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  • Subscribable World Cup 2010 Calendar

    - by jamiet
    I bang on quite a lot on this blog about ways in which data can get published over the web and one of the most interesting ways, in my opinion, of publishing data in a structured manner that is well understood is to use the iCalendar specification. There isn’t much information in the world that doesn’t have some concept of “when” so iCalendar is a great way of distributing that information. You have probably used iCalendar at some point without even knowing about it. All files with a .ics suffix are iCalendar format files and that is why you can happily import them into Outlook, Hotmail Calendar, Google Calendar etc… where they can be parsed and have the semantic data (when, where and who) extracted from them. Importing of iCalendar format data is really only half the trick though; in my opinion the real value of iCalendar-formatted calendar is the ability to subscribe to them. Subscribing has a simple benefit over importing but that single benefit is of massive importance: a subscriber to an iCalendar calendar can periodically check to see if any updates have been made and, if they have, automatically update the local copy. The real benefit to the user is the productivity gain – a single update to an iCalendar means that all subscribers are automatically made aware of the change and there is zero effort on the part of the subscriber; as my former colleague Howard van Rooijen is fond of saying, “work smarter not harder” – nowhere is this edict more ably demonstrated than subscribing versus importing of calendars. If you want to read some more thoughts about iCalendar then go and read my past blog post Calendar syndication - My big hope for 2009's breakthrough technology or better still go and seek out Jon Udell who speaks very authoritatively on the issue of iCalendar. With this subject of iCalendar on my mind I was interested to discover (via Steve Clayton’s blog post Download the world cup fixtures) that the BBC had made a .ics file available containing all of the matches in the upcoming World Cup. As you can probably guess this was a file that was made available so that it could be imported into your calendar of choice. It had one obvious downside though, right now nobody knows who is going to be playing in the knock-out stages so the calendar looks like this: with no teams being named after 25th June. How much more useful would this calendar have been if the BBC had made it possible to subscribe to the calendar instead, thus the calendar could be updated with the teams for the knock out stages when they are known and every subscriber would have a permanently up-to-date record of all the fixtures in their calendar. Better still, the calendar could be updated with match results as well or perhaps even post a match report from the BBC sport pages; when calendars are made subscribable a sea of opportunity opens up for distribution of information. So with that in mind I have decided to go one better than the BBC. I have imported their .ics into a brand new Hotmail calendar and made it publicly available at the following URLs: HTML http://cid-dc1ed121af0476be.calendar.live.com/calendar/World+Cup+2010/index.html iCalendar webcal://cid-dc1ed121af0476be.calendar.live.com/calendar/World+Cup+2010/calendar.ics The link you’re really interested in is the second one - click on that and it should open up in your calendar software of choice. Or, if you want to view it in an online calendar such as Hotmail Calendar or Google Calendar, copy and paste that URL into the appropriate place. Some people have told me they’re having trouble with the iCalendar link in which case hit the HTML link and then click “View ICS” at the resultant web page: I shall endeavour to keep the calendar updated throughout the World Cup and even if I don’t you’re no worse off than if you had imported the BBC’s .ics file so why not give it a try? If I do keep it up to date then you will have a permanent record of the 2010 World Cup available in your calendar. Forever. If you have your calendar synced to your smartphone then you’ll be carrying match reports around with you without you having to do a single thing. Surely that’s worth a quick click isn’t it?   If you have any thoughts let me have them in the comments below. Thanks for reading. @Jamiet Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

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  • VirtualBox - Public Static IP for a Debian Guest on a Dedicated Server

    - by user86296
    Goal: I want to run a Debian-squeeze-Guest in VirtualBox and it's own public static ip. I found tons of threads about this topic, but all in all I'm now trying for 10 hours (reading the manual, the forums, trying to learn about networking concepts & commands) to give a Guest his own public static ip (so that the Guest is similar to a vServer you can order from a hosting company), but wasn't able to. Since I'm a big noob as far as networking stuff is concerned, I'm probably doing something wrong.(please bear with me :-) ) Situation: VirtualBox 4.0.10 (headless no gui) is running on a dedicated Debian-Server, the Guest OS is Debian as well. The server has a static ip and I ordered an additional ip for a VM. Problem description: Upto now I was able to use NAT to access the VM from the outside and to setup an internal network between several Guests and all of this worked very well. When setting NIC 1 to bridged and configuring a public static ip on the guest, the guest was unpingable. (neither from outside, nor from the host) I could connect to the guest via the internal network, from another vm, though. ( VBoxManage controlvm VMGuest nic1 bridged eth0 ) ( configuration attempt of static-ip on the guest '/etc/network/interfaces' is below) Please let me know what I'm doing wrong, or what I can try to get it to work, or if you need more info. I think I've read that with a current VirtualBox-version for bridged networking no special host-configuration is necessary, is that accurate, or might that be the problem? Additional Info Info I got from the hosting company about the additional IP Please note that you can use the IP address only for this server. IP: 46.4.xx.xx Gateway: 46.4.xx.xx Mask: 255.255.255.248 VBoxManage showvminfo VMGuest |less ... NIC 1: MAC: 080027D72F7B, Attachment: Bridged Interface 'eth0', Cable connected: on, Trace: off (file: none), Type: 82540EM, Reported speed: 0 Mbps, Boot priority: 0 NIC 2: MAC: 080027B03B75, Attachment: Internal Network 'InternalNet1', Cable connected: on, Trace: off (file: none), Type: Am79C973, Reported speed: 0 Mbps, Boot priority: 0 NIC 3: disabled (...rest is disabled) cat /etc/network/interfaces on the Host-machine # Loopback device: auto lo iface lo inet loopback # device: eth0 auto eth0 iface eth0 inet static address 46.4.xx.xx broadcast 46.4.xx.xx netmask 255.255.255.224 gateway 46.4.xx.xx post-up mii-tool -F 100baseTx-FD eth0 # default route to access subnet up route add -net 46.4.xx.xx netmask 255.255.255.224 gw 46.4.xx.xx eth0 cat /etc/network/interfaces on the Guest-VM # This file describes the network interfaces available on your system # and how to activate them. For more information, see interfaces(5). # The loopback network interface auto lo iface lo inet loopback # The primary network interface allow-hotplug eth0 auto eth0 iface eth0 inet static address 46.4.xx.xx netmask 255.255.255.248 gateway 46.4.xx.xx auto eth1 iface eth1 inet dhcp ifconfig -a on the Guest shows the correct static ip for eth0 but the Guest is unreachable "over eth0" eth0 Link encap:Ethernet HWaddr 08:00:27:d7:2f:7b inet addr:46.4.xx.xx Bcast:46.4.xx.xx Mask:255.255.255.248 inet6 addr: fe80::a00:27ff:fed7:2f7b/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:21 errors:0 dropped:0 overruns:0 frame:0 TX packets:69 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:1260 (1.2 KiB) TX bytes:3114 (3.0 KiB) eth1 Link encap:Ethernet HWaddr 08:00:27:b0:3b:75 inet addr:192.168.10.3 Bcast:192.168.10.255 Mask:255.255.255.0 inet6 addr: fe80::a00:27ff:feb0:3b75/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:142 errors:0 dropped:0 overruns:0 frame:0 TX packets:92 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:15962 (15.5 KiB) TX bytes:14540 (14.1 KiB) Interrupt:16 Base address:0xd240 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:123 errors:0 dropped:0 overruns:0 frame:0 TX packets:123 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:25156 (24.5 KiB) TX bytes:25156 (24.5 KiB)

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  • More Great Improvements to the Windows Azure Management Portal

    - by ScottGu
    Over the last 3 weeks we’ve released a number of enhancements to the new Windows Azure Management Portal.  These new capabilities include: Localization Support for 6 languages Operation Log Support Support for SQL Database Metrics Virtual Machine Enhancements (quick create Windows + Linux VMs) Web Site Enhancements (support for creating sites in all regions, private github repo deployment) Cloud Service Improvements (deploy from storage account, configuration support of dedicated cache) Media Service Enhancements (upload, encode, publish, stream all from within the portal) Virtual Networking Usability Enhancements Custom CNAME support with Storage Accounts All of these improvements are now live in production and available to start using immediately.  Below are more details on them: Localization Support The Windows Azure Portal now supports 6 languages – English, German, Spanish, French, Italian and Japanese. You can easily switch between languages by clicking on the Avatar bar on the top right corner of the Portal: Selecting a different language will automatically refresh the UI within the portal in the selected language: Operation Log Support The Windows Azure Portal now supports the ability for administrators to review the “operation logs” of the services they manage – making it easy to see exactly what management operations were performed on them.  You can query for these by selecting the “Settings” tab within the Portal and then choosing the “Operation Logs” tab within it.  This displays a filter UI that enables you to query for operations by date and time: As of the most recent release we now show logs for all operations performed on Cloud Services and Storage Accounts.  You can click on any operation in the list and click the “Details” button in the command bar to retrieve detailed status about it.  This now makes it possible to retrieve details about every management operation performed. In future updates you’ll see us extend the operation log capability to apply to all Windows Azure Services – which will enable great post-mortem and audit support. Support for SQL Database Metrics You can now monitor the number of successful connections, failed connections and deadlocks in your SQL databases using the new “Dashboard” view provided on each SQL Database resource: Additionally, if the database is added as a “linked resource” to a Web Site or Cloud Service, monitoring metrics for the linked SQL database are shown along with the Web Site or Cloud Service metrics in the dashboard. This helps with viewing and managing aggregated information across both resources in your application. Enhancements to Virtual Machines The most recent Windows Azure Portal release brings with it some nice usability improvements to Virtual Machines: Integrated Quick Create experience for Windows and Linux VMs Creating a new Windows or Linux VM is now easy using the new “Quick Create” experience in the Portal: In addition to Windows VM templates you can also now select Linux image templates in the quick create UI: This makes it incredibly easy to create a new Virtual Machine in only a few seconds. Enhancements to Web Sites Prior to this past month’s release, users were forced to choose a single geographical region when creating their first site.  After that, subsequent sites could only be created in that same region.  This restriction has now been removed, and you can now create sites in any region at any time and have up to 10 free sites in each supported region: One of the new regions we’ve recently opened up is the “East Asia” region.  This allows you to now deploy sites to North America, Europe and Asia simultaneously.  Private GitHub Repository Support This past week we also enabled Git based continuous deployment support for Web Sites from private GitHub and BitBucket repositories (previous to this you could only enable this with public repositories).  Enhancements to Cloud Services Experience The most recent Windows Azure Portal release brings with it some nice usability improvements to Cloud Services: Deploy a Cloud Service from a Windows Azure Storage Account The Windows Azure Portal now supports deploying an application package and configuration file stored in a blob container in Windows Azure Storage. The ability to upload an application package from storage is available when you custom create, or upload to, or update a cloud service deployment. To upload an application package and configuration, create a Cloud Service, then select the file upload dialog, and choose to upload from a Windows Azure Storage Account: To upload an application package from storage, click the “FROM STORAGE” button and select the application package and configuration file to use from the new blob storage explorer in the portal. Configure Windows Azure Caching in a caching enabled cloud service If you have deployed the new dedicated cache within a cloud service role, you can also now configure the cache settings in the portal by navigating to the configuration tab of for your Cloud Service deployment. The configuration experience is similar to the one in Visual Studio when you create a cloud service and add a caching role.  The portal now allows you to add or remove named caches and change the settings for the named caches – all from within the Portal and without needing to redeploy your application. Enhancements to Media Services You can now upload, encode, publish, and play your video content directly from within the Windows Azure Portal.  This makes it incredibly easy to get started with Windows Azure Media Services and perform common tasks without having to write any code. Simply navigate to your media service and then click on the “Content” tab.  All of the media content within your media service account will be listed here: Clicking the “upload” button within the portal now allows you to upload a media file directly from your computer: This will cause the video file you chose from your local file-system to be uploaded into Windows Azure.  Once uploaded, you can select the file within the content tab of the Portal and click the “Encode” button to transcode it into different streaming formats: The portal includes a number of pre-set encoding formats that you can easily convert media content into: Once you select an encoding and click the ok button, Windows Azure Media Services will kick off an encoding job that will happen in the cloud (no need for you to stand-up or configure a custom encoding server).  When it’s finished, you can select the video in the “Content” tab and then click PUBLISH in the command bar to setup an origin streaming end-point to it: Once the media file is published you can point apps against the public URL and play the content using Windows Azure Media Services – no need to setup or run your own streaming server.  You can also now select the file and click the “Play” button in the command bar to play it using the streaming endpoint directly within the Portal: This makes it incredibly easy to try out and use Windows Azure Media Services and test out an end-to-end workflow without having to write any code.  Once you test things out you can of course automate it using script or code – providing you with an incredibly powerful Cloud Media platform that you can use. Enhancements to Virtual Network Experience Over the last few months, we have received feedback on the complexity of the Virtual Network creation experience. With these most recent Portal updates, we have added a Quick Create experience that makes the creation experience very simple. All that an administrator now needs to do is to provide a VNET name, choose an address space and the size of the VNET address space. They no longer need to understand the intricacies of the CIDR format or walk through a 4-page wizard or create a VNET / subnet. This makes creating virtual networks really simple: The portal also now has a “Register DNS Server” task that makes it easy to register DNS servers and associate them with a virtual network. Enhancements to Storage Experience The portal now lets you register custom domain names for your Windows Azure Storage Accounts.  To enable this, select a storage resource and then go to the CONFIGURE tab for a storage account, and then click MANAGE DOMAIN on the command bar: Clicking “Manage Domain” will bring up a dialog that allows you to register any CNAME you want: Summary The above features are all now live in production and available to use immediately.  If you don’t already have a Windows Azure account, you can sign-up for a free trial and start using them today.  Visit the Windows Azure Developer Center to learn more about how to build apps with it. One of the other cool features that is now live within the portal is our new Windows Azure Store – which makes it incredibly easy to try and purchase developer services from a variety of partners.  It is an incredibly awesome new capability – and something I’ll be doing a dedicated post about shortly. Hope this helps, Scott P.S. In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at: twitter.com/scottgu

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  • How to label a cuboid?

    - by usha
    Hi this is how my 3dcuboid looks, I have attached the complete code. I want to label this cuboid using different names across sides, how is this possible using opengl on android? public class MyGLRenderer implements Renderer { Context context; Cuboid rect; private float mCubeRotation; // private static float angleCube = 0; // Rotational angle in degree for cube (NEW) // private static float speedCube = -1.5f; // Rotational speed for cube (NEW) public MyGLRenderer(Context context) { rect = new Cuboid(); this.context = context; } public void onDrawFrame(GL10 gl) { // TODO Auto-generated method stub gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT); gl.glLoadIdentity(); // Reset the model-view matrix gl.glTranslatef(0.2f, 0.0f, -8.0f); // Translate right and into the screen gl.glScalef(0.8f, 0.8f, 0.8f); // Scale down (NEW) gl.glRotatef(mCubeRotation, 1.0f, 1.0f, 1.0f); // gl.glRotatef(angleCube, 1.0f, 1.0f, 1.0f); // rotate about the axis (1,1,1) (NEW) rect.draw(gl); mCubeRotation -= 0.15f; //angleCube += speedCube; } public void onSurfaceChanged(GL10 gl, int width, int height) { // TODO Auto-generated method stub if (height == 0) height = 1; // To prevent divide by zero float aspect = (float)width / height; // Set the viewport (display area) to cover the entire window gl.glViewport(0, 0, width, height); // Setup perspective projection, with aspect ratio matches viewport gl.glMatrixMode(GL10.GL_PROJECTION); // Select projection matrix gl.glLoadIdentity(); // Reset projection matrix // Use perspective projection GLU.gluPerspective(gl, 45, aspect, 0.1f, 100.f); gl.glMatrixMode(GL10.GL_MODELVIEW); // Select model-view matrix gl.glLoadIdentity(); // Reset } public void onSurfaceCreated(GL10 gl, EGLConfig config) { // TODO Auto-generated method stub gl.glClearColor(0.0f, 0.0f, 0.0f, 1.0f); // Set color's clear-value to black gl.glClearDepthf(1.0f); // Set depth's clear-value to farthest gl.glEnable(GL10.GL_DEPTH_TEST); // Enables depth-buffer for hidden surface removal gl.glDepthFunc(GL10.GL_LEQUAL); // The type of depth testing to do gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_NICEST); // nice perspective view gl.glShadeModel(GL10.GL_SMOOTH); // Enable smooth shading of color gl.glDisable(GL10.GL_DITHER); // Disable dithering for better performance }} public class Cuboid{ private FloatBuffer mVertexBuffer; private FloatBuffer mColorBuffer; private ByteBuffer mIndexBuffer; private float vertices[] = { //width,height,depth -2.5f, -1.0f, -1.0f, 1.0f, -1.0f, -1.0f, 1.0f, 1.0f, -1.0f, -2.5f, 1.0f, -1.0f, -2.5f, -1.0f, 1.0f, 1.0f, -1.0f, 1.0f, 1.0f, 1.0f, 1.0f, -2.5f, 1.0f, 1.0f }; private float colors[] = { // R,G,B,A COLOR 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f, 0.5f, 0.0f, 1.0f, 1.0f, 0.5f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f, 0.0f, 1.0f, 1.0f }; private byte indices[] = { // VERTEX 0,1,2,3,4,5,6,7 REPRESENTATION FOR FACES 0, 4, 5, 0, 5, 1, 1, 5, 6, 1, 6, 2, 2, 6, 7, 2, 7, 3, 3, 7, 4, 3, 4, 0, 4, 7, 6, 4, 6, 5, 3, 0, 1, 3, 1, 2 }; public Cuboid() { ByteBuffer byteBuf = ByteBuffer.allocateDirect(vertices.length * 4); byteBuf.order(ByteOrder.nativeOrder()); mVertexBuffer = byteBuf.asFloatBuffer(); mVertexBuffer.put(vertices); mVertexBuffer.position(0); byteBuf = ByteBuffer.allocateDirect(colors.length * 4); byteBuf.order(ByteOrder.nativeOrder()); mColorBuffer = byteBuf.asFloatBuffer(); mColorBuffer.put(colors); mColorBuffer.position(0); mIndexBuffer = ByteBuffer.allocateDirect(indices.length); mIndexBuffer.put(indices); mIndexBuffer.position(0); } public void draw(GL10 gl) { gl.glFrontFace(GL10.GL_CW); gl.glVertexPointer(3, GL10.GL_FLOAT, 0, mVertexBuffer); gl.glColorPointer(4, GL10.GL_FLOAT, 0, mColorBuffer); gl.glEnableClientState(GL10.GL_VERTEX_ARRAY); gl.glEnableClientState(GL10.GL_COLOR_ARRAY); gl.glDrawElements(GL10.GL_TRIANGLES, 36, GL10.GL_UNSIGNED_BYTE, mIndexBuffer); gl.glDisableClientState(GL10.GL_VERTEX_ARRAY); gl.glDisableClientState(GL10.GL_COLOR_ARRAY); } } public class Draw3drect extends Activity { private GLSurfaceView glView; // Use GLSurfaceView // Call back when the activity is started, to initialize the view @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); glView = new GLSurfaceView(this); // Allocate a GLSurfaceView glView.setRenderer(new MyGLRenderer(this)); // Use a custom renderer this.setContentView(glView); // This activity sets to GLSurfaceView } // Call back when the activity is going into the background @Override protected void onPause() { super.onPause(); glView.onPause(); } // Call back after onPause() @Override protected void onResume() { super.onResume(); glView.onResume(); } }

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  • Extreme Optimization – Numerical Algorithm Support

    - by JoshReuben
    Function Delegates Many calculations involve the repeated evaluation of one or more user-supplied functions eg Numerical integration. The EO MathLib provides delegate types for common function signatures and the FunctionFactory class can generate new delegates from existing ones. RealFunction delegate - takes one Double parameter – can encapsulate most of the static methods of the System.Math class, as well as the classes in the Extreme.Mathematics.SpecialFunctions namespace: var sin = new RealFunction(Math.Sin); var result = sin(1); BivariateRealFunction delegate - takes two Double parameters: var atan2 = new BivariateRealFunction (Math.Atan2); var result = atan2(1, 2); TrivariateRealFunction delegate – represents a function takes three Double arguments ParameterizedRealFunction delegate - represents a function taking one Integer and one Double argument that returns a real number. The Pow method implements such a function, but the arguments need order re-arrangement: static double Power(int exponent, double x) { return ElementaryFunctions.Pow(x, exponent); } ... var power = new ParameterizedRealFunction(Power); var result = power(6, 3.2); A ComplexFunction delegate - represents a function that takes an Extreme.Mathematics.DoubleComplex argument and also returns a complex number. MultivariateRealFunction delegate - represents a function that takes an Extreme.Mathematics.LinearAlgebra.Vector argument and returns a real number. MultivariateVectorFunction delegate - represents a function that takes a Vector argument and returns a Vector. FastMultivariateVectorFunction delegate - represents a function that takes an input Vector argument and an output Matrix argument – avoiding object construction  The FunctionFactory class RealFromBivariateRealFunction and RealFromParameterizedRealFunction helper methods - transform BivariateRealFunction or a ParameterizedRealFunction into a RealFunction delegate by fixing one of the arguments, and treating this as a new function of a single argument. var tenthPower = FunctionFactory.RealFromParameterizedRealFunction(power, 10); var result = tenthPower(x); Note: There is no direct way to do this programmatically in C# - in F# you have partial value functions where you supply a subset of the arguments (as a travelling closure) that the function expects. When you omit arguments, F# generates a new function that holds onto/remembers the arguments you passed in and "waits" for the other parameters to be supplied. let sumVals x y = x + y     let sumX = sumVals 10     // Note: no 2nd param supplied.     // sumX is a new function generated from partially applied sumVals.     // ie "sumX is a partial application of sumVals." let sum = sumX 20     // Invokes sumX, passing in expected int (parameter y from original)  val sumVals : int -> int -> int val sumX : (int -> int) val sum : int = 30 RealFunctionsToVectorFunction and RealFunctionsToFastVectorFunction helper methods - combines an array of delegates returning a real number or a vector into vector or matrix functions. The resulting vector function returns a vector whose components are the function values of the delegates in the array. var funcVector = FunctionFactory.RealFunctionsToVectorFunction(     new MultivariateRealFunction(myFunc1),     new MultivariateRealFunction(myFunc2));  The IterativeAlgorithm<T> abstract base class Iterative algorithms are common in numerical computing - a method is executed repeatedly until a certain condition is reached, approximating the result of a calculation with increasing accuracy until a certain threshold is reached. If the desired accuracy is achieved, the algorithm is said to converge. This base class is derived by many classes in the Extreme.Mathematics.EquationSolvers and Extreme.Mathematics.Optimization namespaces, as well as the ManagedIterativeAlgorithm class which contains a driver method that manages the iteration process.  The ConvergenceTest abstract base class This class is used to specify algorithm Termination , convergence and results - calculates an estimate for the error, and signals termination of the algorithm when the error is below a specified tolerance. Termination Criteria - specify the success condition as the difference between some quantity and its actual value is within a certain tolerance – 2 ways: absolute error - difference between the result and the actual value. relative error is the difference between the result and the actual value relative to the size of the result. Tolerance property - specify trade-off between accuracy and execution time. The lower the tolerance, the longer it will take for the algorithm to obtain a result within that tolerance. Most algorithms in the EO NumLib have a default value of MachineConstants.SqrtEpsilon - gives slightly less than 8 digits of accuracy. ConvergenceCriterion property - specify under what condition the algorithm is assumed to converge. Using the ConvergenceCriterion enum: WithinAbsoluteTolerance / WithinRelativeTolerance / WithinAnyTolerance / NumberOfIterations Active property - selectively ignore certain convergence tests Error property - returns the estimated error after a run MaxIterations / MaxEvaluations properties - Other Termination Criteria - If the algorithm cannot achieve the desired accuracy, the algorithm still has to end – according to an absolute boundary. Status property - indicates how the algorithm terminated - the AlgorithmStatus enum values:NoResult / Busy / Converged (ended normally - The desired accuracy has been achieved) / IterationLimitExceeded / EvaluationLimitExceeded / RoundOffError / BadFunction / Divergent / ConvergedToFalseSolution. After the iteration terminates, the Status should be inspected to verify that the algorithm terminated normally. Alternatively, you can set the ThrowExceptionOnFailure to true. Result property - returns the result of the algorithm. This property contains the best available estimate, even if the desired accuracy was not obtained. IterationsNeeded / EvaluationsNeeded properties - returns the number of iterations required to obtain the result, number of function evaluations.  Concrete Types of Convergence Test classes SimpleConvergenceTest class - test if a value is close to zero or very small compared to another value. VectorConvergenceTest class - test convergence of vectors. This class has two additional properties. The Norm property specifies which norm is to be used when calculating the size of the vector - the VectorConvergenceNorm enum values: EuclidianNorm / Maximum / SumOfAbsoluteValues. The ErrorMeasure property specifies how the error is to be measured – VectorConvergenceErrorMeasure enum values: Norm / Componentwise ConvergenceTestCollection class - represent a combination of tests. The Quantifier property is a ConvergenceTestQuantifier enum that specifies how the tests in the collection are to be combined: Any / All  The AlgorithmHelper Class inherits from IterativeAlgorithm<T> and exposes two methods for convergence testing. IsValueWithinTolerance<T> method - determines whether a value is close to another value to within an algorithm's requested tolerance. IsIntervalWithinTolerance<T> method - determines whether an interval is within an algorithm's requested tolerance.

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  • Changing the sequencing strategy for File/Ftp Adapter

    - by [email protected]
    The File/Ftp Adapter allows the user to configure the outbound write to use a sequence number. For example, if I choose address-data_%SEQ%.txt as the FileNamingConvention, then all my files would be generated as address-data_1.txt, address-data_2.txt,...and so on. But, where does this sequence number come from? The answer lies in the "control directory" for the particular adapter project(or scenario). In general, for every project that use the File or Ftp Adapter, a unique directory is created for book keeping purposes. And since this control directory is required to be unique, the adapter uses a digest to make sure that no two control directories are the same. For example, for my FlatStructure sample, the control information for my project would go under FMW_HOME/user_projects/domains/soainfra/fileftp/controlFiles/[DIGEST]/outbound where the value of DIGEST would differ from one project to another. If you look under this directory, you will see a file control_ob.properties and this is where the sequence number is maintained. Please note that the sequence number is maintained in binary form and you hence you might need a hex editor to view its content. You will also see another zero byte file, SEQ_nnn, but, ignore that for now. We'll get to it some other time. For now, please remember that this extra file is maintained as a backup. One of the challenges faced by the adapter runtime is to guard all writes to the control files so no two threads inadverently try to update them at the same time. And, it does so with the help of a "Mutex". For now, please remember that the mutex comes in different flavors: In-memory DB-based Coherence-based User-defined Again, we will talk about these mutexes some other time. Please note that there might be scenarios, particularly under heavy load, where the mutex might become a bottleneck. The adapter, however,  allows you to change the configuration so that the adapter sequence value comes from a database sequence or a stored procedure and in such situation, the mutex is acually by-passed and thereby resulting in better throughputs. In later releases, the behavior of the adapter would be defaulted to use a db-sequence.  The simplest way to achieve this is by switching your JNDI for the outbound JCA file to use "eis/HAFileAdapter" as shown   But, what does this do? Internally, the adapter runtime creates a sequence on the oracle database. For example, if you do a "select * from user_sequences" in your soa-infra schema, you will see a new sequence being created with name as SEQ_<GUID>__ where the GUID will differ from one project to another. However, if you want to use your own sequence, then it would require you to add a new property to your JCA file called SequenceName as shown below. Please note that you will need to create this sequence on your soainfra schema beforehand.     But, what if we use DB2 or MSSQL Server as the dehydration support? DB2 supports sequences natively but MSSQL Server does not. So, the adapter runtime uses a natively generated sequence for DB2, but, for MSSQL server, the adapter relies on a stored procedure that ships with the product. If you wish to achieve the same result for SOA Suite running DB2 as the dehydration store, simply change your connection factory JNDI name in the JCA file to eis/HAFileAdapterDB2 and for MSSQL, please use eis/HAFileAdapterMSSQL. And, if you wish to use a stored procedure other than the one that ships with the product, you will need to rely on binding properties to override the adapter behavior. Particularly, you will need to instruct the adapter that you wish to use a stored procedure as shown:       Please note that if you're using the File/Ftp Adapter in Append mode, then the adapter runtime degrades the mutex to use pessimistic locks as we don't want writers from different nodes to append to the same file at the same time.                    

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  • How To Get Web Site Thumbnail Image In ASP.NET

    - by SAMIR BHOGAYTA
    Overview One very common requirement of many web applications is to display a thumbnail image of a web site. A typical example is to provide a link to a dynamic website displaying its current thumbnail image, or displaying images of websites with their links as a result of search (I love to see it on Google). Microsoft .NET Framework 2.0 makes it quite easier to do it in a ASP.NET application. Background In order to generate image of a web page, first we need to load the web page to get their html code, and then this html needs to be rendered in a web browser. After that, a screen shot can be taken easily. I think there is no easier way to do this. Before .NET framework 2.0 it was quite difficult to use a web browser in C# or VB.NET because we either have to use COM+ interoperability or third party controls which becomes headache later. WebBrowser control in .NET framework 2.0 In .NET framework 2.0 we have a new Windows Forms WebBrowser control which is a wrapper around old shwdoc.dll. All you really need to do is to drop a WebBrowser control from your Toolbox on your form in .NET framework 2.0. If you have not used WebBrowser control yet, it's quite easy to use and very consistent with other Windows Forms controls. Some important methods of WebBrowser control are. public bool GoBack(); public bool GoForward(); public void GoHome(); public void GoSearch(); public void Navigate(Uri url); public void DrawToBitmap(Bitmap bitmap, Rectangle targetBounds); These methods are self explanatory with their names like Navigate function which redirects browser to provided URL. It also has a number of useful overloads. The DrawToBitmap (inherited from Control) draws the current image of WebBrowser to the provided bitmap. Using WebBrowser control in ASP.NET 2.0 The Solution Let's start to implement the solution which we discussed above. First we will define a static method to get the web site thumbnail image. public static Bitmap GetWebSiteThumbnail(string Url, int BrowserWidth, int BrowserHeight, int ThumbnailWidth, int ThumbnailHeight) { WebsiteThumbnailImage thumbnailGenerator = new WebsiteThumbnailImage(Url, BrowserWidth, BrowserHeight, ThumbnailWidth, ThumbnailHeight); return thumbnailGenerator.GenerateWebSiteThumbnailImage(); } The WebsiteThumbnailImage class will have a public method named GenerateWebSiteThumbnailImage which will generate the website thumbnail image in a separate STA thread and wait for the thread to exit. In this case, I decided to Join method of Thread class to block the initial calling thread until the bitmap is actually available, and then return the generated web site thumbnail. public Bitmap GenerateWebSiteThumbnailImage() { Thread m_thread = new Thread(new ThreadStart(_GenerateWebSiteThumbnailImage)); m_thread.SetApartmentState(ApartmentState.STA); m_thread.Start(); m_thread.Join(); return m_Bitmap; } The _GenerateWebSiteThumbnailImage will create a WebBrowser control object and navigate to the provided Url. We also register for the DocumentCompleted event of the web browser control to take screen shot of the web page. To pass the flow to the other controls we need to perform a method call to Application.DoEvents(); and wait for the completion of the navigation until the browser state changes to Complete in a loop. private void _GenerateWebSiteThumbnailImage() { WebBrowser m_WebBrowser = new WebBrowser(); m_WebBrowser.ScrollBarsEnabled = false; m_WebBrowser.Navigate(m_Url); m_WebBrowser.DocumentCompleted += new WebBrowserDocument CompletedEventHandler(WebBrowser_DocumentCompleted); while (m_WebBrowser.ReadyState != WebBrowserReadyState.Complete) Application.DoEvents(); m_WebBrowser.Dispose(); } The DocumentCompleted event will be fired when the navigation is completed and the browser is ready for screen shot. We will get screen shot using DrawToBitmap method as described previously which will return the bitmap of the web browser. Then the thumbnail image is generated using GetThumbnailImage method of Bitmap class passing it the required thumbnail image width and height. private void WebBrowser_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e) { WebBrowser m_WebBrowser = (WebBrowser)sender; m_WebBrowser.ClientSize = new Size(this.m_BrowserWidth, this.m_BrowserHeight); m_WebBrowser.ScrollBarsEnabled = false; m_Bitmap = new Bitmap(m_WebBrowser.Bounds.Width, m_WebBrowser.Bounds.Height); m_WebBrowser.BringToFront(); m_WebBrowser.DrawToBitmap(m_Bitmap, m_WebBrowser.Bounds); m_Bitmap = (Bitmap)m_Bitmap.GetThumbnailImage(m_ThumbnailWidth, m_ThumbnailHeight, null, IntPtr.Zero); } One more example here : http://www.codeproject.com/KB/aspnet/Website_URL_Screenshot.aspx

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  • Oracle Fusion Middleware 11g next launch phase - what a week of product releases! Feedback from our

    - by Jürgen Kress
      Product releases: SOA Suite 11gR1 Patch Set 2 (PS2) BPM Suite 11gR1 Released Oracle JDeveloper 11g (11.1.1.3.0) (Build 5660) Oracle WebLogic Server 11gR1 (10.3.3) Oracle JRockit (4.0) Oracle Tuxedo 11gR1 (11.1.1.1.0) Enterprise Manager 11g Grid Control Release 1 (11.1.0.1.0) for Linux x86/x86-64 All Oracle Fusion Middleware 11gR1 Software Download   BPM Suite 11gR1 Released by Manoj Das Oracle BPM Suite 11gR1 became available for download from OTN and eDelivery. If you have been following our plans in this area, you know that this is the release unifying BEA ALBPM product, which became Oracle BPM10gR3, with the Oracle stack. Some of the highlights of this release are: BPMN 2.0 modeling and simulation Web based Process Composer for BPMN and Rules authoring Zero-code environment with full access to Oracle SOA Suite’s rich set of application and other adapters Process Spaces – Out-of-box integration with Web Center Suite Process Analytics – Native process cubes as well as integration with Oracle BAM You can learn more about this release from the documentation. Notes about downloading and installing Please note that Oracle BPM Suite 11gR1 is delivered and installed as part of SOA 11.1.1.3.0, which is a sparse release (only incremental patch). To install: Download and install SOA 11.1.1.2.0, which is a full release (you can find the bits at the above location) Download and install SOA 11.1.1.3.0 During configure step (using the Fusion Middleware configuration wizard), use the Oracle Business Process Management template supplied with the SOA Suite11g (11.1.1.3.0) If you plan to use Process Spaces, also install Web Center 11.1.1.3.0, which also is delivered as a sparse release and needs to be installed on top of Web Center 11.1.1.2.0   SOA Suite 11gR1 Patch Set 2 (PS2) released by Demed L'Her We just released SOA Suite 11gR1 Patch Set 2 (PS2)! You can download it as usual from: OTN (main platforms only) eDelivery (all platforms) 11gR1 PS2 is delivered as a sparse installer, that is to say that it is meant to be applied on the latest full install (11gR1 PS1). That’s great for existing PS1 users who simply need to apply the patch and run the patch assistant – but an extra step for new users who will first need to download SOA Suite 11gR1 PS1 (in addition to the PS2 patch). What’s in that release? Bug fixes of course but also several significant new features. Here is a short selection of the most significant ones: Spring component (for native Java extensibility and integration) SOA Partitions (to organize and manage your composites) Direct Binding (for transactional invocations to and from Oracle Service Bus) HTTP binding (for those of you trying to do away with SOAP and looking for simple GET and POST) Resequencer (for ordering out-of-order messages) WS Atomic Transactions (WS-AT) support (for propagation of transactions across heterogeneous environments) Check out the complete list of new features in PS2 for more (including links to the documentation for the above)! But maybe even more importantly we are also releasing Oracle Service Bus 11gR1 and BPM Suite 11gR1 at the same time – all on the same base platform (WebLogic Server 10.3.3)! (NB: it might take a while for all pages and caches to be updated with the new content so if you don’t find what you need today, try again soon!)   Are you Systems Integrations and Independent Software Vendors ready to adopt and to deliver? Make sure that you become trained: Local training calendars Register for the SOA Partner Community & Webcast www.oracle.com/goto/emea/soa What is your feedback?  Who installed the software? please feel free to share your experience at http://twitter.com/soacommunity #soacommunity Technorati Tags: SOA partner community ACE Directoris SOA Suite PS2 BPM11g First feedback from our ACE Directors and key Partners:   Now, these are great times to start the journey into BPM! Hajo Normann Reuse of components across the Oracle 11G Fusion Middleware stack, BPM just is one of the components plugging into the stack and reuses all other components. Mr. Leon Smiers With BPM11g, Oracle offers a very competitive product which will have a big effect on the IT market. Guido Schmutz We have real BPMN 2.0, which get's executed. No more transformation from business models to executable models - just press the run button... Torsten Winterberg Oracle BPM Suite 11g brings Out-of-box integration with WebCenter Suite and Oracle ADF development framework. Andrejus Baranovskis With the release of BPM Suite 11g, Oracle has defined new standards for Business Process platforms. Geoffroy de Lamalle With User Messaging Service you can let Soa Suite 11g do all your Messaging Edwin Biemond

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  • More Quick Interview Tips

    - by Ajarn Mark Caldwell
    In the last couple of years I have conducted a lot of interviews for application and database developers for my company, and I can tell you that the little things can mean a lot.  Here are a few quick tips to help you make a good first impression. A year ago I gave you my #1 interview tip: Do some basic research!  And a year later, I am still stunned by how few technical people do the most basic of research.  I can only guess that it is because it is so engrained in our psyche that technical competence is everything (see How to Manage Technical Employees for more on this idea) that we forget or ignore the importance of soft skills and the art of the interview.  Or maybe it is because we have heard the stories of the uber-geek who has zero personal skills but still makes a fortune working for Microsoft.  Well, here’s another quick tip:  You’re probably not as good as he is; and a large number of companies actually run small to medium sized teams and can’t really afford to have the social outcast in the group.  In a small team, everyone has to get along well, and that’s an important part of what I’m evaluating during the interview process. My #2 tip is to act alive!  I typically conduct screening interviews by phone before I bring someone in for an in-person.  I don’t care how laid-back you are or if you have a “quiet personality”, when we are talking, ACT like you are happy I called and you are interested in getting the job.  If you sound like you are bored-to-death and that you would be perfectly happy to never work again, I am perfectly happy to help you attain that goal, and I’ll move on to the next candidate. And closely related to #2, perhaps we’ll call it #2.1 is this tip:  When I call you on the phone for the interview, don’t answer your phone by just saying, “Hello”.  You know that the odds are about 999-to-1 that it is me calling for the interview because we have specifically arranged this time slot for the call.  And you can see on the caller ID that it is not one of your buddies calling, so identify yourself.  Don’t make me question whether I dialed the right number.  Answer your phone with a, “Hello, this is ___<your full name preferred, but at least your first name>___.”.  And when I say, “Hi, <your name>, this is Mark from <my company>” it would be really nice to hear you say, “Hi, Mark, I have been expecting your call.”  This sets the perfect tone for our conversation.  I know I have the right person; you are professional enough and interested enough in the job or contract to remember your appointments; and now we can move on to a little intro segment and get on with the reason for our call. As crazy as it sounds, I’ve actually had phone interviews that went like this: <Ring…> You:  “Hello?” Me:  “Hi, this is Mark from _______” You:  “Yeah?” Me:  “Is this <your name>?” You:  “Yeah.” Me:  “I had this time in my calendar for us to talk…were you expecting my call?” You:  “Oh, yeah, sure…” I used to be nice and would try to go ahead with the interview even after this bad start, thinking I was giving the candidate the benefit of the doubt…a second chance…but more often than not it was a struggle and 10 minutes into what was supposed to be a 45-minute call, I’m looking for a way to hang up without being rude myself.  It never worked out.  I never brought that person in for an in-person interview, much less offered them the job or contract.  Who knows, maybe they were some sort of wunderkind that we missed out on.  What I know is that they would never fit in with the rest of the team, and around here that is absolutely critical. So, in conclusion… Act alive!  Identify yourself!  And do at least the very basic of research.

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  • 12c??? - Active Data Guard Far Sync

    - by Jian Zhang(??)
    ?? ================ Active Data Guard Far Sync?Oracle 12c????(???Far Sync Standby),Far Sync?????????????(Primary Database)?????????Far Sync??,??(Primary Database) ??(synchronous)??redo?Far Sync??,??Far Sync????redo??(asynchronous)???????(Standby Database)???????????????????????Far Sync????????,init?????????,???????? ??redo ????Maximum Availability??,???????????(Primary Database)?????????Far Sync??,??(Primary Database)??(synchronous)??redo?Far Sync??,???????(zero data loss),?????Far Sync????,??????,??????????????Far Sync????redo??(asynchronous)???????(Standby Database)? ??redo ????Maximum Performance??,???????????(Primary Database)?????????Far Sync??,??(Primary Database) ????redo?Far Sync??,??Far Sync???????redo?????????(Standby Database)????????????????(Standby Database)??redo???(offload)? Far Sync????Data Guard ????(role transitions)????,?switchover/failover?????12c????? ???????Data Guard ????,?switchover/failover,???????????????Far Sync??,??Far Sync???????????????????? ???Far Sync???????,??????????????2?Far Sync??,???????? ???????Far Sync????? Far Sync??? ================ ????Far Sync ================ 1. ??Data Guard,???11.2??,??????«Active Database Duplication for A standby database» 2. ????Far Sync??,Far Sync????????,init?????????,???????? ??Far Sync???????,?????: SQL> ALTER DATABASE CREATE FAR SYNC INSTANCE CONTROLFILE AS '/tmp/controlfs01.ctl'; 3. ????redo?????Far Sync??,????LOG_ARCHIVE_DEST_2??: LOG_ARCHIVE_DEST_2='SERVICE=dg12cfs SYNC AFFIRM MAX_FAILURE=1 ALTERNATE=LOG_ARCHIVE_DEST_3 VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=dg12cfs' 4. ??Far Sync??????redo???,??Far Sync??LOG_ARCHIVE_DEST_2??: LOG_ARCHIVE_DEST_2='SERVICE=dg12cs ASYNC VALID_FOR=(STANDBY_LOGFILES,STANDBY_ROLE) DB_UNIQUE_NAME=dg12cs' 5. ????Far Sync???????,??????????????2?Far Sync??? 6. ???????: SQL> select * from  V$DATAGUARD_CONFIG; DB_UNIQUE_NAME       PARENT_DBUN       DEST_ROLE         CURRENT_SCN     CON_ID ------------------------------ ------------------------------     ----------------- ----------- ---------- dg12cfs                        dg12cp          FAR SYNC INSTANCE      682995          0 dg12cs                         dg12cfs         PHYSICAL STANDBY       682995          0 dg12cp                        NONE             PRIMARY DATABASE      683138          0 ????????????????:Oracle_12c_Active_Data_Guard_Far_Sync_v1.pdf

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  • Collision Detection, player correction

    - by DoomStone
    I am having some problems with collision detection, I have 2 types of objects excluding the player. Tiles and what I call MapObjects. The tiles are all 16x16, where the MapObjects can be any size, but in my case they are all 16x16. When my player runs along the mapobjects or tiles, it get verry jaggy. The player is unable to move right, and will get warped forward when moving left. I have found the problem, and that is my collision detection will move the player left/right if colliding the object from the side, and up/down if collision from up/down. Now imagine that my player is sitting on 2 tiles, at (10,12) and (11,12), and the player is mostly standing on the (11,12) tile. The collision detection will first run on then (10,12) tile, it calculates the collision depth, and finds that is is a collision from the side, and therefore move the object to the right. After, it will do the collision detection with (11,12) and it will move the character up. So the player will not fall down, but are unable to move right. And when moving left, the same problem will make the player warp forward. This problem have been bugging me for a few days now, and I just can't find a solution! Here is my code that does the collision detection. public void ApplyObjectCollision(IPhysicsObject obj, List<IComponent> mapObjects, TileMap map) { PhysicsVariables physicsVars = GetPhysicsVariables(); Rectangle bounds = ((IComponent)obj).GetBound(); int leftTile = (int)Math.Floor((float)bounds.Left / map.GetTileSize()); int rightTile = (int)Math.Ceiling(((float)bounds.Right / map.GetTileSize())) - 1; int topTile = (int)Math.Floor((float)bounds.Top / map.GetTileSize()); int bottomTile = (int)Math.Ceiling(((float)bounds.Bottom / map.GetTileSize())) - 1; // Reset flag to search for ground collision. obj.IsOnGround = false; // For each potentially colliding tile, for (int y = topTile; y <= bottomTile; ++y) { for (int x = leftTile; x <= rightTile; ++x) { IComponent tile = map.Get(x, y); if (tile != null) { bounds = HandelCollision(obj, tile, bounds, physicsVars); } } } // Handel collision for all Moving objects foreach (IComponent mo in mapObjects) { if (mo == obj) continue; if (mo.GetBound().Intersects(((IComponent)obj).GetBound())) { bounds = HandelCollision(obj, mo, bounds, physicsVars); } } } private Rectangle HandelCollision(IPhysicsObject obj, IComponent objb, Rectangle bounds, PhysicsVaraibales physicsVars) { // If this tile is collidable, SpriteCollision collision = ((IComponent)objb).GetCollisionType(); if (collision != SpriteCollision.Passable) { // Determine collision depth (with direction) and magnitude. Rectangle tileBounds = ((IComponent)objb).GetBound(); Vector2 depth = bounds.GetIntersectionDepth(tileBounds); if (depth != Vector2.Zero) { float absDepthX = Math.Abs(depth.X); float absDepthY = Math.Abs(depth.Y); // Resolve the collision along the shallow axis. if (absDepthY <= absDepthX || collision == SpriteCollision.Platform) { // If we crossed the top of a tile, we are on the ground. if (obj.PreviousBound.Bottom <= tileBounds.Top) obj.IsOnGround = true; // Ignore platforms, unless we are on the ground. if (collision == SpriteCollision.Impassable || obj.IsOnGround) { // Resolve the collision along the Y axis. ((IComponent)obj).Position = new Vector2(((IComponent)obj).Position.X, ((IComponent)obj).Position.Y + depth.Y); // If we hit something about us, remove all velosity upwards if (depth.Y > 0 && obj.IsJumping) { obj.Velocity = new Vector2(obj.Velocity.X, 0); obj.JumpTime = physicsVars.MaxJumpTime; } // Perform further collisions with the new bounds. return ((IComponent)obj).GetBound(); } } else if (collision == SpriteCollision.Impassable) // Ignore platforms. { // Resolve the collision along the X axis. ((IComponent)obj).Position = new Vector2(((IComponent)obj).Position.X + depth.X, ((IComponent)obj).Position.Y); // Perform further collisions with the new bounds. return ((IComponent)obj).GetBound(); } } } return bounds; } Update: I have uploaded the source code, if you want to look that through. I think that my general approach might be wrong when i am working with small tiles, I have also be unable to find any good information on physics and collision detection in Platform games. http://dl.dropbox.com/u/3181816/Sogaard.Games.SuperMario.rar

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  • Subterranean IL: Generics and array covariance

    - by Simon Cooper
    Arrays in .NET are curious beasts. They are the only built-in collection types in the CLR, and SZ-arrays (single dimension, zero-indexed) have their own commands and IL syntax. One of their stranger properties is they have a kind of built-in covariance long before generic variance was added in .NET 4. However, this causes a subtle but important problem with generics. First of all, we need to briefly recap on array covariance. SZ-array covariance To demonstrate, I'll tweak the classes I introduced in my previous posts: public class IncrementableClass { public int Value; public virtual void Increment(int incrementBy) { Value += incrementBy; } } public class IncrementableClassx2 : IncrementableClass { public override void Increment(int incrementBy) { base.Increment(incrementBy); base.Increment(incrementBy); } } In the CLR, SZ-arrays of reference types are implicitly convertible to arrays of the element's supertypes, all the way up to object (note that this does not apply to value types). That is, an instance of IncrementableClassx2[] can be used wherever a IncrementableClass[] or object[] is required. When an SZ-array could be used in this fashion, a run-time type check is performed when you try to insert an object into the array to make sure you're not trying to insert an instance of IncrementableClass into an IncrementableClassx2[]. This check means that the following code will compile fine but will fail at run-time: IncrementableClass[] array = new IncrementableClassx2[1]; array[0] = new IncrementableClass(); // throws ArrayTypeMismatchException These checks are enforced by the various stelem* and ldelem* il instructions in such a way as to ensure you can't insert a IncrementableClass into a IncrementableClassx2[]. For the rest of this post, however, I'm going to concentrate on the ldelema instruction. ldelema This instruction pops the array index (int32) and array reference (O) off the stack, and pushes a pointer (&) to the corresponding array element. However, unlike the ldelem instruction, the instruction's type argument must match the run-time array type exactly. This is because, once you've got a managed pointer, you can use that pointer to both load and store values in that array element using the ldind* and stind* (load/store indirect) instructions. As the same pointer can be used for both input and output to the array, the type argument to ldelema must be invariant. At the time, this was a perfectly reasonable restriction, and maintained array type-safety within managed code. However, along came generics, and with it the constrained callvirt instruction. So, what happens when we combine array covariance and constrained callvirt? .method public static void CallIncrementArrayValue() { // IncrementableClassx2[] arr = new IncrementableClassx2[1] ldc.i4.1 newarr IncrementableClassx2 // arr[0] = new IncrementableClassx2(); dup newobj instance void IncrementableClassx2::.ctor() ldc.i4.0 stelem.ref // IncrementArrayValue<IncrementableClass>(arr, 0) // here, we're treating an IncrementableClassx2[] as IncrementableClass[] dup ldc.i4.0 call void IncrementArrayValue<class IncrementableClass>(!!0[],int32) // ... ret } .method public static void IncrementArrayValue<(IncrementableClass) T>( !!T[] arr, int32 index) { // arr[index].Increment(1) ldarg.0 ldarg.1 ldelema !!T ldc.i4.1 constrained. !!T callvirt instance void IIncrementable::Increment(int32) ret } And the result: Unhandled Exception: System.ArrayTypeMismatchException: Attempted to access an element as a type incompatible with the array. at IncrementArrayValue[T](T[] arr, Int32 index) at CallIncrementArrayValue() Hmm. We're instantiating the generic method as IncrementArrayValue<IncrementableClass>, but passing in an IncrementableClassx2[], hence the ldelema instruction is failing as it's expecting an IncrementableClass[]. On features and feature conflicts What we've got here is a conflict between existing behaviour (ldelema ensuring type safety on covariant arrays) and new behaviour (managed pointers to object references used for every constrained callvirt on generic type instances). And, although this is an edge case, there is no general workaround. The generic method could be hidden behind several layers of assemblies, wrappers and interfaces that make it a requirement to use array covariance when calling the generic method. Furthermore, this will only fail at runtime, whereas compile-time safety is what generics were designed for! The solution is the readonly. prefix instruction. This modifies the ldelema instruction to ignore the exact type check for arrays of reference types, and so it lets us take the address of array elements using a covariant type to the actual run-time type of the array: .method public static void IncrementArrayValue<(IncrementableClass) T>( !!T[] arr, int32 index) { // arr[index].Increment(1) ldarg.0 ldarg.1 readonly. ldelema !!T ldc.i4.1 constrained. !!T callvirt instance void IIncrementable::Increment(int32) ret } But what about type safety? In return for ignoring the type check, the resulting controlled mutability pointer can only be used in the following situations: As the object parameter to ldfld, ldflda, stfld, call and constrained callvirt instructions As the pointer parameter to ldobj or ldind* As the source parameter to cpobj In other words, the only operations allowed are those that read from the pointer; stind* and similar that alter the pointer itself are banned. This ensures that the array element we're pointing to won't be changed to anything untoward, and so type safety within the array is maintained. This is a typical example of the maxim that whenever you add a feature to a program, you have to consider how that feature interacts with every single one of the existing features. Although an edge case, the readonly. prefix instruction ensures that generics and array covariance work together and that compile-time type safety is maintained. Tune in next time for a look at the .ctor generic type constraint, and what it means.

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  • Basic WCF Unit Testing

    - by Brian
    Coming from someone who loves the KISS method, I was surprised to find that I was making something entirely too complicated. I know, shocker right? Now I'm no unit testing ninja, and not really a WCF ninja either, but had a desire to test service calls without a) going to a database, or b) making sure that the entire WCF infrastructure was tip top. Who does? It's not the environment I want to test, just the logic I’ve written to ensure there aren't any side effects. So, for the K.I.S.S. method: Assuming that you're using a WCF service library (you are using service libraries correct?), it's really as easy as referencing the service library, then building out some stubs for bunking up data. The service contract We’ll use a very basic service contract, just for getting and updating an entity. I’ve used the default “CompositeType” that is in the template, handy only for examples like this. I’ve added an Id property and overridden ToString and Equals. [ServiceContract] public interface IMyService { [OperationContract] CompositeType GetCompositeType(int id); [OperationContract] CompositeType SaveCompositeType(CompositeType item); [OperationContract] CompositeTypeCollection GetAllCompositeTypes(); } The implementation When I implement the service, I want to be able to send known data into it so I don’t have to fuss around with database access or the like. To do this, I first have to create an interface for my data access: public interface IMyServiceDataManager { CompositeType GetCompositeType(int id); CompositeType SaveCompositeType(CompositeType item); CompositeTypeCollection GetAllCompositeTypes(); } For the purposes of this we can ignore our implementation of the IMyServiceDataManager interface inside of the service. Pretend it uses LINQ to Entities to map its data, or maybe it goes old school and uses EntLib to talk to SQL. Maybe it talks to a tape spool on a mainframe on the third floor. It really doesn’t matter. That’s the point. So here’s what our service looks like in its most basic form: public CompositeType GetCompositeType(int id) { //sanity checks if (id == 0) throw new ArgumentException("id cannot be zero."); return _dataManager.GetCompositeType(id); } public CompositeType SaveCompositeType(CompositeType item) { return _dataManager.SaveCompositeType(item); } public CompositeTypeCollection GetAllCompositeTypes() { return _dataManager.GetAllCompositeTypes(); } But what about the datamanager? The constructor takes care of that. I don’t want to expose any testing ability in release (or the ability for someone to swap out my datamanager) so this is what we get: IMyServiceDataManager _dataManager; public MyService() { _dataManager = new MyServiceDataManager(); } #if DEBUG public MyService(IMyServiceDataManager dataManager) { _dataManager = dataManager; } #endif The Stub Now it’s time for the rubber to meet the road… Like most guys that ever talk about unit testing here’s a sample that is painting in *very* broad strokes. The important part however is that within the test project, I’ve created a bunk (unit testing purists would say stub I believe) object that implements my IMyServiceDataManager so that I can deal with known data. Here it is: internal class FakeMyServiceDataManager : IMyServiceDataManager { internal FakeMyServiceDataManager() { Collection = new CompositeTypeCollection(); Collection.AddRange(new CompositeTypeCollection { new CompositeType { Id = 1, BoolValue = true, StringValue = "foo 1", }, new CompositeType { Id = 2, BoolValue = false, StringValue = "foo 2", }, new CompositeType { Id = 3, BoolValue = true, StringValue = "foo 3", }, }); } CompositeTypeCollection Collection { get; set; } #region IMyServiceDataManager Members public CompositeType GetCompositeType(int id) { if (id <= 0) return null; return Collection.SingleOrDefault(m => m.Id == id); } public CompositeType SaveCompositeType(CompositeType item) { var existing = Collection.SingleOrDefault(m => m.Id == item.Id); if (null != existing) { Collection.Remove(existing); } if (item.Id == 0) { item.Id = Collection.Count > 0 ? Collection.Max(m => m.Id) + 1 : 1; } Collection.Add(item); return item; } public CompositeTypeCollection GetAllCompositeTypes() { return Collection; } #endregion } So it’s tough to see in this example why any of this is necessary, but in a real world application you would/should/could be applying much more logic within your service implementation. This all serves to ensure that between refactorings etc, that it doesn’t send sparking cogs all about or let the blue smoke out. Here’s a simple test that brings it all home, remember, broad strokes: [TestMethod] public void MyService_GetCompositeType_ExpectedValues() { FakeMyServiceDataManager fake = new FakeMyServiceDataManager(); MyService service = new MyService(fake); CompositeType expected = fake.GetCompositeType(1); CompositeType actual = service.GetCompositeType(2); Assert.AreEqual<CompositeType>(expected, actual, "Objects are not equal. Expected: {0}; Actual: {1};", expected, actual); } Summary That’s really all there is to it. You could use software x or framework y to do the exact same thing, but in my case I just didn’t really feel like it. This speaks volumes to my not yet ninja unit testing prowess.

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  • The Joy Of Hex

    - by Jim Giercyk
    While working on a mainframe integration project, it occurred to me that some basic computer concepts are slipping into obscurity. For example, just about anyone can tell you that a 64-bit processor is faster than a 32-bit processer. A grade school child could tell you that a computer “speaks” in ‘1’s and ‘0’s. Some people can even tell you that there are 8 bits in a byte. However, I have found that even the most seasoned developers often can’t explain the theory behind those statements. That is not a knock on programmers; in the age of IntelliSense, what reason do we have to work with data at the bit level? Many computer theory classes treat bit-level programming as a thing of the past, no longer necessary now that storage space is plentiful. The trouble with that mindset is that the world is full of legacy systems that run programs written in the 1970’s.  Today our jobs require us to extract data from those systems, regardless of the format, and that often involves low-level programming. Because it seems knowledge of the low-level concepts is waning in recent times, I thought a review would be in order.       CHARACTER: See Spot Run HEX: 53 65 65 20 53 70 6F 74 20 52 75 6E DECIMAL: 83 101 101 32 83 112 111 116 32 82 117 110 BINARY: 01010011 01100101 01100101 00100000 01010011 01110000 01101111 01110100 00100000 01010010 01110101 01101110 In this example, I have broken down the words “See Spot Run” to a level computers can understand – machine language.     CHARACTER:  The character level is what is rendered by the computer.  A “Character Set” or “Code Page” contains 256 characters, both printable and unprintable.  Each character represents 1 BYTE of data.  For example, the character string “See Spot Run” is 12 Bytes long, exclusive of the quotation marks.  Remember, a SPACE is an unprintable character, but it still requires a byte.  In the example I have used the default Windows character set, ASCII, which you can see here:  http://www.asciitable.com/ HEX:  Hex is short for hexadecimal, or Base 16.  Humans are comfortable thinking in base ten, perhaps because they have 10 fingers and 10 toes; fingers and toes are called digits, so it’s not much of a stretch.  Computers think in Base 16, with numeric values ranging from zero to fifteen, or 0 – F.  Each decimal place has a possible 16 values as opposed to a possible 10 values in base 10.  Therefore, the number 10 in Hex is equal to the number 16 in Decimal.  DECIMAL:  The Decimal conversion is strictly for us humans to use for calculations and conversions.  It is much easier for us humans to calculate that [30 – 10 = 20] in decimal than it is for us to calculate [1E – A = 14] in Hex.  In the old days, an error in a program could be found by determining the displacement from the entry point of a module.  Since those values were dumped from the computers head, they were in hex. A programmer needed to convert them to decimal, do the equation and convert back to hex.  This gets into relative and absolute addressing, a topic for another day.  BINARY:  Binary, or machine code, is where any value can be expressed in 1s and 0s.  It is really Base 2, because each decimal place can have a possibility of only 2 characters, a 1 or a 0.  In Binary, the number 10 is equal to the number 2 in decimal. Why only 1s and 0s?  Very simply, computers are made up of lots and lots of transistors which at any given moment can be ON ( 1 ) or OFF ( 0 ).  Each transistor is a bit, and the order that the transistors fire (or not fire) is what distinguishes one value from  another in the computers head (or CPU).  Consider 32 bit vs 64 bit processing…..a 64 bit processor has the capability to read 64 transistors at a time.  A 32 bit processor can only read half as many at a time, so in theory the 64 bit processor should be much faster.  There are many more factors involved in CPU performance, but that is the fundamental difference.    DECIMAL HEX BINARY 0 0 0000 1 1 0001 2 2 0010 3 3 0011 4 4 0100 5 5 0101 6 6 0110 7 7 0111 8 8 1000 9 9 1001 10 A 1010 11 B 1011 12 C 1100 13 D 1101 14 E 1110 15 F 1111   Remember that each character is a BYTE, there are 2 HEX characters in a byte (called nibbles) and 8 BITS in a byte.  I hope you enjoyed reading about the theory of data processing.  This is just a high-level explanation, and there is much more to be learned.  It is safe to say that, no matter how advanced our programming languages and visual studios become, they are nothing more than a way to interpret bits and bytes.  There is nothing like the joy of hex to get the mind racing.

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  • Books are Dead! Long Live the Books!

    - by smisner
    We live in interesting times with regard to the availability of technical material. We have lots of free written material online in the form of vendor documentation online, forums, blogs, and Twitter. And we have written material that we can buy in the form of books, magazines, and training materials. Online videos and training – some free and some not free – are also an option. All of these formats are useful for one need or another. As an author, I pay particular attention to the demand for books, and for now I see no reason to stop authoring books. I assure you that I don’t get rich from the effort, and fortunately that is not my motivation. As someone who likes to refer to books frequently, I am still a big believer in books and have evidence from book sales that there are others like me. If I can do my part to help others learn about the technologies I work with, I will continue to produce content in a variety of formats, including books. (You can view a list of all of my books on the Publications page of my site and my online training videos at Pluralsight.) As a consumer of technical information, I prefer books because a book typically can get into a topic much more deeply than a blog post, and can provide more context than vendor documentation. It comes with a table of contents and a (hopefully accurate) index that helps me zero in on a topic of interest, and of course I can use the Search feature in digital form. Some people suggest that technology books are outdated as soon as they get published. I guess it depends on where you are with technology. Not everyone is able to upgrade to the latest and greatest version at release. I do assume, however, that the SQL Server 7.0 titles in my library have little value for me now, but I’m certain that the minute I discard the book, I’m going to want it for some reason! Meanwhile, as electronic books overtake physical books in sales, my husband is grateful that I can continue to build my collection digitally rather than physically as the books have a way of taking over significant square footage in our house! Blog posts, on the other hand, are useful for describing the scenarios that come up in real-life implementations that wouldn’t fit neatly into a book. As many years that I have working with the Microsoft BI stack, I still run into new problems that require creative thinking. Likewise, people who work with BI and other technologies that I use share what they learn through their blogs. Internet search engines help us find information in blogs that simply isn’t available anywhere else. Another great thing about blogs, also, is the connection to community and the dialog that can ensue between people with common interests. With the trend towards electronic formats for books, I imagine that we’ll see books continue to adapt to incorporate different forms of media and better ways to keep the information current. At the moment, I wish I had a better way to help readers with my last two Reporting Services books. In the case of the Microsoft® SQL Server™ 2005 Reporting Services Step by Step book, I have heard many cases of readers having problems with the sample database that shipped on CD – either the database was missing or it was corrupt. So I’ve provided a copy of the database on my site for download from http://datainspirations.com/uploads/rs2005sbsDW.zip. Then for the Microsoft® SQL Server™ 2008 Reporting Services Step by Step book, we decided to avoid the database problem by using the AdventureWorks2008 samples that Microsoft published on Codeplex (although code samples are still available on CD). We had this silly idea that the URL for the download would remain constant, but it seems that expectation was ill-founded. Currently, the sample database is found at http://msftdbprodsamples.codeplex.com/releases/view/37109 but I have no idea how long that will remain valid. My latest books (#9 and #10 which are milestones I never anticipated), Building Integrated Business Intelligence Solutions with SQL Server 2008 R2 and Office 2010 (McGraw Hill, 2011) and Business Intelligence in Microsoft SharePoint 2010 (Microsoft Press, 2011), will not ship with a CD, but will provide all code samples for download at a site maintained by the respective publishers. I expect that the URLs for the downloads for the book will remain valid, but there are lots of references to other sites that can change or disappear over time. Does that mean authors shouldn’t make reference to such sites? Personally, I think the benefits to be gained from including links are greater than the risks of the links becoming invalid at some point. Do you think the time for technology books has come to an end? Is the delivery of books in electronic format enough to keep them alive? If technological barriers were no object, what would make a book more valuable to you than other formats through which you can obtain information?

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  • How to draw textures on a model

    - by marc wellman
    The following code is a complete XNA 3.1 program almost unaltered to that code skeleton Visual Studio is creating when creating a new project. The only things I have changed are imported a .x model to the content folder of the VS solution. (the model is a simple square with a texture spanning over it - made in Google Sketchup and exported with several .x exporters) in the Load() method I am loading the .x model into the game. The Draw() method uses a BasicEffect to render the model. Except these three things I haven't added any code. Why does the model does not show the texture ? What can I do to make the texture visible ? This is the texture file (a standard SketchUp texture from the palette): And this is what my program looks like - as you can see: No texture! Find below the complete source code of the program AND the complete .x file: namespace WindowsGame1 { /// <summary> /// This is the main type for your game /// </summary> public class Game1 : Microsoft.Xna.Framework.Game { GraphicsDeviceManager graphics; SpriteBatch spriteBatch; public Game1() { graphics = new GraphicsDeviceManager(this); Content.RootDirectory = "Content"; } /// <summary> /// Allows the game to perform any initialization it needs to before starting to run. /// This is where it can query for any required services and load any non-graphic /// related content. Calling base.Initialize will enumerate through any components /// and initialize them as well. /// </summary> protected override void Initialize() { // TODO: Add your initialization logic here base.Initialize(); } Model newModel; /// <summary> /// LoadContent will be called once per game and is the place to load /// all of your content. /// </summary> protected override void LoadContent() { // Create a new SpriteBatch, which can be used to draw textures. spriteBatch = new SpriteBatch(GraphicsDevice); // TODO: usse this.Content to load your game content here newModel = Content.Load<Model>(@"aau3d"); foreach (ModelMesh mesh in newModel.Meshes) { foreach (ModelMeshPart meshPart in mesh.MeshParts) { meshPart.Effect = new BasicEffect(this.GraphicsDevice, null); } } } /// <summary> /// UnloadContent will be called once per game and is the place to unload /// all content. /// </summary> protected override void UnloadContent() { // TODO: Unload any non ContentManager content here } /// <summary> /// Allows the game to run logic such as updating the world, /// checking for collisions, gathering input, and playing audio. /// </summary> /// <param name="gameTime">Provides a snapshot of timing values.</param> protected override void Update(GameTime gameTime) { // Allows the game to exit if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed) this.Exit(); // TODO: Add your update logic here base.Update(gameTime); } /// <summary> /// This is called when the game should draw itself. /// </summary> /// <param name="gameTime">Provides a snapshot of timing values.</param> protected override void Draw(GameTime gameTime) { if (newModel != null) { GraphicsDevice.Clear(Color.CornflowerBlue); Matrix[] transforms = new Matrix[newModel.Bones.Count]; newModel.CopyAbsoluteBoneTransformsTo(transforms); foreach (ModelMesh mesh in newModel.Meshes) { foreach (BasicEffect effect in mesh.Effects) { effect.EnableDefaultLighting(); effect.TextureEnabled = true; effect.World = transforms[mesh.ParentBone.Index] * Matrix.CreateRotationY(0) * Matrix.CreateTranslation(new Vector3(0, 0, 0)); effect.View = Matrix.CreateLookAt(new Vector3(200, 1000, 200), Vector3.Zero, Vector3.Up); effect.Projection = Matrix.CreatePerspectiveFieldOfView(MathHelper.ToRadians(45.0f), 0.75f, 1.0f, 10000.0f); } mesh.Draw(); } } base.Draw(gameTime); } } } This is the model I am using (.x): xof 0303txt 0032 // SketchUp 6 -> DirectX (c)2008 edecadoudal, supports: faces, normals and textures Material Default_Material{ 1.0;1.0;1.0;1.0;; 3.2; 0.000000;0.000000;0.000000;; 0.000000;0.000000;0.000000;; } Material _Groundcover_RiverRock_4inch_{ 0.568627450980392;0.494117647058824;0.427450980392157;1.0;; 3.2; 0.000000;0.000000;0.000000;; 0.000000;0.000000;0.000000;; TextureFilename { "aau3d.xGroundcover_RiverRock_4inch.jpg"; } } Mesh mesh_0{ 4; -81.6535;0.0000;74.8031;, -0.0000;0.0000;0.0000;, -81.6535;0.0000;0.0000;, -0.0000;0.0000;74.8031;; 2; 3;0,1,2, 3;1,0,3;; MeshMaterialList { 2; 2; 1, 1; { Default_Material } { _Groundcover_RiverRock_4inch_ } } MeshTextureCoords { 4; -2.1168,-3.4022; 1.0000,-0.0000; 1.0000,-3.4022; -2.1168,-0.0000;; } MeshNormals { 4; 0.0000;1.0000;-0.0000; 0.0000;1.0000;-0.0000; 0.0000;1.0000;-0.0000; 0.0000;1.0000;-0.0000;; 2; 3;0,1,2; 3;1,0,3;; } }

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  • Session Report - Modern Software Development Anti-Patterns

    - by Janice J. Heiss
    In this standing-room-only session, building upon his 2011 JavaOne Rock Star “Diabolical Developer” session, Martijn Verburg, this time along with Ben Evans, identified and explored common “anti-patterns” – ways of doing things that keep developers from doing their best work. They emphasized the importance of social interaction and team communication, along with identifying certain psychological pitfalls that lead developers astray. Their emphasis was less on technical coding errors and more how to function well and to keep one’s focus on what really matters. They are the authors of the highly regarded The Well-Grounded Java Developer and are both movers and shakers in the London JUG community and on the Java Community Process. The large room was packed as they gave a fast-moving, witty presentation with lots of laughs and personal anecdotes. Below are a few of the anti-patterns they discussed.Anti-Pattern One: Conference-Driven DeliveryThe theme here is the belief that “Real pros hack code and write their slides minutes before their talks.” Their response to this anti-pattern is an expression popular in the military – PPPPPP, which stands for, “Proper preparation prevents piss-poor performance.”“Communication is very important – probably more important than the code you write,” claimed Verburg. “The more you speak in front of large groups of people the easier it gets, but it’s always important to do dry runs, to present to smaller groups. And important to be members of user groups where you can give presentations. It’s a great place to practice speaking skills; to gain new skills; get new contacts, to network.”They encouraged attendees to record themselves and listen to themselves giving a presentation. They advised them to start with a spouse or friends if need be. Learning to communicate to a group, they argued, is essential to being a successful developer. The emphasis here is that software development is a team activity and good, clear, accessible communication is essential to the functioning of software teams. Anti-Pattern Two: Mortgage-Driven Development The main theme here was that, in a period of worldwide recession and economic stagnation, people are concerned about keeping their jobs. So there is a tendency for developers to treat knowledge as power and not share what they know about their systems with their colleagues, so when it comes time to fix a problem in production, they will be the only one who knows how to fix it – and will have made themselves an indispensable cog in a machine so you cannot be fired. So developers avoid documentation at all costs, or if documentation is required, put it on a USB chip and lock it in a lock box. As in the first anti-pattern, the idea here is that communicating well with your colleagues is essential and documentation is a key part of this. Social interactions are essential. Both Verburg and Evans insisted that increasingly, year by year, successful software development is more about communication than the technical aspects of the craft. Developers who understand this are the ones who will have the most success. Anti-Pattern Three: Distracted by Shiny – Always Use the Latest Technology to Stay AheadThe temptation here is to pick out some obscure framework, try a bit of Scala, HTML5, and Clojure, and always use the latest technology and upgrade to the latest point release of everything. Don’t worry if something works poorly because you are ahead of the curve. Verburg and Evans insisted that there need to be sound reasons for everything a developer does. Developers should not bring in something simply because for some reason they just feel like it or because it’s new. They recommended a site run by a developer named Matt Raible with excellent comparison spread sheets regarding Web frameworks and other apps. They praised it as a useful tool to help developers in their decision-making processes. They pointed out that good developers sometimes make bad choices out of boredom, to add shiny things to their CV, out of frustration with existing processes, or just from a lack of understanding. They pointed out that some code may stay in a business system for 15 or 20 years, but not all code is created equal and some may change after 3 or 6 months. Developers need to know where the code they are contributing fits in. What is its likely lifespan? Anti-Pattern Four: Design-Driven Design The anti-pattern: If you want to impress your colleagues and bosses, use design patents left, right, and center – MVC, Session Facades, SOA, etc. Or the UML modeling suite from IBM, back in the day… Generate super fast code. And the more jargon you can talk when in the vicinity of the manager the better.Verburg shared a true story about a time when he was interviewing a guy for a job and asked him what his previous work was. The interviewee said that he essentially took patterns and uses an approved book of Enterprise Architecture Patterns and applied them. Verburg was dumbstruck that someone could have a job in which they took patterns from a book and applied them. He pointed out that the idea that design is a separate activity is simply wrong. He repeated a saying that he uses, “You should pay your junior developers for the lines of code they write and the things they add; you should pay your senior developers for what they take away.”He explained that by encouraging people to take things away, the code base gets simpler and reflects the actual business use cases developers are trying to solve, as opposed to the framework that is being imposed. He told another true story about a project to decommission a very long system. 98% of the code was decommissioned and people got a nice bonus. But the 2% remained on the mainframe so the 98% reduction in code resulted in zero reduction in costs, because the entire mainframe was needed to run the 2% that was left. There is an incentive to get rid of source code and subsystems when they are no longer needed. The session continued with several more anti-patterns that were equally insightful.

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  • Session Report - Java on the Raspberry Pi

    - by Janice J. Heiss
    On mid-day Wednesday, the always colorful Oracle Evangelist Simon Ritter demonstrated Java on the Raspberry Pi at his session, “Do You Like Coffee with Your Dessert?”. The Raspberry Pi consists of a credit card-sized single-board computer developed in the UK with the intention of stimulating the teaching of basic computer science in schools. “I don't think there is a single feature that makes the Raspberry Pi significant,” observed Ritter, “but a combination of things really makes it stand out. First, it's $35 for what is effectively a completely usable computer. You do have to add a power supply, SD card for storage and maybe a screen, keyboard and mouse, but this is still way cheaper than a typical PC. The choice of an ARM (Advanced RISC Machine and Acorn RISC Machine) processor is noteworthy, because it avoids problems like cooling (no heat sink or fan) and can use a USB power brick. When you add in the enormous community support, it offers a great platform for teaching everyone about computing.”Some 200 enthusiastic attendees were present at the session which had the feel of Simon Ritter sharing a fun toy with friends. The main point of the session was to show what Oracle was doing to support Java on the Raspberry Pi in a way that is entertaining and fun. Ritter pointed out that, in addition to being great for teaching, it’s an excellent introduction to the ARM architecture, and runs well with Java and will get better once it has official hard float support. The possibilities are vast.Ritter explained that the Raspberry Pi Project started in 2006 with the goal of devising a computer to inspire children; it drew inspiration from the BBC Micro literacy project of 1981 that produced a series of microcomputers created by the Acorn Computer company. It was officially launched on February 29, 2012, with a first production of 10,000 boards. There were 100,000 pre-orders in one day; currently about 4,000 boards are produced a day. Ritter described the specification as follows:* CPU: ARM 11 core running at 700MHz Broadcom SoC package Can now be overclocked to 1GHz (without breaking the warranty!) * Memory: 256Mb* I/O: HDMI and composite video 2 x USB ports (Model B only) Ethernet (Model B only) Header pins for GPIO, UART, SPI and I2C He took attendees through a brief history of ARM Architecture:* Acorn BBC Micro (6502 based) Not powerful enough for Acorn’s plans for a business computer * Berkeley RISC Project UNIX kernel only used 30% of instruction set of Motorola 68000 More registers, less instructions (Register windows) One chip architecture to come from this was… SPARC * Acorn RISC Machine (ARM) 32-bit data, 26-bit address space, 27 registers First machine was Acorn Archimedes * Spin off from Acorn, Advanced RISC MachinesNext he presented its features:* 32-bit RISC Architecture–  ARM accounts for 75% of embedded 32-bit CPUs today– 6.1 Billion chips sold last year (zero manufactured by ARM)* Abstract architecture and microprocessor core designs– Raspberry Pi is ARM11 using ARMv6 instruction set* Low power consumption– Good for mobile devices– Raspberry Pi can be powered from 700mA 5V only PSU– Raspberry Pi does not require heatsink or fanHe described the current ARM Technology:* ARMv6– ARM 11, ARM Cortex-M* ARMv7– ARM Cortex-A, ARM Cortex-M, ARM Cortex-R* ARMv8 (Announced)– Will support 64-bit data and addressingHe next gave the Java Specifics for ARM: Floating point operations* Despite being an ARMv6 processor it does include an FPU– FPU only became standard as of ARMv7* FPU (Hard Float, or HF) is much faster than a software library* Linux distros and Oracle JVM for ARM assume no HF on ARMv6– Need special build of both– Raspbian distro build now available– Oracle JVM is in the works, release date TBDNot So RISCPerformance Improvements* DSP Enhancements* Jazelle* Thumb / Thumb2 / ThumbEE* Floating Point (VFP)* NEON* Security Enhancements (TrustZone)He spent a few minutes going over the challenges of using Java on the Raspberry Pi and covered:* Sound* Vision * Serial (TTL UART)* USB* GPIOTo implement sound with Java he pointed out:* Sound drivers are now included in new distros* Java Sound API– Remember to add audio to user’s groups– Some bits work, others not so much* Playing (the right format) WAV file works* Using MIDI hangs trying to open a synthesizer* FreeTTS text-to-speech– Should work once sound works properlyHe turned to JavaFX on the Raspberry Pi:* Currently internal builds only– Will be released as technology preview soon* Work involves optimal implementation of Prism graphics engine– X11?* Once the JavaFX implementation is completed there will be little of concern to developers-- It’s just Java (WORA). He explained the basis of the Serial Port:* UART provides TTL level signals (3.3V)* RS-232 uses 12V signals* Use MAX3232 chip to convert* Use this for access to serial consoleHe summarized his key points. The Raspberry Pi is a very cool (and cheap) computer that is great for teaching, a great introduction to ARM that works very well with Java and will work better in the future. The opportunities are limitless. For further info, check out, Raspberry Pi User Guide by Eben Upton and Gareth Halfacree. From there, Ritter tried out several fun demos, some of which worked better than others, but all of which were greeted with considerable enthusiasm and support and good humor (even when he ran into some glitches).  All in all, this was a fun and lively session.

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  • Maximize Performance and Availability with Oracle Data Integration

    - by Tanu Sood
    Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif"; mso-fareast-font-family:Calibri; mso-bidi-font-family:"Times New Roman";} Alert: Oracle is hosting the 12c Launch Webcast for Oracle Data Integration and Oracle Golden Gate on Tuesday, November 12 (tomorrow) to discuss the new capabilities in detail and share customer perspectives. Hear directly from customer experts and executives from SolarWorld Industries America, British Telecom and Rittman Mead and get your questions answered live by product experts. Register for this complimentary webcast today and join in the discussion tomorrow. Author: Irem Radzik, Senior Principal Product Director, Oracle Organizations that want to use IT as a strategic point of differentiation prefer Oracle’s complete application offering to drive better business performance and optimize their IT investments. These enterprise applications are in the center of business operations and they contain critical data that needs to be accessed continuously, as well as analyzed and acted upon in a timely manner. These systems also need to operate with high-performance and availability, which means analytical functions should not degrade applications performance, and even system maintenance and upgrades should not interrupt availability. Oracle’s data integration products, Oracle Data Integrator, Oracle GoldenGate, and Oracle Enterprise Data Quality, provide the core foundation for bringing data from various business-critical systems to gain a broader, unified view. As a more advance offering to 3rd party products, Oracle’s data integration products facilitate real-time reporting for Oracle Applications without impacting application performance, and provide ability to upgrade and maintain the system without taking downtime. Oracle GoldenGate is certified for Oracle Applications, including E-Business Suite, Siebel CRM, PeopleSoft, and JD Edwards, for moving transactional data in real-time to a dedicated operational reporting environment. This solution allows the app users to offload the resource-heavy queries to the reporting instance(s), reducing CPU utilization, improving OLTP performance, and extending the lifetime of existing IT assets. In addition, having a dedicated reporting instance with up-to-the-second transactional data allows optimizing the reporting environment and even decreasing costs as GoldenGate can move only the required data from expensive mainframe environments to cost-efficient open system platforms.  With real-time data replication capabilities GoldenGate is also certified to enable application upgrades and database/hardware/OS migration without impacting business operations. GoldenGate is certified for Siebel CRM, Communications Billing and Revenue Management and JD Edwards for supporting zero downtime upgrades to the latest app version. GoldenGate synchronizes a parallel, upgraded system with the old version in real time, thus enables continuous operations during the process. Oracle GoldenGate is also certified for minimal downtime database migrations for Oracle E-Business Suite and other key applications. GoldenGate’s solution also minimizes the risk by offering a failback option after the switchover to the new environment. Furthermore, Oracle GoldenGate’s bidirectional active-active data replication is certified for Oracle ATG Web Commerce to enable geographically load balancing and high availability for ATG customers. For enabling better business insight, Oracle Data Integration products power Oracle BI Applications with high performance bulk and real-time data integration. Oracle Data Integrator (ODI) is embedded in Oracle BI Applications version 11.1.1.7.1 and helps to integrate data end-to-end across the full BI Applications architecture, supporting capabilities such as data-lineage, which helps business users identify report-to-source capabilities. ODI is integrated with Oracle GoldenGate and provides Oracle BI Applications customers the option to use real-time transactional data in analytics, and do so non-intrusively. By using Oracle GoldenGate with the latest release of Oracle BI Applications, organizations not only leverage fresh data in analytics, but also eliminate the need for an ETL batch window and minimize the impact on OLTP systems. You can learn more about Oracle Data Integration products latest 12c version in our upcoming launch webcast and access the app-specific free resources in the new Data Integration for Oracle Applications Resource Center.

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  • Troubleshooting Website problems within the local network

    - by HaydnWVN
    Have an external website which opens fine on some PC's, yet seems to time out (or symptoms of timing out, but never actually does) on others. Seems to only affect (some) of our newer HP Pro 3305 MT Workstations. All of which are running Win7 32bit SP1 with all updates. Older PC's (Win7 32bit SP1 & WinXP) are unaffected. Using Google Chrome & Firefox makes no difference. Opening the website in IE9 Compatibility Mode has exactly the same symptoms. All PC's are on the same local network (Workgroup) using the same DNS server & gateway (inhouse) on the same internet connection, on the same subnet. There is no proxy server, no content filtering, no load balancing etc etc. Only group policy in effect (locally) is for Update scheduling. Local firewalls are all the same (Kaspersky WP4) and our external facing firewall has no IP specific settings. I have no control over the external website, traceroute shows the same destination on all PC's. It is a fairly popular website in our industry (Horticulture) and i'm not aware of any other people (even other sites within our sister companies) with the same problem. Update: Used Fiddler2 to monitor the HTTP request, seems its not getting fulfilled for some reason?! Request sent: GET http://www.rhs.org.uk/ HTTP/1.1 Host: www.rhs.org.uk Connection: keep-alive User-Agent: Mozilla/5.0 (Windows NT 6.1) AppleWebKit/536.11 (KHTML, like Gecko) Chrome/20.0.1132.47 Safari/536.11 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8 Accept-Encoding: gzip,deflate,sdch Accept-Language: en-GB,en-US;q=0.8,en;q=0.6 Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3 Log from Fiddler 2 of the request: This session is not yet complete. Press F5 to refresh when session is complete for updated statistics. Request Count: 1 Bytes Sent: 567 (headers:567; body:0) Bytes Received: 0 (headers:0; body:0) ACTUAL PERFORMANCE -------------- ClientConnected: 17:02:33.720 ClientBeginRequest: 17:02:39.118 GotRequestHeaders: 17:02:39.118 ClientDoneRequest: 17:02:39.118 Determine Gateway: 0ms DNS Lookup: 0ms TCP/IP Connect: 46ms HTTPS Handshake: 0ms ServerConnected: 17:02:39.165 FiddlerBeginRequest: 17:02:39.165 ServerGotRequest: 17:02:39.165 ServerBeginResponse: 00:00:00.000 GotResponseHeaders: 00:00:00.000 ServerDoneResponse: 00:00:00.000 ClientBeginResponse: 00:00:00.000 ClientDoneResponse: 00:00:00.000 RESPONSE BYTES (by Content-Type) -------------- ~headers~: 0 Log of a successful request from a working PC (done this morning, excuse the timestamps being different from above): Request Count: 1 Bytes Sent: 493 (headers:493; body:0) Bytes Received: 20,413 (headers:525; body:19,888) ACTUAL PERFORMANCE -------------- ClientConnected: 08:22:47.766 ClientBeginRequest: 08:22:47.766 GotRequestHeaders: 08:22:47.766 ClientDoneRequest: 08:22:47.766 Determine Gateway: 0ms DNS Lookup: 26ms TCP/IP Connect: 30ms HTTPS Handshake: 0ms ServerConnected: 08:22:47.828 FiddlerBeginRequest: 08:22:47.828 ServerGotRequest: 08:22:47.828 ServerBeginResponse: 08:22:48.905 GotResponseHeaders: 08:22:48.905 ServerDoneResponse: 08:22:48.905 ClientBeginResponse: 08:22:48.905 ClientDoneResponse: 08:22:48.905 Overall Elapsed: 00:00:01.1388020 RESPONSE BYTES (by Content-Type) -------------- text/html: 19,888 ~headers~: 525 So my question has evolved into: What is the difference between the 2 requests and how do I determine why 1 PC is not getting a reply to it's GET request?

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  • NetBeans, JSF, and MySQL Primary Keys using AUTO_INCREMENT

    - by MarkH
    I recently had the opportunity to spin up a small web application using JSF and MySQL. Having developed JSF apps with Oracle Database back-ends before and possessing some small familiarity with MySQL (sans JSF), I thought this would be a cakewalk. Things did go pretty smoothly...but there was one little "gotcha" that took more time than the few seconds it really warranted. The Problem Every DBMS has its own way of automatically generating primary keys, and each has its pros and cons. For the Oracle Database, you use a sequence and point your Java classes to it using annotations that look something like this: @GeneratedValue(strategy=GenerationType.SEQUENCE, generator="POC_ID_SEQ") @SequenceGenerator(name="POC_ID_SEQ", sequenceName="POC_ID_SEQ", allocationSize=1) Between creating the actual sequence in the database and making sure you have your annotations right (watch those typos!), it seems a bit cumbersome. But it typically "just works", without fuss. Enter MySQL. Designating an integer-based field as PRIMARY KEY and using the keyword AUTO_INCREMENT makes the same task seem much simpler. And it is, mostly. But while NetBeans cranks out a superb "first cut" for a basic JSF CRUD app, there are a couple of small things you'll need to bring to the mix in order to be able to actually (C)reate records. The (RUD) performs fine out of the gate. The Solution Omitting all design considerations and activity (!), here is the basic sequence of events I followed to create, then resolve, the JSF/MySQL "Primary Key Perfect Storm": Fire up NetBeans. Create JSF project. Create Entity Classes from Database. Create JSF Pages from Entity Classes. Test run. Try to create record and hit error. It's a simple fix, but one that was fun to find in its completeness. :-) Even though you've told it what to do for a primary key, a MySQL table requires a gentle nudge to actually generate that new key value. Two things are needed to make the magic happen. First, you need to ensure the following annotation is in place in your Java entity classes: @GeneratedValue(strategy = GenerationType.IDENTITY) All well and good, but the real key is this: in your controller class(es), you'll have a create() function that looks something like this, minus the comment line and the setId() call in bold red type:     public String create() {         try {             // Assign 0 to ID for MySQL to properly auto_increment the primary key.             current.setId(0);             getFacade().create(current);             JsfUtil.addSuccessMessage(ResourceBundle.getBundle("/Bundle").getString("CategoryCreated"));             return prepareCreate();         } catch (Exception e) {             JsfUtil.addErrorMessage(e, ResourceBundle.getBundle("/Bundle").getString("PersistenceErrorOccured"));             return null;         }     } Setting the current object's primary key attribute to zero (0) prior to saving it tells MySQL to get the next available value and assign it to that record's key field. Short and simple…but not inherently obvious if you've never used that particular combination of NetBeans/JSF/MySQL before. Hope this helps! All the best, Mark

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  • OpenVPN - client-to-client traffic working in one direction but not the other

    - by user42055
    I have the following VPN configuration: +------------+ +------------+ +------------+ | outpost |----------------| kino |----------------| guchuko | +------------+ +------------+ +------------+ OS: FreeBSD 6.2 OS: Gentoo 2.6.32 OS: Gentoo 2.6.33.3 Keyname: client3 Keyname: server Keyname: client1 eth0: 10.0.1.254 eth0: 203.x.x.x eth0: 192.168.0.6 tun0: 192.168.150.18 tun0: 192.168.150.1 tun0: 192.168.150.10 P-t-P: 192.166.150.17 P-t-P: 192.168.150.2 P-t-P: 192.168.150.9 Kino is the server and has client-to-client enabled. All three machines have ip forwarding enabled, by this on the gentoo boxes: net.ipv4.conf.all.forwarding = 1 And this on the FreeBSD box: net.inet.ip.forwarding: 1 In the server's "ccd" directory is the following files: client1: iroute 192.168.0.0 255.255.255.0 client3: iroute 10.0.1.0 255.255.255.0 The server config has these routes configured: push "route 192.168.0.0 255.255.255.0" push "route 10.0.1.0 255.255.255.0" route 192.168.0.0 255.255.255.0 route 10.0.1.0 255.255.255.0 Kino's routing table looks like this: 192.168.150.0 192.168.150.2 255.255.255.0 UG 0 0 0 tun0 10.0.1.0 192.168.150.2 255.255.255.0 UG 0 0 0 tun0 192.168.0.0 192.168.150.2 255.255.255.0 UG 0 0 0 tun0 192.168.150.2 0.0.0.0 255.255.255.255 UH 0 0 0 tun0 Outpost's like this: 192.168.150 192.168.150.17 UGS 0 17 tun0 192.168.0 192.168.150.17 UGS 0 2 tun0 192.168.150.17 192.168.150.18 UH 3 0 tun0 And Guchuko's like this: 192.168.150.0 192.168.150.9 255.255.255.0 UG 0 0 0 tun0 10.0.1.0 192.168.150.9 255.255.255.0 UG 0 0 0 tun0 192.168.150.9 0.0.0.0 255.255.255.255 UH 0 0 0 tun0 Now, the tests. Pings from Guchuko to Outpost's LAN IP work OK, as does the reverse - pings from Outpost to Guchuko's LAN IP. However... Pings from Outpost, to a machine on Guchuko's LAN work fine: .(( root@outpost )). (( 06:39 PM )) :: ~ :: # ping 192.168.0.3 PING 192.168.0.3 (192.168.0.3): 56 data bytes 64 bytes from 192.168.0.3: icmp_seq=0 ttl=63 time=462.641 ms 64 bytes from 192.168.0.3: icmp_seq=1 ttl=63 time=557.909 ms But a ping from Guchuko, to a machine on Outpost's LAN does not: .(( root@guchuko )). (( 06:43 PM )) :: ~ :: # ping 10.0.1.253 PING 10.0.1.253 (10.0.1.253) 56(84) bytes of data. --- 10.0.1.253 ping statistics --- 3 packets transmitted, 0 received, 100% packet loss, time 2000ms Guchuko's tcpdump of tun0 shows: 18:46:27.716931 IP 192.168.150.10 > 10.0.1.253: ICMP echo request, id 63009, seq 1, length 64 18:46:28.716715 IP 192.168.150.10 > 10.0.1.253: ICMP echo request, id 63009, seq 2, length 64 18:46:29.716714 IP 192.168.150.10 > 10.0.1.253: ICMP echo request, id 63009, seq 3, length 64 Outpost's tcpdump on tun0 shows: 18:44:00.333341 IP 192.168.150.10 > 10.0.1.253: ICMP echo request, id 63009, seq 3, length 64 18:44:01.334073 IP 192.168.150.10 > 10.0.1.253: ICMP echo request, id 63009, seq 4, length 64 18:44:02.331849 IP 192.168.150.10 > 10.0.1.253: ICMP echo request, id 63009, seq 5, length 64 So Outpost is receiving the ICMP request destined for the machine on it's subnet, but appears not be forwarding it. Outpost has gateway_enable="YES" in its rc.conf which correctly sets net.inet.ip.forwarding to 1 as mentioned earlier. As far as I know, that's all that's required to make a FreeBSD box forward packets between interfaces. Is there something else I could be forgetting ?

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  • Dynamic DNS registration for VPN clients

    - by Eric Falsken
    I've got a VPN server set up in my Active Directory on a remote network. (VPN Server is separate box from DNS/AD) When I dial into the network (client machine is not a member of the AD) the machine does not register its IP or Hostname in the DNS. I've played with all possible combinations of DHCP and RRAS-allocated IP pools, and none of them seem to cause my client to register. Is it because my client has to be a member of the domain? Are there some security settins I can tweak so that it can register its hostname/ip? I've looked in the event logs (System and Security) for the AD, DNS, DHCP, RRAS, and the client machine, and don't see anything relating to DNS Registration. Here's the IPConfig on the client machine (once connected): PPP adapter My VPN Name: Connection-specific DNS Suffix . : mydomain.local Description . . . . . . . . . . . : My VPN Name Physical Address. . . . . . . . . : DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes IPv4 Address. . . . . . . . . . . : 192.168.1.22(Preferred) Subnet Mask . . . . . . . . . . . : 255.255.255.255 Default Gateway . . . . . . . . . : DNS Servers . . . . . . . . . . . : 192.168.1.52 <- DC1 192.168.1.53 <- DC2 NetBIOS over Tcpip. . . . . . . . : Enabled

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  • Hanging of host network connections when starting KVM guest on bridge

    - by Chris Phillips
    Hi, I've a KVM system upon which I'm running a network bridge directly between all VM's and a bond0 (eth0, eth1) on the host OS. As such, all machines are presented on the same subnet, available outside of the box. The bond is doing mode 1 active / passive, with an arp_ip_target set to the default gateway, which has caused some issues in itself, but I can't see the bond configs mattering here myself. I'm seeing odd things most times when I stop and start a guest on the platform, in that on the host I lose network connectivity (icmp, ssh) for about 30 seconds. I don't lose connectivity on the other already running VM's though... they can always ping the default GW, but the host can't. I say "about 30 seconds" but from some tests it actually seems to be 28 seconds usually (or at least, I lose 28 pings...) and I'm wondering if this somehow relates to the bridge config. I'm not running STP on the bridge at all, and the forwarding delay is set to 1 second, path cost on the bond0 lowered to 10 and port priority of bond0 also lowered to 1. As such I don't think that the bridge should ever be able to think that bond0 is not connected just fine (as continued guest connectivity implies) yet the IP of the host, which is on the bridge device (... could that matter?? ) becomes unreachable. I'm fairly sure it's about the bridged networking, but at the same time as this happens when a VM is started there are clearly loads of other things also happening so maybe I'm way off the mark. Lack of connectivity: # ping 10.20.11.254 PING 10.20.11.254 (10.20.11.254) 56(84) bytes of data. 64 bytes from 10.20.11.254: icmp_seq=1 ttl=255 time=0.921 ms 64 bytes from 10.20.11.254: icmp_seq=2 ttl=255 time=0.541 ms type=1700 audit(1293462808.589:325): dev=vnet6 prom=256 old_prom=0 auid=42949672 95 ses=4294967295 type=1700 audit(1293462808.604:326): dev=vnet7 prom=256 old_prom=0 auid=42949672 95 ses=4294967295 type=1700 audit(1293462808.618:327): dev=vnet8 prom=256 old_prom=0 auid=42949672 95 ses=4294967295 kvm: 14116: cpu0 unimplemented perfctr wrmsr: 0x186 data 0x130079 kvm: 14116: cpu0 unimplemented perfctr wrmsr: 0xc1 data 0xffdd694a kvm: 14116: cpu0 unimplemented perfctr wrmsr: 0x186 data 0x530079 64 bytes from 10.20.11.254: icmp_seq=30 ttl=255 time=0.514 ms 64 bytes from 10.20.11.254: icmp_seq=31 ttl=255 time=0.551 ms 64 bytes from 10.20.11.254: icmp_seq=32 ttl=255 time=0.437 ms 64 bytes from 10.20.11.254: icmp_seq=33 ttl=255 time=0.392 ms brctl output of relevant bridge: # brctl showstp brdev brdev bridge id 8000.b2e1378d1396 designated root 8000.b2e1378d1396 root port 0 path cost 0 max age 19.99 bridge max age 19.99 hello time 1.99 bridge hello time 1.99 forward delay 0.99 bridge forward delay 0.99 ageing time 299.95 hello timer 0.50 tcn timer 0.00 topology change timer 0.00 gc timer 0.04 flags vnet5 (3) port id 8003 state forwarding designated root 8000.b2e1378d1396 path cost 100 designated bridge 8000.b2e1378d1396 message age timer 0.00 designated port 8003 forward delay timer 0.00 designated cost 0 hold timer 0.00 flags vnet0 (2) port id 8002 state forwarding designated root 8000.b2e1378d1396 path cost 100 designated bridge 8000.b2e1378d1396 message age timer 0.00 designated port 8002 forward delay timer 0.00 designated cost 0 hold timer 0.00 flags bond0 (1) port id 0001 state forwarding designated root 8000.b2e1378d1396 path cost 10 designated bridge 8000.b2e1378d1396 message age timer 0.00 designated port 0001 forward delay timer 0.00 designated cost 0 hold timer 0.00 flags I do see the new port listed as learning, but in line with the forward delay, only for 1 or 2 seconds when polling the brctl output on a loop. All pointers, tips or stabs in the dark appreciated.

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  • Accelerating 2d object collision with other objects [on hold]

    - by Silent Cave
    Making my very first attempt at game programming with SDL/OpenGL. So I made an object Actor witch can move in all four sides with acceleration. And there are bunch of other rectangles to collide to. the image Movement and collision detection alghorythms work just fine by itself, but when combined to prevent the green rectangle from crossing black rectangles, it gives me a kind of funny resault. Let me show you the code first: from Actor.h class Actor{ public: SDL_Rect * dim; alphaColor * col; float speed; float xlGrav, xrGrav, yuGrav, ydGrav; float acceleration; bool left,right,up,down; Actor(SDL_Rect * dim,alphaColor * col, float speed, float acceleration); bool colides(const SDL_Rect & rect); bool check_for_collisions(const std::vector<SDL_Rect*> & gameObjects ); }; from actor.cpp bool Actor::colides(const SDL_Rect & rect){ if (dim->x + dim->w < rect.x) return false; if (dim->x > rect.x + rect.w) return false; if (dim->y + dim->h < rect.y) return false; if (dim->y > rect.y + rect.h) return false; return true; } movement logic from main.cpp if (actor->left){ if(actor->xlGrav < actor->speed){ actor->xlGrav += actor->speed*actor->acceleration; }else actor->xlGrav = actor->speed; actor->dim->x -= actor->xlGrav; if(actor->check_for_collisions(gameObjects)){ actor->dim->x += actor->xlGrav; actor->xlGrav = 0; } } if (!actor->left){ if(actor->xlGrav - actor->speed*actor->acceleration > 0){ actor->xlGrav -= actor->speed*actor->acceleration; }else actor->xlGrav = 0; actor->dim->x -= actor->xlGrav; if(actor->check_for_collisions(gameObjects)){ actor->dim->x += actor->xlGrav; actor->xlGrav = 0; } } if (actor->right){ if(actor->xrGrav < actor->speed){ actor->xrGrav += actor->speed*actor->acceleration; }else actor->xrGrav = actor->speed; actor->dim->x += actor->xrGrav; if(actor->check_for_collisions(gameObjects)){ actor->dim->x -= actor->xrGrav; actor->xrGrav = 0; } } if (!actor->right){ if(actor->xrGrav - actor->speed*actor->acceleration > 0){ actor->xrGrav -= actor->speed*actor->acceleration; }else actor->xrGrav = 0; actor->dim->x += actor->xrGrav; if(actor->check_for_collisions(gameObjects)){ actor->dim->x -= actor->xrGrav; actor->xrGrav = 0; } } if (actor->up){ if(actor->yuGrav < actor->speed){ actor->yuGrav += actor->speed*actor->acceleration; }else actor->yuGrav = actor->speed; actor->dim->y -= actor->yuGrav; if(actor->check_for_collisions(gameObjects)){ actor->dim->y += actor->yuGrav; actor->yuGrav = 0; } } if (!actor->up){ if(actor->yuGrav - actor->speed*actor->acceleration > 0){ actor->yuGrav -= actor->speed*actor->acceleration; }else actor->yuGrav = 0; actor->dim->y -= actor->yuGrav; if(actor->check_for_collisions(gameObjects)){ actor->dim->y += actor->yuGrav; actor->yuGrav = 0; } } if (actor->down){ if(actor->ydGrav < actor->speed){ actor->ydGrav += actor->speed*actor->acceleration; }else actor->ydGrav = actor->speed; actor->dim->y += actor->ydGrav; if(actor->check_for_collisions(gameObjects)){ actor->dim->y -= actor->ydGrav; actor->ydGrav = 0; } } if (!actor->down){ if(actor->ydGrav - actor->speed*actor->acceleration > 0){ actor->ydGrav -= actor->speed*actor->acceleration; }else actor->ydGrav = 0; actor->dim->y += actor->ydGrav; if(actor->check_for_collisions(gameObjects)){ actor->dim->y -= actor->ydGrav; actor->ydGrav = 0; } } So, if the green box approaches an obstacle from up or left, everything goes as planned - object stops, and it's acceleration drops to zero. But if it comes from bottom or right, it enters into obstacles inner space and starts strangely dance, I'd rather say move in inverted controls. What do I fail to see?

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