Search Results

Search found 8268 results on 331 pages for 'difference'.

Page 285/331 | < Previous Page | 281 282 283 284 285 286 287 288 289 290 291 292  | Next Page >

• Sql Server 2005 Database Tables - Row Comparison Column By Column.

  - by Goober

  Scenario I have an TWO datbase tables of exactly the SAME STRUCTURE. The difference between these tables is that one contains data populated by one application and the other is populated by a different application. Each application is trying to produce the same result, but using two different methods of implementation. Proposed Idea What I want to do, is run both applications, which will roughly produce 35000 rows containing 10 columns each - So all in all, 70000 rows of data, I then want to compare each row of data, COLUMN BY COLUMN to check whether the values are the same or not. Current Thoughts Since there is so much data to compare, I feel that the best way in which to do this would be to write an application, preferably in C# (but if necessary, T-sql), to compare each row of data column by column, and write out any failed comparisons to a text log file. Question Could anybody suggest an efficient way in which to perform column by column row comparison for 70000 rows worth of data? I'm struggling for ideas on how to tackle this problem. Extra Detail The two applications are both written in C# .Net 3.5. The Database is running on Sql Server 2005. Help greatly appreciated.

  Read the article

• Where are possible locations of queueing/buffering delays in Linux multicast?

  - by Matt

  We make heavy use of multicasting messaging across many Linux servers on a LAN. We are seeing a lot of delays. We basically send an enormous number of small packages. We are more concerned with latency than throughput. The machines are all modern, multi-core (at least four, generally eight, 16 if you count hyperthreading) machines, always with a load of 2.0 or less, usually with a load less than 1.0. The networking hardware is also under 50% capacity. The delays we see look like queueing delays: the packets will quickly start increasing in latency, until it looks like they jam up, then return back to normal. The messaging structure is basically this: in the "sending thread", pull messages from a queue, add a timestamp (using gettimeofday()), then call send(). The receiving program receives the message, timestamps the receive time, and pushes it in a queue. In a separate thread, the queue is processed, analyzing the difference between sending and receiving timestamps. (Note that our internal queues are not part of the problem, since the timestamps are added outside of our internal queuing.) We don't really know where to start looking for an answer to this problem. We're not familiar with Linux internals. Our suspicion is that the kernel is queuing or buffering the packets, either on the send side or the receive side (or both). But we don't know how to track this down and trace it. For what it's worth, we're using CentOS 4.x (RHEL kernel 2.6.9).

  Read the article

• SQL Compact performance on device

  - by Ben M

  My SQL Compact database is very simple, with just three tables and a single index on one of the tables (the table with 200k rows; the other two have less than a hundred each). The first time the .sdf file is used by my Compact Framework application on the target Windows Mobile device, the system hangs for well over a minute while "something" is done to the database: when deployed, the DB is 17 megabytes, and after this first usage, it balloons to 24 megs. All subsequent usage is pretty fast, so I'm assuming there's some sort of initialization / index building going on during this first usage. I'd rather not subject the user to this delay, so I'm wondering what this initialization process is and whether it can be performed before deployment. For now, I've copied the "initialized" database back to my desktop for use in the setup project, but I'd really like to have a better answer / solution. I've tried "full compact / repair" in the VS Database Properties dialog, but this made no difference. Any ideas? For the record, I should add that the database is only read from by the device application -- no modifications are made by that code.

  Read the article

• Does breaking chained Select()s in LINQ to objects hurt performance?

  - by Justin

  Take the following pseudo C# code: using System; using System.Data; using System.Linq; using System.Collections.Generic; public IEnumerable<IDataRecord> GetRecords(string sql) { // DB logic goes here } public IEnumerable<IEmployer> Employers() { string sql = "select EmployerID from employer"; var ids = GetRecords(sql).Select(record => (record["EmployerID"] as int?) ?? 0); return ids.Select(employerID => new Employer(employerID) as IEmployer); } Would it be faster if the two Select() calls were combined? Is there an extra iteration in the code above? Is the following code faster? public IEnumerable<IEmployer> Employers() { string sql = "select EmployerID from employer"; return Query.Records(sql).Select(record => new Employer((record["EmployerID"] as int?) ?? 0) as IEmployer); } I think the first example is more readable if there is no difference in performance.

  Read the article

• Inline function v. Macro in C -- What's the Overhead (Memory/Speed)?

  - by Jason R. Mick

  I searched Stack Overflow for the pros/cons of function-like macros v. inline functions. I found the following discussion: Pros and Cons of Different macro function / inline methods in C ...but it didn't answer my primary burning question. Namely, what is the overhead in c of using a macro function (with variables, possibly other function calls) v. an inline function, in terms of memory usage and execution speed? Are there any compiler-dependent differences in overhead? I have both icc and gcc at my disposal. My code snippet I'm modularizing is: double AttractiveTerm = pow(SigmaSquared/RadialDistanceSquared,3); double RepulsiveTerm = AttractiveTerm * AttractiveTerm; EnergyContribution += 4 * Epsilon * (RepulsiveTerm - AttractiveTerm); My reason for turning it into an inline function/macro is so I can drop it into a c file and then conditionally compile other similar, but slightly different functions/macros. e.g.: double AttractiveTerm = pow(SigmaSquared/RadialDistanceSquared,3); double RepulsiveTerm = pow(SigmaSquared/RadialDistanceSquared,9); EnergyContribution += 4 * Epsilon * (RepulsiveTerm - AttractiveTerm); (note the difference in the second line...) This function is a central one to my code and gets called thousands of times per step in my program and my program performs millions of steps. Thus I want to have the LEAST overhead possible, hence why I'm wasting time worrying about the overhead of inlining v. transforming the code into a macro. Based on the prior discussion I already realize other pros/cons (type independence and resulting errors from that) of macros... but what I want to know most, and don't currently know is the PERFORMANCE. I know some of you C veterans will have some great insight for me!!

  Read the article

• Python coin-toss

  - by Andy

  i am new to Python, and i can't wrap my head around this. I have following function defined: def FlipCoins(num_flips): heads_rounds_won = 0 for i in range(10000): heads = 0 tails = 0 for j in range(num_flips): dice = random.randint(0,1) if dice==1: heads += 1 else: tails += 1 if heads > tails: heads_rounds_won += 1 return heads_rounds_won Here is what it should do (but apparently doesn't): flip a coin num_flip times, count heads and tails, and see if there are more heads than tails. If yes, increment head_rounds_won by 1. Repeat 10000 times. I would assume that head_rounds_won will approximate 5000 (50%). And it does that for odd numbers as input. For example, 3, 5 or 7 will produce about 50%. However, even numbers will produce much lower results, more like 34%. Small numbers especially, with higher even numbers, like for example 800, the difference to 50% is much narrower. Why is this the case? Shouldn't any input produce about 50% heads/tails?

  Read the article

• How to find every possible combination of an arbitrary number of arrays in PHP

  - by Travis

  I have an arbitrary number of nested arrays in php. For example: Array ( [0] => Array ( [0] => 36 [0] => 2 [0] => 9 ) [1] => Array ( [0] => 95 [1] => 21 [2] => 102 [3] => 38 ) [2] => Array ( [0] => 3 [1] => 5 ) ) I want to find the most efficient way to combine all possible combinations of each of these nested arrays. I'd like to end up with something that looks like this... Array ( [0] => "36,95,3" [1] => "36,95,5" [2] => "36,21,3" [3] => "36,21,5" etc... ) The order the results are combined in is not important. That is to say, there is no difference between "3,95,36", "36,95,3", and "95,36,3". I would like to omit these redundant combinations. Any suggestions on how to go about this would be much appreciated. Thanks in advance,

  Read the article

• so i got an econ degree...computing science or software systems (software engineering) degree ?

  - by sofreakinghigh

  okay so here's the story. i want to work in developing software (not QA or writing tests), so although I am currently starting computing science this summer, i came across Software Systems (aka s.e.) program which is "applied" but under computing science.... so what is the difference between the 2 disciplines ? if i choose software engineering, would it require more in depth expertise with calculus (i fail at it), and more coding time ? i am looking for a way to write better and more efficient code. I want to go to school, so i wont get lazy. i want to pick a program that would directly aid me in writing and developing software. graduating with an Econ degree in last year doesn't really help in landing jobs requiring comp sci/software engineering degrees....i should've studied harder in Economics (and maybe land a job) but i was obsessed with learning how to program with various languages since day 1 at University, but i didn't think i was smart enough to pass comp sci courses (so i just relied on books + irc...) and my parents said software jobs are being outsourced to India so i thought this obsession was just a "phase" and i should keep it as a hobby. but yes, it's quite funny why i hadn't pursued this field much earlier. as Joelonsoftware.com says economics degree starts with a bang (microeconomics the only course you only need really)....predicting stock prices (ridiculous!) + realizing China's potential power to meltdown US economy and vice versa + interest rate is inversely related to bond premium which is inversely related to stock market it would absolutely awesome if there was a program that combined finance + programming.

  Read the article

• Legacy application creates dialogs in non-ui thread.

  - by Frater

  I've been working support for a while on a legacy application and I've noticed a bit of a problem. The system is an incredibly complex client/server with standard and custom frameworks. One of the custom frameworks built into the application involves validating workflow actions. It finds potential errors, separates them into warnings and errors, and passes the results back to the client. The main difference between warnings and errors is that warnings ask the user if they wish to ignore the error. The issue I have is that the dialog for this prompt is created on a non-ui thread, and thus we get cross-threading issues when the dialog is shown. I have attempted to invoke the showing of the dialog, however this fails because the window handle has not been created. (InvokeRequired returns false, which I assume in this case means it cannot find a decent handle in its parent tree, rather than that it doesn't require it.) Does anyone have any suggestions for how I can create this dialog and get the UI thread to set it up and call it?

  Read the article

• rbind.zoo doesn't seem create consistent zoo object

  - by a-or-b

  I want to rbind.zoo two zoo object together. When I was testing I came across the following issue(?)... Note: The below is an example, there is clearly no point to it apart from being illustrative. I have an zoo object, call it, 'X'. I want to break it into two parts and then rbind.zoo them together. When I compare it to the original object then all.equal gives differences. It appears that the '$class' attribute differs, but I can't see how or why. Is I make these xts objects then the all.equal works as expected. i.e. ..... X.date <- as.POSIXct(paste("2003-", rep(1:4, 4:1), "-", sample(1:28, 10, replace = TRUE), sep = "")) X <- zoo(matrix(rnorm(24), ncol = 2), X.date) a <- X[c(1:3), ] # first 3 elements b <- X[c(4:6), ] # second 3 elements c <- rbind.zoo(a, b) # rbind into an object of 6 elements d <- X[c(1:6), ] # all 6 elements all.equal(c, d) # are they equal? ~~~~ all.equal gives me the following difference: "Attributes: < Component 3: Attributes: < Length mismatch: comparison on first 1 components "

  Read the article

• PHP: Opening/closing tags & performance?

  - by Tom

  Hi, This may be a silly question, but as someone relatively new to PHP, I'm wondering if there are any performance-related issues to frequently opening and closing PHP tags in HTML template code, and if so, what might be best practices in terms of working with php tags? My question is not about the importance/correctness of closing tags, or about which type of code is more readable than another, but rather about how the document gets parsed/executed and what impact it might have on performance. To illustrate, consider the following two extremes: Mixing PHP and HTML tags: <?php echo '<tr> <td>'.$variable1.'</td> <td>'.$variable2.'</td> <td>'.$variable3.'</td> <td>'.$variable4.'</td> <td>'.$variable5.'</td> </tr>' ?> // PHP tag opened once Separating PHP and HTML tags: <tr> <td><?php echo $variable1 ?></td> <td><?php echo $variable2 ?></td> <td><?php echo $variable3 ?></td> <td><?php echo $variable4 ?></td> <td><?php echo $variable5 ?></td> </tr> // PHP tag opened five times Would be interested in hearing some views on this, even if it's just to hear that it makes no difference. Thanks.

  Read the article

• avoiding code duplication in Rails 3 models

  - by Dustin Frazier

  I'm working on a Rails 3.1 application where there are a number of different enum-like models that are stored in the database. There is a lot of identical code in these models, as well as in the associated controllers and views. I've solved the code duplication for the controllers and views via a shared parent controller class and the new view/layout inheritance that's part of Rails 3. Now I'm trying to solve the code duplication in the models, and I'm stuck. An example of one of my enum models is as follows: class Format < ActiveRecord::Base has_and_belongs_to_many :videos attr_accessible :name validates :name, presence: true, length: { maximum: 20 } before_destroy :verify_no_linked_videos def verify_no_linked_videos unless self.videos.empty? self.errors[:base] << "Couldn't delete format with associated videos." raise ActiveRecord::RecordInvalid.new self end end end I have four or five other classes with nearly identical code (the association declaration being the only difference). I've tried creating a module with the shared code that they all include (which seems like the Ruby Way), but much of the duplicate code relies on ActiveRecord, so the methods I'm trying to use in the module (validate, attr_accessible, etc.) aren't available. I know about ActiveModel, but that doesn't get me all the way there. I've also tried creating a common, non-persistent parent class that subclasses ActiveRecord::Base, but all of the code I've seen to accomplish this assumes that you won't have subclasses of your non-persistent class that do persist. Any suggestions for how best to avoid duplicating these identical lines of code across many different enum models?

  Read the article

• how to programatically compare permissions of login/user in sql server 2005

  - by titanium

  There's a login/user in SQL Server who is having a problem importing accounts in production server. I don't have an idea what method he is doing this. According to the one importing, this import is working fine in development server. But when he did the same import in production it is giving him errors. Below are the errors he is getting for each accounts. 2009-06-05 18:01:05.8254 ERROR [engine-1038] Task [1038:00001 - Members]: Step 1.0 [<Insert step description>]: Task.RunStep(): StoreRow has failed 2009-06-05 18:01:05.9035 ERROR [engine-1038] Task [1038:00001 - Members]: Step 1.0 [<Insert step description>]: Task.RunStep(): StoreRow exception: Exception caught while storing Data. [Microsoft][ODBC SQL Server Driver][SQL Server]'ACCOUNT1' is not a valid login or you do not have permission. Please note that 'ACCOUNT1' is not the real account name. I just changed it for security reason. Using SQL Server Management Studio (SSMS), I viewed/checked the permissions of the user/login who is performing the import from development server and production for comparison. I found no difference. My question is: Is there a way to programmatically query permissions in server and database level of a particular login/user so I can compare/contrast for any differences?

  Read the article

• Why doesn't this CompiledQuery give a performance improvement?

  - by Grammarian

  I am trying to speed up an often used query. Using a CompiledQuery seemed to be the answer. But when I tried the compiled version, there was no difference in performance between the compiled and non-compiled versions. Can someone please tell me why using Queries.FindTradeByTradeTagCompiled is not faster than using Queries.FindTradeByTradeTag? static class Queries { // Pre-compiled query, as per http://msdn.microsoft.com/en-us/library/bb896297 private static readonly Func<MyEntities, int, IQueryable<Trade>> mCompiledFindTradeQuery = CompiledQuery.Compile<MyEntities, int, IQueryable<Trade>>( (entities, tag) => from trade in entities.TradeSet where trade.trade_tag == tag select trade); public static Trade FindTradeByTradeTagCompiled(MyEntities entities, int tag) { IQueryable<Trade> tradeQuery = mCompiledFindTradeQuery(entities, tag); return tradeQuery.FirstOrDefault(); } public static Trade FindTradeByTradeTag(MyEntities entities, int tag) { IQueryable<Trade> tradeQuery = from trade in entities.TradeSet where trade.trade_tag == tag select trade; return tradeQuery.FirstOrDefault(); } }

  Read the article

• Cost of logic in a query

  - by FrustratedWithFormsDesigner

  I have a query that looks something like this: select xmlelement("rootNode", (case when XH.ID is not null then xmlelement("xhID", XH.ID) else xmlelement("xhID", xmlattributes('true' AS "xsi:nil"), XH.ID) end), (case when XH.SER_NUM is not null then xmlelement("serialNumber", XH.SER_NUM) else xmlelement("serialNumber", xmlattributes('true' AS "xsi:nil"), XH.SER_NUM) end), /*repeat this pattern for many more columns from the same table...*/ FROM XH WHERE XH.ID = 'SOMETHINGOROTHER' It's ugly and I don't like it, and it is also the slowest executing query (there are others of similar form, but much smaller and they aren't causing any major problems - yet). Maintenance is relatively easy as this is mostly a generated query, but my concern now is for performance. I am wondering how much of an overhead there is for all of these case expressions. To see if there was any difference, I wrote another version of this query as: select xmlelement("rootNode", xmlforest(XH.ID, XH.SER_NUM,... (I know that this query does not produce exactly the same, thing, my plan was to move the logic to PL/SQL or XSL) I tried to get execution plans for both versions, but they are the same. I'm guessing that the logic does not get factored into the execution plan. My gut tells me the second version should execute faster, but I'd like some way to prove that (other than writing a PL/SQL test function with timing statements before and after the query and running that code over and over again to get a test sample). Is it possible to get a good idea of how much the case-when will cost? Also, I could write the case-when using the decode function instead. Would that perform better (than case-statements)?

  Read the article

• Pure CSS3 show/hide full height div with transition

  - by user1898838

  Dear Stackoverflow readers, I've been breaking my head over something I've seen at Tympanus, and I can't figure out how to properly do such a thing. In this link: http://tympanus.net/Tutorials/FullscreenBookBlock/ you can see that the menu is completely hidden, and only visible when you click on an icon. It has a lovely transition, and it basically roughly sums up what I'm trying to accomplish. The only difference with the above example is that I don't want to completely hide this full-height element, and I'd like to accomplish the above effect with a hover instead of having to click a button. So in an ideal world you'd see a vertical bar, and when you hover over that bar (or click on it with your finger if you're on a tablet), it "opens up" and shows you the full content inside the opened div. Now, I can make a decent bit in html5 and css3, but the above explained effect that I'm trying to accomplish has given me serious headaches, hehe. Does anyone happen to know a tutorial I might have missed that does this exact thing? p.s.: I have tried to take apart Tympanus' html/css, but with the page-fold effect that's also implemented in it I can't seem to figure it out, hence my hope for someone here to help me on my way :)

  Read the article

• "Ghost" values in PHP/Smarty.

  - by Kyle Sevenoaks

  I've been working on a site for a while changing the layout and skin of a webshop checkout process. I've noticed that if you go all the way through the process until the last page, then click the link to go back to the view products page, the delivery method price displays underneath the navigation buttons, until you refresh and it goes away again. I've downloaded both sourced from the browser (Chrome, but this bug applies to all browsers) and used a file difference tool to display the differences, the result being only: < error.html vs > normal.html 34c34 < <link href="gzip.php?file=167842c1496093fbcd391b41cf7b03da.css&time=1272272181" rel="Stylesheet" type="text/css"/> --- > <link href="gzip.php?file=167842c1496093fbcd391b41cf7b03da.css&time=1272272348" rel="Stylesheet" type="text/css"/> Which is just the way it zips up the CSS stylesheets. (afaik) Has anyone ever encountered such a problem, or anything similar? Normal: Error: I can't even hazard a guess as to what is causing this, at all. I've searched over Google for anything and come up with nothing. What could be causing this? The site in question is Euroworker.no. HTML @ Pastebin. Smarty snippet: {if !$CANONICAL} {canonical}{self}{/canonical} {/if} <link rel="canonical" href="{$CANONICAL}" /> <!-- Css includes --> {includeCss file="frontend/Frontend.css"} {includeCss file="backend/stat.css"} {if {isRTL}} {includeCss file="frontend/FrontendRTL.css"} {/if} {compiledCss glue=true nameMethod=hash} <!--[if lt IE 8]> <link href="stylesheet/frontend/FrontendIE.css" rel="Stylesheet" type="text/css"/> {if $ieCss} <link href="{$ieCss}" rel="Stylesheet" type="text/css"/> {/if} <![endif]--> Thanks.

  Read the article

• SQLite DB open time really long Problem

  - by sxingfeng

  I am using sqlite in c++ windows, And I have a db size about 60M, When I open the sqlite db, It takes about 13 second. sqlite3* mpDB; nRet = sqlite3_open16(szFile, &mpDB); And if I closed my application and reopen it again. It takse only less then 1 second. First, I thought It is because of disk cache. So I preload the 60M db file before sqlite open, and read the file using CFile, However, after preloading, the first time is still very slow. BOOL CQFilePro::PreLoad(const CString& strPath) { boost::shared_array<BYTE> temp = boost::shared_array<BYTE>(new BYTE[PRE_LOAD_BUFFER_LENGTH]); int nReadLength; try { CFile file; if (file.Open(strPath, CFile::modeRead) == FALSE) { return FALSE; } do { nReadLength = file.Read(temp.get(), PRE_LOAD_BUFFER_LENGTH); } while (nReadLength == PRE_LOAD_BUFFER_LENGTH); file.Close(); } catch(...) { } return TRUE; } My question is what is the difference between first open and second open. How can I accelerate the sqlite open-process.

  Read the article

• Service behavior not being applied correctly

  - by Rubans

  I have a custom behavior for a service where I want to specify a receive timeout value, I have created a behavior and on the build service header. I use the declarative attribute to apply the behavior or as I thought. But the behavior seems to make no difference, i.e. the set timeout value is not being applied as expected. However when I have noticed the behavior is only being applied when the host is opened rather than when created. The same behavior when applied explicitly through does work. Any ideas? Behavior: [AttributeUsage(AttributeTargets.Class)] public class BuildServiceBindingBehavior : Attribute, IServiceBehavior { public BuildServiceBindingBehavior( string p_receiveTime ) { ReceiveTimeout = TimeSpan.Parse( p_receiveTime ); } #region IServiceBehavior Members public void AddBindingParameters( ServiceDescription serviceDescription, ServiceHostBase serviceHostBase, System.Collections.ObjectModel.Collection<ServiceEndpoint> endpoints, System.ServiceModel.Channels.BindingParameterCollection bindingParameters ) { } public void ApplyDispatchBehavior( ServiceDescription serviceDescription, ServiceHostBase serviceHostBase ) { // add this behavior to each endpoint foreach ( var endPoint in serviceDescription.Endpoints ) { endPoint.Binding.ReceiveTimeout = ReceiveTimeout; } } public void Validate( ServiceDescription serviceDescription, ServiceHostBase serviceHostBase ) { } #endregion internal TimeSpan ReceiveTimeout { get; set; } } Service code: [ServiceBehavior(Name = "DotNetBuildsService", InstanceContextMode = InstanceContextMode.PerSession, ConcurrencyMode = ConcurrencyMode.Single )] // Set receieve time out [BuildServiceBindingBehavior( "0:0:1" )] public class BuildService : IBuildTasksService { //implementation code }

  Read the article

• What is a mantainable way of saving "star rating" in a database?

  - by Montecristo

  I'll use the jQuery plugin for presenting the user with a nice interface The request is to display 5 stars, up to a total score of 10 (2 points per star). By now I thought about using 7/10 as a format for that value, but what if at some point in the future I'll receive a request like We would like to give users more choice, let's increase the total score to 20 (so that each star contributes with a maximum of 4 points) I'll end up with a table with mixed values for the "star rating" column: some will be like 7/10 while others will be like 14/20. Is it ok for you to have this difference in the database and deal with it in the logic layer to have it consistent? Or is preferred another way so that querying the table will not result in inconsistent results outside the application? Maybe floating point values could help me, is it better to store that value as a number less than or equal to one? So in each of the two examples the resulting value stored in the database would be 0,7, as a number, not a varchar, which can be queried also outside the application. What do you think?

  Read the article

• What are the Limitations for Connecting to an Access Query in Excel

  - by thornomad

  I have an Access 2007 database that has a number of tables, some are fairly large (100,000+ records); I have created a union query to pull some of the same types of data from multiple tables into one large query for pivot table manipulation and reporting. For example: SELECT Language FROM Table1 UNION ALL SELECT Language FROM Table2 UNION ALL SELECT Language FROM Table3; This works. I found, quickly, however, that a union query will not show up when connecting to the datasource from Excel 2007. So, I created a second query to reference the union query. Like so: SELECT * FROM [The Above Union Query]; This query works and it, initially, was accessible from Excel. Time passed, I've added more data. Suddenly, when I connect to my Access database from Excel my query referencing the union has disappeared. MS Access shows no signs of an issue (data displays in Access) and my other non-union queries are showing up in Excel 2007 ... but not the one that references the union. What could be going on? Why did it disappear? I noticed if I switch some of the referenced tables in the union query to a smaller table (with less rows) all of sudden the query appears in Excel again. At least, I think that's what the difference is. I really can't put my finger on why some of the union queries won't show up and some will. Am stumped and need some guidance. Thanks.

  Read the article

• Noise with multi-threaded raytracer

  - by herber88

  This is my first multi-threaded implementation, so it's probably a beginners mistake. The threads handle the rendering of every second row of pixels (so all rendering is handled within each thread). The problem persists if the threads render the upper and lower parts of the screen respectively. Both threads read from the same variables, can this cause any problems? From what I've understood only writing can cause concurrency problems... Can calling the same functions cause any concurrency problems? And again, from what I've understood this shouldn't be a problem... The only time both threads write to the same variable is when saving the calculated pixel color. This is stored in an array, but they never write to the same indices in that array. Can this cause a problem? Multi-threaded rendered image (Spam prevention stops me from posting images directly..) Ps. I use the exactly same implementation in both cases, the ONLY difference is a single vs. two threads created for the rendering.

  Read the article

• What /else/ causes this?

  - by Mordachai

  MFC Toolbox Library.lib(SimpleFileIO.obj) : error LNK2005: _wcsnlen already defined in libcmtd.lib(wcslen_s.obj) fatal error LNK1169: one or more multiply defined symbols found This is driving me nuts. Normally, one would get this if the various projects that are a part of their solution do not agree on which CRT to use (single threaded, multi-threaded, release or debug). However, I have been over this thing about 500 times now, and they all agree. Background: this is a VS 2010 project just converted from VS 2008. MFC Toolbox Library.lib is set to compile as a static library, using /MTd, as is the target .exe I am trying to compile in this solution. Further, the solution that this is being converted from (VS 2008) already compiles & links properly!!! So it's not like that there is a disagreement between the two .vcproj's - or at least there wasn't before the conversion. Furthermore, the MFC Toolbox Library is used by about 25 other projects in another solution - and in that solution (Master Build English) it compiles & links against those other projects without complaint in both debug and release targets. I have just spent the last hour going over every single project property for this target project (Cimex Header Viewer) vs. several different target exe projects in Master Build English solution - and I cannot find a difference. They appear to be identical, excepting that they're different names. I've tried doing a clean & build all. I'm simply out of ideas. Does anyone have a thought on what else I might investigate??? I think I'm ready to start chewing glass. :(

  Read the article

• When is a bool not a bool (compiler warning C4800)

  - by omatai

  Consider this being compiled in MS Visual Studio 2005 (and probably others): CPoint point1( 1, 2 ); CPoint point2( 3, 4 ); const bool point1And2Identical( point1 == point2 ); // C4800 warning const bool point1And2TheSame( ( point1 == point2 ) == TRUE ); // no warning What the...? Is the MSVC compiler brain-dead? As far as I can tell, TRUE is #defined as 1, without any type information. So by what magic is there any difference between these two lines? Surely the type of the expression inside the brackets is the same in both cases? [This part of the question now satisfactorily answered in the comments just below] Personally, I think that avoiding the warning by using the == TRUE option is ugly (though less ugly than the != 0 alternative, despite being more strictly correct), and it is better to use #pragma warning( disable:4800 ) to imply "my code is good, the compiler is an ass". Agree? Note - I have seen all manner of discussion on C4800 talking about assigning ints to bools, or casting a burger combo with large fries (hold the onions) to a bool, and wondering why there are strange results. I can't find a clear answer on what seems like a much simpler question... that might just shine line on C4800 in general.

  Read the article

• [IE6] Cannot upload non-existent file

  - by geff_chang

  I am asking the same question as this: http://stackoverflow.com/questions/691323/trying-to-upload-a-non-existent-file-in-internet-explorer-form-is-not-submitted I'm not sure if the topic starter found a solution, since he did not post the answer. So, I'd like to ask you guys this question again. I have type=input in my form, and a submit button. If I type garbage input into the textbox (like the text "abc") in the file control's textbox, and click the submit button, the form is not submitted to the server. AND, no feedback is given to the user. Instead of this "Is-the-submit-button-broken?" behavior, is there a way I could notify the user that the file does not exist? (I am aware this is not possible, except with ActiveX, but I don't want to go into that) My client wants to hide the textbox of the file control, but I'm not sure if this is a good design. What do you guys suggest? (If it makes any difference, I am also using this jquery plugin: http://www.fyneworks.com/jquery/multiple-file-upload/)

  Read the article

< Previous Page | 281 282 283 284 285 286 287 288 289 290 291 292  | Next Page >