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• Smithsonian Showcases Video Game History with The Art of Video Games [Video]

  - by Jason Fitzpatrick

  The Art of Video Games is the Smithsonian’s look at the history of video games; check out this video trailer to see what the exhibition is all about and hear from some notable folks. From the Smithsonian listing for the exhibition: The Art of Video Games is one of the first exhibitions to explore the forty-year evolution of video games as an artistic medium, with a focus on striking visual effects and the creative use of new technologies. It features some of the most influential artists and designers during five eras of game technology, from early pioneers to contemporary designers. The exhibition focuses on the interplay of graphics, technology and storytelling through some of the best games for twenty gaming systems ranging from the Atari VCS to the PlayStation 3. The exhibit will be at the Smithsonian until the end of September and will then begin touring the country. Hit up the link below for more information. The Art of Video Games Tour [via Neatorama] How To Properly Scan a Photograph (And Get An Even Better Image) The HTG Guide to Hiding Your Data in a TrueCrypt Hidden Volume Make Your Own Windows 8 Start Button with Zero Memory Usage

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• FileNameColumnName property, Flat File Source Adapter : SSIS Nugget

  - by jamiet

  I saw a question on MSDN’s SSIS forum the other day that went something like this: I’m loading data into a table from a flat file but I want to be able to store the name of that file as well. Is there a way of doing that? I don’t want to come across as disrespecting those who took the time to reply but there was a few answers along the lines of “loop over the files using a For Each, store the file name in a variable yadda yadda yadda” when in fact there is a much much simpler way of accomplishing this; it just happens to be a little hidden away as I shall now explain! The Flat File Source Adapter has a property called FileNameColumnName which for some reason it isn’t exposed through the Flat File Source editor, it is however exposed via the Advanced Properties: You’ll see in the screenshot above that I have set FileNameColumnName=“Filename” (it doesn’t matter what name you use, anything except a non-zero string will work). What this will do is create a new column in our dataflow called “Filename” that contains, unsurprisingly, the name of the file from which the row was sourced. All very simple. This is particularly useful if you are extracting data from multiple files using the MultiFlatFile Connection Manager as it allows you to differentiate between data from each of the files as you can see in the following screenshot: So there you have it, the FileNameColumnName property; a little known secret of SSIS. I hope it proves to be useful to someone out there. @Jamiet Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

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• Z axis in isometric tilemap

  - by gyhgowvi

  I'm experimenting with isometric tile maps in JavaScript and HTML5 Canvas. I'm storing tile map data in JavaScript 2D array. // 0 - Grass // 1 - Dirt // ... var mapData = [ [0, 0, 0, 0, 0], [0, 0, 1, 0, 0, ... ] and draw for(var i = 0; i < mapData.length; i++) { for(var j = 0; j < mapData[i].length; j++) { var p = iso2screen(i, j, 0); // X, Y, Z context.drawImage(tileArray[mapData[i][j]], p.x, p.y); } } but this function mean's all tile Z axis is equal to zero. var p = iso2screen(i, j, 0); Maybe anyone have idea and how to do something like mapData[0][0] Z axis equal to 3 mapData[5][5] Z axis equal to 5? I have idea: Write function for grass, dirt and store this function to 2D array and draw and later mapData[0][0].setZ(3); But it is good idea to write functions for each tiles?

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• Zipcodes in CSV Generation

  - by BRADINO

  When exporting to CSV format, then opening in a spreadsheet program like Excel zipcodes that start with a zero or zeroes have the preceding zeros stripped off. Obviously it is because the spreadsheet sees that column as integers and preceding zeros in integers are useless. A quick and dirty trick to force Excel (hopefully you are using OpenOffice) to display the full zipcode, we wrap it in double quotes and put an equal sign in front of it, to force it to be a string like this: $zipcode = 00123; $data = '="' . $zipcode . '"' ; So if you are doing the straight query to CSV export, using the fputcsv function it would look something like this. Basically just overwrite the value in the row and then continue along. while ($row = mysql_fetch_assoc($query)){         $row['zipcode'] = '="'.$row['zipcode'].'"';     fputcsv($output, $row); } php csv zipcode csv number csv force string

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• FileNameColumnName property, Flat File Source Adapter : SSIS Nugget

  - by jamiet

  I saw a question on MSDN’s SSIS forum the other day that went something like this: I’m loading data into a table from a flat file but I want to be able to store the name of that file as well. Is there a way of doing that? I don’t want to come across as disrespecting those who took the time to reply but there was a few answers along the lines of “loop over the files using a For Each, store the file name in a variable yadda yadda yadda” when in fact there is a much much simpler way of accomplishing this; it just happens to be a little hidden away as I shall now explain! The Flat File Source Adapter has a property called FileNameColumnName which for some reason it isn’t exposed through the Flat File Source editor, it is however exposed via the Advanced Properties: You’ll see in the screenshot above that I have set FileNameColumnName=“Filename” (it doesn’t matter what name you use, anything except a non-zero string will work). What this will do is create a new column in our dataflow called “Filename” that contains, unsurprisingly, the name of the file from which the row was sourced. All very simple. This is particularly useful if you are extracting data from multiple files using the MultiFlatFile Connection Manager as it allows you to differentiate between data from each of the files as you can see in the following screenshot: So there you have it, the FileNameColumnName property; a little known secret of SSIS. I hope it proves to be useful to someone out there. @Jamiet Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

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• Queued Loadtest to remove Concurrency issues using Shared Data Service in OpenScript

  - by stefan.thieme(at)oracle.com

  Queued Processing to remove Concurrency issues in Loadtest ScriptsSome scripts act on information returned by the server, e.g. act on first item in the returned list of pending tasks/actions. This may lead to concurrency issues if the virtual users simulated in a load test scenario are not synchronized in some way.As the load test cases should be carried out in a comparable and straight forward manner simply cancel a transaction in case a collision occurs is clearly not an option. In case you increase the number of virtual users this approach would lead to a high number of requests for the early steps in your transaction (e.g. login, retrieve list of action points, assign an action point to the virtual user) but later steps would be rarely visited successfully or at all, depending on the application logic.A way to tackle this problem is to enqueue the virtual users in a Shared Data Service queue. Only the first virtual user in this queue will be allowed to carry out the critical steps (retrieve list of action points, assign an action point to the virtual user) in your transaction at any one time.Once a virtual user has passed the critical path it will dequeue himself from the head of the queue and continue with his actions. This does theoretically allow virtual users to run in parallel all steps of the transaction which are not part of the critical path.In practice it has been seen this is rarely the case, though it does not allow adding more than N users to perform a transaction without causing delays due to virtual users waiting in the queue. N being the time of the total transaction divided by the sum of the time of all critical steps in this transaction.While this problem can be circumvented by allowing multiple queues to act on individual segments of the list of actions, e.g. per country filter, ends with 0..9 filter, etc.This would require additional handling of these additional queues of slots for the virtual users at the head of the queue in order to maintain the mutually exclusive access to the first element in the list returned by the server at any one time of the load test. Such an improved handling of multiple queues and/or multiple slots is above the subject of this paper.Shared Data Services Pre-RequisitesStart WebLogic Server to host Shared Data ServicesYou will have to make sure that your WebLogic server is installed and started. Shared Data Services may not work if you installed only the minimal installation package for OpenScript. If however you installed the default package including OLT and OTM, you may follow the instructions below to start and verify WebLogic installation.To start the WebLogic Server deployed underneath of Oracle Load Testing and/or Oracle Test Manager you can go to your Start menu, Oracle Application Testing Suite and select the Restart Oracle Application Testing Suite Application Service entry from the Tools submenu.To verify the service has been started you can run the Microsoft Management Console for Services by Selecting Run from the Start Menu and entering services.msc. Look for the entry that reads Oracle Application Testing Suite Application Service, once it has changed it status from Starting to Started you can proceed to verify the login. Please note that this may take several minutes, I would say up to 10 minutes depending on the strength of your CPU horse-power.Verify WebLogic Server user credentialsYou will have to make sure that your WebLogic Server is installed and started. Next open the Oracle WebLogic Server Adminstration Console on http://localhost:8088/console.It may take a while until the application is deployed and started. It may display the following until the Administration Console has been deployed on the fly.Afterwards you can login using the username oats and the password that you selected during install time for your Application Testing Suite administrative purposes.This will bring up the Home page of you WebLogic Server. You have actually verified that you are able to login with these credentials already. However if you want to check the details, navigate to Security Realms, myrealm, Users and Groups tab.Here you could add users to your WebLogic Server which could be used in the later steps. Details on the Groups required for such a custom user to work are exceeding this quick overview and have to be selected with the WebLogic Server Adminstration Guide in mind.Shared Data Services pre-requisites for Load testingOpenScript Preferences have to be set to enable Encryption and provide a default Shared Data Service Connection for Playback.These are pre-requisites you want to use for load testing with Shared Data Services.Please note that the usage of the Connection Parameters (individual directive in the script) for Shared Data Services did not playback reliably in the current version 9.20.0370 of Oracle Load Testing (OLT) and encryption of credentials still seemed to be mandatory as well.General Encryption settingsSelect OpenScript Preferences from the View menu and navigate to the General, Encryption entry in the tree on the left. Select the Encrypt script data option from the list and enter the same password that you used for securing your WebLogic Server Administration Console.Enable global shared data access credentialsSelect OpenScript Preferences from the View menu and navigate to the Playback, Shared Data entry in the tree on the left. Enable the global shared data access credentials and enter the Address, User name and Password determined for your WebLogic Server to host Shared Data Services.Please note, that you may want to replace the localhost in Address with the hosts realname in case you plan to run load tests with Loadtest Agents running on remote systems.Queued Processing of TransactionsEnable Shared Data Services Module in Script PropertiesThe Shared Data Services Module has to be enabled for each Script that wants to employ the Shared Data Service Queue functionality in OpenScript. It can be enabled under the Script menu selecting Script Properties. On the Script Properties Dialog select the Modules section and check Shared Data to enable Shared Data Service Module for your script. Checking the Shared Data Services option will effectively add a line to your script code that adds the sharedData ScriptService to your script class of IteratingVUserScript.@ScriptService oracle.oats.scripting.modules.sharedData.api.SharedDataService sharedData;Record your scriptRecord your script as usual and then add the following things for Queue handling in the Initialize code block, before the first step and after the last step of your critical path and in the Finalize code block.The java code to be added at individual locations is explained in the following sections in full detail.Create a Shared Data Queue in InitializeTo create a Shared Data Queue go to the Java view of your script and enter the following statements to the initialize() code block.info("Create queueA with life time of 120 minutes");sharedData.createQueue("queueA", 120);This will create an instantiation of the Shared Data Queue object named queueA which is maintained for upto 120 minutes.If you want to use the code for multiple scripts, make sure to use a different queue name for each one here and in the subsequent steps. You may even consider to use a dynamic queueName based on filters of your result list being concurrently accessed.Prepare a unique id for each IterationIn order to keep track of individual virtual users in our queue we need to create a unique identifier from the virtual user id and the used username right after retrieving the next record from our databank file.getDatabank("Usernames").getNextDatabankRecord();getVariables().set("usernameValue1","VU_{{@vuid}}_{{@iterationnum}}_{{db.Usernames.Username}}_{{@timestamp}}_{{@random(10000)}}");String usernameValue = getVariables().get("usernameValue1");info("Now running virtual user " + usernameValue);As you can see from the above code block, we have set the OpenScript variable usernameValue1 to VU_{{@vuid}}_{{@iterationnum}}_{{db.Usernames.Username}}_{{@timestamp}}_{{@random(10000)}} which is a concatenation of the virtual user id and the iterationnumber for general uniqueness; as well as the username from our databank, the timestamp and a random number for making it further unique and ease spotting of errors.Not all of these fields are actually required to make it really unique, but adding the queue name may also be considered to help troubleshoot multiple queues.The value is then retrieved with the getVariables.get() method call and assigned to the usernameValue String used throughout the script.Please note that moving the getDatabank("Usernames").getNextDatabankRecord(); call to the initialize block was later considered to remove concurrency of multiple virtual users running with the same userid and therefor accessing the same "My Inbox" in step 6. This will effectively give each virtual user a userid from the databank file. Make sure you have enough userids to remove this second hurdle.Enqueue and attend Queue before Critical PathTo maintain the right order of virtual users being allowed into the critical path of the transaction the following pseudo step has to be added in front of the first critical step. In the case of this example this is right in front of the step where we retrieve the list of actions from which we select the first to be assigned to us.beginStep("[0] Waiting in the Queue", 0);{info("Enqueued virtual user " + usernameValue + " at the end of queueA");sharedData.offerLast("queueA", usernameValue);info("Wait until the user is the first in queueA");String queueValue1 = null;do {// we wait for at least 0.7 seconds before we check the head of the// queue. This is the time it takes one user to move through the// critical path, i.e. pass steps [5] Enter country and [6] Assign// to meThread.sleep(700);queueValue1 = (String) sharedData.peekFirst("queueA");info("The first user in queueA is currently: '" + queueValue1 + "' " + queueValue1.getClass() + " length " + queueValue1.length() );info("The current user is '"+ usernameValue + "' " + usernameValue.getClass() + " length " + usernameValue.length() + ": indexOf " + usernameValue.indexOf(queueValue1) + " equals " + usernameValue.equals(queueValue1) );} while ( queueValue1.indexOf(usernameValue) < 0 );info("Now the user is the first in queueA");}endStep();This will enqueue the username to the tail of our Queue. It will will wait for at least 700 milliseconds, the time it takes for one user to exit the critical path and then compare the head of our queue with it's username. This last step will be repeated while the two are not equal (indexOf less than zero). If they are equal the indexOf will yield a value of zero or larger and we will perform the critical steps.Dequeue after Critical PathAfter the virtual user has left the critical path and complete its last step the following code block needs to dequeue the virtual user. In the case of our example this is right after the action has been actually assigned to the virtual user. This will allow the next virtual user to retrieve the list of actions still available and in turn let him make his selection/assignment.info("Get and remove the current user from the head of queueA");String pollValue1 = (String) sharedData.pollFirst("queueA");The current user is removed from the head of the queue. The next one will now be able to match his username against the head of the queue.Clear and Destroy Queue for FinishWhen the script has completed, it should clear and destroy the queue. This code block can be put in the finish block of your script and/or in a separate script in order to clear and remove the queue in case you have spotted an error or want to reset the queue for some reason.info("Clear queueA");sharedData.clearQueue("queueA");info("Destroy queueA");sharedData.destroyQueue("queueA");The users waiting in queueA are cleared and the queue is destroyed. If you have scripts still executing they will be caught in a loop.I found it better to maintain a separate Reset Queue script which contained only the following code in the initialize() block. I use to call this script to make sure the queue is cleared in between multiple Loadtest runs. This script could also even be added as the first in a larger scenario, which would execute it only once at very start of the Loadtest and make sure the queues do not contain any stale entries.info("Create queueA with life time of 120 minutes");sharedData.createQueue("queueA", 120);info("Clear queueA");sharedData.clearQueue("queueA");This will create a Shared Data Queue instance of queueA and clear all entries from this queue.Monitoring QueueWhile creating the scripts it was useful to monitor the contents, i.e. the current first user in the Queue. The following code block will make sure the Shared Data Queue is accessible in the initialize() block.info("Create queueA with life time of 120 minutes");sharedData.createQueue("queueA", 120);In the run() block the following code will continuously monitor the first element of the Queue and write an informational message with the current username Value to the Result window.info("Monitor the first users in queueA");String queueValue1 = null;do {queueValue1 = (String) sharedData.peekFirst("queueA");if (queueValue1 != null)info("The first user in queueA is currently: '" + queueValue1 + "' " + queueValue1.getClass() + " length " + queueValue1.length() );} while ( true );This script can be run from OpenScript parallel to a loadtest performed by the Oracle Load Test.However it is not recommend to run this in a production loadtest as the performance impact is unknown. Accessing the Queue's head with the peekFirst() method has been reported with about 2 seconds response time by both OpenScript and OTL. It is advised to log a Service Request to see if this could be lowered in future releases of Application Testing Suite, as the pollFirst() and even offerLast() writing to the tail of the Queue usually returned after an average 0.1 seconds.Debugging QueueWhile debugging the scripts the following was useful to remove single entries from its head, i.e. the current first user in the Queue. The following code block will make sure the Shared Data Queue is accessible in the initialize() block.info("Create queueA with life time of 120 minutes");sharedData.createQueue("queueA", 120);In the run() block the following code will remove the first element of the Queue and write an informational message with the current username Value to the Result window.info("Get and remove the current user from the head of queueA");String pollValue1 = (String) sharedData.pollFirst("queueA");info("The first user in queueA was currently: '" + pollValue1 + "' " + pollValue1.getClass() + " length " + pollValue1.length() );ReferencesOracle Functional Testing OpenScript User's Guide Version 9.20 [E15488-05]Chapter 17 Using the Shared Data Modulehttp://download.oracle.com/otn/nt/apptesting/oats-docs-9.21.0030.zipOracle Fusion Middleware Oracle WebLogic Server Administration Console Online Help 11g Release 1 (10.3.4) [E13952-04]Administration Console Online Help - Manage users and groupshttp://download.oracle.com/docs/cd/E17904_01/apirefs.1111/e13952/taskhelp/security/ManageUsersAndGroups.htm

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• Quotas - Using quotas on ZFSSA shares and projects and users

  - by Steve Tunstall

  So you don't want your users to fill up your entire storage pool with their MP3 files, right? Good idea to make some quotas. There's some good tips and tricks here, including a helpful workflow (a script) that will allow you to set a default quota on all of the users of a share at once. Let's start with some basics. I mad a project called "small" and inside it I made a share called "Share1". You can set quotas on the project level, which will affect all of the shares in it, or you can do it on the share level like I am here. Go the the share's General property page. First, I'm using a Windows client, so I need to make sure I have my SMB mountpoint. Do you know this trick yet? Go to the Protocol page of the share. See the SMB section? It needs a resource name to make the UNC path for the SMB (Windows) users. You do NOT have to type this name in for every share you make! Do this at the Project level. Before you make any shares, go to the Protocol properties of the Project, and set the SMB Resource name to "On". This special code will automatically make the SMB resource name of every share in the project the same as the share name. Note the UNC path name I got below. Since I did this at the Project level, I didn't have to lift a finger for it to work on every share I make in this project. Simple. So I have now mapped my Windows "Z:" drive to this Share1. I logged in as the user "Joe". Note that my computer shows my Z: drive as 34GB, which is the entire size of my Pool that this share is in. Right now, Joe could fill this drive up and it would fill up my pool.  Now, go back to the General properties of Share1. In the "Space Usage" area, over on the right, click on the "Show All" text under the Users & Groups section. Sure enough, Joe and some other users are in here and have some data. Note this is also a handy window to use just to see how much space your users are using in any given share.  Ok, Joe owes us money from lunch last week, so we want to give him a quota of 100MB. Type his name in the Users box. Notice how it now shows you how much data he's currently using. Go ahead and give him a 100M quota and hit the Apply button. If I go back to "Show All", I can see that Joe now has a quota, and no one else does. Sure enough, as soon as I refresh my screen back on Joe's client, he sees that his Z: drive is now only 100MB, and he's more than half way full.  That was easy enough, but what if you wanted to make the whole share have a quota, so that the share itself, no matter who uses it, can only grow to a certain size? That's even easier. Just use the Quota box on the left hand side. Here, I use a Quota on the share of 300MB.  So now I log off as Joe, and log in as Steve. Even though Steve does NOT have a quota, it is showing my Z: drive as 300MB. This would effect anyone, INCLUDING the ROOT user, becuase you specified the Quota to be on the SHARE, not on a person.  Note that back in the Share, if you click the "Show All" text, the window does NOT show Steve, or anyone else, to have a quota of 300MB. Yet we do, because it's on the share itself, not on any user, so this panel does not see that. Ok, here is where it gets FUN.... Let's say you do NOT want a quota on the SHARE, because you want SOME people, like Root and yourself, to have FULL access to it and you want the ability to fill the whole thing up if you darn well feel like it. HOWEVER, you want to give the other users a quota. HOWEVER you have, say, 200 users, and you do NOT feel like typing in each of their names and giving them each a quota, and they are not all members of a AD global group you could use or anything like that.  Hmmmmmm.... No worries, mate. We have a handy-dandy script that can do this for us. Now, this script was written a few years back by Tim Graves, one of our ZFSSA engineers out of the UK. This is not my script. It is NOT supported by Oracle support in any way. It does work fine with the 2011.1.4 code as best as I can tell, but Oracle, and I, are NOT responsible for ANYTHING that you do with this script. Furthermore, I will NOT give you this script, so do not ask me for it. You need to get this from your local Oracle storage SC. I will give it to them. I want this only going to my fellow SCs, who can then work with you to have it and show you how it works.  Here's what it does...Once you add this workflow to the Maintenance-->Workflows section, you click it once to run it. Nothing seems to happen at this point, but something did.   Go back to any share or project. You will see that you now have four new, custom properties on the bottom.  Do NOT touch the bottom two properties, EVER. Only touch the top two. Here, I'm going to give my users a default quota of about 40MB each. The beauty of this script is that it will only effect users that do NOT already have any kind of personal quota. It will only change people who have no quota at all. It does not effect the Root user.  After I hit Apply on the Share screen. Nothing will happen until I go back and run the script again. The first time you run it, it creates the custom properties. The second and all subsequent times you run it, it checks the shares for any users, and applies your quota number to each one of them, UNLESS they already have one set. Notice in the readout below how it did NOT apply to my Joe user, since Joe had a quota set.  Sure enough, when I go back to the "Show All" in the share properties, all of the users who did not have a quota, now have one for 39.1MB. Hmmm... I did my math wrong, didn't I?    That's OK, I'll just change the number of the Custom Default quota again. Here, I am adding a zero on the end.  After I click Apply, and then run the script again, all of my users, except Joe, now have a quota of 391MB  You can customize a person at any time. Here, I took the Steve user, and specifically gave him a Quota of zero. Now when I run the script again, he is different from the rest, so he is no longer effected by the script. Under Show All, I see that Joe is at 100, and Steve has no Quota at all. I can do this all day long. es, you will have to re-run the script every time new users get added. The script only applies the default quota to users that are present at the time the script is ran. However, it would be a simple thing to schedule the script to run each night, or to make an alert to run the script when certain events occur.  For you power users, if you ever want to delete these custom properties and remove the script completely, you will find these properties under the "Schema" section under the Shares section. You can remove them here. There's no need to, however, they don't hurt a thing if you just don't use them.  I hope these tips have helped you out there. Quotas can be fun. 

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• 2.5D game development

  - by ne5tebiu

  2.5D ("two-and-a-half-dimensional"), 3/4 perspective and pseudo-3D are terms used to describe either: graphical projections and techniques which cause a series of images or scenes to fake or appear to be three-dimensional (3D) when in fact they are not, or gameplay in an otherwise three-dimensional video game that is restricted to a two-dimensional plane. (Information taken from Wikipedia.org) I have a question based on 2.5D game development. As stated before, 2.5D uses graphical projections and techniques to make fake 3d or a gameplay restricted to a two-dimensional plane. A good example is a TQ Digital made game: Zero Online (screenshot) the whole map is made of 2d images and only NPCs and players are 3d. The maps were drawn manually by hand without any 3d software rendering. As I'm playing the game I feel like I'm going from a lower part of the map (ground) to a higher one (some metal platform) and it feels like I'm moving in 3 dimensions. But when I look closely, I see that the player size didn't change and the shadow too but I'm still feeling like I'm somehow higher then before (I had rendered a simple map myself that I made in 3dmax but it didn't quite give the result I wanted). How to accomplish such an effect?

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• Inside the Concurrent Collections: ConcurrentBag

  - by Simon Cooper

  Unlike the other concurrent collections, ConcurrentBag does not really have a non-concurrent analogy. As stated in the MSDN documentation, ConcurrentBag is optimised for the situation where the same thread is both producing and consuming items from the collection. We'll see how this is the case as we take a closer look. Again, I recommend you have ConcurrentBag open in a decompiler for reference. Thread Statics ConcurrentBag makes heavy use of thread statics - static variables marked with ThreadStaticAttribute. This is a special attribute that instructs the CLR to scope any values assigned to or read from the variable to the executing thread, not globally within the AppDomain. This means that if two different threads assign two different values to the same thread static variable, one value will not overwrite the other, and each thread will see the value they assigned to the variable, separately to any other thread. This is a very useful function that allows for ConcurrentBag's concurrency properties. You can think of a thread static variable: [ThreadStatic] private static int m_Value; as doing the same as: private static Dictionary<Thread, int> m_Values; where the executing thread's identity is used to automatically set and retrieve the corresponding value in the dictionary. In .NET 4, this usage of ThreadStaticAttribute is encapsulated in the ThreadLocal class. Lists of lists ConcurrentBag, at its core, operates as a linked list of linked lists: Each outer list node is an instance of ThreadLocalList, and each inner list node is an instance of Node. Each outer ThreadLocalList is owned by a particular thread, accessible through the thread local m_locals variable: private ThreadLocal<ThreadLocalList<T>> m_locals It is important to note that, although the m_locals variable is thread-local, that only applies to accesses through that variable. The objects referenced by the thread (each instance of the ThreadLocalList object) are normal heap objects that are not specific to any thread. Thinking back to the Dictionary analogy above, if each value stored in the dictionary could be accessed by other means, then any thread could access the value belonging to other threads using that mechanism. Only reads and writes to the variable defined as thread-local are re-routed by the CLR according to the executing thread's identity. So, although m_locals is defined as thread-local, the m_headList, m_nextList and m_tailList variables aren't. This means that any thread can access all the thread local lists in the collection by doing a linear search through the outer linked list defined by these variables. Adding items So, onto the collection operations. First, adding items. This one's pretty simple. If the current thread doesn't already own an instance of ThreadLocalList, then one is created (or, if there are lists owned by threads that have stopped, it takes control of one of those). Then the item is added to the head of that thread's list. That's it. Don't worry, it'll get more complicated when we account for the other operations on the list! Taking & Peeking items This is where it gets tricky. If the current thread's list has items in it, then it peeks or removes the head item (not the tail item) from the local list and returns that. However, if the local list is empty, it has to go and steal another item from another list, belonging to a different thread. It iterates through all the thread local lists in the collection using the m_headList and m_nextList variables until it finds one that has items in it, and it steals one item from that list. Up to this point, the two threads had been operating completely independently. To steal an item from another thread's list, the stealing thread has to do it in such a way as to not step on the owning thread's toes. Recall how adding and removing items both operate on the head of the thread's linked list? That gives us an easy way out - a thread trying to steal items from another thread can pop in round the back of another thread's list using the m_tail variable, and steal an item from the back without the owning thread knowing anything about it. The owning thread can carry on completely independently, unaware that one of its items has been nicked. However, this only works when there are at least 3 items in the list, as that guarantees there will be at least one node between the owning thread performing operations on the list head and the thread stealing items from the tail - there's no chance of the two threads operating on the same node at the same time and causing a race condition. If there's less than three items in the list, then there does need to be some synchronization between the two threads. In this case, the lock on the ThreadLocalList object is used to mediate access to a thread's list when there's the possibility of contention. Thread synchronization In ConcurrentBag, this is done using several mechanisms: Operations performed by the owner thread only take out the lock when there are less than three items in the collection. With three or greater items, there won't be any conflict with a stealing thread operating on the tail of the list. If a lock isn't taken out, the owning thread sets the list's m_currentOp variable to a non-zero value for the duration of the operation. This indicates to all other threads that there is a non-locked operation currently occuring on that list. The stealing thread always takes out the lock, to prevent two threads trying to steal from the same list at the same time. After taking out the lock, the stealing thread spinwaits until m_currentOp has been set to zero before actually performing the steal. This ensures there won't be a conflict with the owning thread when the number of items in the list is on the 2-3 item borderline. If any add or remove operations are started in the meantime, and the list is below 3 items, those operations try to take out the list's lock and are blocked until the stealing thread has finished. This allows a thread to steal an item from another thread's list without corrupting it. What about synchronization in the collection as a whole? Collection synchronization Any thread that operates on the collection's global structure (accessing anything outside the thread local lists) has to take out the collection's global lock - m_globalListsLock. This single lock is sufficient when adding a new thread local list, as the items inside each thread's list are unaffected. However, what about operations (such as Count or ToArray) that need to access every item in the collection? In order to ensure a consistent view, all operations on the collection are stopped while the count or ToArray is performed. This is done by freezing the bag at the start, performing the global operation, and unfreezing at the end: The global lock is taken out, to prevent structural alterations to the collection. m_needSync is set to true. This notifies all the threads that they need to take out their list's lock irregardless of what operation they're doing. All the list locks are taken out in order. This blocks all locking operations on the lists. The freezing thread waits for all current lockless operations to finish by spinwaiting on each m_currentOp field. The global operation can then be performed while the bag is frozen, but no other operations can take place at the same time, as all other threads are blocked on a list's lock. Then, once the global operation has finished, the locks are released, m_needSync is unset, and normal concurrent operation resumes. Concurrent principles That's the essence of how ConcurrentBag operates. Each thread operates independently on its own local list, except when they have to steal items from another list. When stealing, only the stealing thread is forced to take out the lock; the owning thread only has to when there is the possibility of contention. And a global lock controls accesses to the structure of the collection outside the thread lists. Operations affecting the entire collection take out all locks in the collection to freeze the contents at a single point in time. So, what principles can we extract here? Threads operate independently Thread-static variables and ThreadLocal makes this easy. Threads operate entirely concurrently on their own structures; only when they need to grab data from another thread is there any thread contention. Minimised lock-taking Even when two threads need to operate on the same data structures (one thread stealing from another), they do so in such a way such that the probability of actually blocking on a lock is minimised; the owning thread always operates on the head of the list, and the stealing thread always operates on the tail. Management of lockless operations Any operations that don't take out a lock still have a 'hook' to force them to lock when necessary. This allows all operations on the collection to be stopped temporarily while a global snapshot is taken. Hopefully, such operations will be short-lived and infrequent. That's all the concurrent collections covered. I hope you've found it as informative and interesting as I have. Next, I'll be taking a closer look at ThreadLocal, which I came across while analyzing ConcurrentBag. As you'll see, the operation of this class deserves a much closer look.

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• Nice take on Open Source

  - by EmbeddedInsider

  I just revisited the “Micro Framework”- Microsoft’s bootable runtime, essentially an OS that allows managed code to run on small 32bit CPUs, even without Memory Management.  Things are happening http://msdn.microsoft.com/en-us/netframework/bb267253.aspx Abstract The Microsoft .NET Micro Framework is a bootable runtime module that brings the advantages of .NET programming to devices too resource-constrained to run other Microsoft embedded platforms. The benefits of developing with the .NET Micro Framework include the C# programming language, a managed execution environment, a substantial subset of the .NET libraries, and Visual Studio™ deployment and debugging. In this white paper we explain why the .NET Micro Framework is an ideal choice for embedded development and provide technical details of the platform’s Hardware Abstraction Layer (HAL) and Common Language Runtime (CLR). “Micro Framework” is an interesting product, it is very low cost, like zero. And it is largely community controlled under the Apache License.  A partner network is building, and the application environment is .NET. I have been following this for some time, and the community open source approach seems to be working.  There are new features/packages emerging, for example an F# programming language (ARGH! I am still wresting with VB and C#). Anyway, what I found most interesting was a port to Tron.  Tron is a very popular Japanese open source intuitive.  It is a very real time, very compact kernel, and is, like the Micro Framework, ‘free as beer’.  One limit on MF was it was not real time.  But the merger with Tron may eliminate that problem.  Certainly, if I were dealing with a consumer product with quantities in the millions (like a SmartGrid device, or a toy) I would seriously consider something out of this technology pool.

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• SQL SERVER – Copy Statistics from One Server to Another Server

  - by pinaldave

  I was recently working on a performance tuning project in Dubai (yeah I was able to see the tallest tower from the window of my work place). I had a very interesting learning experience there. There was a situation where we wanted to receive the schema of original database from a certain client. However, the client was not able to provide us any data due to privacy issues. The schema was very important because without having an access to underlying data, it was a bit difficult to judge the queries etc. For example, without any primary data, all the queries are running in 0 (zero) milliseconds and all were using nested loop as there were no data to be returned. Even though we had CPU offending queries, they were not doing anything without the data in the tables. This was really a challenge as I did not have access to production server data and I could not recreate the scenarios as production without data. Well, I was confused but Ruben from Solid Quality Mentors, Spain taught me new tricks. He suggested that when table schema is generated, we can create the statistics consequently. Here is how we had done that: Once statistics is created along with the schema, without data in the table, all the queries will work as how they will work on production server. This way, without access to the data, we were able to recreate the same scenario as production server on development server. When observed at the script, you will find that the statistics were also generated along with the query. You will find statistics included in WITH STATS_STREAM clause. What a very simple and effective script. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQLServer, T SQL, Technology Tagged: SQL Statistics, Statistics

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• What is the difference between String and string in C#

  - by SAMIR BHOGAYTA

  string : ------ The string type represents a sequence of zero or more Unicode characters. string is an alias for String in the .NET Framework. 'string' is the intrinsic C# datatype, and is an alias for the system provided type "System.String". The C# specification states that as a matter of style the keyword ('string') is preferred over the full system type name (System.String, or String). Although string is a reference type, the equality operators (== and !=) are defined to compare the values of string objects, not references. This makes testing for string equality more intuitive. For example: String : ------ A String object is called immutable (read-only) because its value cannot be modified once it has been created. Methods that appear to modify a String object actually return a new String object that contains the modification. If it is necessary to modify the actual contents of a string-like object Difference between string & String : ---------- ------- ------ - ------ the string is usually used for declaration while String is used for accessing static string methods we can use 'string' do declare fields, properties etc that use the predefined type 'string', since the C# specification tells me this is good style. we can use 'String' to use system-defined methods, such as String.Compare etc. They are originally defined on 'System.String', not 'string'. 'string' is just an alias in this case. we can also use 'String' or 'System.Int32' when communicating with other system, especially if they are CLR-compliant. I.e. - if I get data from elsewhere, I'd deserialize it into a System.Int32 rather than an 'int', if the origin by definition was something else than a C# system.

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• Overriding GetHashCode in a mutable struct - What NOT to do?

  - by Kyle Baran

  I am using the XNA Framework to make a learning project. It has a Point struct which exposes an X and Y value; for the purpose of optimization, it breaks the rules for proper struct design, since its a mutable struct. As Marc Gravell, John Skeet, and Eric Lippert point out in their respective posts about GetHashCode() (which Point overrides), this is a rather bad thing, since if an object's values change while its contained in a hashmap (ie, LINQ queries), it can become "lost". However, I am making my own Point3D struct, following the design of Point as a guideline. Thus, it too is a mutable struct which overrides GetHashCode(). The only difference is that mine exposes and int for X, Y, and Z values, but is fundamentally the same. The signatures are below: public struct Point3D : IEquatable<Point3D> { public int X; public int Y; public int Z; public static bool operator !=(Point3D a, Point3D b) { } public static bool operator ==(Point3D a, Point3D b) { } public Point3D Zero { get; } public override int GetHashCode() { } public override bool Equals(object obj) { } public bool Equals(Point3D other) { } public override string ToString() { } } I have tried to break my struct in the way they describe, namely by storing it in a List<Point3D>, as well as changing the value via a method using ref, but I did not encounter they behavior they warn about (maybe a pointer might allow me to break it?). Am I being too cautious in my approach, or should I be okay to use it as is?

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• RAID5 over LVM on Ubuntu Server 12.04.3

  - by April Ethereal

  I'm trying to create a RAID5 software array using LVM. I use VirtualBox as I'm only learning how LVM works. So I've created 4 virtual SCSI drives and then did the following: pvcreate /dev/sd[b-e] vgcreate /dev/sd[b-e] raid5_vg lvcreate --type raid5 -i 3 -L 1G -n raid_lv raid5_vg However, I get an error after the last command: WARNING: Unrecognised segment type raid5 Using default stripesize 64.00 KiB Rounding size (256 extents) up to stripe boundary size (258 extents) Cannot update volume group raid5_vg with unknown segments in it! So it looks like raid5 is not a valid segment type. "lvm segtypes" also doesn't contain 'raid5' entry: root@ubuntu-lvm:~# lvm segtypes striped zero error free snapshot mirror So my question is - how could I create RAID5 logical volume using LVM only? It seems that it is possible, I saw a few references (not for Ubuntu, unfortunately) for RedHat and Gentoo systems. I don't want to use mdadm for now, until I find out that it is mandatory. Some info about my system is below: root@ubuntu-lvm:~# uname -a Linux ubuntu-lvm 3.8.0I use Ubuntu Server 12.04.3 (i686)-29-generic #42~precise1-Ubuntu SMP Wed Aug 14 15:31:16 UTC 2013 i686 i686 i386 GNU/Linux root@ubuntu-lvm:~# dpkg -l | grep lvm ii lvm2 2.02.66-4ubuntu7.3 The Linux Logical Volume Manager Thanks.

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• Squeezing hardware

  - by [email protected]

  It's very common that high availability means duplicate hardware so costs grows up.Nowadays, CIOs and DBAs has the main challenge of reduce the money spent increasing the performance and the availability. Since Grid Infrastructure 11gR2, there is a new feature that helps them to afford this challenge: Server PoolsNow, in Grid Infrastructure 11gR2, you can define server pools across the cluster setting up the minimum number of servers, the maximum and how important is the pool.For example:Consider  that "Velasco, Boixeda & co"  has 3 apps in a 6 servers cluster.First One is the main core business appSecond one is Mid RangeAnd third it's a database not very important.We Define the following resource requirements for expected workload:1- Main App 2 servers required2- Mid Range App requires 1 server3- Is not a required app in case of disasterThe we define 3 server pools across the cluster:1- Main pool min two servers, max three servers, importance four2- Mid pool, min one server max two servers, importance two3- test pool,min zero servers, max one server, importance oneSo the initial configuration is:-Main pool has three servers-Mid pool has two servers-Test pool has one serverLogically, we can see the cluster like this:If any server fails, the following algorithm will be applied:1.-The server pool of least importance2.-IF server pools are of the same importance,   THEN then the Server Pool that has more than its defined minimum servers Is chosenHope it helps 

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• SQL SERVER – Weekly Series – Memory Lane – #049

  - by Pinal Dave

  Here is the list of selected articles of SQLAuthority.com across all these years. Instead of just listing all the articles I have selected a few of my most favorite articles and have listed them here with additional notes below it. Let me know which one of the following is your favorite article from memory lane. 2007 Two Connections Related Global Variables Explained – @@CONNECTIONS and @@MAX_CONNECTIONS @@CONNECTIONS Returns the number of attempted connections, either successful or unsuccessful since SQL Server was last started. @@MAX_CONNECTIONS Returns the maximum number of simultaneous user connections allowed on an instance of SQL Server. The number returned is not necessarily the number currently configured. Query Editor – Microsoft SQL Server Management Studio This post may be very simple for most of the users of SQL Server 2005. Earlier this year, I have received one question many times – Where is Query Analyzer in SQL Server 2005? I wrote small post about it and pointed many users to that post – SQL SERVER – 2005 Query Analyzer – Microsoft SQL SERVER Management Studio. Recently I have been receiving similar question. OUTPUT Clause Example and Explanation with INSERT, UPDATE, DELETE SQL Server 2005 has a new OUTPUT clause, which is quite useful. OUTPUT clause has access to insert and deleted tables (virtual tables) just like triggers. OUTPUT clause can be used to return values to client clause. OUTPUT clause can be used with INSERT, UPDATE, or DELETE to identify the actual rows affected by these statements. OUTPUT clause can generate a table variable, a permanent table, or temporary table. Even though, @@Identity will still work with SQL Server 2005, however I find the OUTPUT clause very easy and powerful to use. Let us understand the OUTPUT clause using an example. Find Name of The SQL Server Instance Based on database server stored procedures has to run different logic. We came up with two different solutions. 1) When database schema is very much changed, we wrote completely new stored procedure and deprecated older version once it was not needed. 2) When logic depended on Server Name we used global variable @@SERVERNAME. It was very convenient while writing migrating script which depended on the server name for the same database. Explanation of TRY…CATCH and ERROR Handling With RAISEERROR Function One of the developers at my company thought that we can not use the RAISEERROR function in new feature of SQL Server 2005 TRY… CATCH. When asked for an explanation he suggested SQL SERVER – 2005 Explanation of TRY… CATCH and ERROR Handling article as excuse suggesting that I did not give example of RAISEERROR with TRY…CATCH. We all thought it was funny. Just to keep records straight, TRY… CATCH can sure use RAISEERROR function. Different Types of Cache Objects Serveral kinds of objects can be stored in the procedure cache: Compiled Plans: When the query optimizer finishes compiling a query plan, the principal output is compiled plan. Execution contexts: While executing a compiled plan, SQL Server has to keep track of information about the state of execution. Cursors: Cursors track the execution state of server-side cursors, including the cursor’s current location within a resultset. Algebrizer trees: The Algebrizer’s job is to produce an algebrizer tree, which represents the logic structure of a query. Open SSMS From Command Prompt – sqlwb.exe Example This article is written by request and suggestion of Sr. Web Developer at my organization. Due to the nature of this article most of the content is referred from Book On-Line. sqlwbcommand prompt utility which opens SQL Server Management Studio. Squib command does not run queries from the command prompt. sqlcmd utility runs queries from command prompt, read for more information. 2008 Puzzle – Solution – Computed Columns Datatype Explanation Just a day before I wrote article SQL SERVER – Puzzle – Computed Columns Datatype Explanation which was inspired by SQL Server MVP Jacob Sebastian. I suggest that before continuing this article read the original puzzle question SQL SERVER – Puzzle – Computed Columns Datatype Explanation.The question was if the computed column was of datatype TINYINT how to create a Computed Column of datatype INT? 2008 – Find If Index is Being Used in Database It is very often I get a query that how to find if any index is being used in the database or not. If any database has many indexes and not all indexes are used it can adversely affect performance. If the number of indices are higher it reduces the INSERT / UPDATE / DELETE operation but increase the SELECT operation. It is recommended to drop any unused indexes from table to improve the performance. 2009 Interesting Observation – Execution Plan and Results of Aggregate Concatenation Queries If you want to see what’s going on here, I think you need to shift your point of view from an implementation-centric view to an ANSI point of view. ANSI does not guarantee processing the order. Figure 2 is interesting, but it will be potentially misleading if you don’t understand the ANSI rule-set SQL Server operates under in most cases. Implementation thinking can certainly be useful at times when you really need that multi-million row query to finish before the backup fire off, but in this case, it’s counterproductive to understanding what is going on. SQL Server Management Studio and Client Statistics Client Statistics are very important. Many a times, people relate queries execution plan to query cost. This is not a good comparison. Both parameters are different, and they are not always related. It is possible that the query cost of any statement is less, but the amount of the data returned is considerably larger, which is causing any query to run slow. How do we know if any query is retrieving a large amount data or very little data? 2010 I encourage all of you to go through complete series and write your own on the subject. If you write an article and send it to me, I will publish it on this blog with due credit to you. If you write on your own blog, I will update this blog post pointing to your blog post. SQL SERVER – ORDER BY Does Not Work – Limitation of the View 1 SQL SERVER – Adding Column is Expensive by Joining Table Outside View – Limitation of the View 2 SQL SERVER – Index Created on View not Used Often – Limitation of the View 3 SQL SERVER – SELECT * and Adding Column Issue in View – Limitation of the View 4 SQL SERVER – COUNT(*) Not Allowed but COUNT_BIG(*) Allowed – Limitation of the View 5 SQL SERVER – UNION Not Allowed but OR Allowed in Index View – Limitation of the View 6 SQL SERVER – Cross Database Queries Not Allowed in Indexed View – Limitation of the View 7 SQL SERVER – Outer Join Not Allowed in Indexed Views – Limitation of the View 8 SQL SERVER – SELF JOIN Not Allowed in Indexed View – Limitation of the View 9 SQL SERVER – Keywords View Definition Must Not Contain for Indexed View – Limitation of the View 10 SQL SERVER – View Over the View Not Possible with Index View – Limitations of the View 11 SQL SERVER – Get Query Running in Session I was recently looking for syntax where I needed a query running in any particular session. I always remembered the syntax and ha d actually written it down before, but somehow it was not coming to mind quickly this time. I searched online and I ended up on my own article written last year SQL SERVER – Get Last Running Query Based on SPID. I felt that I am getting old because I forgot this really simple syntax. Find Total Number of Transaction on Interval In one of my recent Performance Tuning assignments I was asked how do someone know how many transactions are happening on a server during certain interval. I had a handy script for the same. Following script displays transactions happened on the server at the interval of one minute. You can change the WAITFOR DELAY to any other interval and it should work. 2011 Here are two DMV’s which are newly introduced in SQL Server 2012 and provides vital information about SQL Server. DMV – sys.dm_os_volume_stats – Information about operating system volume DMV – sys.dm_os_windows_info – Information about Operating System SQL Backup and FTP – A Quick and Handy Tool I have used this tool extensively since 2009 at numerous occasion and found it to be very impressive. What separates it from the crowd the most – it is it’s apparent simplicity and speed. When I install SQLBackupAndFTP and configure backups – all in 1 or 2 minutes, my clients are always impressed. Quick Note about JOIN – Common Questions and Simple Answers In this blog post we are going to talk about join and lots of things related to the JOIN. I recently started office hours to answer questions and issues of the community. I receive so many questions that are related to JOIN. I will share a few of the same over here. Most of them are basic, but note that the basics are of great importance. 2012 Importance of User Without Login Question: “In recent version of SQL Server we can create user without login. What is the use of it?” Great question indeed. Let me first attempt to answer this question but after reading my answer I need your help. I want you to help him as well with adding more value to it. Preserve Leading Zero While Coping to Excel from SSMS Earlier I wrote two articles about how to efficiently copy data from SSMS to Excel. Since I wrote that post there are plenty of interest generated on this subject. There are a few questions I keep on getting over this subject. One of the question is how to get the leading zero preserved while copying the data from SSMS to Excel. Well it is almost the same way as my earlier post SQL SERVER – Excel Losing Decimal Values When Value Pasted from SSMS ResultSet. The key here is in EXCEL and not in SQL Server. Solution – 2 T-SQL Puzzles – Display Star and Shortest Code to Display 1 Earlier on this blog we had asked two puzzles. The response from all of you is nothing but Amazing. I have received 350+ responses. Many are valid and many were indeed something I had not thought about it. I strongly suggest you read all the puzzles and their answers here - trust me if you start reading the comments you will not stop till you read every single comment. Seriously trust me on it. Personally I have learned a lot from it. Identify Most Resource Intensive Queries – SQL in Sixty Seconds #028 – Video http://www.youtube.com/watch?v=TvlYy-TGaaA Importance of User Without Login – T-SQL Demo Script Earlier I wrote a blog post about SQL SERVER – Importance of User Without Login and my friend and SQL Expert Vinod Kumar has written excellent follow up blog post about Contained Databases inside SQL Server 2012. Now lots of people asked me if I can also explain the same concept again so here is the small demonstration for it. Let me show you how login without user can help. Before we continue on this subject I strongly recommend that you read my earlier blog post here. In following demo I am going to demonstrate following situation. Login using the System Admin account Create a user without login Checking Access Impersonate the user without login Checking Access Revert Impersonation Give Permission to user without login Impersonate the user without login Checking Access Revert Impersonation Clean up Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Memory Lane, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• Screen space to world space

  - by user13414

  I am writing a 2D game where my game world has x axis running left to right, y axis running top to bottom, and z axis out of the screen: Whilst my game world is top-down, the game is rendered on a slight tilt: I'm working on projecting from world space to screen space, and vice-versa. I have the former working as follows: var viewport = new Viewport(0, 0, this.ScreenWidth, this.ScreenHeight); var screenPoint = viewport.Project(worldPoint.NegateY(), this.ProjectionMatrix, this.ViewMatrix, this.WorldMatrix); The NegateY() extension method does exactly what it sounds like, since XNA's y axis runs bottom to top instead of top to bottom. The screenshot above shows this all working. Basically, I have a bunch of points in 3D space that I then render in screen space. I can modify camera properties in real time and see it animate to the new position. Obviously my actual game will use sprites rather than points and the camera position will be fixed, but I'm just trying to get all the math in place before getting to that. Now, I am trying to convert back the other way. That is, given an x and y point in screen space above, determine the corresponding point in world space. So if I point the cursor at, say, the bottom-left of the green trapezoid, I want to get a world space reading of (0, 480). The z coordinate is irrelevant. Or, rather, the z coordinate will always be zero when mapping back to world space. Essentially, I want to implement this method signature: public Vector2 ScreenPointToWorld(Vector2 point) I've tried several things to get this working but am just having no luck. My latest thinking is that I need to call Viewport.Unproject twice with differing near/far z values, calculate the resultant Ray, normalize it, then calculate the intersection of the Ray with a Plane that basically represents ground-level of my world. However, I got stuck on the last step and wasn't sure whether I was over-complicating things. Can anyone point me in the right direction on how to achieve this?

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• CodePlex Daily Summary for Thursday, May 20, 2010

  CodePlex Daily Summary for Thursday, May 20, 2010New ProjectsAlphaChannel: Closed projectAragon Online Client: The Aragon Online Client is a front-end application allowing users to play the online game http://aragon-online.net The client fetches game data a...BISBCarManager: Car managerBlammo.Net: Blammo.Net is a simple logging system that allows for multiple files, has simple configuration, and is modular.C# IMAPI2 Samples: This project is my effort to port the VB Script IMAPI2 samples to C# 4.0 and provide CD/DVD Burning capabilities in C#. This takes advantage of th...DemotToolkit: A toolbox to help you enjoy the demotivators.FMI Silverlight Course: This is the site for the final project of the Silverlight course taught at the Sofia University in the summer semester of 2010.InfoPath Publisher Helper: Building a large set of InfoPath Templates? Bored of the repetive stsadm commands to deploy an online form? This tool will allow you to submit ...JSBallBounce - HTML5 Stereocopy: A demo of basic stereoscopy in HTML5Kindler: Kindler allows you to easily convert simply HTML into documents that can be easily read on the Amazon Kindle.Maybe: Maybe or IfNotNull using lambdas for deep expressions. int? CityId= employee.Maybe(e=>e.Person.Address.City);PopCorn Project : play music with system beeps: PopCorn is an application that can play monophonic music through system beeps. You can launch music on the local machine, or on a remote server thr...RuneScape 2 Chronos - Emulation done right.: RuneScape 2 Chronos is a RuneScape 2 Emulator framework. It is completely open-source and is programmed in a way in which should be simpler for it'...RWEntregas: Projeto do Rogrigo e Wender referente a entregasSilverAmp: A media player to demonstrate lots of new Silverlight 4 features. Running out of browser and reading files from the MyMusic folder are two of them....Silverlight Scheduler: A light-weight silverlight scheduler control.SimpleContainer: SimpleContainer is very simple IoC container that consists of one class that implements two remarkable methods: one for registration and one for re...sqlserverextensions: This project will provide some use operations for files and directories. Further development will include extended string operations.TechWorks Portugal Sample BI Project: Techworks is a complete Microsoft BI sample project customized for Portugal to be used in demo and learning scenarios. It is based in SQL Server 20...Test4Proj: Test4ProjTV Show Renamer: TV Show Renamer is a program that is designed to take files downloaded off the internet and rename them to a more user friendly file name. It is fo...UnFreeZeMouSeW7: This small application disable or enable the standby mode on Windows 7 devices. As the mouse pointer freezes or the latency increase on some device...VianaNET - Videoanalysis for physical motion: The VianaNET project targets physics education. The software enables to analyze the motion of colored objects in life-video and video files. The da...Visual Studio 2010 extension for helping SharePoint 2010 debugging: This is a Visual Studio 2010 extensibility project that extends the debugging support for the built-in SharePoint 2010 tools with new menu items an...Visual Studio 2010 Load Test Plugins Library: Useful plugin library for Visual Studio Load Test 2010 version. (Best for web tests).VMware Lab Manager Powershell Cmdlet: This is a simple powershell cmdlet which connects you with the VMware lab manager internal soap api.Webgame UI: Bot to webgameNew ReleasesActipro WPF Controls Contrib: v2010.1: Minor tweaks and updated to target Actipro WPF Studio 2010.1. Addition of Editors.Interop.Datagrid project, which allows Actipro Editors for WPF t...Blammo.Net: Blammo.Net 1.0: This is the initial release of Blammo.Net.Build Version Increment Add-In Visual Studio: Shared Assembly Info Setup: Example solution that makes use of one shared assembly info file.CSS 360 Planetary Calendar: Zero Feature Release: =============================================================================== Zero Feature Release Version: 0.0 Description: This is a binar...DotNetNuke® Community Edition: 05.04.02: Updated the Installation Wizard's Polish & German language packs. Improved performance of Sql script for listing modules by portal. Improved De...DotNetNuke® Store: 02.01.36: What's New in this release? Bugs corrected: - The reference to resource.zip has been commented in the Install package. Sorry for that it's my mista...Extend SmallBasic: Teaching Extensions v.016: added turtle tree quizExtremeML: ExtremeML v1.0 Beta 2: Following the decision to terminate development of the Premium Edition of ExtremeML, this release includes all code previously restricted to the Pr...InfoPath Publisher Helper: 1st Release: InfoPath Publisher Helper Tool The version is mostly stable. There are some UI errors, which can be ignored. The code has not been cleaned up so t...JSBallBounce - HTML5 Stereocopy: HTML5 Stereoscopic Bouncing Balls Demo: Stereoscopic rendering in HTML5kdar: KDAR 0.0.22: KDAR - Kernel Debugger Anti Rootkit - signature's bases updated - ALPC port jbject check added - tcpip internal critical area checks added - some ...Lightweight Fluent Workflow: Objectflow core: Release Notes Fixed minor defects Framework changes Added IsFalse for boolean conditions Defects fixed IsTrue works with Not operator Installati...LiquidSilver SharePoint Framework: LiquidSilver 0.2.0.0 Beta: Changes in this version: - Fixed a bug in HgListItem when parsing double and int fields. - Added the LiquidSilver.Extra project. - Added the Liquid...Matrix: MatrixPlugin-0.5.1: Works with UniqueRoutes plugin on Google Code Works in Linux (path changes, variable usage etc) Builds .st2plugin by default Adapted to ST3MRDS Samples: MRDS Samples 1.0: Initial Release Please read the installation instructions on the Read Me page carefully before you unzip the samples. 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Read the readme.txt on how to install.SQL Trim: 20100519: Improved releasesqlserverextensions: V 0.1 alpha: Version 0.1 Alphasvchost viewer: svchost viewer ver. 0.5.0.1: Got some feedback from a user, with some nice ideas so here they are: • Made the program resizable. • Program now saves the size and position when...Tribe.Cache: Tribe.Cache RC: Release Candidate There are breaking changes between BETA and RC :- 1) Cache Dictionary is now not exposed to the client. 2) Completly Thread Sa...TV Show Renamer: TV Show Renamer: This is the first public release. Don't worry that it is version 2.1 that is because i keep adding features to it and then upping the version numbe...UnFreeZeMouSeW7: UnFreeZeMouSeW7 0.1: First releaseVCC: Latest build, v2.1.30519.0: Automatic drop of latest buildVianaNET - Videoanalysis for physical motion: VianaNET V1.1 - alpha: This is the first alpha release of the completely rewritten Viana. Known issues are: - sometimes black frame at initial load of video - no abilit...visinia: visinia_1: The beta is gone, the visinia is here with visinia 1. now you can confidently install visinia use visinia and enjoy visinia. This version of visini...visinia: visinia_1_Src: The beta is gone, the visinia is here with visinia 1. now you can confidently install visinia use visinia and enjoy visinia. This version of visini...Visual Studio 2010 extension for helping SharePoint 2010 debugging: 1.0 First public release: The extension is released as a Visual Studio 2010 solution. See my related blog post at http://pholpar.wordpress.com/2010/05/20/visual-studio-2010-...Visual Studio 2010 Load Test Plugins Library: version 1 stable: version 1 stableVMware Lab Manager Powershell Cmdlet: LMCmdlet 1.0.0: first Release. You need to be an Administrator to install this cmdlet. After you run setup open powershell type: Get-PSSnapin -Registered you sh...WF Personalplaner: Personalplaner v1.7.29.10139: - Wenn ein Schema erstellt wird mit der Checkbox "Als neues Schema speichern" wurde pro Person ein Schema erstellt - Wenn ein Pensum geändert wurde...XAM.NET: XAM 1.0p2 + Issue Tracker 8396: Patch release for Issue Tracker 8396Xrns2XMod: Xrns2XMod 1.2: Fixed 32 bit flac conversion - Thanks to Yuri for updating FlacBox librariesMost Popular ProjectsRawrWBFS ManagerAJAX Control ToolkitMicrosoft SQL Server Product Samples: DatabaseSilverlight ToolkitWindows Presentation Foundation (WPF)patterns & practices – Enterprise LibraryMicrosoft SQL Server Community & SamplesPHPExcelASP.NETMost Active Projectspatterns & practices – Enterprise LibraryRawrPHPExcelGMap.NET - Great Maps for Windows Forms & PresentationCustomer Portal Accelerator for Microsoft Dynamics CRMBlogEngine.NETWindows Azure Command-line Tools for PHP DevelopersCassiniDev - Cassini 3.5/4.0 Developers EditionSQL Server PowerShell ExtensionsFluent Ribbon Control Suite

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• Game physics presentation by Richard Lord, some questions

  - by Steve

  I been implementing (in XNA) the examples in this physics presentation by Richard Lord where he discusses various integration techniques. Bearing in mind that I am a newcomer to game physics (and physics in general) I have some questions. 15 slides in he shows ActionScript code for a gravity example and an animation showing a bouncing ball. The ball bounces higher and higher until it is out of control. I implemented the same in C# XNA but my ball appeared to be bouncing at a constant height. The same applies to the next example where the ball bounces lower and lower. After some experimentation I found that if I switched to a fixed timestep and then on the first iteration of Update() I set the time variable to be equal to elapsed milliseconds (16.6667) I would see the same behaviour. Doing this essentially set the framerate, velocity and acceleration to zero for the first update and introduced errors(?) into the algorithm causing the ball's velocity to increase (or decrease) over time. I think! My question is, does this make the integration method used poor? Or is it demonstrating that it is poor when used with variable timestep because you can't pass in a valid value for the first lot of calculations? (because you cannot know the framerate in advance). I will continue my research into physics but can anyone suggest a good method to get my feet wet? I would like to experiment with variable timestep, acceleration that changes over time and probably friction. Would the Time Corrected Verlet be OK for this?

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• Get Ready to Meet Oracle GoldenGate 11gR2 at OpenWorld

  - by Irem Radzik

    Oracle GoldenGate 11g Release 2 could not come at a better time. At Oracle OpenWorld 2012 we have a great set of sessions and demos for Oracle GoldenGate users: deep dives into the new features of Oracle GoldenGate 11gR2, as well as great customer presentations from Comcast, Bank of America, Turk Telekom, Ticketmaster, St. Jude Medical Center, and more. Here are 3 must-attend sessions for GoldenGate users and for those who want to get to know GoldenGate’s capabilities: Real-World Zero-Downtime Operations with Oracle GoldenGate: Customer Panel Oct 1st 1:45 PM Moscone West – 3005 Oracle GoldenGate 11g Release 2 New Features Oct 1st 3:15 PM Moscone West – 3005 Real-World Operational Reporting with Oracle GoldenGate: Customer Panel Oct 2nd 11:45 AM Moscone West - 3005 For a full list of GoldenGate and data integration sessions, please check out our Focus-On for Data Integration. Similar to last year, Hands-on-Labs will be available for those who want to experience the power of GoldenGate first hand. One of these instructor-led sessions provides “Deep Dive into Oracle GoldenGate” will be held on Thursday Oct 4th 11:15am at Marriott Marquis - Salon ½. I expect the spots will fill out fast in this session. Oracle GoldenGate Demos will be running Monday through Wednesday in Moscone South in both Oracle Database and Oracle Fusion Middleware sections of the Oracle demo grounds. We will be showcasing: Monitoring Oracle GoldenGate for End-to-End Visibility Oracle GoldenGate 11gR2 New Features Oracle GoldenGate 11gR2: Real-Time, Transactional Database Replication Oracle GoldenGate Veridata Oracle Maximum Availability Architecture If you are not able to attend OpenWorld, you should not miss this week’s live webcast introducing Oracle GoldenGate 11g Release 2. On Wednesday the webcast will present the new features of GoldenGate and attendees will have a long, live Q&A panel session with the PM team.  I also recommend checking out the resources for GoldenGate to download new white papers. The whole team is looking forward to sharing with you the latest and greatest features of GoldenGate at the launch webcast and at OpenWorld.

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• MSDN article on jQuery Mobile

  - by Wallym

  My article on jQuery Mobile has been published.  Please check it out.There’s no doubt about it. Wherever developers look and whoever they talk to, mobile is at the top of the list. Talk to a C-level executive, and the conversation turns to mobile, and the question “How do I get me some of that?” comes up. Talk to other developers, and they tell you they’re targeting mobile devices. Mobile has become a big deal as smartphones have taken hold in the consumer marketplace.In the years leading up to the current focus on mobile applications and devices, Web developers have been adding more and more client-side functionality to their applications. You can see this in the use of client-side JavaScript libraries like jQuery.With the growth of the market for mobile devices, the ability to create applications that run across platforms is very important for developers and for businesses that are trying to keep their expenses in check. There are a set of applications, mostly in the area of content consumption (think Amazon.com), that run well in a mobile Web browser. Unfortunately, there are differences between Web browsers on various mobile devices. The goal of the recently introduced jQuery Mobile (jQM) library is to provide cross-browser support to allow developers to build applications that can run across the various mobile Web browsers and provide the same—or at least a very similar—user interface.The jQuery Mobile library was introduced in an alpha release in the fall of 2010 and released to manufacturing in November 2011. At the time of this writing, the current version of jQuery Mobile is 1.1.1. By the time you read this, jQuery Mobile will almost certainly have reached version 1.2.0. The library has been embraced by Microsoft, Adobe and other companies for mobile Web development. In August 2011, jQM had 32 percent market share compared with other mobile JavaScript frameworks such as iWebKit and jQTouch. This market share is impressive given that it started from zero little more than 12 months ago, and the 1.0 release is the first officially supported release.

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• Managing user privileges, best practice.

  - by Loïc N.

  I'm am new to web development. I'm creating a website where different user can have different privileges, such as creating/editing/deleting a news, or adding/editing/deleting whatever kind of content on the website. I started by creating a "user type" that would indicate the user's privileges (such as "user", "newser", "moderator", "admin", and so on), but i quickly started noticing issues that made me think that this might be a naive approach to this issue. What if i want to give a regular user the right to edit a news (for whatever reason)? Then the user would be half "user", half "newser". But the system i use can only handle one user-type. So what would be the best practice here? I was thinking of removing the concept of roles (or "user-types" such as newser) and only have the concept of "privilege", where every user could have zero to many privileges. So, to re-use the above example, if i wanted a user to have the right to edit some news, i would only have to give him a "edit news" privilege. Is this the way to go?

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• Per Pixel Collision Detection

  - by CJ Cohorst

  Just a quick question, I have this collision detection code: public bool PerPixelCollision(Player player, Game1 dog) { Matrix atob = player.Transform * Matrix.Invert(dog.Transform); Vector2 stepX = Vector2.TransformNormal(Vector2.UnitX, atob); Vector2 stepY = Vector2.TransformNormal(Vector2.UnitY, atob); Vector2 iBPos = Vector2.Transform(Vector2.Zero, atob); for(int deltax = 0; deltax < player.playerTexture.Width; deltax++) { Vector2 bpos = iBPos; for (int deltay = 0; deltay < player.playerTexture.Height; deltay++) { int bx = (int)bpos.X; int by = (int)bpos.Y; if (bx >= 0 && bx < dog.dogTexture.Width && by >= 0 && by < dog.dogTexture.Height) { if (player.TextureData[deltax + deltay * player.playerTexture.Width].A > 150 && dog.TextureData[bx + by * dog.Texture.Width].A > 150) { return true; } } bpos += stepY; } iBPos += stepX; } return false; } What I want to know is where to put in the code where something happens. For example, I want to put in player.playerPosition.X -= 200 just as a test, but I don't know where to put it. I tried putting it under the return true and above it, but under it, it said unreachable code, and above it nothing happened. I also tried putting it by bpos += stepY; but that didn't work either. Where do I put the code? Any help is appreciated. Thanks in advance!

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• Copy wrongs and Copyright

  - by Tony Davis

  Recently, a Chinese blog website copied, wholesale and without permission, a Simple-Talk article on troubleshooting locking and blocking. Our initial reaction was exasperation and anger, tempered slightly by the fact that there was, at the top, a clear link to the original, and the book from which it was extracted. On the day the copy was posted, our original article saw a 30K spike in visits, so the site clearly has a substantial following! This made us pause for thought. Indeed, we wondered whether it might not be more profitable, and certainly more enjoyable, to notify the offender of similar content and serve a "put up" notice, rather than the usual DMCA "take down" . The DMCA request, issued to protect our and our authors' assets, is a necessary but tiresome, chore. So often, simple communication and negotiation could have averted the need for it. We are, after all, in the business of presenting knowledge, information and help to the SQL Server Community. If only they had asked! Of course, one's attitude changes according to the motivation behind the copying of content. One of the motivations seems to be pure vanity; they do it to try to enhance their CV, or their company's expertise, by pretending to expertise they don't possess. There is a class of plagiariser, however, that is doing it purely for money, getting advertising revenue by attracting hapless readers to their site. Not content with stealing content, sites can invest in services that provide 'load-testing' for websites that is so realistic that even the search engines can be fooled. Stolen content, fake visitors, swindled advertisers. Zero-tolerance is really the only way of dealing with plagiarism, and action will only be completely effective once Bing, Google, and the other search engines strike out from their listings the rogue sites that refuse to take down plagiarised content. It is, after all in everyone else's interests. Cheers, Tony.

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• Getting SQL table row counts via sysindexes vs. sys.indexes

  - by Bill Osuch

  Among the many useful SQL snippets I regularly use is this little bit that will return row counts in a table: SELECT so.name as TableName, MAX(si.rows) as [RowCount] FROM sysobjects so JOIN sysindexes si ON si.id = OBJECT_ID(so.name) WHERE so.xtype = 'U' GROUP BY so.name ORDER BY [RowCount] DESC This is handy to find tables that have grown wildly, zero-row tables that could (possibly) be dropped, or other clues into the data. Right off the bat you may spot some "non-ideal" code - I'm using sysobjects rather than sys.objects. What's the difference? In SQL Server 2005 and later, sysobjects is no longer a table, but a "compatibility view", meant for backward compatibility only. SELECT * from each and you'll see the different data that each returns. Microsoft advises that sysindexes could be removed in a future version of SQL Server, but this has never really been an issue for me since my company is still using SQL 2000. However, there are murmurs that we may actually migrate to 2008 some year, so I might as well go ahead and start using an updated version of this snippet on the servers that can handle it: SELECT so.name as TableName, ddps.row_count as [RowCount] FROM sys.objects so JOIN sys.indexes si ON si.OBJECT_ID = so.OBJECT_ID JOIN sys.dm_db_partition_stats AS ddps ON si.OBJECT_ID = ddps.OBJECT_ID  AND si.index_id = ddps.index_id WHERE si.index_id < 2  AND so.is_ms_shipped = 0 ORDER BY ddps.row_count DESC

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