Search Results

Search found 35444 results on 1418 pages for 'lock down computer'.

Page 492/1418 | < Previous Page | 488 489 490 491 492 493 494 495 496 497 498 499  | Next Page >

• jQuery Accordion + Anchor Tag 'stuck as block' bug?

  - by DA

  Sample page: http://jsbin.com/ohuze/2 This is a simple jQuery UI Accordion. Each accordion panel has an UL (an OL works the same) with this markup: <ol> <li><a href="">Lorep ipsum dolor lorem ipsum dolor lorem ipsum dolor</a>?</li> <li><a href="">Lorep ipsum dolor lorem ipsum dolor lorem ipsum dolor</a>?</li> </ol> In IE6, you'll see that the <a> tag appears to be getting rendered as a block element, so the question mark ends up being pushed outside and not at the end of the line of text. In addition, the bullet and/or list item number is now bottom-aligned with the text rather than top-aligned. I've narrowed it down to the javascript that executes to make the accordion. It's not an issue with jQuery's CSS as disabling that, alone, doesn't resolve the issue. Anyone know what might be going on in IE6 to cause this rendering issue? UPDATE: Apparently, this is also an IE7 issue. UPDATE 2: After some more playing, I've narrowed things down a bit more: the bug has nothing to do with lists. The issue is any anchor tag within a jQuery Accordion will appear as display: block (even though it appears that the CSS still indicates display: inline) the bug has nothing to do with the actual CSS that jQuery UI uses to create the accordion. I created a test page that uses the fully rendered jQuery Accordion post-processed source code and the accompanying CSS. In that situation, the anchor tags remain inline. In conclusion: It appears that the process of rendering the accordion via javascript is messing up the display of the anchor tags. It may be a show/hide issue?

  Read the article

• PHP/MySQL won't update decimal field

  - by Serhiy

  I have this query: UPDATE table_name SET field_1 = field_1 +100, field_2 = field_2 +100, field_3 = field_3 +100 WHERE id = 1 LIMIT 1; Where Field_1 is regular integer, Field_2 is decimal(15,6) and Field_3 is double(15,6). When I run this query from php script they update just field_1 and nothing happen with field_2 and field_3 they just stay as before. But when I run in phpMyAdmin it's work without any problems. I'm tried to lock tables, make round() before run update, nothing help. Please help... why I can't update decimal and float fields from php? PHP version: 5.2 Mysql version 5

  Read the article

• problem with joomla, php and json

  - by sebastian

  hi, i have a problem with a joomla component. i'm, unsing php and json for some dynamic drop down boxes. here is the code:` jQuery( function () { //jQuery.ajaxSetup({error : function (a,b) {console.dir(a); console.dir(b);}}); jQuery("#util, #loc").change( function() { var locatie = jQuery("#loc").val(); var utilitate = jQuery("#util").val(); if ( (locatie!= '---') && (utilitate!='---') ) jQuery.getJSON( "index.php?option=com_calculator&opt=json_contor&format=raw", { locatie: locatie, utilitate: utilitate }, function (data) { var html = ""; if ( data.success == 'ok' ) for (var i in data.val) html += "<option name=den_contor value ='"+ i+"' >" + data.val[i]+ " </option>"; jQuery("#den_contor").html( html ) } ) }) }); the query works, but only on one PC. we have exactly the same xampp server, exactly the same files. on one pc it works, and on a online server and on my pc it doesn't. EDIT: i have three drop down boxes, the first is populated directly from the database, the second has 4 predefined values. and the third is populated depending on combination of the first two. i have a test site online. http://contor.redxart.com must be logged in to use Calculator in the menu. you can make an new account :) "Adaugare Index" is the part that isn't working any ideas? thanks, sebastian

  Read the article

• Regarding some Update Stored procedure

  - by Serenity

  I have two Tables as follows:- Table1:- ------------------------------------- PageID|Content|TitleID(FK)|LanguageID ------------------------------------- 1 |abc |101 |1 2 |xyz |102 |1 -------------------------------------- Table2:- ------------------------- TitleID|Title |LanguageID ------------------------- 101 |Title1|1 102 |Title2|1 ------------------------ I don't want to add duplicates in my Table1(Content Table). Like..there can be no two Pages with the same Title. What check do I need to add in my Insert/Update Stored Procedure ? How do I make sure duplicates are never added. I have tried as follows:- CREATE PROC InsertUpdatePageContent ( @PageID int, @Content nvarchar(2000), @TitleID int ) AS BEGIN IF(@PageID=-1) BEGIN IF(NOT EXISTS(SELECT TitleID FROM Table1 WHERE LANGUAGEID=@LANGUAGEID)) BEGIN INSERT INTO Table1(Content,TitleID) VALUES(@Content,@TitleID) END END ELSE BEGIN IF(NOT EXISTS(SELECT TitleID FROM Table1 WHERE LANGUAGEID=@LANGUAGEID)) BEGIN UPDATE Table1 SET Content=@Content,TitleID=@TitleID WHERE PAGEID=@PAGEID END END END Now what is happening is that it is inserting new records alright and won't allow duplicates to be added but when I update its giving me problem. On my aspx Page I have a drop down list control that is bound to DataSource that returns Table 2(Title Table) and I have a text box in which user types Page's content to be stored. When I update, like lets say I have a row in my Table 1 as shown above with PageID=1. Now when I am updating this row, like I didn't change the Title from the drop down and only changed Content in the text box, its not updating the record ..and when Stored procedure's Update Query does not execute it displays a Label that says "Page with this title exists already." So whenever I am updating an existing record that label is displayed on screen.How do I change that IF condition in my Update Stored procedure?? EDIT:- @gbn :: Will that IF condition work in case of update? I mean lets say I am updating the Page with TitleID=1, I changed its content, then when I update, it's gonna execute that IF condition and it still won't update coz TitleID=1 already exits!It will only update if TitleID=1 is not there in Table1. Isn't it? Guess I am getting confused. Please answer.Thanks.

  Read the article

• How to catch YouTube embed code and turn into URL

  - by Jonathan Vanasco

  I need to strip YouTube embed codes down to their URL only. This is the exact opposite of all but one question on StackOverflow. Most people want to turn the URL into an embed code. This question addresses the usage patttern I want, but is tied to a specific embed code's regex ( Strip YouTube Embed Code Down to URL Only ) I'm not familiar with how YouTube has offered embeds over the years - or how the sizes differ. According to their current site, there are 2 possible embed templates and a variety of options. If that's it, I can handle a regex myself -- but I was hoping someone had more knowledge they could share, so I could write a proper regex pattern that matches them all and not run into endless edge-cases. The full use case scenario : user enters content in web based wysiwig editor backend cleans out youtube & other embed codes; reformats approved embeds into an internal format as the text is all converted to markdown. on display, appropriate current template/code display for youtube or other 3rd party site is generated At a previous company, our tech-team devised a plan where YouTube videos were embedded by listing the URL only. That worked great , but it was in a CMS where everyone was trained. I'm trying to create a similar storage, but for user-generated-content.

  Read the article

• Database for managing large volumes of (system) metrics

  - by symcbean

  Hi, I'm looking at building a system for managing and reporting stats on web page performance. I'll be collecting a lot more stats than are available in the standard log formats (approx 20 metrics) but compared to most types of database applications, the base data structure will be very simple. My problem is that I'll be accumulating a lot of data - in the region of 100,000 records (i.e. sets of metrics) per hour. Of course, resources are very limited! So that its possible to sensibly interact with the data, I'd need to consolidate each metric into one minute bins, broken down by URL, then for anything more than 1 day old, consolidated into 10 minute bins, then at 1 week, hourly bins. At the front end, I want to provide a view (prefereably as plots) of the last hour of data, with the facility for users to drill up/down through defined hierarchies of URLs (which do not always map directly to the hierarchy expressed in the path of the URL) and to view different time frames. Rather than coding all this myself and using a relational database, I was wondering if there were tools available which would facilitate both the management of the data and the reporting. I had a look at Mondrian however I can't see from the documentation I've looked at whether it's possible to drop the more granular information while maintaining the consolidated views of the data. RRDTool looks promising in terms of managing the data consolidation, but seems to be rather limited in terms of querying the dataset as a multi-dimensional/relational database. What else whould I be looking at?

  Read the article

• How can I share an entity framework model across website users

  - by richardmoss

  Hello, Currently my website is based around MVC and the Entity Framework running against a SQL Server 2005 database. So far, it has all been running very smoothly, and I really enjoy MVC and its slimmer more concise code (and no huge viewstates or soul destroying postbacks ;)) Recently I was working on upgrading the site to use a simple forum system, and this is where I started running into problems. When I was testing the site using two different browsers, if I created or replied to a post in one browser, the other browser couldn't see the post. At the moment, each visitor to the site gets their own copy of the entity model, which I store in their session data. Obviously this is the problem as updates to one model aren't getting carried to the other. As a test, I tried storing a single copy of the model which all visitors would access by assigning the model to a static variable. This worked, and both browsers could see each others modifications. However, it had its side effects. For example, if I fired up both browsers at the same time and the model was initialized, one browser would crash, and the other would work fine, despite me using a locking object so in theory one of them should have been delayed until the model was ready (of course I could have implemented this wrong ;)). Also, originally this site did use one model for all visitors and when it was live, it frequently shut down - killing the IIS application pool while it did. Now I'm not sure if this was related, but I don't really want to reintroduce whatever bug I had that caused this shut down. So, my question is a simple one really - what is the best way of either using the same model for all website users so they all see updates, or if they do have separate copies (which I imagine will have a performance impact in time) how can the models detect changes in the database and update themselves according. Thanks in advance for any advice! Regards; Richard Moss

  Read the article

• Data access strategy for a site like SO - sorted SQL queries and simultaneous updates that affect th

  - by Kaleb Brasee

  I'm working on a Grails web app that would be similar in access patterns to StackOverflow or MyLifeIsAverage - users can vote on entries, and their votes are used to sort a list of entries based on the number of votes. Votes can be placed while the sorted select queries are being performed. Since the selects would lock a large portion of the table, it seems that normal transaction locking would cause updates to take forever (given enough traffic). Has anyone worked on an app with a data access pattern such as this, and if so, did you find a way to allow these updates and selects to happen more or less concurrently? Does anyone know how sites like SO approach this? My thought was to make the sorted selects dirty reads, since it is acceptable if they're not completely up to date all of the time. This is my only idea for possibly improving performance of these selects and updates, but I thought someone might know a better way.

  Read the article

• Using Kerberos authentication for SQL Server 2008

  - by vivek m

  I am trying to configure my SQL Server to use Kerberos authentication. My setup is like this - My setup is like this- I have 2 virtual PCs in a Windows XP Pro SP3 host. Both VPCs are Windows Server 2003 R2. One VPC acts as the DC, DNS Server, DHCP server, has Active Directory installed and the SQL Server default instance is also running on this VPC. The second VPC is the domain member and it acts as the SQL Server client machine. I configured the SPN on the SQL Server service account to get the Kerberos working. On the client VPC it seems like it is using Kerberos authentication (as desired)- C:\Documents and Settings\administrator.SHAREPOINTSVC>sqlcmd -S vm-winsrvr2003 1> select auth_scheme from sys.dm_exec_connections where session_id=@@spid 2> go auth_scheme ---------------------------------------- KERBEROS (1 rows affected) 1> but on the server computer (where the SQL Server instance is actually running) it looks like it is still using NTLM authentication- . This is not a remote instance, the sql server is local to this machine. C:\Documents and Settings\Administrator>sqlcmd 1> select auth_scheme from sys.dm_exec_connections where session_id=@@spid 2> go auth_scheme ---------------------------------------- NTLM (1 rows affected) 1> What can i do so that it uses Kerberos on the server computer as well ? (or is this something that I should not expect)

  Read the article

• Android SDK not recognizing debug-able device.

  - by kal.zekdor

  I'm new to Android development, and am attempting to run a test application on my actual device. I followed the instructions at http://developer.android.com/guide/developing/device.html (and related links), but the Android Debug Bridge (adb) doesn't recognize my connected device. Some quick background info, I'm running WinXP, developing with Eclipse, with a Motorola Droid running Android 2.1 as my physical device. An overview of the steps I've taken: Installed the Android SDK, downloading all necessary packages. Enabled USB Debugging on my device. Connected Device via USB, installing the driver from the SDK folder. I'll stop here (though I continued to setup my application to be debug-able in Eclipse), because I at this point I noticed a problem. Running "sdk\tools\adb devices" at this point (at least, by my understanding), should list my device as connected. However, running this yields only: List of devices attached My device recognizes that it's connected to a computer in debug mode, and my computer recognizes the device. However, I can't seem to get the sdk to recognize it. I'll leave out the steps I used to setup Eclipse for debugging on a device, as it doesn't seem relevant to the problem. I'll include them if requested. If anyone has any ideas, I'd greatly appreciate some assistance. Thanks in advance for your time.

  Read the article

• Java/C++ communication via pipe on Windows

  - by Warlax

  Hi, I have two separate programs, one in Java and one in C++, both running on Windows. We need to do bidirectional interprocess communication between the two. Up until now, we were using this awkward solution of writing to text files and reading them on the other side, where the producer would generate a .lock file when it's done writing and the consumer would remove that when it's done reading... like I said, awkward. If we were on *nix, we would use a pipe using popen() on the C++ and RadomAccessFile on the Java side. It seems to work well. What can we do on Windows? Can we use named pipes? Thank you.

  Read the article

• unique constraint (w/o Trigger) on "one-to-many" relation

  - by elgcom

  To illustrate the problem, I make an example: A tag_bundle consists of one or more than one tags. A unique tag combination can map to a unique tag_bundle, vice versa. tag_bundle tag tag_bundle_relation +---------------+ +--------+ +---------------+--------+ | tag_bundle_id | | tag_id | | tag_bundle_id | tag_id | +---------------+ +--------+ +---------------+--------+ | 1 | | 100 | | 1 | 100 | +---------------+ +--------+ +---------------+--------+ | 101 | | 1 | 101 | +--------+ +---------------+--------+ There can't be another tag_bundle having the combination from tag 100 and tag 101. How can I ensure such unique constraint when executing SQL "concurrently"!! that is, to prevent concurrently adding two bundles with the same tag combination Adding a simple unique constraint on any table does not work, Is there any solution other than Trigger or explicit lock. I come to only this simple way: make tag combination into string, and let it be unique. tag_bundle (unique on tags) tag tag_bundle_relation +---------------+--------+ +--------+ +---------------+--------+ | tag_bundle_id | tags | | tag_id | | tag_bundle_id | tag_id | +---------------+--------+ +--------+ +---------------+--------+ | 1 | 100,101| | 100 | | 1 | 100 | +---------------+--------+ +--------+ +---------------+--------+ | 101 | | 1 | 101 | +--------+ +---------------+--------+ but it seems not a good way :(

  Read the article

• caching previous return values of procedures in scheme

  - by Brock

  In Chapter 16 of "The Seasoned Schemer", the authors define a recursive procedure "depth", which returns 'pizza nested in n lists, e.g (depth 3) is (((pizza))). They then improve it as "depthM", which caches its return values using set! in the lists Ns and Rs, which together form a lookup-table, so you don't have to recurse all the way down if you reach a return value you've seen before. E.g. If I've already computed (depthM 8), when I later compute (depthM 9), I just lookup the return value of (depthM 8) and cons it onto null, instead of recursing all the way down to (depthM 0). But then they move the Ns and Rs inside the procedure, and initialize them to null with "let". Why doesn't this completely defeat the point of caching the return values? From a bit of experimentation, it appears that the Ns and Rs are being reinitialized on every call to "depthM". Am I misunderstanding their point? I guess my question is really this: Is there a way in Scheme to have lexically-scoped variables preserve their values in between calls to a procedure, like you can do in Perl 5.10 with "state" variables?

  Read the article

• Global javascript variable not accessible in jquery change event

  - by Dan

  I have to be missing something simple, but I'm really not sure what. I'm not a JS veteran, so this may be an easy answer - sure hope so :). I have a button that, when clicked, gets JSON data. When a drop-down is changed, I check to see if there is data, if there is, I want to clear it out as the drop-down indicates what data to retrieve when the button is clicked The Code: var selected, $locDialog; var locations = []; $(function() { // Save the selected Name selected = $("#selected option:selected").val(); // Setup Dialog for Locations $locDialog = $('#location-dialog').dialog({ autoOpen: false }); // If user changes the selected // 1. Prompt for confirmation // 2. If users confirms, clear data $('#selected').change(function() { if (locations) { var confirmed = confirm("Oh Rly?"); if (confirmed) { // Clear data var locations; } } }); // When user clicks "Location" Button.. $('.loc-select button').click(function() { if (!locations) { $.getJSON("/Controller/JSONAction", { selectedId: selected, pageNum: 1, pageSize: 100 }, function(data) { locations = data; $.each(locations, function(index, loc) { var $tr = $('<tr/>') .append($('<td/>') .append('<input type="checkbox" name="TEST-'+index+'" value="'+loc.Id+'"/>')) .append('<td>' + loc.Name + '</td>'); $("#location-dialog table tbody").append($tr); }); }); } $locDialog.dialog('open'); return false; }); }); Here's the thing, Inside the .click(...) callback, I can see locations is []. Now, when I am in the .change(...) callback, I see locations is undefined. Any help/insight, as always, is appreciated!

  Read the article

• How can two threads access a common array of buffers with minimal blocking ? (c#)

  - by Jelly Amma

  Hello, I'm working on an image processing application where I have two threads on top of my main thread: 1 - CameraThread that captures images from the webcam and writes them into a buffer 2 - ImageProcessingThread that takes the latest image from that buffer for filtering. The reason why this is multithreaded is because speed is critical and I need to have CameraThread to keep grabbing pictures and making the latest capture ready to pick up by ImageProcessingThread while it's still processing the previous image. My problem is about finding a fast and thread-safe way to access that common buffer and I've figured that, ideally, it should be a triple buffer (image[3]) so that if ImageProcessingThread is slow, then CameraThread can keep on writing on the two other images and vice versa. What sort of locking mechanism would be the most appropriate for this to be thread-safe ? I looked at the lock statement but it seems like it would make a thread block-waiting for another one to be finished and that would be against the point of triple buffering. Thanks in advance for any idea or advice. J.

  Read the article

• ExecutorSerrvice memory leak on exception

  - by TofuBeer

  I am having a hard time tracking this down since the profiler keeps crashing (hotspot error). Before I go too deep into figuring it out I'd like to know if I really have a problem or not :-) I have a few thread pools created via: Executors.newFixedThreadPool(10); The threads connect to different web sites and, on occasion, I get connection refused and wind up throwing an exception. When I later on call Future.get() to get the result it will then catch the ExecutionException that wraps the exception that was thrown when the connection could not be made. The program uses a fairly constant amount of memory up until the point in time that the exceptions get thrown (they tend to happen in batches when a particular site is overloaded). After that point the memory again remains constant but at a higher level. So my question is along the lines of is the memory behaviour (reported by "top" on Unix) expected because the exceptions just triggered something or do I probably have an actual leak that I'll need to track down? Additionally when Future.get() throws an exception is there anything else I need to do besides catch the exception (such as call Future.cancel() on it)?

  Read the article

• Javascript to fire event when a key pressed on the Ajax Toolkit Combo box.

  - by Paul Chapman

  I have the following drop down list which is using the Ajax Toolkit to provide a combo box <cc1:ComboBox ID="txtDrug" runat="server" style="font-size:8pt; width:267px;" Font-Size="8pt" DropDownStyle="DropDownList" AutoCompleteMode="SuggestAppend" AutoPostBack="True" ontextchanged="txtDrug_TextChanged" /> Now I need to load this up with approx 7,000 records which takes a considerable time, and effects the response times when the page is posted back and forth. The code which loads these records is as follows; dtDrugs = wsHelper.spGetAllDrugs(); txtDrug.DataValueField = "pkDrugsID"; txtDrug.DataTextField = "drugName"; txtDrug.DataSource = dtDrugs; txtDrug.DataBind(); However if I could get an event to fire when a letter is typed instead of having to load 7000 records it is reduced to less than 50 in most instances. I think this can be done in Javascript. So the question is how can I get an event to fire such that when the form starts there is nothing in the drop down, but as soon as a key is pressed it searches for those records starting with that letter. The .Net side of things I'm sure about - it is the Javascript I'm not. Thanks in advance

  Read the article

• how to make a software and preserve database integrity and correctness and please help confused

  - by user287745

  i have made an application project in vs 08 c#, sql server from vs 08. the database has like 20 tables and many fields in each have made an interface for adding deleting editting and retrieving data according to predefined needs of the users. now i have to 1) make to project in to a software which i can deliver to professor. that is he can just double click the icon and the software simply starts. no vs 08 needed to start the debugging 2) the database will be on one powerful computer (dual core latest everything win xp) and the user will access it from another computer connected using LAN i am able to change the connection string to the shared database using vs 08/ debugger whenever the server changes but how am i supposed to do that when its a software? 3)there will by many clients am i supposed to give the same software to every one, so they all can connect to the database, how will the integrity and correctness of the database be maintained? i mean the db.mdf file will be in a folder which will be shared with read and write access. so its not necessary that only one user will write at a time. so is there any coding for this or? please help me out here i am stuck do not know what to do i have no practical experience, would appreciate all the help thank you

  Read the article

• What happens to class members when malloc is used instead of new?

  - by Felix

  I'm studying for a final exam and I stumbled upon a curious question that was part of the exam our teacher gave last year to some poor souls. The question goes something like this: Is the following program correct, or not? If it is, write down what the program outputs. If it's not, write down why. The program: #include<iostream.h> class cls { int x; public: cls() { x=23; } int get_x(){ return x; } }; int main() { cls *p1, *p2; p1=new cls; p2=(cls*)malloc(sizeof(cls)); int x=p1->get_x()+p2->get_x(); cout<<x; return 0; } My first instinct was to answer with "the program is not correct, as new should be used instead of malloc". However, after compiling the program and seeing it output 23 I realize that that answer might not be correct. The problem is that I was expecting p2->get_x() to return some arbitrary number (whatever happened to be in that spot of the memory when malloc was called). However, it returned 0. I'm not sure whether this is a coincidence or if class members are initialized with 0 when it is malloc-ed. Is this behavior (p2->x being 0 after malloc) the default? Should I have expected this? What would your answer to my teacher's question be? (besides forgetting to #include <stdlib.h> for malloc :P)

  Read the article

• Simplification / optimization of GPS track

  - by GreyCat

  I've got a GPS track, produces by gpxlogger(1) (supplied as a client for gpsd). GPS receiver updates its coordinates every 1 second, gpxlogger's logic is very simple, it writes down location (lat, lon, ele) and a timestamp (time) received from GPS every n seconds (n = 3 in my case). After writing down a several hours worth of track, gpxlogger saves several megabyte long GPX file that includes several thousands of points. Afterwards, I try to plot this track on a map and use it with OpenLayers. It works, but several thousands of points make using the map a sloppy and slow experience. I understand that having several thousands of points of suboptimal. There are myriads of points that can be deleted without losing almost anything: when there are several points making up roughly the straight line and we're moving with the same constant speed between them, we can just leave the first and the last point and throw anything else. I thought of using gpsbabel for such track simplification / optimization job, but, alas, it's simplification filter works only with routes, i.e. analyzing only geometrical shape of path, without timestamps (i.e. not checking that the speed was roughly constant). Is there some ready-made utility / library / algorithm available to optimize tracks? Or may be I'm missing some clever option with gpsbabel?

  Read the article

• What does MySqlDataAdapter.Fill return when the results are empty?

  - by Brian

  I have a 'worker' function that will be processing any and all sql queries in my program. I will need to execute queries that return result sets and ones that just execute stored procedures without any results. Is this possible with MySqlDataAdapter.Fill or do I need to use the MySqlCommand.ExecuteNonQuery() method? Here is my 'worker' function for reference: private DataSet RunQuery(string SQL) { MySqlConnection connection; MySqlCommand command; MySqlDataAdapter adapter; DataSet dataset = new DataSet(); lock(locker) { connection = new MySqlConnection(MyConString); command = new MySqlCommand(); command = connection.CreateCommand(); command.CommandText = SQL; adapter = new MySqlDataAdapter(); adapter.Fill(dataset); } return dataset; }

  Read the article

• User management with aspnet membership provider

  - by 109221793

  Hi guys, Just a general question really. I have taken on the management of an application written in C# MVC that uses the asp.net membership api. With this a user can register, change their password, etc. My application consists of two areas, administrator and user. This adminstrator's area has lots of custom admin functionality relating to the application, however has no functionality utilizing the membership api. I want to be able to use the membership api for user management functions such as resetting a password of a user who has forgotten theirs, lock users out, etc. Are there any resources or articles out there that delve into this aspect of using the membership api? Any help would be appreciated :) thanks

  Read the article

• Preventing concurrent data modification in Web based app

  - by Manoj

  Hi, I am building a web app in Silverlight which allows users to view and edit a database. In order to prevent multiple users from editing the same data, I was thinking of implementing a lock and key mechanism, so that other users are made to wait when one particular user is editing the data. Is there any way in which we can have variable(flag specifying if a user is editing data) in the server which can be shared across multiple clients? Is there a better way to manage this type of conurrent data access issues?

  Read the article

• efficient way to detect if an image is empty

  - by Jos

  Hi, I need a very fast method to detect if an image is empty. Im my case then all pixels are white and transparant. The images are png's. My current method is to load them in a memory bitmap and check each pixel value, but this is way to slow. Is there a more efficient way? This is my current code: 'Lock the bitmap bits. Dim bmpData As System.Drawing.Imaging.BitmapData = bmp.LockBits(rectBmp, _ Drawing.Imaging.ImageLockMode.ReadOnly, bmp.PixelFormat) Try Dim x As Integer Dim y As Integer For y = 0 To bmpData.Height - 1 For x = 0 To bmpData.Width - 1 If System.Runtime.InteropServices.Marshal.ReadByte(bmpData.Scan0, (bmpData.Stride * y) + (4 * x) + 3) <> 0 Then Return True Exit For End If Next Next Finally bmp.UnlockBits(bmpData) End Try

  Read the article

• Thread management advice - Is TPL a good idea?

  - by Ian

  I'm hoping to get some advice on the use of thread managment and hopefully the task parallel library, because I'm not sure I've been going down the correct route. Probably best is that I give an outline of what I'm trying to do. Given a Problem I need to generate a Solution using a heuristic based algorithm. I start of by calculating a base solution, this operation I don't think can be parallelised so we don't need to worry about. Once the inital solution has been generated, I want to trigger n threads, which attempt to find a better solution. These threads need to do a couple of things: They need to be initalized with a different 'optimization metric'. In other words they are attempting to optimize different things, with a precedence level set within code. This means they all run slightly different calculation engines. I'm not sure if I can do this with the TPL.. If one of the threads finds a better solution that the currently best known solution (which needs to be shared across all threads) then it needs to update the best solution, and force a number of other threads to restart (again this depends on precedence levels of the optimization metrics). I may also wish to combine certain calculations across threads (e.g. keep a union of probabilities for a certain approach to the problem). This is probably more optional though. The whole system needs to be thread safe obviously and I want it to be running as fast as possible. I tried quite an implementation that involved managing my own threads and shutting them down etc, but it started getting quite complicated, and I'm now wondering if the TPL might be better. I'm wondering if anyone can offer any general guidance? Thanks...

  Read the article

< Previous Page | 488 489 490 491 492 493 494 495 496 497 498 499  | Next Page >