ждет в последнем эпизоде программы на неделю This Week on Channel 9 (это редкий супердлинный эпизод).

Что мы наверняка сможем, так это сделать наши материалы более доступными. Кроме того, у нас заготовлено несколько сюрпризов.

Мы также начинаем собственную программу на Channel9 под названием Coding4Fun TV (EN)! Брайан Пик (Brian Peek), автор c#-библиотеки для WiiMote (EN), — главный вдохновитель этой идеи, а его первая программа посвящена обучающей программе по физике на Silverlight (EN).

Personnaliser le fond d’écran de Windows 7

spapp — Sat, 04 Jul 2009 08:30:46 GMT

Mes interlocuteurs récents ont pu découvrir les images superbes de Paris que mon collègue Olivier Le FESSANT a mis à disposition ici et là sur son espace de partage de photos et que j’utilise en fond d’écran.

Si le changement du fond d’écran de l’utilisateur courant est relativement simple, en revanche le changement de l’image avant ouverture de session ou session verrouillée est moins intuitif et, surtout, la démarche pour y parvenir a changé depuis que j’utilise Windows 7.

L’astuce consiste à créer une clé OEMBackground de type DWORD à 1 dans :

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Authentication\LogonUI\Background

Une fois cette clé crée, vous pouvez aller modifier les images de :

%windir%\system32\oobe\info\backgrounds

Faites attention à ne déposer des images que de moins de 256Ko !

L’image backgroundDefault.jpg est utilisée et redimensionnée si les autres images dans les résolutions suivantes ne sont pas présentent :

background768×1280.jpg
background900×1440.jpg
background960×1280.jpg
background1024×1280.jpg
background1280×1024.jpg
background1024×768.jpg
background1280×960.jpg
background1600×1200.jpg
background1440×900.jpg
background1920×1200.jpg
background1280×768.jpg
background1360×768.jpg

[PL] Nowy WPF Toolkit zawiera wykresy

danieb — Sat, 04 Jul 2009 08:02:30 GMT

W czerwcu opublikowano nową wersję WPF Toolkit:
http://wpf.codeplex.com/Release/ProjectReleases.aspx?ReleaseId=29117

W niej pojawiły się kontrolki z wykresami, jak ten poniżej:

Więcej informacji na tym blogu:
http://blogs.msdn.com/delay/archive/2009/06/25/wpf-charting-it-s-official-june-2009-release-of-the-wpf-toolkit-is-now-available.aspx

Oczywiście istniejące kontrolki i kod zostały też znacząco poprawione, o czym możecie przeczytać w Release Notes.

Disponibilité générale versus livraison à la fabrication

spapp — Sat, 04 Jul 2009 07:53:59 GMT

En cette période de disponibilité générale (GA, pour General Availability) de System Center Operations Manager 2007 R2, il est intéressant de noter la différence qui existe dans le vocabulaire Microsoft (certains parlent de Microspeak, comme si c’était une nouvelle langue ou novlangue) entre cette disponibilité générale et la livraison à la fabrication ou RTM (Release To Manufacturing).

La RTM était annoncée ici le 22 mai dernier. Depuis cette date, on peut supposer que les médias ont été fabriqués, puis distribués vers les grossistes de manière à permettre leur achat. Pour les clients qui ont accès aux serveurs des licences en volume, les serveurs ont été mis à jour de manière à permettre le téléchargement de cette édition. Certains pourraient penser qu’un grand mois est largement suffisant pour cette opération, mais les faits éprouvés par nos clients français qui attendaient l’apparition de ces fichiers pour démarrer leur installation tendraient à prouver le contraire. Nous en sommes allés jusqu’à évoquer le décalage horaire pour justifier leur absence. Il est plus probable que des considérations juridiques justifient que l’opération n’ait pas débuté avant le 1er juillet.

Dans un autre domaine, la disponibilité générale de Windows 7 a été annoncée pour le 22 octobre prochain comme évoqué ici. Pour un produit comme Windows 7, le délai entre la très prochaine RTM et la GA sera mise à profit pour préparer la livraison d’ordinateurs équipés de cette version de Windows.

Les équipes en charge de construire le service pack 2 (SP2) de System Center Configuration Manager 2007 (ConfigMgr) se sont engagées à le livrer dans les 90 jours qui suivront la RTM de Windows 7. En effet, parmi les objectifs de ce SP2 figure le support de Windows 7 et de Windows Server 2008 R2. Il ne faut pas faire partir le chronomètre à partir du 22 octobre, date de disponibilité générale, car ces équipes pourront commencer à travailler pour produire une version définitive du sp2 dès que le code de Windows 7 et de Windows Server 2008 R2 sera figé.

[PL] Kodu juz jest na Xboxie (400 MSP)

danieb — Sat, 04 Jul 2009 07:41:38 GMT

Dla posiadaczy Xboxów zainteresowanych wyklikaniem prostych gier. Kodu Game Lab jest już dostepne na XboX Games Market Place w sekcji – Community Games (Independent Games).

Prasa branżowa zdąrzyła się już na ten temat rozpisać, poniżej kilka ciekawych artykułów:
IGN: http://xboxlive.ign.com/articles/100/1000340p1.html
Gamasutra: http://www.gamasutra.com/php-bin/news_index.php?story=24275
(Wow, i komentarz Mateusza Kierepki :>)
Polygamia.pl: http://polygamia.pl/Polygamia/1,95336,6786186,Co_potrafi_Kodu_.html

Ja dopiero dzisiaj znalazłem chwilkę aby pobrać Kodu na swoim Xboxie i sprawdzić w praktyce finalną wersję. 400MSP to około 20zł, za które na pewno będzie mnóstwo zabawy.

C# Compiler Optimization

cisg — Sat, 04 Jul 2009 07:31:53 GMT

Gaurav Sharma here, I’m a developer with the Information Security Tools team.

A couple of months back when I was trying to understanding the .NET compilation model I encountered an interesting thing. I created a small program to print an Int32 type array to a console. The code follows.

   1:  using System;

2:

   3:  namespace Optimization

   4:  {

   5:    class Program

   6:    {

   7:      static void Main(string[] args)

   8:      {

   9:        Int32[] arr ={ 1, 2, 3, 4, 5, 6, 7, 8, 9, 0,11 };

  10:        for (Int32 i = 0; i<=arr.Length-1;i++)

  11:        {

  12:          Console.WriteLine(arr[i]);

  13:        }

  14:        Console.ReadLine();

  15:      }

  16:    }

  17:  }

I then checked the IL that is generated from this small code snippet. I checked various function calls that were made by the C# compiler and noticed an interesting thing. The C# compiler had optimized the above code by intelligently adding new instructions and removing unnecessary instructions. The IL generated follows.

The compiler stores the array length in IL_0000. After this step, as you can see that there is no call made to Array.Length property i.e. get_Length() method.

Only three calls are added by C# compiler;

Initialize Array
Write Line, and
Read Line

The C# compiler had optimized my code internally so that there is no need to call Array.get_Length() method with every loop iteration. It uses the Array Length stored in the beginning of the instruction set. So, if you are working on similar kind of code snippet then there is no need to declare a variable to store the array length just before the loop and use that variable in the loop condition check; the C# compiler does that for you in the background!

Now my Tip of the Day for writing better code with Visual Studio

No one likes unwanted using or Imports statement in the beginning of your C# or VB.NET code file. There is a quick solution for this:

Happy coding!

Azaas demos their Silverlight 3 application

chism — Sat, 04 Jul 2009 07:22:00 GMT

I had a chance to meet up with Azaas, one of our Microsoft BizSpark startups, a few days ago to check out the Silverlight 3 application they built.

Here are some things that stood out for me when I talked to these guys:

They went ahead developing their app on Silverlight 3, even before it was officially launched
The demo they showed was built within three weeks, considering they haven't done any Silverlight development before. Nice!
We were pulling data from China, through a mobile broadband USB, in the demo. Silverlight data compression in action.

Check out the video interview here!

If you want to get in touch with Azaas, you can email Choon Ngee (choon [at] azaas.com) or Kai Boo (kaiboo [at] azaas.com). You can also get in touch with me (chism [at] microsoft.com) if you have some cool stuff to show like Azaas :)

Time flies.... Time to move on....

lchong — Sat, 04 Jul 2009 06:40:10 GMT

With effect from 4 July 2009, I will be moving on to a new role in Microsoft and that is Senior Project Manager with Microsoft Consulting Services in Singapore. My portfolio includes project management and presales engagement, focusing primarily on application development opportunities and engagements such as .NET consulting, solution architecture, SOA, SQL Server/BizTalk/SharePoint consulting, etc. I am no stranger to Services business as I was previously working for IBM Consulting Services for...(read more)

Time flies.... Time to move on....

Architect Evangelist - Linda Chong's Blog — Sat, 04 Jul 2009 06:40:10 GMT

Síguenos en Twitter!

ricardoj — Sat, 04 Jul 2009 06:07:39 GMT

Desde hace un tiempo para acá que venimos usando Twitter cada vez más. Te invitamos a que te conectes siguiendo nuestros usuarios para mantenerte al tanto de todo lo que hacemos en tiempo real.

Nuestras cuentas son:

Nuestros comentarios oficiales para desarrolladores de software de la región: MCAMSDN
Mis comentarios personales sobre desarrollo de software, mercadeo digital y muchos temas más: RicardoJ

Los esperamos!

Imagine Cup 2009 kick off

obloch — Sat, 04 Jul 2009 05:32:36 GMT

So yesterday was kick off day for Imagine Cup 2009 Egypt. We had the different briefings for judges and competitors and then buses picked up every single participant to bring them to the Citadel (see previous post) for the opening ceremony. Prior to the ceremony we were given the opportunity to visit the Mohammad Ali Mosque. You can see on the pictures how amazing this place is on this slide show . Our embedded judges enjoyed the visit :-) From left to right: Professor James Hamblen (Georgia Tech),...(read more)

Lessons Learned from Bruce Lee

J.D. Meier — Sat, 04 Jul 2009 05:16:58 GMT

I have a post on Lessons Learned from Bruce Lee on Sources of Insight. Bruce Lee was one of my early inspirations. He was a patterns and practices kind of a guy. In fact, Bruce influenced my software engineering approach. Rather than lock into a single style, he took the best techniques from various martial arts and measured against effectiveness. For example, he took a boxer's hands and a wreslter's grappling skills.

Here is a summary of my lessons from Bruce:

Be YOUR best.
Absorb what is useful.
Keep an open mind.
Aim past your target.
Stay flexible.
Focus on growth.
Master your mind and body.
Apply what you know.
Make things happen.

My favorite Bruce Lee quote is "Absorb what is useful, Discard what is not, Add what is uniquely your own.” It's all about finding what works for you and not blindly adopting things.

I've included a more exhaustive list of my favorite Bruce Lee quotes in my post, Lessons Learned from Bruce Lee. Whether you're a Bruce Lee fan or on a path of personal development, I think you'll enjoy the tour of Bruce's insight and words of wisdom.

Imagine Cup 2009レポートその2 （7/3午後）

hiwatan@microsoft.com — Sat, 04 Jul 2009 05:06:00 GMT

引き続き、Imagine Cup 2009世界大会のレポート続けます。
16:30の競技者ブリフィーングまで、少し時間があるので、部屋に戻って、明日の競技に備えるNISLab++のメンバー。
ちなみに、NISLab++メンバーの部屋は、4人相部屋ですが、ベッドルームが2つもあるスィートルームです。

16:30からは、いよいよ、競技者ブリフィーングがスタートです。
気合十分のチームCLFSのメンバー。

海外メディアの熱い視線も受けていた写真部門の寺田さん。

こちらは、2年目で少し余裕ある感じでしょうか？チームNISLab++のメンバー。

世界中の学生（出場チーム）と交流できるのもImagine Cupの世界大会の良いところです。
コロンビア代表チームとNISLab++のメンバー。

オーストラリア代表チームとNISLab++のメンバー。

オープニングセレモニー開始前は、会場となるモスク見学です。

煌びやかなモスクの中も見学しました。

20:30スタートのオープニングセレモニーは、モスクの近くに設置された特設野外ステージで行われました。

オープニングセレモニーでは、オリンピックと同様に、アルファベット順に各国代表の学生たちが入場してきます。
Japanというコールの後、日本代表チームの学生たちが入場してくる姿がステージの大型スクリーンに映し出されると、
自分が日本人であることを実感しました。感動しました。がんばれニッポン！

Deep Dive to .NET Framework CLR を作成中です

shozoa — Sat, 04 Jul 2009 04:54:00 GMT

TechEd 2009 横浜で「Deep Dive to .NET Framework CLR」というセッションを担当します。この資料を作成しています。このセッションは、私の著書である「The Root of .NET Framework」という書籍をモチーフにして、資料を構成しています。どのような内容が良いか、悩みながら作成を行っています。その途中経過を以下に引用します。

PEヘッダーから CLIヘッダーのアドレスを見つけて

CLI ヘッダーを読み解くのが、上記のスライドです。ここまで来るとメタデータが、どのように格納されているかを知りたくなることでしょう。それらも作成しているのですが、どこまで作るかが難しいところです。

これ以外にも、GCやCLRのホストインターフェース、RCWなどとアイディアがあるのですが、如何とも時間の制約がありますので作成したスライドを全部、説明しきれないかもしれません。現時点で30スライド程度が出来上がっていて、ここから SOSデバッガ拡張や.NET Framework 4.0の話を入れようと思っていますので。まだまだ、悩みは尽きません。公開されているセッションレベルは400番台なので、最低でも16進数ダンプの見方を知っている方が対象になると思います。

Problem mapping user profile properties

Tajeshwar — Sat, 04 Jul 2009 04:16:00 GMT

One of my colleague pinged me with a strange problem he was encountering in user profile property mapping. He wasn't able to add or edit user profile property import mappings because the 'Data source field to map' drop down and the 'Enter field to map' text box were missing from the 'User Profile Property' page in SSP. The page was coming without the dropdowns and showing 'The selection of directory service properties is disabled because the portal is in an untrusted domain or no directory service import is configured yet';

I initially thought it to be some issue with security permissions on reading some specific AD attributes. But that was not the case as he has succesfully imported the profiles from AD. Later on it was realized that the account under which he was running the SSP was a local box account and not a domain account. While importing profile he was prompted for domain account for importing profiles, that's why he was able to succesfully import the profiles. But when the profile property page tried to connect using the SSP account, it failed and hence disabled the drop downs.

So if you are facing this issue, just make sure that the account used for import has read access to the directory store which generally the domain accounts will have.

Performance Boost for SQL Queries – Filtered Index in SQL Server 2008

Ravi S.Maniam — Sat, 04 Jul 2009 03:09:59 GMT

SQL Server 2008 introduces an enhancement to the way the indexes are created which helps to get better performance from the same queries. This new little guy is known as ‘Filtered Index’. This is actually an Optimized Non-Clustered index which is well suited to cover the subset of data with in a table.

Every organization has a specific data usage pattern and if we have an idea of the data usage pattern then we can create the filtered indexes to cover the subsets of data that can actually yield faster results from our same query / stored proc.

Thank you very much for visiting this article. In case if you are not on the MSDN blogs then I would request you to please visit my blog at http://blogs.msdn.com/manisblog because at times I improve the existing articles after reading emails from people who enthusiastically provide their feedback. These improvements might not be reflected on the other blog sites who have indexed this article.

Let’s say the sample database “AdventureWorks” is used by a company that sells spare parts and they have different departments that sell specific products and lets say the racing bikes being the hottest in the market, it drives more sales for the racing bike spare parts. This means that more transactions are being done related to a specific product(s) so most of the times the data is filtered, is based on a specific Product Id. Moreover if there are millions of Rows in the table, it becomes really necessary to choose the indexes correctly and carefully because of the storage space involved to store them.

For example the queries (like the following one) are executed based on a selection criteria very frequently then the filtered indexes will help you a lot.

SELECT * FROM [AdventureWorks].[Purchasing].[PurchaseOrderDetail]

Where ProductID =709 OR ProductID = 879 OR ProductID = 877

Let see generally how indexes speed up the queries. During the SELECT, UPDATE, DELETE operations the SQL optimizer will look for indexes and determine the most efficient method to complete an operation. In this process SQL Optimizer determines to use an index or to go for a table scan. The SQL Optimizer does this operation to reduce the query execution time and improve the performance.

Index seeks are preferred for the selective queries like the one above and the index seeks happen only when the optimizer finds the index on the table useful, otherwise it will scan all the records. Generally, searching an index to spot a matching record is faster than a table scan because it is ordered and less number of columns means small set of data which in turn means less hops to find the match. Unique indexes are faster and table partitions speeds it up more. Well ….discussing the anatomy of indexes and strategy for indexing the tables is a huge subject and there are books available for that so …let me get back to the topic where I left it.

So why a filtered index ? A filtered index can be used as an index for a subset of data rather than the entire set of data. The filtered index takes less space to store the index because it stores only index information related to a subset of data unlike an usual non-clustered index. In no way this is a substitute for a regular Clustered and Non-Clustered indexes. This is an additional enhancement that can help you in tuning specific highly selective queries.

What are the advantages of Filtered Indexes :

Improved query performance and plan quality

A well-designed filtered index improves query performance and execution plan quality because it is smaller than a full-table non-clustered index and has filtered statistics. The filtered statistics are more accurate than full-table statistics because they cover only the rows in the filtered index.

Reduced index maintenance costs

An index is maintained only when data manipulation language (DML) statements affect the data in the index. A filtered index reduces index maintenance costs compared with a full-table non-clustered index because it is smaller and is only maintained when the data in the index is affected. It is possible to have a large number of filtered indexes, especially when they contain data that is affected infrequently. Similarly, if a filtered index contains only the frequently affected data, the smaller size of the index reduces the cost of updating the statistics.

Reduced index storage costs

Creating a filtered index can reduce disk storage for non-clustered indexes when a full-table index is not necessary. You can replace a full-table non-clustered index with multiple filtered indexes without significantly increasing the storage requirements.

You can also determine the space required for an index. Please visit : http://msdn.microsoft.com/en-us/library/ms191163.aspx

How to create a Filtered Index ?

Let’s see an example :

USE AdventureWorks

--Drop if the index already exists

IF EXISTS (SELECT name FROM sys.indexes

WHERE name = N'FNC_PurchaseOrderDetail_Bikes'

AND object_id = OBJECT_ID ('Purchasing.PurchaseOrderDetail'))

DROP INDEX FNC_PurchaseOrderDetail_Bikes

ON Purchasing.PurchaseOrderDetail;

--Create a new index

CREATE NONCLUSTERED INDEX FNC_PurchaseOrderDetail_Bikes

ON Purchasing.PurchaseOrderDetail(ProductID)

WHERE ProductID IN(709, 879, 877)

So simple .. just add a WHERE clause to the index. You need to choose the WHERE clause carefully.

When to Use Filtered Indexes

Filtered indexes are useful when columns contain well-defined subsets of data that queries reference in SELECT statements. Examples are:

Sparse columns that contain only a few non-NULL values.
Heterogeneous columns that contain categories of data.
Columns that contain ranges of values such as dollar amounts, time, and dates.
Table partitions that are defined by simple comparison logic for column values.

Reduced maintenance costs for filtered indexes are most noticeable when the number of rows in the index is small compared with a full-table index. If the filtered index includes most of the rows in the table, it could cost more to maintain than a full-table index. In this case, you should use a full-table index instead of a filtered index.

Filtered indexes are defined on one table and only support simple comparison operators. If you need a filter expression that references multiple tables or has complex logic, you should create a view.

Please visit books online to know more about filtered indexes and keep reading my blogs.

Bye Now !! :-)

Julio 3, 2009. Estado de la innovación y conocimiento en Iberoamérica

luisdans — Sat, 04 Jul 2009 02:22:41 GMT

Para países de idiomas Español y Portugués en Europa y América Latina, el Estado de la ciencia 2008 revela la problemática respecto la vinculación academia-empresa, señalando que los mayores retos se encuentran en “la empresa”. Academia . No abordaré a fondo el aspecto académico, vale la pena examinar el mapa de producción de conocimiento relacionado a Ciencias de Computación en nuestra región. Un esfuerzo específico de Microsoft orientado a investigación en TIC en nuestra geografía es LACCIR . Vinculación...(read more)

Windows Mobile – Pushing the device to more for you

shivbijlani — Sat, 04 Jul 2009 02:00:03 GMT

I own an HTC Touch Diamond. I have owned an HTC Touch, TyTn and Wizard. Most experienced users of Windows Mobile phones will know nothing of great value comes from an out of the box experience. Anything interesting is a result of a workaround or a hack.

The device’s UI (TOUCHFLO) is basically a very sophisticated Today plug-in, hiding the user from the horrid native interface.

The following posts will enumerate my experiences with this device and some not so obvious tricks.

Первый день – полёт нормальный

sos — Fri, 03 Jul 2009 23:54:00 GMT

Уже второй час ночи, а для меня только что завершается первый день #imaginecup – а впереди самый сложный день, основная часть соревнований пройдёт именно завтра! Но обо всём по порядку.

Сегодня с утра мы слегка выспались, позавтракали, и начали с репетиций. В комнате примерно с таким вот видом из окна собралась вся российская делегация, включая прессу, и мы начали задавать ребятам из обоих команд коварные вопросы.

Вот в какой обстановке это проходило:

Затем пообедали, и прослушали брифинг для участников, на котором рассказали, как собственно будут проходить соревнования завтра. Начнётся всё в 8:30 утра, выступление нашей SDI-команды – в 12:05 по местному времени (13:05 по Москве – посылайте нам твиттер-приветствия и мысленные посылы удачи!), Embedded скорее всего выступают ещё раньше. Уже к обеду мы будем знать, кто прошёл в Top12 команд, а к вечеру – определятся уже 6 лучших команд в каждой из категорий! Так что ждите от нас завтра новостей, этот день для нас самый важный!

Вот как выглядел брифинг, и комната, в которой нам завтра выступать:

После брифинга мы поехали на автобусах в цитадель – это крепость, примерно по получасе езды от гостиницы. Если гостиница и окружающий её комплекс – это отдельный “город в городе”, то выехав на улицы Каира, проезжая через бедные кварталы мы ощутили Египетскую жизнь в её реалиях, welcome to the real world. Египет, конечно, производит лучшее впечатление, чем Агра в Индии, но всё равно очень аутентичное.

Сама цитадель – красивое зрелище, из неё открывается замечательный вид на Каир, а также видны пирамиды – это был наш первый взгляд на них издалека. На правой фотографии примерно в центре вы тоже сможете при желании их заметить:

Вот несколько фотографий наших ребят в Египте (жмите на фотографию для увеличения):

После осмотра цитадели (внутри которой расположена мечеть), у наших ребят взяли небольшое интервью (пару вопросов), и мы пешком пошли в другую часть цитадели на открытие. Нас отделили от студентов-участников, которых строили по алфавиту (по названиям стран) для последующего парада. Длительное ожидание, холодный тоник со льдом, фотографии по дороге – но зато потом зрелищная церемония открытия, начиная от главного менеджера Майкрософта в Египте, вице-президента по MEA, главного директора студенческих инициатив Джо Вилсона и наконец Рея Оззи – главного по технологиям в Майкрософт! Практически никогда до этого Imagine Cup не открывал человек такого уровня, практически successor Билла Гейтса!

Затем было лазерное шоу, жареные сосиски, от которых шел зловонный дым и которых пришлось ждать в очереди – но это всё уже не так важно. Сейчас студенты отдыхают, я заканчиваю этот краткий отчёт за день и тоже собираюсь спать.

Пожелайте нам удачи – утром как раз тот момент, когда она нам понадобится! А ещё – наслаждайтесь фотографиями Египта и Российской команды на #imaginecup!

LAgent: an agent framework in F# – Part VI – Hot swapping of code (and something silly)

lucabol — Fri, 03 Jul 2009 22:23:00 GMT

Hot swapping of code

Let’s get back a couple of steps and consider what happens when you get an error. Sure, your agent will continue processing messages, but it might be doing the wrong thing. Your message handling code might be buggy.

Ideally you’d want to patch things on the fly. You’d want to replace the message processing code for an agent without stopping it.

Here is how you do it:

let counter2 = spawnAgent (fun msg state -> printfn "From %i to %i" state (state + msg);
                                                                              state + msg) 0
counter2 <-- 2
                                         
counter2 <-- SetAgentHandler(fun msg state –>
                printfn "From %i to %i via multiplication" state (state * msg); msg * state)
counter2 <-- 3

Which generates:

From 0 to 2
From 2 to 6 via multiplication

After the agent receives a SetAgentHandler message, it switch from a ‘+’ agent to a ‘*’ agent on the fly!! All the messages that come after that one gets multiplied to the state. Also, the state is preserved between changes in behavior.

It might not be immediately apparent how to load a function at runtime, but it is really simple. Imagine that I get the data on the function to load from somewhere (i.e. a management console UI).

let assemblyNameFromSomewhere, typeNameFromSomewhere, methodNameFromSomewhere = 
                                                "mscorlib.dll", "System.Console", "WriteLine"

I can then use it to dynamically load a message handler (in this case Console.Writeline).

let a = Assembly.Load(assemblyNameFromSomewhere)
let c = a.GetType(typeNameFromSomewhere)
let m = c.GetMethod(methodNameFromSomewhere, [|"".GetType()|])
let newF = fun (msg:string) (state:obj) -> m.Invoke(null, [| (msg:>obj) |])

And then it is as simple as posting a SetAgentHandler.

counter2 <-- SetAgentHandler(newF)
counter2 <-- "blah"

Now our counter2 agent has become an echo agent on the fly, having loaded Console.WriteLine dynamically. Note how the agent moved from being a ‘+’ agent taking integers to being a ‘*’ agent taking integers to being an ‘echo’ agent taking strings. And it didn’t stop processing messages for the whole time.

Obviously, you can do the same thing with workers:

echo <-- SetWorkerHandler(fun msg -> printfn "I'm an echo and I say: %s" msg)
echo <-- "Hello"

And parallelWorkers:

parallelEcho <-- SetWorkerHandler(fun msg -> tprint ("I'm new and " + msg))
messages |> Seq.iter (fun msg -> parallelEcho <-- msg)

A silly interlude

As a way to show some agents talking to each other, here is a simple program that simulates marital interactions (of the worst kind):

let rec husband = spawnWorker (fun (To, msg) -> printfn "Husband says: %s" msg; To <-- msg)
let rec wife = spawnWorker (fun msg -> printfn "Wife says: screw you and your '%s'" msg)
husband <-- (wife, "Hello")
husband <-- (wife, "But darling ...")
husband <-- (wife, "ok")

Which produces:

Husband says: Hello
Husband says: But darling ...
Wife says: screw you and your 'Hello'
Wife says: screw you and your 'But darling ...'
Husband says: ok
Wife says: screw you and your 'ok'

And yes, you cannot expect messages to be in the right sequence … Next up is an auction application.

[PL] Wstęp do kryptografii, bardzo sprytny Cipher Code

danieb — Fri, 03 Jul 2009 21:48:38 GMT

Na stronach Wall Street Journal opublikowano bardzo interesujący artykuł na temat kryptografii. Historia mająca ponad 200 lat już teraz z czasów Washingtona, Jeffersona, Pattersona i całej tej spółki, która wystartowała z Wujkiem Samem i przy okazji (o czym większość z nas mogła się dowiedzieć z Skarbu Narodów) bawiła się w tzw. Amerykańskie Towarzystwo Filozoficzne (American Philosophical Society).

Sprawa dotyczy korespondencji pomiędzy Robertem Pattersonem a Thomasem Jeffersonem.
Patterson wysłał list zaszyfrowany całkiem sprytnym Cipher Code’em, który dopiero teraz rozszyfrowano. Dobry wstęp do kryptografii dla osób nieobeznanych z tematem. Zwłaszcza, że napisane językiem bardziej opisującym fantastyczną historię, niż jakiś “geek’s talk”.

Kod do rozszyfrowania wiadomości to: 13, 34, 57, 65, 22, 78, 49.. aż kontrolnie porównałem go z Lost’em. Inny.

Przy takich sytuacjach żałuję, że w naszej prasie nie ma takich niestworzonych historii o polskich matematykach, którzy “rozbroili” Enigmę i innych. U nas w prasie niestety głównie sprawy doczesne tak bardzo, że bez kontekstu historycznego patrząc w przeszłość i bez kontekstu na jutro, abym dobrze zrozumiał co z tego ma wyniknąć…

Odnośniki w języku angielskim.

Closing An Incident (Case) That Has Open Activities

Simon Hutson — Fri, 03 Jul 2009 21:47:00 GMT

In The Lap Of The Gods… Every so often I come across a feature in CRM that makes me wonder “why was it designed like that?”. The one that catches me out almost every time I demo is the inability to close or cancel a incident when there are associated open activities. This wouldn’t be so bad except that many of these activities are generated automatically by workflow, so when you cancel these activities manually, workflow processes continue to run and create still more activities. Solving this problem...(read more)

Competition is now underway!

AndrewParsons — Fri, 03 Jul 2009 21:34:33 GMT

Wow, this is easily the most epic event I’ve ever been involved in. If you’re following my twitter feed (@mrandypuppy) you’ll know that I’ve been using words like “awesome”, “cool” and “wow” a lot as well as a bunch of exclamation marks. I’m conscious of it but I keep getting wowed by the experience, and I know this is just the beginning.

So far I’ve experienced:

Catching a flight from Singapore to Cairo via Dubai with 60+ passengers being Imagine Cup competitors, their mentors and several of my peers. I was told about solutions that teams had come up with and the passion these kids have is inspiring, but with good reason. I mean, when an Indonesian talks for 30 minutes non-stop about a Malaria early detection system they developed, it’s hard to not be engaged.
Carrying the Cup through Customs at Cairo and being questioned about the mysterious box.
Today was briefing day – briefings for students, mentors, judges, employees, briefings everywhere. At first I thought it was over the top, but there is so much information to consume that it is totally warranted.
Tonight was the official opening of the Imagine Cup competition. The highlights were:

Student parade of the countries, a la the Olympics. Huge response as each team entered and again I was struck by how many countries are represented and how some of them strike me as out of this world – seriously, I never really thought about a team of students from Senegal showing solid innovation, or the inspiring stories of some of the teams just getting here like Palestine and Indonesia.
Ray Ozzie, Chief Software Architect for Microsoft, telling the students that they truly are the future of creativity in technology because they’re not hampered by previous experience and preconceptions.
Joe Wilson, the man who makes Imagine Cup happen every year (well, the man, behind the team of awesome dudes and dudettes that make it happen every year) pumping the students up and getting them ready for the competition and having all 445 students on the edge of their seats, hanging on every word.
The Egyptian student who stood up during the proceedings to thank his government for their support of Imagine Cup and the roar of the crowd in appreciation.

sigh.

Tomorrow – first EPIC day of the competition. All 67 Software Development teams present, as well as Game Development, Embedded Development and other teams – all in action. The logistics to make all this happen are nightmarish, but everyone behind the scenes are positive and upbeat and just making it all happen.

That Was The Week That Was 6/29-7/3

GhostCatfish5 — Fri, 03 Jul 2009 20:47:00 GMT

Once you're done with the hamburgers, hot dogs, and fireworks for the U.S. Independence Day, spend some time on Xbox.com checking out these links and playing games.

Through the weekend, the Deal of the Week is the Knothole Island add-on for Fable II for only 560 Microsoft Points, 30% off regular rate.
July 3 through July 6 is Double-XP Weekend for Call of Duty: World at War. Level up, soldier!

Tomorrow, July 4, we have a Game with Developers session with Team17 Software who made Worms 2: Armageddon, and we'll be playing Fight Night Round 4 in our All-Nighter. The next day on the 5th we'll be playing the folks from Battlemouth.com in Left 4 Dead. Then, get ready for next Saturday July 11, when you can play the developers NinjaBee in their game Band of Bugs. There's big news with the game as of July 8, the game will now support in-game avatars meaning you can play with your own character creation. Also on July 11, you can play the metal band Static-X in Halo 3, and be sure to save the date of July 29 for a Game with Fame with the band Killswitch Engage.
Forza Motorsport 3 has announced that it will include three Japanese race tracks and a slew of hot Japanese cars.
The Gamer Spotlight shines on Jake8bitJoystik, the man behind 8bitjoystick.com.
Reader Jay wanted to point out this cool article from Carnegie Mellon University on graduate Arnold Blinn, who had a hand in the upcoming melding of Xbox 360 and Twitter.
We've posted some additional info and new discussion forums on upcoming games, including the innovative new music title DJ Hero, the funny and fast Cars Race-O-Rama, and the supremely commanding Supreme Commander 2.