Search Results

Search found 19055 results on 763 pages for 'high performance'.

Page 721/763 | < Previous Page | 717 718 719 720 721 722 723 724 725 726 727 728  | Next Page >

• Execution plan issue requires reset on SQL Server 2005, how to determine cause?

  - by Tony Brandner

  We have a web application that delivers training to thousands of corporate students running on top of SQL Server 2005. Recently, we started seeing that a single specific query in the application went from 1 second to about 30 seconds in terms of execution time. The application started throwing timeouts in that area. Our first thought was that we may have incorrect indexes, so we reviewed the tables and indexes. However, similar queries elsewhere in the application also run quickly. Reviewing the indexes showed us that they were configured as expected. We were able to narrow it down to a single query, not a stored procedure. Running this query in SQL Studio also runs quickly. We tried running the application in a different server environment. So a different web server with the same query, parameters and database. The query still ran slow. The query is a fairly large one related to determining a student's current list of training. It includes joins and left joins on a dozen tables and subqueries. A few of the tables are fairly large (hundreds of thousands of rows) and some of the other tables are small lookup tables. The query uses a grouping clause and a few where conditions. A few of the tables are quite active and the contents change often but the volume of added rows doesn't seem extreme. These symptoms led us to consider the execution plan. First off, as soon as we reset the execution plan cache with the SQL command 'DBCC FREEPROCCACHE', the problem went away. Unfortunately, the problem started to reoccur within a few days. The problem has continued to plague us for awhile now. It's usually the same query, but we did appear to see the problem occur in another single query recently. It happens enough to be a nuisance. We're having a heck of a time trying to fix it since we can't reproduce it in any other environment other than production. I have downloaded the High Availability guide from Red Gate and I read up more on execution plans. I hope to run the profiler on the live server, but I'm a bit concerned about impact. I would like to ask - what is the best way to figure out what is triggering this problem? Has anyone else seen this same issue?

  Read the article

• Akka framework support for finding duplicate messages

  - by scala_is_awesome

  I'm trying to build a high-performance distributed system with Akka and Scala. If a message requesting an expensive (and side-effect-free) computation arrives, and the exact same computation has already been requested before, I want to avoid computing the result again. If the computation requested previously has already completed and the result is available, I can cache it and re-use it. However, the time window in which duplicate computation can be requested may be arbitrarily small. e.g. I could get a thousand or a million messages requesting the same expensive computation at the same instant for all practical purposes. There is a commercial product called Gigaspaces that supposedly handles this situation. However there seems to be no framework support for dealing with duplicate work requests in Akka at the moment. Given that the Akka framework already has access to all the messages being routed through the framework, it seems that a framework solution could make a lot of sense here. Here is what I am proposing for the Akka framework to do: 1. Create a trait to indicate a type of messages (say, "ExpensiveComputation" or something similar) that are to be subject to the following caching approach. 2. Smartly (hashing etc.) identify identical messages received by (the same or different) actors within a user-configurable time window. Other options: select a maximum buffer size of memory to be used for this purpose, subject to (say LRU) replacement etc. Akka can also choose to cache only the results of messages that were expensive to process; the messages that took very little time to process can be re-processed again if needed; no need to waste precious buffer space caching them and their results. 3. When identical messages (received within that time window, possibly "at the same time instant") are identified, avoid unnecessary duplicate computations. The framework would do this automatically, and essentially, the duplicate messages would never get received by a new actor for processing; they would silently vanish and the result from processing it once (whether that computation was already done in the past, or ongoing right then) would get sent to all appropriate recipients (immediately if already available, and upon completion of the computation if not). Note that messages should be considered identical even if the "reply" fields are different, as long as the semantics/computations they represent are identical in every other respect. Also note that the computation should be purely functional, i.e. free from side-effects, for the caching optimization suggested to work and not change the program semantics at all. If what I am suggesting is not compatible with the Akka way of doing things, and/or if you see some strong reasons why this is a very bad idea, please let me know. Thanks, Is Awesome, Scala

  Read the article

• Commitment to Zend Framework - any arguments against?

  - by Pekka

  I am refurbishing a big CMS that I have been working on for quite a number of years now. The product itself is great, but some components, the Database and translation classes for example, need urgent replacing - partly self-made as far back as 2002, grown into a bit of a chaos over time, and might have trouble surviving a security audit. So, I've been looking closely at a number of frameworks (or, more exactly, component Libraries, as I do not intend to change the basic structure of the CMS) and ended up with liking Zend Framework the best. They offer a solid MVC model but don't force you into it, and they offer a lot of professional components that have obviously received a lot of attention (Did you know there are multiple plurals in Russian, and you can't translate them using a simple ($number == 0) or ($number > 1) switch? I didn't, but Zend_Translate can handle it. Just to illustrate the level of thorougness the library seems to have been built with.) I am now literally at the point of no return, starting to replace key components of the system by the Zend-made ones. I'm not really having second thoughts - and I am surely not looking to incite a flame war - but before going onward, I would like to step back for a moment and look whether there is anything speaking against tying a big system closely to Zend Framework. What I like about Zend: As far as I can see, very high quality code Extremely well documented, at least regarding introductions to how things work (Haven't had to use detailed API documentation yet) Backed by a company that has an interest in seeing the framework prosper Well received in the community, has a considerable user base Employs coding standards I like Comes with a full set of unit tests Feels to me like the right choice to make - or at least, one of the right choices - in terms of modern, professional PHP development. I have been thinking about encapsulating and abstracting ZF's functionality into own classes to be able to switch frameworks more easily, but have come to the conclusion that this would not be a good idea because: it would be an unnecessary level of abstraction it could cost performance the big advantage of using a framework - the existence of a developer base that is familiar with its components - would partly be cancelled out therefore, the commitment to ZF would be a deep one. Thus my question: Is there anything substantial speaking against committing to the Zend Framework? Do you have insider knowledge of plans of Zend Inc.'s to go evil in 2011, and make it a closed source library? Is Zend Inc. run by vampires? Are there conceptual flaws in the code base you start to notice when you've transitioned all your projects to it? Is the appearance of quality code an illusion? Does the code look good, but run terribly slow on anything below my quad-core workstation?

  Read the article

• Implementing Object Oriented: ansi-C approach

  - by No Money

  Hey there, I am an Intermediate programmer in Java and know some of the basics in C++. I recently started to scam over "C language" [please note that i emphasized on C language and want to stick with C as i found it to be a perfect tool, so no need for suggestions focusing on why should i move back to C++ or Java or any other crappy language (e.g: C#)]. Moving on, I code an Object Oriented approach in C but kindda scramble with the pointers part. Please understand that I am just a noob trying to extend my knowledge beyond what i learned in High School. Here is my code..... #include <stdio.h> typedef struct per{ int privateint; char *privateString; struct per (*New) (); void (*deleteperOBJ) (struct t_person *); void (*setperNumber) ((struct*) t_person,int); void (*setperString) ((struct*) t_person,char *); void (*dumpperState) ((struct*) t_person); }t_person; void setperNumber(t_person *const per,int num){ if(per==NULL) return; per->privateint=num; } void setperString(t_person *const per,char *string){ if(per==NULL) return; per->privateString=string; } void dumpperState(t_person *const per){ if(per==NULL) return; printf("value of private int==%d\n", per->privateint); printf("value of private string==%s\n", per->privateString); } void deleteperOBJ(struct t_person *const per){ free((void*)t_person->per); t_person ->per = NULL; } main(){ t_person *const per = (struct*) malloc(sizeof(t_person)); per = t_person -> struct per -> New(); per -> setperNumber (t_person *per, 123); per -> setperString(t_person *per, "No money"); dumpperState(t_person *per); deleteperOBJ(t_person *per); } Just to warn you, this program has several errors and since I am a beginner I couldn't help except to post this thread as a question. I am looking forward for assistance. Thanks in advance.

  Read the article

• Thread sleep and thread join.

  - by Dhruv Gairola

  hi guys, if i put a thread to sleep in a loop, netbeans gives me a caution saying Invoking Thread.sleep in loop can cause performance problems. However, if i were to replace the sleep with join, no such caution is given. Both versions compile and work fine tho. My code is below (check the last few lines for "Thread.sleep() vs t.join()"). public class Test{ //Display a message, preceded by the name of the current thread static void threadMessage(String message) { String threadName = Thread.currentThread().getName(); System.out.format("%s: %s%n", threadName, message); } private static class MessageLoop implements Runnable { public void run() { String importantInfo[] = { "Mares eat oats", "Does eat oats", "Little lambs eat ivy", "A kid will eat ivy too" }; try { for (int i = 0; i < importantInfo.length; i++) { //Pause for 4 seconds Thread.sleep(4000); //Print a message threadMessage(importantInfo[i]); } } catch (InterruptedException e) { threadMessage("I wasn't done!"); } } } public static void main(String args[]) throws InterruptedException { //Delay, in milliseconds before we interrupt MessageLoop //thread (default one hour). long patience = 1000 * 60 * 60; //If command line argument present, gives patience in seconds. if (args.length > 0) { try { patience = Long.parseLong(args[0]) * 1000; } catch (NumberFormatException e) { System.err.println("Argument must be an integer."); System.exit(1); } } threadMessage("Starting MessageLoop thread"); long startTime = System.currentTimeMillis(); Thread t = new Thread(new MessageLoop()); t.start(); threadMessage("Waiting for MessageLoop thread to finish"); //loop until MessageLoop thread exits while (t.isAlive()) { threadMessage("Still waiting..."); //Wait maximum of 1 second for MessageLoop thread to //finish. /*******LOOK HERE**********************/ Thread.sleep(1000);//issues caution unlike t.join(1000) /**************************************/ if (((System.currentTimeMillis() - startTime) > patience) && t.isAlive()) { threadMessage("Tired of waiting!"); t.interrupt(); //Shouldn't be long now -- wait indefinitely t.join(); } } threadMessage("Finally!"); } } As i understand it, join waits for the other thread to complete, but in this case, arent both sleep and join doing the same thing? Then why does netbeans throw the caution?

  Read the article

• Primary language - QtC++, C#, Java?

  - by Airjoe

  I'm looking for some input, but let me start with a bit of background (for tl;dr skip to end). I'm an IT major with a concentration in networking. While I'm not a CS major nor do I want to program as a vocation, I do consider myself a programmer and do pretty well with the concepts involved. I've been programming since about 6th grade, started out with a proprietary game creation language that made my transition into C++ at college pretty easy. I like to make programs for myself and friends, and have been paid to program for local businesses. A bit about that- I wrote some programs for a couple local businesses in my senior year in high school. I wrote management systems for local shops (inventory, phone/pos orders, timeclock, customer info, and more stuff I can't remember). It definitely turned out to be over my head, as I had never had any formal programming education. It was a great learning experience, but damn was it crappy code. Oh yeah, by the way, it was all vb6. So, I've used vb6 pretty extensively, I've used c++ in my classes (intro to programming up to algorithms), used Java a little bit in another class (had to write a ping client program, pretty easy) and used Java for some simple Project Euler problems to help learn syntax and such when writing the program for the class. I've also used C# a bit for my own simple personal projects (simple programs, one which would just generate an HTTP request on a list of websites and notify if one responded unexpectedly or not at all, and another which just held a list of things to do and periodically reminded me to do them), things I would've written in vb6 a year or two ago. I've just started using Qt C++ for some undergrad research I'm working on. Now I've had some formal education, I [think I] understand organization in programming a lot better (I didn't even use classes in my vb6 programs where I really should have), how it's important to structure code, split into functions where appropriate, document properly, efficiency both in memory and speed, dynamic and modular programming etc. I was looking for some input on which language to pick up as my "primary". As I'm not a "real programmer", it will be mostly hobby projects, but will include some 'real' projects I'm sure. From my perspective: QtC++ and Java are cross platform, which is cool. Java and C# run in a virtual machine, but I'm not sure if that's a big deal (something extra to distribute, possibly a bit slower? I think Qt would require additional distributables too, right?). I don't really know too much more than this, so I appreciate any help, thanks! TL;DR Am an avocational programmer looking for a language, want quick and straight forward development, liked vb6, will be working with database driven GUI apps- should I go with QtC++, Java, C#, or perhaps something else?

  Read the article

• [NHibernate and ASP.NET MVC] How can I implement a robust session-per-request pattern in my project,

  - by Guillaume Gervais

  I'm currently building an ASP.NET MVC project, with NHibernate as its persistance layer. For now, some functionnalities have been implemented, but only use local NHibernate sessions: each method that accessed the database (read or write) needs to instanciate its own NHibernate session, with the "using()" directive. The problem is that I want to leverage NHibernate's Lazy-Loading capabilities to improve the performance of my project. This implies an open NHibernate session per request until the view is rendered. Furthermore, simultaneous request must be supported (multiple Sessions at the same time). How can I achieve that as cleanly as possible? I searched the Web a little bit and learned about the session-per-request pattern. Most of the implementations I saw used some sort of Http* (HttpContext, etc.) object to store the session. Also, using the Application_BeginRequest/Application_EndRequest functions is complicated, since they get fired for each HTTP request (aspx files, css files, js files, etc.), when I only want to instanciate a session once per request. The concern that I have is that I don't want my views or controllers to have access to NHibernate sessions (or, more generally, NHibernate namespaces and code). That means that I do not want to handle sessions at the controller level nor the view one. I have a few options in mind. Which one seems the best ? Use interceptors (like in GRAILS) that get triggered before and after the controller action. These would open and close sessions/transactions. Is it possible in the ASP.NET MVC world? Use the CurrentSessionContext Singleton provided by NHibernate in a Web context. Using this page as an example, I think this is quite promising, but that still requires filters at the controller level. Use the HttpContext.Current.Items to store the request session. This, coupled with a few lines of code in Global.asax.cs, can easily provide me with a session on the request level. However, it means that dependencies will be injected between NHibernate and my views (HttpContext). Thank you very much!

  Read the article

• WPF PathGeometry/RotateTransform optimization

  - by devinb

  I am having performance issues when rendering/rotating WPF triangles If I had a WPF triangle being displayed and it will be rotated to some degree around a centrepoint, I can do it one of two ways: Programatically determine the points and their offset in the backend, use XAML to simply place them on the canvas where they belong, it would look like this: <Path Stroke="Black"> <Path.Data> <PathGeometry> <PathFigure StartPoint ="{Binding CalculatedPointA, Mode=OneWay}"> <LineSegment Point="{Binding CalculatedPointB, Mode=OneWay}" /> <LineSegment Point="{Binding CalculatedPointC, Mode=OneWay}" /> <LineSegment Point="{Binding CalculatedPointA, Mode=OneWay}" /> </PathFigure> </PathGeometry> </Path.Data> </Path> Generate the 'same' triangle every time, and then use a RenderTransform (Rotate) to put it where it belongs. In this case, the rotation calculations are being obfuscated, because I don't have any access to how they are being done. <Path Stroke="Black"> <Path.Data> <PathGeometry> <PathFigure StartPoint ="{Binding TriPointA, Mode=OneWay}"> <LineSegment Point="{Binding TriPointB, Mode=OneWay}" /> <LineSegment Point="{Binding TriPointC, Mode=OneWay}" /> <LineSegment Point="{Binding TriPointA, Mode=OneWay}" /> </PathFigure> </PathGeometry> </Path.Data> <Path.RenderTransform> <RotateTransform CenterX="{Binding Centre.X, Mode=OneWay}" CenterY="{Binding Centre.Y, Mode=OneWay}" Angle="{Binding Orientation, Mode=OneWay}" /> </Path.RenderTransform> </Path> My question is which one is faster? I know I should test it myself but how do I measure the render time of objects with such granularity. I would need to be able to time how long the actual rendering time is for the form, but since I'm not the one that's kicking off the redraw, I don't know how to capture the start time.

  Read the article

• Missing part of the image when taking screenshot while supporting Retina Display

  - by Spaft

  I'm currently working on enabling support for retina display for my game. In the game, we have a feature that the user can take screenshot. We are using these part of code we found online a while ago and it's working fine when we are not supporting retina display: CCDirector* director = [CCDirector sharedDirector]; CGSize size = [director winSizeInPixels]; //Create buffer for pixels GLuint bufferLength = size.width * size.height * 4; GLubyte* buffer = (GLubyte*)malloc(bufferLength); //Read Pixels from OpenGL glReadPixels(0, 100, size.width, size.height, GL_RGBA, GL_UNSIGNED_BYTE, buffer); //Make data provider with data. CGDataProviderRef provider = CGDataProviderCreateWithData(NULL, buffer, bufferLength, NULL); //Configure image int bitsPerComponent = 8; int bitsPerPixel = 32; int bytesPerRow = 4 * size.width; CGColorSpaceRef colorSpaceRef = CGColorSpaceCreateDeviceRGB(); CGBitmapInfo bitmapInfo = kCGBitmapByteOrderDefault; CGColorRenderingIntent renderingIntent = kCGRenderingIntentDefault; CGImageRef iref = CGImageCreate(size.width, size.height, bitsPerComponent, bitsPerPixel, bytesPerRow, colorSpaceRef, bitmapInfo, provider, NULL, NO, renderingIntent); uint32_t* pixels = (uint32_t*)malloc(bufferLength); CGContextRef context = CGBitmapContextCreate(pixels, size.width, size.height, 8, size.width * 4, CGImageGetColorSpace(iref), kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big); CGContextTranslateCTM(context, 0, size.height); CGContextScaleCTM(context, 1.0f, -1.0f); switch (director.deviceOrientation) { case CCDeviceOrientationPortrait: break; case CCDeviceOrientationPortraitUpsideDown: CGContextRotateCTM(context, CC_DEGREES_TO_RADIANS(180)); CGContextTranslateCTM(context, -size.width, -size.height); break; case CCDeviceOrientationLandscapeLeft: CGContextRotateCTM(context, CC_DEGREES_TO_RADIANS(-90)); CGContextTranslateCTM(context, -size.width, 0); break; case CCDeviceOrientationLandscapeRight: CGContextRotateCTM(context, CC_DEGREES_TO_RADIANS(90)); CGContextTranslateCTM(context, size.width * 0.5f, -size.height); break; } CGContextDrawImage(context, CGRectMake(0.0f, 0.0f, size.width, size.height), iref); UIImage *outputImage = [UIImage imageWithCGImage:CGBitmapContextCreateImage(context)]; //Dealloc CGDataProviderRelease(provider); CGImageRelease(iref); CGContextRelease(context); free(buffer); free(pixels); return outputImage; But when we enabled retina display in cocos 0.99.5. This functionality is a little messed up since it will miss a little left part of the image while the high is still correct. So I'm wondering if there is anything wrong with the code or am I doing anything wrong here? Thank you in advance for any reply!

  Read the article

• Adding a clustered index to a SQL table: what dangers exist for a live production system?

  - by MoSlo

  Right, keep in mind i need to describe this by abstracting all possible confidential info: I've been put in charge of a 10-year old transactional system of which the majority business logic is implemented at database level (triggers, stored procedures etc). Win2000 server, MSSQL 2000 Enterprise. No immediate plans for replacing/updating the system are being considered :( The core process is a program that executes transactions - specifically, it executes a stored procedure with various parameters, lets call it sp_ProcessTrans. The program executes the stored procedure at asynchronous intervals. By itself, things work fine. But there are 30 instances of this program on remotely located workstations, all of them asynchronously executing sp_ProcessTrans and then retrieving data from the SQL server (execution is pretty regular - ranging 0 to 60 times a minute, depending on what items the program instance is responsible for) . Performance of the system has dropped considerably with 10 yrs of data growth: the reason is the deadlocks and specifically deadlock wait times. The deadlock is on the Employee table. I have discovered: In sp_ProcessTrans' execution, it selects from an Employee table 7 times (dont ask) The select is done on a field that is NOT the primary key No index exists on this field. Thus a table scan is performed. 7 times. per transaction So the reason for deadlocks is clear. I created a non-unique ordered clustered index on the field (field looks good, almost unique, NUM(7), very rarely changes). Immediate improvement in the test environment. The problem is that i cannot simulate the deadlocks in a test environment (I'd need 30 workstations; i'd need to simulate 'realistic' activity on those stations, so visualization is out). I need to know if i must schedule downtime. Creating an index shouldn't be a risky operation for MSSQL, but is there any danger (data corruption in transactions/select statements/extra wait time etc) to create this field index on the production database while the transactions are still taking place? (although i can select a time when transactions are fairly quiet through the 30 stations) Are there any hidden dangers i'm not seeing (not looking forward to needing to restore the DB if something goes wrong, restoring would take a lot of time with 10yrs of data).

  Read the article

• AudioTrack lag: obtainBuffer timed out

  - by BTR

  I'm playing WAVs on my Android phone by loading the file and feeding the bytes into AudioTrack.write() via the FileInputStream BufferedInputStream DataInputStream method. The audio plays fine and when it is, I can easily adjust sample rate, volume, etc on the fly with nice performance. However, it's taking about two full seconds for a track to start playing. I know AudioTrack has an inescapable delay, but this is ridiculous. Every time I play a track, I get this: 03-13 14:55:57.100: WARN/AudioTrack(3454): obtainBuffer timed out (is the CPU pegged?) 0x2e9348 user=00000960, server=00000000 03-13 14:55:57.340: WARN/AudioFlinger(72): write blocked for 233 msecs, 9 delayed writes, thread 0xba28 I've noticed that the delayed write count increases by one every time I play a track -- even across multiple sessions -- from the time the phone has been turned on. The block time is always 230 - 240ms, which makes sense considering a minimum buffer size of 9600 on this device (9600 / 44100). I've seen this message in countless searches on the Internet, but it usually seems to be related to not playing audio at all or skipping audio. In my case, it's just a delayed start. I'm running all my code in a high priority thread. Here's a truncated-yet-functional version of what I'm doing. This is the thread callback in my playback class. Again, this works (only playing 16-bit, 44.1kHz, stereo files right now), it just takes forever to start and has that obtainBuffer/delayed write message every time. public void run() { // Load file FileInputStream mFileInputStream; try { // mFile is instance of custom file class -- this is correct, // so don't sweat this line mFileInputStream = new FileInputStream(mFile.path()); } catch (FileNotFoundException e) {} BufferedInputStream mBufferedInputStream = new BufferedInputStream(mFileInputStream, mBufferLength); DataInputStream mDataInputStream = new DataInputStream(mBufferedInputStream); // Skip header try { if (mDataInputStream.available() > 44) mDataInputStream.skipBytes(44); } catch (IOException e) {} // Initialize device mAudioTrack = new AudioTrack(AudioManager.STREAM_MUSIC, ConfigManager.SAMPLE_RATE, AudioFormat.CHANNEL_CONFIGURATION_STEREO, AudioFormat.ENCODING_PCM_16BIT, ConfigManager.AUDIO_BUFFER_LENGTH, AudioTrack.MODE_STREAM); mAudioTrack.play(); // Initialize buffer byte[] mByteArray = new byte[mBufferLength]; int mBytesToWrite = 0; int mBytesWritten = 0; // Loop to keep thread running while (mRun) { // This flag is turned on when the user presses "play" while (mPlaying) { try { // Check if data is available if (mDataInputStream.available() > 0) { // Read data from file and write to audio device mBytesToWrite = mDataInputStream.read(mByteArray, 0, mBufferLength); mBytesWritten += mAudioTrack.write(mByteArray, 0, mBytesToWrite); } } catch (IOException e) { } } } } If I can get past the artificially long lag, I can easily deal with the inherit latency by starting my write at a later, predictable position (ie, skip past the minimum buffer length when I start playing a file).

  Read the article

• Add console.profile statements to JavaScript/jQuery code on the fly.

  - by novogeek

  Hi folks, We have a thick client app using jQuery heavily and want to profile the performance of the code using firebug's console.profile API. The problem is, I don't want to change the code to write the profile statements. Take this example: var search=function(){ this.init=function(){ console.log('init'); } this.ajax=function(){ console.log('ajax'); //make ajax call using $.ajax and do some DOM manipulations here.. } this.cache=function(){ console.log('cache'); } } var instance=new search(); instance.ajax(); I want to profile my instance.ajax method, but I dont want to add profile statements in the code, as that makes it difficult to maintain the code. I'm trying to override the methods using closures, like this: http://www.novogeek.com/post/2010/02/27/Overriding-jQueryJavaScript-functions-using-closures.aspx but am not very sure how I can achieve. Any pointers on this? I think this would help many big projects to profile the code easily without a big change in code. Here is the idea. Just run the below code in firebug console, to know what I'm trying to achieve. var search=function(){ this.init=function(){ console.log('init'); } this.ajax=function(){ console.log('ajax'); //make ajax call using $.ajax and do some DOM manipulations here.. } this.cache=function(){ console.log('cache'); } } var instance=new search(); $.each(instance, function(functionName, functionBody){ (function(){ var dup=functionBody functionBody=function(){ console.log('modifying the old function: ',functionName); console.profile(functionName); dup.apply(this,arguments); console.profileEnd(functionName); } })(); console.log(functionName, '::', functionBody()); }); Now what I need is, if i say instance.ajax(), I want the new ajax() method to be called, along with the console.profile statements. Hope I'm clear with the requirement. Please improvise the above code. Regards, Krishna, http://www.novogeek.com

  Read the article

• Device drivers and Windows

  - by b-gen-jack-o-neill

  Hi, I am trying to complete the picture of how the PC and the OS interacts together. And I am at point, where I am little out of guess when it comes to device drivers. Please, don´t write things like its too complicated, or you don´t need to know when using high programming laguage and winapi functions. I want to know, it´s for study purposes. So, the very basic structure of how OS and PC (by PC I mean of course HW) is how I see it is that all other than direct CPU commands, which can CPU do on itself (arithmetic operation, its registers access and memory access) must pass thru OS. Mainly becouse from ring level 3 you cannot use in and out intructions which are used for acesing other HW. I know that there is MMIO,but it must be set by port comunication first. It was not like this all the time. Even I am bit young to remember MSDOS, I know you could access HW directly, becouse there ws no limitation, no ring mode. So you could to write string to diplay use wheather DOS function, or directly acess video card memory and write it by yourself. But as OS developed, there is no longer this possibility. But it is fine, since OS now handles all the HW comunication, and frankly it more convinient and much more safe (I would say the only option) in multitasking environment. So nowdays you instead of using int instructions to use BIOS mapped function or DOS function you call dll which internally than handles everything you don´t need to know about. I understand this. I also undrstand that device drivers is the piece of code that runs in ring level 0, so it can do all the HW interactions. But what I don´t understand is connection between OS and device driver. Let´s take a example - I want to make a sound card make a sound. So I call windows API to acess sound card, but what happens than? Does windows call device drivers to do so? But if it does call device driver, does it mean, that all device drivers which can be called by winAPI function, must have routines named in some specific way? I mean, when I have new sound card, must its drivers have functions named same as the old one? So Windows can actually call the same function from its perspective? But if Windows have predefined sets of functions requored by device drivers, that it cannot use new drivers that doesent existed before last version of OS came out. Please, help me understand this mess. I am really getting mad. Thanks.

  Read the article

• Should I HttpCombine Google Jquery Hosted File?

  - by chobo2

  Hi I am using something called HttpCombiner: http://code.msdn.microsoft.com/HttpCombiner An HTTP handler that combines multiple CSS, Javascript or URL into one response for faster page load. It can combine, compress and cache response which results in faster page load and better scalability of web application It's a good practice to use many small Javascript and CSS files instead of one large Javascript/CSS file for better code maintainability, but bad in terms of website performance. Although you should write your Javascript code in small files and break large CSS files into small chunks but when browser requests those javascript and css files, it makes one Http request per file. Every Http Request results in a network roundtrip form your browser to the server and the delay in reaching the server and coming back to the browser is called latency. So, if you have four javascripts and three css files loaded by a page, you are wasting time in seven network roundtrips. Within USA, latency is average 70ms. So, you waste 7x70 = 490ms, about half a second of delay. Outside USA, average latency is around 200ms. So, that means 1400ms of waiting. Browser cannot show the page properly until Css and Javascripts are fully loaded. So, the more latency you have, the slower page loads. You can reduce the wait time by using a CDN. Read my previous blog post about using CDN. However, a better solution is to deliver multiple files over one request using an HttpHandler that combines several files and delivers as one output. So, instead of putting many or tag, you just put one and one tag, and point them to the HttpHandler. You tell the handler which files to combine and it delivers those files in one response. This saves browser from making many requests and eliminates the latency. This Http Handler reads the file names defined in a configuration and combines all those files and delivers as one response. It delivers the response as gzip compressed to save bandwidth. Moreover, it generates proper cache header to cache the response in browser cache, so that, browser does not request it again on future visit. Now I am wondering since it can handle adding links should I put in it the jquery file? The reason I am not sure is if it gets combined with my other files I think I might close the advantages of it being hosted on googles servers such as caching(my thinking is if it gets combined it will look different so even if a user has it in it's cache I am not sure if it will use the one for the cahce or not). So should I combine it or only the finals that I am using locally?

  Read the article

• Query performs poorly unless a temp table is used

  - by Paul McLoughlin

  The following query takes about 1 minute to run, and has the following IO statistics: SELECT T.RGN, T.CD, T.FUND_CD, T.TRDT, SUM(T2.UNITS) AS TotalUnits FROM dbo.TRANS AS T JOIN dbo.TRANS AS T2 ON T2.RGN=T.RGN AND T2.CD=T.CD AND T2.FUND_CD=T.FUND_CD AND T2.TRDT<=T.TRDT JOIN TASK_REQUESTS AS T3 ON T3.CD=T.CD AND T3.RGN=T.RGN AND T3.TASK = 'UPDATE_MEM_BAL' GROUP BY T.RGN, T.CD, T.FUND_CD, T.TRDT (4447 row(s) affected) Table 'TRANSACTIONS'. Scan count 5977, logical reads 7527408, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0. Table 'TASK_REQUESTS'. Scan count 1, logical reads 11, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0. SQL Server Execution Times: CPU time = 58157 ms, elapsed time = 61437 ms. If I instead introduce a temporary table then the query returns quickly and performs less logical reads: CREATE TABLE #MyTable(RGN VARCHAR(20) NOT NULL, CD VARCHAR(20) NOT NULL, PRIMARY KEY([RGN],[CD])); INSERT INTO #MyTable(RGN, CD) SELECT RGN, CD FROM TASK_REQUESTS WHERE TASK='UPDATE_MEM_BAL'; SELECT T.RGN, T.CD, T.FUND_CD, T.TRDT, SUM(T2.UNITS) AS TotalUnits FROM dbo.TRANS AS T JOIN dbo.TRANS AS T2 ON T2.RGN=T.RGN AND T2.CD=T.CD AND T2.FUND_CD=T.FUND_CD AND T2.TRDT<=T.TRDT JOIN #MyTable AS T3 ON T3.CD=T.CD AND T3.RGN=T.RGN GROUP BY T.RGN, T.CD, T.FUND_CD, T.TRDT (4447 row(s) affected) Table 'Worktable'. Scan count 5974, logical reads 382339, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0. Table 'TRANSACTIONS'. Scan count 4, logical reads 4547, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0. Table '#MyTable________________________________________________________________000000000013'. Scan count 1, logical reads 2, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0. SQL Server Execution Times: CPU time = 1420 ms, elapsed time = 1515 ms. The interesting thing for me is that the TASK_REQUEST table is a small table (3 rows at present) and statistics are up to date on the table. Any idea why such different execution plans and execution times would be occuring? And ideally how to change things so that I don't need to use the temp table to get decent performance? The only real difference in the execution plans is that the temp table version introduces an index spool (eager spool) operation.

  Read the article

• Can I use the [] operator in C++ to create virtual arrays

  - by Shane MacLaughlin

  I have a large code base, originally C ported to C++ many years ago, that is operating on a number of large arrays of spatial data. These arrays contain structs representing point and triangle entities that represent surface models. I need to refactor the code such that the specific way these entities are stored internally varies for specific scenarios. For example if the points lie on a regular flat grid, I don't need to store the X and Y coordinates, as they can be calculated on the fly, as can the triangles. Similarly, I want to take advantage of out of core tools such as STXXL for storage. The simplest way of doing this is replacing array access with put and get type functions, e.g. point[i].x = XV; becomes Point p = GetPoint(i); p.x = XV; PutPoint(i,p); As you can imagine, this is a very tedious refactor on a large code base, prone to all sorts of errors en route. What I'd like to do is write a class that mimics the array by overloading the [] operator. As the arrays already live on the heap, and move around with reallocs, the code already assumes that references into the array such as point *p = point + i; may not be used. Is this class feasible to write? For example writing the methods below in terms of the [] operator; void MyClass::PutPoint(int Index, Point p) { if (m_StorageStrategy == RegularGrid) { int xoffs,yoffs; ComputeGridFromIndex(Index,xoffs,yoffs); StoreGridPoint(xoffs,yoffs,p.z); } else m_PointArray[Index] = p; } } Point MyClass::GetPoint(int Index) { if (m_StorageStrategy == RegularGrid) { int xoffs,yoffs; ComputeGridFromIndex(Index,xoffs,yoffs); return GetGridPoint(xoffs,yoffs); // GetGridPoint returns Point } else return m_PointArray[Index]; } } My concern is that all the array classes I've seen tend to pass by reference, whereas I think I'll have to pass structs by value. I think it should work put other than performance, can anyone see any major pitfalls with this approach. n.b. the reason I have to pass by value is to get point[a].z = point[b].z + point[c].z to work correctly where the underlying storage type varies.

  Read the article

• Table row height in Internet Explorer

  - by Fritz H

  I have the following table: <table> <tr> <td style="height: 7px; width: 7px"> A1 </td> <td style="height: 7px"> B1 </td> <td style="height: 7px; width: 7px"> C1 </td> </tr> <tr> <td style="width: 7px"> A2 </td> <td> B2 </td> <td style="width: 7px"> C2 </td> </tr> <tr> <td style="height: 7px; width: 7px"> A3 </td> <td style="height: 7px"> B3 </td> <td style="height: 7px; width: 7px"> C3 </td> </tr> </table> The basic idea is that the first row must be 7 pixels high. The left- and rightmost cells (A1 and C1) must be 7px wide, and the middle cell (B1) must scale according to the width of the table. The same goes for the bottom row (A3, B3, C3). The middle row, however, needs to scale in height - in other words, it needs to be (tableheight - 14px). The left- and rightmost cells (A2, C2) need to be 7 pixels wide. An example: 7px x 7px |------|-------------------------|------| --- +------+-------------------------+------+ | | | | | | 7px | | | | | | | | | --- +------+-------------------------+------+ | | | | | | | | | | | | | | | | | | | | | y | | | | | | | | | | | | | | | | | | | | | | | | --- +------+-------------------------+------+ | | | | | | 7px | | | | | | | | | --- +------+-------------------------+------+ HOWEVER: In Internet Explorer, the widths work fine (columns A and C are 7px, column B scales dynamically) - but the heights don't. Rows 1, 2 and 3 turn out to be exactly 33% of the height of the table, no matter what I do. Unfortunately I have to use this table, so replacing it with a set of DIVs is not an option. I have the following DOCTYPE: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> I need to keep this, as some other elements on the page rely on some complex CSS-based layouts. Can anyone point me in the right direction to whip this into shape for IE? EDIT: Should have mentioned earlier - this table is resized on the fly using javascript.

  Read the article

• Hot to get rid of memory allocations/deallocations in swig wrappers?

  - by Dmitriy Matveev

  I want to use swig for generation of read-only wrappers for a complex object. The object which I want to wrap will always be existent while I will read it. And also I will only use my wrappers at the time that object is existent, thus I don't need any memory management from SWIG. For following swig interface: %module test %immutable; %inline %{ struct Foo { int a; }; struct Bar { int b; Foo f; }; %} I will have a wrappers which will have a lot of garbage in generated interfaces and do useless work which will reduce performance in my case. Generated java wrapper for Bar class will be like this: public class Bar { private long swigCPtr; protected boolean swigCMemOwn; protected Bar(long cPtr, boolean cMemoryOwn) { swigCMemOwn = cMemoryOwn; swigCPtr = cPtr; } protected static long getCPtr(Bar obj) { return (obj == null) ? 0 : obj.swigCPtr; } protected void finalize() { delete(); } public synchronized void delete() { if (swigCPtr != 0) { if (swigCMemOwn) { swigCMemOwn = false; testJNI.delete_Bar(swigCPtr); } swigCPtr = 0; } } public int getB() { return testJNI.Bar_b_get(swigCPtr, this); } public Foo getF() { return new Foo(testJNI.Bar_f_get(swigCPtr, this), true); } public Bar() { this(testJNI.new_Bar(), true); } } I don't need 'swigCMemOwn' field in my wrapper since it always will be false. All code related to this field will also be useless. There are also unnecessary logic in native code: SWIGEXPORT jlong JNICALL Java_some_testJNI_Bar_1f_1get(JNIEnv *jenv, jclass jcls, jlong jarg1, jobject jarg1_) { jlong jresult = 0 ; struct Bar *arg1 = (struct Bar *) 0 ; Foo result; (void)jenv; (void)jcls; (void)jarg1_; arg1 = *(struct Bar **)&jarg1; result = ((arg1)->f); { Foo * resultptr = (Foo *) malloc(sizeof(Foo)); memmove(resultptr, &result, sizeof(Foo)); *(Foo **)&jresult = resultptr; } return jresult; } I don't need these calls to malloc and memmove. I want to force swig to resolve both of these problems, but don't know how. Is it possible?

  Read the article

• Problems with starting windows service on windows xp SP3

  - by Michiel Peeters

  I'm currently facing a problem which I can not resolve and I really don't know what to do anymore. When I'm trying to start the service I receive the message: "The service is started but again also stopped, this because that some of the services will stop if they have nothing to do, for example the performance logs and the alerts service". I've looked into the Windows Logs but nothing is written there which could describe why my service is all the time stopping. I've also tried to fire the windows service via the command prompt which gives me the message: "The service is not started, but the service didn't return any faults.". I've tried to remove all keys which references to my service, which didn't resolve the issue. I've searched on google (maybe not good enough) to find an answer but I didn't found any. I did found some websites which describes what I could do, but all of these suggestions didn't work. This is kinda ** because I do not know where to look. I do not have any error message, i do not have any id which i can use to search on. I really don't know where to start and I hope you guys can help me on this one. Detailed explanation about the windows service OS: Windows XP SP3 .Net Framework: .Net 4.0 Client Profile Language: C# Development environment: Visual Studio 2010 Professional (but Visual Studio 2012 RC is installed) Communications: WCF (Named Pipes), WCF (BasicHTTPBinding) Named Pipes: I have chosen for this solution because I wanted to communicate from a windows service to a windows form application. It worked now for quite some time but suddenly my windows service shuts it self down and I couldn't restart it anymore. There are two named pipes services implemented: An event service which will send any notification to the windows form application and an management service which gives my windows form application the possibility to maintain my windows service. BasicHTTPBinding: The basic http binding makes the connection to a central server. This connection is then used for streaming information from the client to the server. I do not know which additional information you will need, but if you guys need something then I'll try to give it as detailed as possible. Thank you in advance.

  Read the article

• c# video equivalent to image.fromstream? Or changing the scope of the following script to allow vide

  - by Daniel

  The following is a part of an upload class in a c# script. I'm a php programmer, I've never messed with c# much but I'm trying to learn. This upload script will not handle anything except images, I need to adapt this class to handle other types of media also, or rewrite it all together. If I'm correct, I realize that using (Image image = Image.FromStream(file.InputStream)) basically says that the scope of the following is Image, only an image can be used or the object is discarded? And also that the variable image is being created from an Image from the file stream, which I understand to be, like... the $_FILES array in php? I dunno, I don't really care about making thumbnails right now either way, so if this can be taken out and still process the upload I'm totally cool with that, I just haven't had any luck getting this thing to take anything but images, even when commenting out that whole part of the class... protected void Page_Load(object sender, EventArgs e) { string dir = Path.Combine(Request.PhysicalApplicationPath, "files"); if (Request.Files.Count == 0) { // No files were posted Response.StatusCode = 500; } else { try { // Only one file at a time is posted HttpPostedFile file = Request.Files[0]; // Size limit 100MB if (file.ContentLength > 102400000) { // File too large Response.StatusCode = 500; } else { string id = Request.QueryString["userId"]; string[] folders = userDir(id); foreach (string folder in folders) { dir = Path.Combine(dir, folder); if (!Directory.Exists(dir)) Directory.CreateDirectory(dir); } string path = Path.Combine(dir, String.Concat(Request.QueryString["batchId"], "_", file.FileName)); file.SaveAs(path); // Create thumbnail int dot = path.LastIndexOf('.'); string thumbpath = String.Concat(path.Substring(0, dot), "_thumb", path.Substring(dot)); using (Image image = Image.FromStream(file.InputStream)) { // Find the ratio that will create maximum height or width of 100px. double ratio = Math.Max(image.Width / 100.0, image.Height / 100.0); using (Image thumb = new Bitmap(image, new Size((int)Math.Round(image.Width / ratio), (int)Math.Round(image.Height / ratio)))) { using (Graphics graphic = Graphics.FromImage(thumb)) { // Make sure thumbnail is not crappy graphic.SmoothingMode = SmoothingMode.HighQuality; graphic.InterpolationMode = InterpolationMode.High; graphic.CompositingQuality = CompositingQuality.HighQuality; // JPEG ImageCodecInfo codec = ImageCodecInfo.GetImageEncoders()[1]; // 90% quality EncoderParameters encode = new EncoderParameters(1); encode.Param[0] = new EncoderParameter(Encoder.Quality, 90L); // Resize graphic.DrawImage(image, new Rectangle(0, 0, thumb.Width, thumb.Height)); // Save thumb.Save(thumbpath, codec, encode); } } } // Success Response.StatusCode = 200; } } catch { // Something went wrong Response.StatusCode = 500; } } }

  Read the article

• Delete duplicate rows, do not preserve one row

  - by Radley

  I need a query that goes through each entry in a database, checks if a single value is duplicated elsewhere in the database, and if it is - deletes both entries (or all, if more than two). Problem is the entries are URLs, up to 255 characters, with no way of identifying the row. Some existing answers on Stackoverflow do not work for me due to performance limitations, or they use uniqueid which obviously won't work when dealing with a string. Long Version: I have two databases containing URLs (and only URLs). One database has around 3,000 urls and the other around 1,000. However, a large majority of the 1,000 urls were taken from the 3,000 url database. I need to merge the 1,000 into the 3,000 as new entries only. For this, I made a third database with combined URLs from both tables, about 4,000 entries. I need to find all duplicate entries in this database and delete them (Both of them, without leaving either). I have followed the query of a few examples on this site, but whenever I try to delete both entries it ends up deleting all the entries, or giving sql errors. Alternatively: I have two databases, each containing the separate database. I need to check each row from one database against the other to find any that aren't duplicates, and then add those to a third database. Edit: I've got my own PHP solution which is pretty hacky, but works. I cannot answer my own question for 8 hours because I'm new, so here it is for now: I went with a PHP script to accomplish this, as I'm more familiar with PHP than MySQL. This generates a simple list of urls that only exist in the target database, but not both. If you have more than 7,000 entries to parse this may take awhile, and you will need to copy/paste the results into a text file or expand the script to store them back into a database. I'm just doing it manually to save time. Note: Uses MeekroDB <pre> <?php require('meekrodb.2.1.class.php'); DB::$user = 'root'; DB::$password = ''; DB::$dbName = 'testdb'; $all = DB::query('SELECT * FROM old_urls LIMIT 7000'); foreach($all as $row) { $test = DB::query('SELECT url FROM new_urls WHERE url=%s', $row['url']); if (!is_array($test)) { echo $row['url'] . "\n"; }else{ if (count($test) == 0) { echo $row['url'] . "\n"; } } } ?> </pre>

  Read the article

• Is 4-5 years the “Midlife Crisis” for a programming career?

  - by Jeffrey

  I’ve been programming C# professionally for a bit over 4 years now. For the past 4 years I’ve worked for a few small/medium companies ranging from “web/ads agencies”, small industry specific software shops to a small startup. I've been mainly doing "business apps" that involves using high-level programming languages (garbage collected) and my overall experience was that all of the works I’ve done could have been more professional. A lot of the things were done incorrectly (in a rush) mainly due to cost factor that people always wanted something “now” and with the smallest amount of spendable money. I kept on thinking maybe if I could work for a bigger companies or a company that’s better suited for programmers, or somewhere that's got the money and time to really build something longer term and more maintainable I may have enjoyed more in my career. I’ve never had a “mentor” that guided me through my 4 years career. I am pretty much blog / google / self taught programmer other than my bachelor IT degree. I’ve also observed another issue that most so called “senior” programmer in “my working environment” are really not that senior skill wise. They are “senior” only because they’ve been a long time programmer, but the code they write or the decisions they make are absolutely rubbish! They don't want to learn, they don't want to be better they just want to get paid and do what they've told to do which make sense and most of us are like that. Maybe that’s why they are where they are now. But I don’t want to become like them I want to be better. I’ve run into a mental state that I no longer intend to be a programmer for my future career. I started to think maybe there are better things out there to work on. The more blogs I read, the more “best practices” I’ve tried the more I feel I am drifting away from “my reality”. But I am not a great programmer otherwise I don't think I am where I am now. I think 4-5 years is a stage that can be a step forward career wise or a step out of where you are. I just wanted to hear what other have to say about what I’ve mentioned above and whether you’ve experienced similar situation in your past programming career and how you dealt with it. Thanks.

  Read the article

• JPanel's child components paint/layout problem

  - by Tom Brito

  I'm having a problem that when my frame is shown (after a login dialog) the buttons are not on correct position, then in some miliseconds they go to the right position (the center of the panel with border layout). When I make a SSCCE, it works correct, but when I run my whole code I have this fast-miliseconds delay to the buttons to go to the correct place. Unfortunately, I can't post the whole code, but the method that shows the frame is: public void login(JComponent userView) { centerPanel.removeAll(); centerPanel.add(userView); centerPanel.revalidate(); centerPanel.repaint(); frame.setVisible(true); } What would cause this delay to the panel layout? (I'm running everything in the EDT) -- update In my machine, this SSCCE shows the layout problem in 2 of 10 times I run it: import java.awt.BorderLayout; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.SwingUtilities; public class TEST { public static void main(String[] args) throws Exception { SwingUtilities.invokeAndWait(new Runnable() { @Override public void run() { System.out.println("Debug test..."); JPanel btnPnl = new JPanel(); btnPnl.add(new JButton("TEST")); JFrame f = new JFrame("TEST"); f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); f.getContentPane().setLayout(new BorderLayout()); f.getContentPane().add(btnPnl); f.pack(); f.setSize(800, 600); f.setVisible(true); System.out.println("End debug test!"); } }); } } The button first appers in the up-left, and then it goes to the center. Please, note that I'm understand, not just correct. Is it a java bug? --update OK, so the SSCCE don't show the problem with you that tried till now. Maybe it's my computer performance problem. But this don't answer the question, I still think Java Swing is creating new threads for make the layout behind the scenes.

  Read the article

• C# - periodic data reading and Thread.Sleep()

  - by CaldonCZE

  Hello, my C# application reads data from special USB device. The data are read as so-called "messages", each of them having 24 bytes. The amount of messages that must be read per second may differ (maximal frequency is quite high, about 700 messages per second), but the application must read them all. The only way to read the messages is by calling function "ReadMessage", that returns one message read from the device. The function is from external DLL and I cannot modify it. My solution: I've got a seperate thread, that is running all the time during the program run and it's only job is to read the messages in cycle. The received messages are then processed in main application thread. The function executed in the "reading thread" is the following: private void ReadingThreadFunction() { int cycleCount; try { while (this.keepReceivingMessages) { cycleCount++; TRxMsg receivedMessage; ReadMessage(devHandle, out receivedMessage); //...do something with the message... } } catch { //... catch exception if reading failed... } } This solution works fine and all messages are correctly received. However, the application consumes too much resources, the CPU of my computer runs at more than 80%. Therefore I'd like to reduce it. Thanks to the "cycleCount" variable I know that the "cycling speed" of the thread is about 40 000 cycles per second. This is unnecessarily too much, since I need to receive maximum 700 messagges/sec. (and the device has buffer for about 100 messages, so the cycle speed can be even a little lower) I tried to reduce the cycle speed by suspending the thread for 1 ms by Thread.Sleep(1); command. Of course, this didn't work and the cycle speed became about 70 cycles/second which was not enough to read all messages. I know that this attempt was silly, that putting the thread to sleep and then waking him up takes much longer than 1 ms. However, I don't know what else to do: Is there some other way how to slow the thread execution down (to reduce CPU consumption) other than Thread.Sleep? Or am I completely wrong and should I use something different for this task instead of Thread, maybe Threading.Timer or ThreadPool? Thanks a lot in advance for all suggestions. This is my first question here and I'm a beginner at using threads, so please excuse me if it's not clear enough.

  Read the article

• When to use new layouts and when to use new activities?

  - by cmdfrg

  I'm making a game in Android and I'm trying to add a set of menu screens. Each screen takes up the whole display and has various transitions available to other screens. As a rough summary, the menu screens are: Start screen Difficult select screen Game screen. Pause screen. Game over screen. And there are several different ways you can transition between screen: 1 - 2 2 - 3 3 - 4 (pause game) 4 - 1 (exit game) 4 - 3 (resume game) 3 - 5 (game ends) Obviously, I need some stored state when moving between screens, such as the difficulty level select when starting a game and what the player's score is when the game over screen is shown. Can anyone give me some advice for the easiest way to implement the above screens and transitions in Android? All the create/destroy/pause/resume methods make me nervous about writing brittle code if I'm not careful. I'm not fond of using an Activity for each screen. It seems too heavy weight, having to pass data around using intents seems like a real pain and each screen isn't a useful module by itself. As the "back" button doesn't always go back to the previous screen either, my menu layout doesn't seem to fit the activity model well. At the moment, I'm representing each screen as an XML layout file and I have one activity. I set the different buttons on each layout to call setContentView to update the screen the main activity is showing (e.g. the pause button changes the layout to the pause screen). The activity holds onto all the state needed (e.g. the current difficulty level and the game high score), which makes it easy to share data between screens. This seems roughly similar to the LunarLander sample, except I'm using multiple screens. Does what I have at the moment sound OK or am I not doing things the typical Android way? Is there a class I can use (e.g. something like ViewFlipper) that could make my life easier? By the way, my game screen is implemented as a SurfaceView that stores the game state. I need the state in this view to persist between calls to setContentView (e.g. to resume from paused). Is the right idea to create the game view when the activity starts, keep a reference to it and then use this reference with setContentView whenever I want the game screen to appear?

  Read the article

< Previous Page | 717 718 719 720 721 722 723 724 725 726 727 728  | Next Page >