Search Results

Search found 502 results on 21 pages for 'primitive'.

Page 17/21 | < Previous Page | 13 14 15 16 17 18 19 20 21  | Next Page >

  • Parallel doseq for Clojure

    - by andrew cooke
    I haven't used multithreading in Clojure at all so am unsure where to start. I have a doseq whose body can run in parallel. What I'd like is for there always to be 3 threads running (leaving 1 core free) that evaluate the body in parallel until the range is exhausted. There's no shared state, nothing complicated - the equivalent of Python's multiprocessing would be just fine. So something like: (dopar 3 [i (range 100)] ; repeated 100 times in 3 parallel threads... ...) Where should I start looking? Is there a command for this? A standard package? A good reference? So far I have found pmap, and could use that (how do I restrict to 3 at a time? looks like it uses 32 at a time - no, source says 2 + number of processors), but it seems like this is a basic primitive that should already exist somewhere. clarification: I really would like to control the number of threads. I have processes that are long-running and use a fair amount of memory, so creating a large number and hoping things work out OK isn't a good approach (example which uses a significant chunk available mem). update: Starting to write a macro that does this, and I need a semaphore (or a mutex, or an atom i can wait on). Do semaphores exist in Clojure? Or should I use a ThreadPoolExecutor? It seems odd to have to pull so much in from Java - I thought parallel programming in Clojure was supposed to be easy... Maybe I am thinking about this completely the wrong way? Hmmm. Agents?

    Read the article

  • How to avoid concurrent execution of a time-consuming task without blocking?

    - by Diego V
    I want to efficiently avoid concurrent execution of a time-consuming task in a heavily multi-threaded environment without making threads wait for a lock when another thread is already running the task. Instead, in that scenario, I want them to gracefully fail (i.e. skip its attempt to execute the task) as fast as possible. To illustrate the idea considerer this unsafe (has race condition!) code: private static boolean running = false; public void launchExpensiveTask() { if (running) return; // Do nothing running = true; try { runExpensiveTask(); } finally { running = false; } } I though about using a variation of Double-Checked Locking (consider that running is a primitive 32-bit field, hence atomic, it could work fine even for Java below 5 without the need of volatile). It could look like this: private static boolean running = false; public void launchExpensiveTask() { if (running) return; // Do nothing synchronized (ThisClass.class) { if (running) return; running = true; try { runExpensiveTask(); } finally { running = false; } } } Maybe I should also use a local copy of the field as well (not sure now, please tell me). But then I realized that anyway I will end with an inner synchronization block, that still could hold a thread with the right timing at monitor entrance until the original executor leaves the critical section (I know the odds usually are minimal but in this case we are thinking in several threads competing for this long-running resource). So, could you think in a better approach?

    Read the article

  • Moving x,y position of all array objects every frame in actionscript 3?

    - by Dylan Gallardo
    I have my code setup so that I have an movieclip in my library a class called "block" being duplicated multiple times and added into an array like this: function makeblock(e:Event){ newblock=new block; newblock.x=10; newblock.y=10; addChild(newblock); myarray[counter] = newblock; //adds a newblock object into array counter += 1; } Then I have a loop with a currently primitive way of handling my problem: stage.addEventListener(Event.ENTER_FRAME, gameloop); function gameloop(evt:Event):void { if (moveright==true){ myarray[0].x += 5; myarray[1].x += 5; myarray[2].x += 5 -(and so on)- My question is how can I change x,y values every frame for new objects duplicated into the array, along with the previous ones that were added. Of course with a more elegant way than writing it out myself... array[0].x += 5, array[1], array[2], array[3] etc. Ideally I would like this to go up to 500 or more array objects for one array so obviously I don't want to be writing it out individually haha, I also need it to be consistent with performance so using a for loop or something to loop through the whole array and move each x += 5 wouldn't work would it? Anyway, if anyone has any ideas that'd be great!

    Read the article

  • Java: over-typed structures? To have many types in Object[]?

    - by HH
    Term over-type structure = a data structure that accepts different types, can be primitive or user-defined. I think ruby supports many types in structures such as tables. I tried a table with types 'String', 'char' and 'File' in Java but errs. How can I have over-typed structure in Java? How to show types in declaration? What about in initilization? Suppose a structure: INDEX VAR FILETYPE //0 -> file FILE //1 -> lineMap SizeSequence //2 -> type char //3 -> binary boolean //4 -> name String //5 -> path String Code import java.io.*; import java.util.*; public class Object { public static void print(char a) { System.out.println(a); } public static void print(String s) { System.out.println(s); } public static void main(String[] args) { Object[] d = new Object[6]; d[0] = new File("."); d[2] = 'T'; d[4] = "."; print(d[2]); print(d[4]); } } Errors Object.java:18: incompatible types found : java.io.File required: Object d[0] = new File("."); ^ Object.java:19: incompatible types found : char required: Object d[2] = 'T'; ^

    Read the article

  • Learning Java and logic using debugger. Did I cheat?

    - by centr0
    After a break from coding in general, my way of thinking logically faded (as if it was there to begin with...). I'm no master programmer. Intermediate at best. I decided to see if i can write an algorithm to print out the fibonacci sequence in Java. I got really frustrated because it was something so simple, and used the debugger to see what was going on with my variables. solved it in less than a minute with the help of the debugger. Is this cheating? When I read code either from a book or someone else's, I now find that it takes me a little more time to understand. If the alghorithm is complex (to me) i end up writing notes as to whats going on in the loop. A primitive debugger if you will. When you other programmers read code, do you also need to write things down as to whats the code doing? Or are you a genius and and just retain it?

    Read the article

  • Audit many-to-many relationship in NHibernate

    - by Kendrick
    I have implemented listeners to audit changes to tables in my application using IPreUpdateEventListener and IPreInsertEventListener and everything works except for my many-to-many relationships that don't have additional data in the joining table (i.e. I don't have a POCO for the joining table). Each auditable object implements an IAuditable interface, so the event listener checks to see if a POCO is of type IAuditable, and if it is it records any changes to the object. Look up tables implement an IAuditableProperty inteface, so if a property of the IAuditable POCO is pointing to a lookup table, the changes are recorded in the log for the main POCO. So, the question is, how should I determine I'm working with a many-to-many collection and record the changes in my audit table? //first two checks for LastUpdated and LastUpdatedBy ommitted for brevity else if (newState[i] is IAuditable) { //Do nothing, these will record themselves separately } else if (!(newState[i] is IAuditableProperty) && (newState[i] is IList<object> || newState[i] is ISet)) { //Do nothing, this is a collection and individual items will update themselves if they are auditable //I believe this is where my many-to-many values are being lost } else if (!isUpdateEvent || !Equals(oldState[i], newState[i]))//Record only modified fields when updating { changes.Append(preDatabaseEvent.Persister.PropertyNames[i]) .Append(": "); if (newState[i] is IAuditableProperty) { //Record changes to values in lookup tables if (isUpdateEvent) { changes.Append(((IAuditableProperty)oldState[i]).AuditPropertyValue) .Append(" => "); } changes.Append(((IAuditableProperty)newState[i]).AuditPropertyValue); } else { //Record changes for primitive values if(isUpdateEvent) { changes.Append(oldState[i]) .Append(" => "); } changes.Append(newState[i]); } changes.AppendLine(); }

    Read the article

  • Dynamic Data Extract Tools

    - by Kevin McGovern
    I've been searching around for a few weeks now for a tool that either is fully built or a direction of something I could build for dynamically extracting data via a web interface. Basically, what I'm looking for is a way to give users a list of all available data objects from our database and then let them pick ones from the list they'd like to view and set parameters then export the results to an excel file. Right now we're doing it purely with SQL statements but we have hundreds of objects so as you might imagine, those statements are really complex and prone to errors. It would be great if there was a tool available to do this or if someone had an idea of an easy way to organize this. Any help would be greatly appreciated. We've looked at BI tools like QlikView and Tableau but that is probably overkill for what we're trying to do. The open-source BI tools we've looked at seemed really primitive in their functionality. The other thing we looked at was MSAS (our DB is SQL Server) but I'd prefer something that was more database-agnostic and lived on a web server instead of on the database.

    Read the article

  • Simulate Golf Game Strategy

    - by Mitchel Sellers
    I am working on what at best could be considered a "primitive" golf game, where after a certain bit of randomness is introduced I need to play out a hole of golf. The hole is static and I am not concerned about the UI aspect as I just have to draw a line on a graphic of the hole after the ball has been hit showing where it traveled. I'm looking for input on thoughts of how to manage the "logic" side of the puzzle, below are some of my thoughts on the matter, input, suggestions, or references are greatly appreciated. Map out the hole into an array with a specific amount of precision, noting the type of surface: out of bounds, fairway, rough, green, sand, water, and most important the hole. Map out "regions" and if the ball is contained inside one of these regions setup parameters for "maximum" angle of departure. (For example the first part of the hole the shot must be between certain angles Using the current placement of the ball, and the region contained in #2, define a routine to randomly select the shooting angle, and power then move the ball, adjust the trajectory and move again. I know this isn't the "most elegant" solution, but in reality, we are looking for a quick and dirty solution, as I just have to do this a few times, set it and forget it afterward. From a languages perspective I'll be using ASP.NET and C# to get this done.

    Read the article

  • How do I make this Java code operate properly? [Multi-threaded, race condition]

    - by Fixee
    I got this code from a student, and it does not work properly because of a race condition involving x++ and x--. He added synchronized to the run() method trying to get rid of this bug, but obviously this only excludes threads from entering run() on the same object (which was never a problem in the first place) but doesn't prevent independent objects from updating the same static variable x at the same time. public class DataRace implements Runnable { static volatile int x; public synchronized void run() { for (int i = 0; i < 10000; i++) { x++; x--; } } public static void main(String[] args) throws Exception { Thread [] threads = new Thread[100]; for (int i = 0; i < threads.length; i++) threads[i] = new Thread(new DataRace()); for (int i = 0; i < threads.length; i++) threads[i].start(); for (int i = 0; i < threads.length; i++) threads[i].join(); System.out.println(x); // x not always 0! } } Since we cannot synchronize on x (because it is primitive), the best solution I can think of is to create a new static object like static String lock = ""; and enclose the x++ and x-- within a synchronized block, locking on lock. But this seems really awkward. Is there a better way?

    Read the article

  • Automatically Persisting a Complex Java Object

    - by VeeArr
    For a project I am working on, I need to persist a number of POJOs to a database. The POJOs class definitions are sometimes highly nested, but they should flatten okay, as the nesting is tree-like and contains no cycles (and the base elements are eventually primitives/Strings). It is preferred that the solution used create one table per data type and that the tables will have one field per primitive member in the POJO. Subclassing and similar problems are not issues for this particular project. Does anybody know of any existing solutions that can: Automatically generate a CREATE TABLE definition from the class definition Automatically generate a query to persist an object to the database, given an instance of the object Automatically generate a query to retrieve an object from the database and return it as a POJO, given a key. Solutions that can do this with minimum modifications/annotions to the class files and minimum external configuration are preferred. Example: Java classes //Class to be persisted class TypeA { String guid; long timestamp; TypeB data1; TypeC data2; } class TypeB { int id; int someData; } class TypeC { int id; int otherData; } Could map to CREATE TABLE TypeA ( guid CHAR(255), timestamp BIGINT, data1_id INT, data1_someData INT, data2_id INt, data2_otherData INT ); Or something similar.

    Read the article

  • Question about SharedPreferences

    - by chobo2
    I am looking an android Shared Preferences and I am wondering is there a way to just check if the preferences file exists. SharedPreferences mySharedPreferences ; mySharedPreferences=getSharedPreferences(“Name_of_your_preference”,mode); This above code leads me to believe that "Name_of_Your_preferene" is stored as a file or some sort of container that will contain your preferences. I am wondering is there away to check if this exists or not. When a user loads up an activity I want to save all the settings into this file with some default values(off for all settings). However I only want to do this if they are going to the page for the first time. Otherwise if I would do something like this every time the page loads up SharedPreferences.Editor editor= mySharedPreferences.edit(); /* now store your primitive type values. In this case it is true, 1f and Hello! World */ editor.putBolean(“myBoolean”,true); editor.putFloat(“myFloat”,1f); editor.putString(“myString”,” Hello! World”); I am guessing it would override all settings even ones they set.

    Read the article

  • Interview questions about ASP.NET Web services.

    - by Jalpesh P. Vadgama
    I have seen there are lots of myth’s about asp.net web services in fresher level asp.net developers. So I decided to write a blog post about asp.net web services interview questions. Because I think this is the best way to reach fresher asp.net developers. Followings are few questions about asp.net web services. 1) What is asp.net web services? Ans: Web services are used to support http requests that formatted using xml,http and SOAP syntax. They interact with through standards xml messages through Soap. They are used to support interoperability. It has .asmx extension and .NET framework contains http handlers for web services to support http requested directly. 2) What kind of data can be returned web services web methods? Ans: It supports all the primitive data types and custom data types that can be encoded and serialized by xml. You can find more information about that from the following link. http://msdn.microsoft.com/en-us/library/bb552900.aspx 3) Is web services are only written in asp.net? Ans: No, It can be written by Java and PHP languages also. 4) Explain web method attributes in web services Ans: Web method attributes are added to a public class method to indicate that this method is exposed as a part of XML web services. You can have multiple web methods in a class. But it should be having public attributes as it will be exposed as xml web service part. You can find more information about web method attributes from following link. http://msdn.microsoft.com/en-us/library/byxd99hx(v=vs.71).aspx 5) What is SOA? Ans: SOA stands for “Services Oriented Architecture”. It is kind of service oriented architecture used to support different kind of computing platforms and applications. Web services in asp.net are one of the technologies that supports that kind of architecture.  You can call asp.net web services from any computing platforms and applications. 6) What is SOAP,WDSL and UDDI? Ans: SOAP stands “Simple Object Access protocol”. Web services will be interact with SOAP messages written in XML. SOAP is sometimes referred as “data wrapper” or “data envelope”.Its contains different xml tag that creates a whole SOAP message.  WSDL stand for “Web services Description Language”.  It is an xml document which is written according to standard specified by W3c. It is a kind of manual or document that describes how we can use and consume web service. Web services development software processes the WSDL document and generates SOAP messages that are needed for specific web service. UDDI stand for “Universal Discovery, Description and Integration”. Its is used for web services registries. You can find addresses of web services from UDDI.

    Read the article

  • Part 15: Fail a build based on the exit code of a console application

    In the series the following parts have been published Part 1: Introduction Part 2: Add arguments and variables Part 3: Use more complex arguments Part 4: Create your own activity Part 5: Increase AssemblyVersion Part 6: Use custom type for an argument Part 7: How is the custom assembly found Part 8: Send information to the build log Part 9: Impersonate activities (run under other credentials) Part 10: Include Version Number in the Build Number Part 11: Speed up opening my build process template Part 12: How to debug my custom activities Part 13: Get control over the Build Output Part 14: Execute a PowerShell script Part 15: Fail a build based on the exit code of a console application When you have a Console Application or a batch file that has errors, the exitcode is set to another value then 0. You would expect that the build would see this and report an error. This is not true however. First we setup the scenario. Add a ConsoleApplication project to your solution you are building. In the Main function set the ExitCode to 1     class Program    {        static void Main(string[] args)        {            Console.WriteLine("This is an error in the script.");            Environment.ExitCode = 1;        }    } Checkin the code. You can choose to include this Console Application in the build or you can decide to add the exe to source control Now modify the Build Process Template CustomTemplate.xaml Add an argument ErrornousScript Scroll down beneath the TryCatch activity called “Try Compile, Test, and Associate Changesets and Work Items” Add an Sequence activity to the template In the Sequence, add a ConvertWorkspaceItem and an InvokeProcess activity (see Part 14: Execute a PowerShell script  for more detailed steps) In the FileName property of the InvokeProcess use the ErrornousScript so the ConsoleApplication will be called. Modify the build definition and make sure that the ErrornousScript is executing the exe that is setting the ExitCode to 1. You have now setup a build definition that will execute the errornous Console Application. When you run it, you will see that the build succeeds. This is not what you want! To solve this, you can make use of the Result property on the InvokeProcess activity. So lets change our Build Process Template. Add the new variables (scoped to the sequence where you run the Console Application) called ExitCode (type = Int32) and ErrorMessage Click on the InvokeProcess activity and change the Result property to ExitCode In the Handle Standard Output of the InvokeProcess add a Sequence activity In the Sequence activity, add an Assign primitive. Set the following properties: To = ErrorMessage Value = If(Not String.IsNullOrEmpty(ErrorMessage), Environment.NewLine + ErrorMessage, "") + stdOutput And add the default BuildMessage to the sequence that outputs the stdOutput Add beneath the InvokeProcess activity and If activity with the condition ExitCode <> 0 In the Then section add a Throw activity and set the Exception property to New Exception(ErrorMessage) The complete workflow looks now like When you now check in the Build Process Template and run the build, you get the following result And that is exactly what we want.   You can download the full solution at BuildProcess.zip. It will include the sources of every part and will continue to evolve.

    Read the article

  • ArchBeat Link-o-Rama Top 10 for September 9-15, 2012

    - by Bob Rhubart
    The Top 10 most-viewed items shared on the OTN ArchBeat Facebook page for the week of September 9-15, 2017. 15 Lessons from 15 Years as a Software Architect | Ingo Rammer In this presentation from the GOTO Conference in Copenhagen, Ingo Rammer shares 15 tips regarding people, complexity and technology that he learned doing software architecture for 15 years. Attend OTN Architect Day – by Architects, for Architects – October 25 You won't need 3D glasses to take in these live presentations (8 sessions, two tracks) on Cloud computing, SOA, and engineered systems. And the ticket price is: Zero. Nothing. Absolutely free. Register now for Oracle Technology Network Architect Day in Los Angeles. Thursday October 25, 2012, 8:00 a.m. – 5:00 p.m. Sofitel Los Angeles , 8555 Beverly Boulevard , Los Angeles, CA 90048. Cloud API and service designers, stop thinking small | Cloud Computing - InfoWorld "The focus must shift away from fine-grained APIs that provide some type of primitive service, such as pushing data to a block of storage or perhaps making a request to a cloud-rooted database," says InfoWorld's David Linthicum. "To go beyond primitives, you must understand how these services should be used in a much larger architectural context. In other words, you need to understand how businesses will employ these services to form real workplace solutions—inside and outside the enterprise." Adding a runtime picker to a taskflow parameter in WebCenter | Yannick Ongena Oracle ACE Yannick Ongena shows how to create an Oracle WebCenter popup to allow users to "select items or do more complex things." Oracle IAM 11g R2 docs are now available "One of the great things about the new doc set is the inclusion of ePub files," says Fusion Middleware A-Team blogger Chris Johnson. "This means that if you have an iPad you can load up the doc library onto that and read the docs on the couch." Setting up a local Yum Server using the Exalogic ZFS Storage Appliance | Donald A concise technical post from the man named Donald. What's New in Oracle VM VirtualBox 4.2? | The Fat Bloke Sings "One of the trends we've seen is that as the average host platform becomes more powerful, our users are consistently running more and more vm's," says The Fat Bloke. "Some of our users have large libraries of vm's of various vintages, whilst others have groups of vm's that are run together as an assembly of the various tiers in a multi-tiered software solution, for example, a database tier, middleware tier, and front-ends." The new VirtualBox release, a year in the making, addresses the needs of these users, he explains. Configuring Oracle Business Intelligence 11g MDS XML Source Control Management with Git Version Control | Christian Screen Oracle ACE Christian Screen developed this tutorial for those interested in learning how to configure the Oracle Business Intelligence 11g (11.1.1.6) metadata repository for development using the new MDS XML source control management functionality. Identity and Access Management at Oracle Open World 2012 | Brian Eidelman Fusion Middleware A-Team blogger Brian Eideleman highlights three Oracle Openworld sessions that will put Identity and Access Management in the spotlight, and shares a link to the "Focus On: Identity Management" document, a comprehensive listing of Openworld activities also dealing with IM. Starting and stopping WebLogic automatically using Upstart | Chris Johnson "In Ubuntu, RedHat and Oracle Linux there's a new flavor of init called Upstart that all the kids are using," says Oracle Fusion Middleware A-Team member Chris Johnson. "It's the new hotness when it comes to making programs into daemons and wiring them to start and stop at appropriate times." Thought for the Day "The purpose of software engineering is to control complexity, not to create it." — Pamela Zave Source: SoftwareQuotes.com

    Read the article

  • Clever memory usage through the years

    - by Ben Emmett
    A friend and I were recently talking about the really clever tricks people have used to get the most out of memory. I thought I’d share my favorites, and would love to hear yours too! Interleaving on drum memory Back in the ye olde days before I’d been born (we’re talking the 50s / 60s here), working memory commonly took the form of rotating magnetic drums. These would spin at a constant speed, and a fixed head would read from memory when the correct part of the drum passed it by, a bit like a primitive platter disk. Because each revolution took a few milliseconds, programmers took to manually arranging information non-sequentially on the drum, timing when an instruction or memory address would need to be accessed, then spacing information accordingly around the edge of the drum, thus reducing the access delay. Similar techniques were still used on hard disks and floppy disks into the 90s, but have become irrelevant with modern disk technologies. The Hashlife algorithm Conway’s Game of Life has attracted numerous implementations over the years, but Bill Gosper’s Hashlife algorithm is particularly impressive. Taking advantage of the repetitive nature of many cellular automata, it uses a quadtree structure to store the hashes of pieces of the overall grid. Over time there are fewer and fewer new structures which need to be evaluated, so it starts to run faster with larger grids, drastically outperforming other algorithms both in terms of speed and the size of grid which can be simulated. The actual amount of memory used is huge, but it’s used in a clever way, so makes the list . Elite’s procedural generation Ok, so this isn’t exactly a memory optimization – more a storage optimization – but it gets an honorable mention anyway. When writing Elite, David Braben and Ian Bell wanted to build a rich world which gamers could explore, but their 22K memory was something of a limitation (for comparison that’s about the size of my avatar picture at the top of this page). They procedurally generated all the characteristics of the 2048 planets in their virtual universe, including the names, which were stitched together using a lookup table of parts of names. In fact the original plans were for 2^52 planets, but it was decided that that was probably too many. Oh, and they did that all in assembly language. Other games of the time used similar techniques too – The Sentinel’s landscape generation algorithm being another example. Modern Garbage Collectors Garbage collection in managed languages like Java and .NET ensures that most of the time, developers stop needing to care about how they use and clean up memory as the garbage collector handles it automatically. Achieving this without killing performance is a near-miraculous feet of software engineering. Much like when learning chemistry, you find that every time you think you understand how the garbage collector works, it turns out to be a mere simplification; that there are yet more complexities and heuristics to help it run efficiently. Of course introducing memory problems is still possible (and there are tools like our memory profiler to help if that happens to you) but they’re much, much rarer. A cautionary note In the examples above, there were good and well understood reasons for the optimizations, but cunningly optimized code has usually had to trade away readability and maintainability to achieve its gains. Trying to optimize memory usage without being pretty confident that there’s actually a problem is doing it wrong. So what have I missed? Tell me about the ingenious (or stupid) tricks you’ve seen people use. Ben

    Read the article

  • Musings on the launch of SQL Monitor

    - by Phil Factor
    For several years, I was responsible for the smooth running of a large number of enterprise database servers. We ran a network monitoring tool that was primitive by today’s standards but which performed the useful function of polling every system, including all the Servers in my charge. It ran a configurable script for each service that you needed to monitor that was merely required to return one of a number of integer values. These integer values represented the pain level of the service, from 10 (“hurtin’ real bad”) to 1 (“Things is great”). Not only could you program the visual appearance of each server on the network diagram according to the value of the integer, but you could even opt to run a sound file. Very soon, we had a large TFT Screen, high on the wall of the server room, with every server represented by an icon, and a speaker next to it that would give out a series of grunts, groans, snores, shrieks and funeral marches, depending on the problem. One glance at the display, and you could dive in with iSQL/QA/SSMS and check what was going on with your favourite diagnostic tools. If you saw a server icon burst into flames on the screen or droop like a jelly, you dropped your mug of coffee to do it.  It was real fun, but I remember it more for the huge difference it made to have that real-time visibility into how your servers are performing. The management soon stopped making jokes about the real reason we wanted the TFT screen. (It rendered DVDs beautifully they said; particularly flesh-tints). If you are instantly alerted when things start to go wrong, then there was a good chance you could fix it before being alerted to the problem by the users of the system.  There is a world of difference between this sort of tool, one that gives whoever is ‘on watch’ in the server room the first warning of a potential problem on one of any number of servers, and the breed of tool that attempts to provide some sort of prosthetic DBA Brain. I like to get the early warning, to get the right information to help to diagnose a problem: No auto-fix, but just the information. I prefer to leave the task of ascertaining the exact cause of a problem to my own routines, custom code, intuition and forensic instincts. A simulated aircraft cockpit doesn’t do anything for me, especially before I know where I should be flying.  Time has moved on, and that TFT screen is now, with SQL Monitor, an iPad or any other mobile or static device that can support a browser. Rather than trying to reproduce the conceptual topology of the servers, it lists them in their groups so as to give a display that scales with the increasing number of databases you monitor.  It gives the history of the major events and trends for the servers. It gives the icons and colours that you can spot out of the corner of your eye, but goes on to give you just enough information in drill-down to give you a much clearer idea of where to look with your DBA tools and routines. It doesn't swamp you with information.  Whereas a few server and database-level problems are pretty easily fixed, others depend on judgement and experience to sort out.  Although the idea of an application that automates the bulk of a DBA’s skills is attractive to many, I can’t see it happening soon. SQL Server’s complexity increases faster than the panaceas can be created. In the meantime, I believe that the best way of helping  DBAs  is to make the monitoring process as simple and effective as possible,  and provide the right sort of detail and ‘evidence’ to allow them to decide on the fix. In the end, it is still down to the skill of the DBA.

    Read the article

  • NHibernate Pitfalls: Custom Types and Detecting Changes

    - by Ricardo Peres
    This is part of a series of posts about NHibernate Pitfalls. See the entire collection here. NHibernate supports the declaration of properties of user-defined types, that is, not entities, collections or primitive types. These are used for mapping a database columns, of any type, into a different type, which may not even be an entity; think, for example, of a custom user type that converts a BLOB column into an Image. User types must implement interface NHibernate.UserTypes.IUserType. This interface specifies an Equals method that is used for comparing two instances of the user type. If this method returns false, the entity is marked as dirty, and, when the session is flushed, will trigger an UPDATE. So, in your custom user type, you must implement this carefully so that it is not mistakenly considered changed. For example, you can cache the original column value inside of it, and compare it with the one in the other instance. Let’s see an example implementation of a custom user type that converts a Byte[] from a BLOB column into an Image: 1: [Serializable] 2: public sealed class ImageUserType : IUserType 3: { 4: private Byte[] data = null; 5: 6: public ImageUserType() 7: { 8: this.ImageFormat = ImageFormat.Png; 9: } 10: 11: public ImageFormat ImageFormat 12: { 13: get; 14: set; 15: } 16: 17: public Boolean IsMutable 18: { 19: get 20: { 21: return (true); 22: } 23: } 24: 25: public Object Assemble(Object cached, Object owner) 26: { 27: return (cached); 28: } 29: 30: public Object DeepCopy(Object value) 31: { 32: return (value); 33: } 34: 35: public Object Disassemble(Object value) 36: { 37: return (value); 38: } 39: 40: public new Boolean Equals(Object x, Object y) 41: { 42: return (Object.Equals(x, y)); 43: } 44: 45: public Int32 GetHashCode(Object x) 46: { 47: return ((x != null) ? x.GetHashCode() : 0); 48: } 49: 50: public override Int32 GetHashCode() 51: { 52: return ((this.data != null) ? this.data.GetHashCode() : 0); 53: } 54: 55: public override Boolean Equals(Object obj) 56: { 57: ImageUserType other = obj as ImageUserType; 58: 59: if (other == null) 60: { 61: return (false); 62: } 63: 64: if (Object.ReferenceEquals(this, other) == true) 65: { 66: return (true); 67: } 68: 69: return (this.data.SequenceEqual(other.data)); 70: } 71: 72: public Object NullSafeGet(IDataReader rs, String[] names, Object owner) 73: { 74: Int32 index = rs.GetOrdinal(names[0]); 75: Byte[] data = rs.GetValue(index) as Byte[]; 76: 77: this.data = data as Byte[]; 78: 79: if (data == null) 80: { 81: return (null); 82: } 83: 84: using (MemoryStream stream = new MemoryStream(this.data ?? new Byte[0])) 85: { 86: return (Image.FromStream(stream)); 87: } 88: } 89: 90: public void NullSafeSet(IDbCommand cmd, Object value, Int32 index) 91: { 92: if (value != null) 93: { 94: Image data = value as Image; 95: 96: using (MemoryStream stream = new MemoryStream()) 97: { 98: data.Save(stream, this.ImageFormat); 99: value = stream.ToArray(); 100: } 101: } 102: 103: (cmd.Parameters[index] as DbParameter).Value = value ?? DBNull.Value; 104: } 105: 106: public Object Replace(Object original, Object target, Object owner) 107: { 108: return (original); 109: } 110: 111: public Type ReturnedType 112: { 113: get 114: { 115: return (typeof(Image)); 116: } 117: } 118: 119: public SqlType[] SqlTypes 120: { 121: get 122: { 123: return (new SqlType[] { new SqlType(DbType.Binary) }); 124: } 125: } 126: } In this case, we need to cache the original Byte[] data because it’s not easy to compare two Image instances, unless, of course, they are the same.

    Read the article

  • IP failover with 2 nodes on different subnet: cannot ping virtual IP from second node?

    - by quanta
    I'm going to setup redundant failover Redmine: another instance was installed on the second server without problem MySQL (running on the same machine with Redmine) was configured as master-master replication Because they are in different subnet (192.168.3.x and 192.168.6.x), it seems that VIPArip is the only choice. /etc/ha.d/ha.cf on node1 logfacility none debug 1 debugfile /var/log/ha-debug logfile /var/log/ha-log autojoin none warntime 3 deadtime 6 initdead 60 udpport 694 ucast eth1 node2.ip keepalive 1 node node1 node node2 crm respawn /etc/ha.d/ha.cf on node2: logfacility none debug 1 debugfile /var/log/ha-debug logfile /var/log/ha-log autojoin none warntime 3 deadtime 6 initdead 60 udpport 694 ucast eth0 node1.ip keepalive 1 node node1 node node2 crm respawn crm configure show: node $id="6c27077e-d718-4c82-b307-7dccaa027a72" node1 node $id="740d0726-e91d-40ed-9dc0-2368214a1f56" node2 primitive VIPArip ocf:heartbeat:VIPArip \ params ip="192.168.6.8" nic="lo:0" \ op start interval="0" timeout="20s" \ op monitor interval="5s" timeout="20s" depth="0" \ op stop interval="0" timeout="20s" \ meta is-managed="true" property $id="cib-bootstrap-options" \ stonith-enabled="false" \ dc-version="1.0.12-unknown" \ cluster-infrastructure="Heartbeat" \ last-lrm-refresh="1338870303" crm_mon -1: ============ Last updated: Tue Jun 5 18:36:42 2012 Stack: Heartbeat Current DC: node2 (740d0726-e91d-40ed-9dc0-2368214a1f56) - partition with quorum Version: 1.0.12-unknown 2 Nodes configured, unknown expected votes 1 Resources configured. ============ Online: [ node1 node2 ] VIPArip (ocf::heartbeat:VIPArip): Started node1 ip addr show lo: 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet 192.168.6.8/32 scope global lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever I can ping 192.168.6.8 from node1 (192.168.3.x): # ping -c 4 192.168.6.8 PING 192.168.6.8 (192.168.6.8) 56(84) bytes of data. 64 bytes from 192.168.6.8: icmp_seq=1 ttl=64 time=0.062 ms 64 bytes from 192.168.6.8: icmp_seq=2 ttl=64 time=0.046 ms 64 bytes from 192.168.6.8: icmp_seq=3 ttl=64 time=0.059 ms 64 bytes from 192.168.6.8: icmp_seq=4 ttl=64 time=0.071 ms --- 192.168.6.8 ping statistics --- 4 packets transmitted, 4 received, 0% packet loss, time 3000ms rtt min/avg/max/mdev = 0.046/0.059/0.071/0.011 ms but cannot ping virtual IP from node2 (192.168.6.x) and outside. Did I miss something? PS: you probably want to set IP2UTIL=/sbin/ip in the /usr/lib/ocf/resource.d/heartbeat/VIPArip resource agent script if you get something like this: Jun 5 11:08:10 node1 lrmd: [19832]: info: RA output: (VIPArip:stop:stderr) 2012/06/05_11:08:10 ERROR: Invalid OCF_RESK EY_ip [192.168.6.8] http://www.clusterlabs.org/wiki/Debugging_Resource_Failures Reply to @DukeLion: Which router receives RIP updates? When I start the VIPArip resource, ripd was run with below configuration file (on node1): /var/run/resource-agents/VIPArip-ripd.conf: hostname ripd password zebra debug rip events debug rip packet debug rip zebra log file /var/log/quagga/quagga.log router rip !nic_tag no passive-interface lo:0 network lo:0 distribute-list private out lo:0 distribute-list private in lo:0 !metric_tag redistribute connected metric 3 !ip_tag access-list private permit 192.168.6.8/32 access-list private deny any

    Read the article

  • SSAS: Using fake dimension and scopes for dynamic ranges

    - by DigiMortal
    In one of my BI projects I needed to find count of objects in income range. Usual solution with range dimension was useless because range where object belongs changes in time. These ranges depend on calculation that is done over incomes measure so I had really no option to use some classic solution. Thanks to SSAS forums I got my problem solved and here is the solution. The problem – how to create dynamic ranges? I have two dimensions in SSAS cube: one for invoices related to objects rent and the other for objects. There is measure that sums invoice totals and two calculations. One of these calculations performs some computations based on object income and some other object attributes. Second calculation uses first one to define income ranges where object belongs. What I need is query that returns me how much objects there are in each group. I cannot use dimension for range because on one date object may belong to one range and two days later to another income range. By example, if object is not rented out for two days it makes no money and it’s income stays the same as before. If object is rented out after two days it makes some income and this income may move it to another income range. Solution – fake dimension and scopes Thanks to Gerhard Brueckl from pmOne I got everything work fine after some struggling with BI Studio. The original discussion he pointed out can be found from SSAS official forums thread Create a banding dimension that groups by a calculated measure. Solution was pretty simple by nature – we have to define fake dimension for our range and use scopes to assign values for object count measure. Object count measure is primitive – it just counts objects and that’s it. We will use it to find out how many objects belong to one or another range. We also need table for fake ranges and we have to fill it with ranges used in ranges calculation. After creating the table and filling it with ranges we can add fake range dimension to our cube. Let’s see now how to solve the problem step-by-step. Solving the problem Suppose you have ranges calculation defined like this: CASE WHEN [Measures].[ComplexCalc] < 0 THEN 'Below 0'WHEN [Measures].[ComplexCalc] >=0 AND  [Measures].[ComplexCalc] <=50 THEN '0 - 50'...END Let’s create now new table to our analysis database and name it as FakeIncomeRange. Here is the definition for table: CREATE TABLE [FakeIncomeRange] (     [range_id] [int] IDENTITY(1,1) NOT NULL,     [range_name] [nvarchar](50) NOT NULL,     CONSTRAINT [pk_fake_income_range] PRIMARY KEY CLUSTERED      (         [range_id] ASC     ) ) Don’t forget to fill this table with range labels you are using in ranges calculation. To use ranges from table we have to add this table to our data source view and create new dimension. We cannot bind this table to other tables but we have to leave it like it is. Our dimension has two attributes: ID and Name. The next thing to create is calculation that returns objects count. This calculation is also fake because we override it’s values for all ranges later. Objects count measure can be defined as calculation like this: COUNT([Object].[Object].[Object].members) Now comes the most crucial part of our solution – defining the scopes. Based on data used in this posting we have to define scope for each of our ranges. Here is the example for first range. SCOPE([FakeIncomeRange].[Name].&[Below 0], [Measures].[ObjectCount])     This=COUNT(            FILTER(                [Object].[Object].[Object].members,                 [Measures].[ComplexCalc] < 0          )     ) END SCOPE To get these scopes defined in cube we need MDX script blocks for each line given here. Take a look at the screenshot to get better idea what I mean. This example is given from SQL Server books online to avoid conflicts with NDA. :) From previous example the lines (MDX scripts) are: Line starting with SCOPE Block for This = Line with END SCOPE And now it is time to deploy and process our cube. Although you may see examples where there are semicolons in the end of statements you don’t need them. Visual Studio BI tools generate separate command from each script block so you don’t need to worry about it.

    Read the article

  • Knockoutjs - stringify to handling observables and custom events

    - by Renso
    Goal: Once you viewmodel has been built and populated with data, at some point it goal of it all is to persist the data to the database (or some other media). Regardless of where you want to save it, your client-side viewmodel needs to be converted to a JSON string and sent back to the server. Environment considerations: jQuery 1.4.3+ Knockoutjs version 1.1.2   How to: So let’s set the stage, you are using Knockoutjs and you have a viewmodel with some Knockout dependencies. You want to make sure it is in the proper JSON format and via ajax post it to the server for persistence.   First order of business is to deal with the viewmodel (JSON) object. To most the JSON stringifier sounds familiar. The JSON stringifier converts JavaScript data structures into JSON text. JSON does not support cyclic data structures, so be careful to not give cyclical structures to the JSON stringifier. You may ask, is this the best way to do it? What about those observables and other Knockout properties that I don’t want to persist or want their actual value persisted and not their function, etc. Not sure if you were aware, but KO already has a method; ko.utils.stringifyJson() - it's mostly just a wrapper around JSON.stringify. (which is native in some browsers, and can be made available by referencing json2.js in others). What does it do that the regular stringify does not is that it automatically converts observable, dependentObservable, or observableArray to their underlying value to JSON. Hold on! There is a new feature in this version of Knockout, the ko.toJSON. It is part of the core library and it will clone the view model’s object graph, so you don’t mess it up after you have stringified  it and unwrap all its observables. It's smart enough to avoid reference cycles. Since you are using the MVVM pattern it would assume you are not trying to reference DOM nodes from your view. Wait a minute. I can already see this info on the http://knockoutjs.com/examples/contactsEditor.html website, why mention it all here? First of this is a much nicer blog, no orange ? At this time, you may want to have a look at the blog and see what I am talking about. See the save event, how they stringify the view model’s contacts only? That’s cool but what if your view model is a representation of your object you want to persist, meaning it has no property that represents the json object you want to persist, it is the view model itself. The example in http://knockoutjs.com/examples/contactsEditor.html assumes you have a list of contacts you may want to persist. In the example here, you want to persist the view model itself. The viewmodel here looks something like this:     var myViewmodel = {         accountName: ko.observable(""),         accountType: ko.observable("Active")     };     myViewmodel.isItActive = ko.dependentObservable(function () {         return myViewmodel.accountType() == "Active";     });     myViewmodel.clickToSaveMe = function() {         SaveTheAccount();     }; Here is the function in charge of saving the account: Function SaveTheAccount() {     $.ajax({         data: ko.toJSON(viewmodel),         url: $('#ajaxSaveAccountUrl').val(),         type: "POST",         dataType: "json",         async: false,         success: function (result) {             if (result && result.Success == true) {                 $('#accountMessage').html('<span class="fadeMyContainerSlowly">The account has been saved</span>').show();                 FadeContainerAwaySlowly();             }         },         error: function (xmlHttpRequest, textStatus, errorThrown) {             alert('An error occurred: ' + errorThrown);         }     }); //ajax }; Try run this and your browser will eventually freeze up or crash. Firebug will tell you that you have a repetitive call to the first function call in your model that keeps firing infinitely.  What is happening is that Knockout serializes the view model to a JSON string by traversing the object graph and firing off the functions, again-and-again. Not sure why it does that, but it does. So what is the work around: Nullify your function calls and then post it:         var lightweightModel = viewmodel.clickToSaveMe = null;         data: ko.toJSON(lightweightModel), So then I traced the JSON string on the server and found it having issues with primitive types. C#, by the way. So I changed ko.toJSON(model) to ko.toJS(model), and that solved my problem. Of course you could just create a property on the viewmodel for the account itself, so you only have to serialize the property and not the entire viewmodel. If that is an option then that would be the way to go. If your view model contains other properties in the view model that you also want to post then that would not be an option and then you’ll know what to watch out for. Hope this helps.

    Read the article

  • ASP.NET MVC: Converting business objects to select list items

    - by DigiMortal
    Some of our business classes are used to fill dropdown boxes or select lists. And often you have some base class for all your business classes. In this posting I will show you how to use base business class to write extension method that converts collection of business objects to ASP.NET MVC select list items without writing a lot of code. BusinessBase, BaseEntity and other base classes I prefer to have some base class for all my business classes so I can easily use them regardless of their type in contexts I need. NB! Some guys say that it is good idea to have base class for all your business classes and they also suggest you to have mappings done same way in database. Other guys say that it is good to have base class but you don’t have to have one master table in database that contains identities of all your business objects. It is up to you how and what you prefer to do but whatever you do – think and analyze first, please. :) To keep things maximally simple I will use very primitive base class in this example. This class has only Id property and that’s it. public class BaseEntity {     public virtual long Id { get; set; } } Now we have Id in base class and we have one more question to solve – how to better visualize our business objects? To users ID is not enough, they want something more informative. We can define some abstract property that all classes must implement. But there is also another option we can use – overriding ToString() method in our business classes. public class Product : BaseEntity {     public virtual string SKU { get; set; }     public virtual string Name { get; set; }       public override string ToString()     {         if (string.IsNullOrEmpty(Name))             return base.ToString();           return Name;     } } Although you can add more functionality and properties to your base class we are at point where we have what we needed: identity and human readable presentation of business objects. Writing list items converter Now we can write method that creates list items for us. public static class BaseEntityExtensions {            public static IEnumerable<SelectListItem> ToSelectListItems<T>         (this IList<T> baseEntities) where T : BaseEntity     {         return ToSelectListItems((IEnumerator<BaseEntity>)                    baseEntities.GetEnumerator());     }       public static IEnumerable<SelectListItem> ToSelectListItems         (this IEnumerator<BaseEntity> baseEntities)     {         var items = new HashSet<SelectListItem>();           while (baseEntities.MoveNext())         {             var item = new SelectListItem();             var entity = baseEntities.Current;               item.Value = entity.Id.ToString();             item.Text = entity.ToString();               items.Add(item);         }           return items;     } } You can see here to overloads of same method. One works with List<T> and the other with IEnumerator<BaseEntity>. Although mostly my repositories return IList<T> when querying data there are always situations where I can use more abstract types and interfaces. Using extension methods in code In your code you can use ToSelectListItems() extension methods like shown on following code fragment. ... var model = new MyFormModel(); model.Statuses = _myRepository.ListStatuses().ToSelectListItems(); ... You can call this method on all your business classes that extend your base entity. Wanna have some fun with this code? Write overload for extension method that accepts selected item ID.

    Read the article

  • Advanced donut caching: using dynamically loaded controls

    - by DigiMortal
    Yesterday I solved one caching problem with local community portal. I enabled output cache on SharePoint Server 2007 to make site faster. Although caching works fine I needed to do some additional work because there are some controls that show different content to different users. In this example I will show you how to use “donut caching” with user controls – powerful way to drive some content around cache. About donut caching Donut caching means that although you are caching your content you have some holes in it so you can still affect the output that goes to user. By example you can cache front page on your site and still show welcome message that contains correct user name. To get better idea about donut caching I suggest you to read ScottGu posting Tip/Trick: Implement "Donut Caching" with the ASP.NET 2.0 Output Cache Substitution Feature. Basically donut caching uses ASP.NET substitution control. In output this control is replaced by string you return from static method bound to substitution control. Again, take a look at ScottGu blog posting I referred above. Problem If you look at Scott’s example it is pretty plain and easy by its output. All it does is it writes out current user name as string. Here are examples of my login area for anonymous and authenticated users:    It is clear that outputting mark-up for these views as string is pretty lame to implement in code at string level. Every little change in design will end up with new version of controls library because some parts of design “live” there. Solution: using user controls I worked out easy solution to my problem. I used cache substitution and user controls together. I have three user controls: LogInControl – this is the proxy control that checks which “real” control to load. AnonymousLogInControl – template and logic for anonymous users login area. AuthenticatedLogInControl – template and logic for authenticated users login area. This is the control we render for each user separately because it contains user name and user profile fill percent. Anonymous control is not very interesting because it is only about keeping mark-up in separate file. Interesting parts are LogInControl and AuthenticatedLogInControl. Creating proxy control The first thing was to create control that has substitution area where “real” control is loaded. This proxy control should also be available to decide which control to load. The definition of control is very primitive. <%@ Control EnableViewState="false" Inherits="MyPortal.Profiles.LogInControl" %> <asp:Substitution runat="server" MethodName="ShowLogInBox" /> But code is a little bit tricky. Based on current user instance we decide which login control to load. Then we create page instance and load our control through it. When control is loaded we will call DataBind() method. In this method we evaluate all fields in loaded control (it was best choice as Load and other events will not be fired). Take a look at the code. public static string ShowLogInBox(HttpContext context) {     var user = SPContext.Current.Web.CurrentUser;     string controlName;       if (user != null)         controlName = "AuthenticatedLogInControl.ascx";     else         controlName = "AnonymousLogInControl.ascx";       var path = "~/_controltemplates/" + controlName;     var output = new StringBuilder(10000);       using(var page = new Page())     using(var ctl = page.LoadControl(path))     using(var writer = new StringWriter(output))     using(var htmlWriter = new HtmlTextWriter(writer))     {         ctl.DataBind();         ctl.RenderControl(htmlWriter);     }     return output.ToString(); } When control is bound to data we ask to render it its contents to StringBuilder. Now we have the output of control as string and we can return it from our method. Of course, notice how correct I am with resources disposing. :) The method that returns contents for substitution control is static method that has no connection with control instance because hen page is read from cache there are no instances of controls available. Conclusion As you saw it was not very hard to use donut caching with user controls. Instead of writing mark-up of controls to static method that is bound to substitution control we can still use our user controls.

    Read the article

  • Getting to grips with the stack in nasm

    - by MarkPearl
    Today I spent a good part of my day getting to grips with the stack and nasm. After looking at my notes on nasm I think this is one area for the course I am doing they could focus more on… So here are some snippets I have put together that have helped me understand a little bit about the stack… Simplest example of the stack You will probably see examples like the following in circulation… these demonstrate the simplest use of the stack… org 0x100 bits 16 jmp main main: push 42h push 43h push 44h mov ah,2h ;set to display characters pop dx    ;get the first value int 21h   ;and display it pop dx    ;get 2nd value int 21h   ;and display it pop dx    ;get 3rd value int 21h   ;and display it int 20h The output from above code would be… DCB Decoupling code using “call” and “ret” This is great, but it oversimplifies what I want to use the stack for… I do not know if this goes against the grain of assembly programmers or not, but I want to write loosely coupled assembly code – and I want to use the stack as a mechanism for passing values into my decoupled code. In nasm we have the call and return instructions, which provides a mechanism for decoupling code, for example the following could be done… org 0x100 bits 16 jmp main ;---------------------------------------- displayChar: mov ah,2h mov dx,41h int 21h ret ;---------------------------------------- main: call displayChar int 20h   This would output the following to the console A So, it would seem that call and ret allow us to jump to segments of our code and then return back to the calling position – a form of segmenting the code into what we would called in higher order languages “functions” or “methods”. The only issue is, in higher order languages there is a way to pass parameters into the functions and return results. Because of the primitive nature of the call and ret instructions, this does not seem to be obvious. We could of course use the registers to pass values into the subroutine and set values coming out, but the problem with this is we… Have a limited number of registers Are threading our code with tight coupling (it would be hard to migrate methods outside of their intended use in a particular program to another one) With that in mind, I turn to the stack to provide a loosely coupled way of calling subroutines… First attempt with the Stack Initially I thought this would be simple… we could use code that looks as follows to achieve what I want… org 0x100 bits 16 jmp main ;---------------------------------------- displayChar: mov ah,2h pop dx int 21h ret ;---------------------------------------- main: push 41h call displayChar int 20h   However running this application does not give the desired result, I want an ‘A’ to be returned, and I am getting something totally different (you will to). Reading up on the call and ret instructions a discovery is made… they are pushing and popping things onto and off the stack as well… When the call instruction is executed, the current value of IP (the address of the instruction to follow) is pushed onto the stack, when ret is called, the last value on the stack is popped off into the IP register. In effect what the above code is doing is as follows with the stack… push 41h push current value of ip pop current value of ip to dx pop 41h to ip This is not what I want, I need to access the 41h that I pushed onto the stack, but the call value (which is necessary) is putting something in my way. So, what to do? Remember we have other registers we can use as well as a thing called indirect addressing… So, after some reading around, I came up with the following approach using indirect addressing… org 0x100 bits 16 jmp main ;---------------------------------------- displayChar: mov bp,sp mov ah,2h mov dx,[bp+2] int 21h ret ;---------------------------------------- main: push 41h call displayChar int 20h In essence, what I have done here is used a trick with the stack pointer… it goes as follows… Push 41 onto the stack Make the call to the function, which will push the IP register onto the stack and then jump to the displayChar label Move the value in the stack point to the bp register (sp currently points at IP register) Move the at the location of bp minus 2 bytes to dx (this is now the value 41h) display it, execute the ret instruction, which pops the ip value off the stack and goes back to the calling point This approach is still very raw, some further reading around shows that I should be pushing the value of bp onto the stack before replacing it with sp, but it is the starting thread to getting loosely coupled subroutines. Let’s see if you get what the following output would be? org 0x100 bits 16 jmp main ;---------------------------------------- displayChar: mov bp,sp mov ah,2h mov dx,[bp+4] int 21h mov dx,[bp+2] int 21h ret ;---------------------------------------- main: push 41h push 42h call displayChar int 20h The output is… AB Where to from here? If by any luck some assembly programmer comes along and see this code and notices that I have made some fundamental flaw in my logic… I would like to know, so please leave a comment… appreciate any feedback!

    Read the article

  • Driver error when using multiple shaders

    - by Jinxi
    I'm using 3 different shaders: a tessellation shader to use the tessellation feature of DirectX11 :) a regular shader to show how it would look without tessellation and a text shader to display debug-info such as FPS, model count etc. All of these shaders are initialized at the beginning. Using the keyboard, I can switch between the tessellation shader and regular shader to render the scene. Additionally, I also want to be able toggle the display of debug-info using the text shader. Since implementing the tessellation shader the text shader doesn't work anymore. When I activate the DebugText (rendered using the text-shader) my screens go black for a while, and Windows displays the following message: Display Driver stopped responding and has recovered This happens with either of the two shaders used to render the scene. Additionally: I can start the application using the regular shader to render the scene and then switch to the tessellation shader. If I try to switch back to the regular shader I get the same error as with the text shader. What am I doing wrong when switching between shaders? What am I doing wrong when displaying text at the same time? What file can I post to help you help me? :) thx P.S. I already checked if my keyinputs interrupt at the wrong time (during render or so..), but that seems to be ok Testing Procedure Regular Shader without text shader Add text shader to Regular Shader by keyinput (works now, I built the text shader back to only vertex and pixel shader) (somthing with the z buffer is stil wrong...) Remove text shader, then change shader to Tessellation Shader by key input Then if I add the Text Shader or switch back to the Regular Shader Switching/Render Shader Here the code snipet from the Renderer.cpp where I choose the Shader according to the boolean "m_useTessellationShader": if(m_useTessellationShader) { // Render the model using the tesselation shader ecResult = m_ShaderManager->renderTessellationShader(m_D3D->getDeviceContext(), meshes[lod_level]->getIndexCount(), worldMatrix, viewMatrix, projectionMatrix, textures, texturecount, m_Light->getDirection(), m_Light->getAmbientColor(), m_Light->getDiffuseColor(), (D3DXVECTOR3)m_Camera->getPosition(), TESSELLATION_AMOUNT); } else { // todo: loaded model depends on distance to camera // Render the model using the light shader. ecResult = m_ShaderManager->renderShader(m_D3D->getDeviceContext(), meshes[lod_level]->getIndexCount(), lod_level, textures, texturecount, m_Light->getDirection(), m_Light->getAmbientColor(), m_Light->getDiffuseColor(), worldMatrix, viewMatrix, projectionMatrix); } And here the code snipet from the Mesh.cpp where I choose the Typology according to the boolean "useTessellationShader": // RenderBuffers is called from the Render function. The purpose of this function is to set the vertex buffer and index buffer as active on the input assembler in the GPU. Once the GPU has an active vertex buffer it can then use the shader to render that buffer. void Mesh::renderBuffers(ID3D11DeviceContext* deviceContext, bool useTessellationShader) { unsigned int stride; unsigned int offset; // Set vertex buffer stride and offset. stride = sizeof(VertexType); offset = 0; // Set the vertex buffer to active in the input assembler so it can be rendered. deviceContext->IASetVertexBuffers(0, 1, &m_vertexBuffer, &stride, &offset); // Set the index buffer to active in the input assembler so it can be rendered. deviceContext->IASetIndexBuffer(m_indexBuffer, DXGI_FORMAT_R32_UINT, 0); // Check which Shader is used to set the appropriate Topology // Set the type of primitive that should be rendered from this vertex buffer, in this case triangles. if(useTessellationShader) { deviceContext->IASetPrimitiveTopology(D3D11_PRIMITIVE_TOPOLOGY_3_CONTROL_POINT_PATCHLIST); }else{ deviceContext->IASetPrimitiveTopology(D3D11_PRIMITIVE_TOPOLOGY_TRIANGLELIST); } return; } RenderShader Could there be a problem using sometimes only vertex and pixel shader and after switching using vertex, hull, domain and pixel shader? Here a little overview of my architecture: TextClass: uses font.vs and font.ps deviceContext-VSSetShader(m_vertexShader, NULL, 0); deviceContext-PSSetShader(m_pixelShader, NULL, 0); deviceContext-PSSetSamplers(0, 1, &m_sampleState); RegularShader: uses vertex.vs and pixel.ps deviceContext-VSSetShader(m_vertexShader, NULL, 0); deviceContext-PSSetShader(m_pixelShader, NULL, 0); deviceContext-PSSetSamplers(0, 1, &m_sampleState); TessellationShader: uses tessellation.vs, tessellation.hs, tessellation.ds, tessellation.ps deviceContext-VSSetShader(m_vertexShader, NULL, 0); deviceContext-HSSetShader(m_hullShader, NULL, 0); deviceContext-DSSetShader(m_domainShader, NULL, 0); deviceContext-PSSetShader(m_pixelShader, NULL, 0); deviceContext-PSSetSamplers(0, 1, &m_sampleState); ClearState I'd like to switch between 2 shaders and it seems they have different context parameters, right? In clearstate methode it says it resets following params to NULL: I found following in my Direct3D Class: depth-stencil state - m_deviceContext-OMSetDepthStencilState rasterizer state - m_deviceContext-RSSetState(m_rasterState); blend state - m_device-CreateBlendState viewports - m_deviceContext-RSSetViewports(1, &viewport); I found following in every Shader Class: input/output resource slots - deviceContext-PSSetShaderResources shaders - deviceContext-VSSetShader to - deviceContext-PSSetShader input layouts - device-CreateInputLayout sampler state - device-CreateSamplerState These two I didn't understand, where can I find them? predications - ? scissor rectangles - ? Do I need to store them all localy so I can switch between them, because it doesn't feel right to reinitialize the Direct3d and the Shaders by every switch (key input)?!

    Read the article

  • problem with loading in .FBX meshes in DirectX 10

    - by N0xus
    I'm trying to load in meshes into DirectX 10. I've created a bunch of classes that handle it and allow me to call in a mesh with only a single line of code in my main game class. How ever, when I run the program this is what renders: In the debug output window the following errors keep appearing: D3D10: ERROR: ID3D10Device::DrawIndexed: Input Assembler - Vertex Shader linkage error: Signatures between stages are incompatible. The reason is that Semantic 'TEXCOORD' is defined for mismatched hardware registers between the output stage and input stage. [ EXECUTION ERROR #343: DEVICE_SHADER_LINKAGE_REGISTERINDEX ] D3D10: ERROR: ID3D10Device::DrawIndexed: Input Assembler - Vertex Shader linkage error: Signatures between stages are incompatible. The reason is that the input stage requires Semantic/Index (POSITION,0) as input, but it is not provided by the output stage. [ EXECUTION ERROR #342: DEVICE_SHADER_LINKAGE_SEMANTICNAME_NOT_FOUND ] The thing is, I've no idea how to fix this. The code I'm using does work and I've simply brought all of that code into a new project of mine. There are no build errors and this only appears when the game is running The .fx file is as follows: float4x4 matWorld; float4x4 matView; float4x4 matProjection; struct VS_INPUT { float4 Pos:POSITION; float2 TexCoord:TEXCOORD; }; struct PS_INPUT { float4 Pos:SV_POSITION; float2 TexCoord:TEXCOORD; }; Texture2D diffuseTexture; SamplerState diffuseSampler { Filter = MIN_MAG_MIP_POINT; AddressU = WRAP; AddressV = WRAP; }; // // Vertex Shader // PS_INPUT VS( VS_INPUT input ) { PS_INPUT output=(PS_INPUT)0; float4x4 viewProjection=mul(matView,matProjection); float4x4 worldViewProjection=mul(matWorld,viewProjection); output.Pos=mul(input.Pos,worldViewProjection); output.TexCoord=input.TexCoord; return output; } // // Pixel Shader // float4 PS(PS_INPUT input ) : SV_Target { return diffuseTexture.Sample(diffuseSampler,input.TexCoord); //return float4(1.0f,1.0f,1.0f,1.0f); } RasterizerState NoCulling { FILLMODE=SOLID; CULLMODE=NONE; }; technique10 Render { pass P0 { SetVertexShader( CompileShader( vs_4_0, VS() ) ); SetGeometryShader( NULL ); SetPixelShader( CompileShader( ps_4_0, PS() ) ); SetRasterizerState(NoCulling); } } In my game, the .fx file and model are called and set as follows: Loading in shader file //Set the shader flags - BMD DWORD dwShaderFlags = D3D10_SHADER_ENABLE_STRICTNESS; #if defined( DEBUG ) || defined( _DEBUG ) dwShaderFlags |= D3D10_SHADER_DEBUG; #endif ID3D10Blob * pErrorBuffer=NULL; if( FAILED( D3DX10CreateEffectFromFile( TEXT("TransformedTexture.fx" ), NULL, NULL, "fx_4_0", dwShaderFlags, 0, md3dDevice, NULL, NULL, &m_pEffect, &pErrorBuffer, NULL ) ) ) { char * pErrorStr = ( char* )pErrorBuffer->GetBufferPointer(); //If the creation of the Effect fails then a message box will be shown MessageBoxA( NULL, pErrorStr, "Error", MB_OK ); return false; } //Get the technique called Render from the effect, we need this for rendering later on m_pTechnique=m_pEffect->GetTechniqueByName("Render"); //Number of elements in the layout UINT numElements = TexturedLitVertex::layoutSize; //Get the Pass description, we need this to bind the vertex to the pipeline D3D10_PASS_DESC PassDesc; m_pTechnique->GetPassByIndex( 0 )->GetDesc( &PassDesc ); //Create Input layout to describe the incoming buffer to the input assembler if (FAILED(md3dDevice->CreateInputLayout( TexturedLitVertex::layout, numElements,PassDesc.pIAInputSignature, PassDesc.IAInputSignatureSize, &m_pVertexLayout ) ) ) { return false; } model loading: m_pTestRenderable=new CRenderable(); //m_pTestRenderable->create<TexturedVertex>(md3dDevice,8,6,vertices,indices); m_pModelLoader = new CModelLoader(); m_pTestRenderable = m_pModelLoader->loadModelFromFile( md3dDevice,"armoredrecon.fbx" ); m_pGameObjectTest = new CGameObject(); m_pGameObjectTest->setRenderable( m_pTestRenderable ); // Set primitive topology, how are we going to interpet the vertices in the vertex buffer md3dDevice->IASetPrimitiveTopology( D3D10_PRIMITIVE_TOPOLOGY_TRIANGLELIST ); if ( FAILED( D3DX10CreateShaderResourceViewFromFile( md3dDevice, TEXT( "armoredrecon_diff.png" ), NULL, NULL, &m_pTextureShaderResource, NULL ) ) ) { MessageBox( NULL, TEXT( "Can't load Texture" ), TEXT( "Error" ), MB_OK ); return false; } m_pDiffuseTextureVariable = m_pEffect->GetVariableByName( "diffuseTexture" )->AsShaderResource(); m_pDiffuseTextureVariable->SetResource( m_pTextureShaderResource ); Finally, the draw function code: //All drawing will occur between the clear and present m_pViewMatrixVariable->SetMatrix( ( float* )m_matView ); m_pWorldMatrixVariable->SetMatrix( ( float* )m_pGameObjectTest->getWorld() ); //Get the stride(size) of the a vertex, we need this to tell the pipeline the size of one vertex UINT stride = m_pTestRenderable->getStride(); //The offset from start of the buffer to where our vertices are located UINT offset = m_pTestRenderable->getOffset(); ID3D10Buffer * pVB=m_pTestRenderable->getVB(); //Bind the vertex buffer to input assembler stage - md3dDevice->IASetVertexBuffers( 0, 1, &pVB, &stride, &offset ); md3dDevice->IASetIndexBuffer( m_pTestRenderable->getIB(), DXGI_FORMAT_R32_UINT, 0 ); //Get the Description of the technique, we need this in order to loop through each pass in the technique D3D10_TECHNIQUE_DESC techDesc; m_pTechnique->GetDesc( &techDesc ); //Loop through the passes in the technique for( UINT p = 0; p < techDesc.Passes; ++p ) { //Get a pass at current index and apply it m_pTechnique->GetPassByIndex( p )->Apply( 0 ); //Draw call md3dDevice->DrawIndexed(m_pTestRenderable->getNumOfIndices(),0,0); //m_pD3D10Device->Draw(m_pTestRenderable->getNumOfVerts(),0); } Is there anything I've clearly done wrong or are missing? Spent 2 weeks trying to workout what on earth I've done wrong to no avail. Any insight a fresh pair eyes could give on this would be great.

    Read the article

< Previous Page | 13 14 15 16 17 18 19 20 21  | Next Page >