Search Results

Search found 46295 results on 1852 pages for 'system messaging'.

Page 185/1852 | < Previous Page | 181 182 183 184 185 186 187 188 189 190 191 192  | Next Page >

  • Do really need a count lock on Multi threads with one CPU core?

    - by MrROY
    If i have some code looks like this(Please ignore the syntax, i want to understand it without a specified language): count = 0 def countDown(): count += 1 if __name__ == '__main__': thread1(countDown) thread2(countDown) thread3(countDown) Here i have a CPU with only one core, do i really need a lock to the variable count in case of it could be over-written by other threads. I don't know, but if the language cares a lot, please explain it under Java?C and Python, So many thanks.

    Read the article

  • How do I invert a colour?

    - by ThePower
    I know that this won't directly invert a colour, it will just 'oppose' it. I was wondering if anyone knew a simple way (a few lines of code) to invert a colour from any given colour? At the moment I have this (which isn't exactly the definition of an invert): const int RGBMAX = 255; Color InvertMeAColour(Color ColourToInvert) { return Color.FromArgb(RGBMAX - ColourToInvert.R, RGBMAX - ColourToInvert.G, RGBMAX - ColourToInvert.B); }

    Read the article

  • How can I implement "real time" messaging on Google AppEngine?

    - by Freed
    I'm creating a web application on Google AppEngine where I want the user to be notified a quickly as possible after certain events occour. The problem is similar to say a chat server in that I need something happening on one connection (someone is writing a message in a chat room) to propagate to a number of other connections (other people in that chat room gets the message). To get speedy updates from the server to the client I'm planning on using long polling with XmlHttpRequest, hoping that AppEngine won't interfere other than possibly restriing the timeout. The real problem however is efficient notification between connections on AppEngine. Is there any support for this type of cross connection notification on AppEngine that does not involve busy-waiting? The only tools I can think of to do this at all is either using the data storage (slow) or memcache (unreliable), and none of them would let me avoid busy-waiting. Note: I know about XMPP support on AppEngine. It's related, but I want a browser based solution, sending messages to the users by XMPP is not an option.

    Read the article

  • How to R/W hard disk when CPU is in Protect Mode?

    - by smwikipedia
    I am doing some OS experiment. Until now, all my code utilized the real mode BIOS interrupt to manipulate hard disk and floppy. But once my code enabled the Protect Mode of the CPU, all the real mode BIOS interrupt service routine won't be available. How could I R/W the hard disk and floppy? I have a feeling that I need to do some hardware drivers now. Am I right? Is this why an OS is so difficult to develop? I know that hardwares are all controlled by reading from and writing to certain control or data registers. For example, I know that the Command Block Registers of hard disk range from 0x1F0 to 0x1F7. But I am wondering whether the register addresses of so many different hardwares are the same on the PC platform? Or do I have to detect that before using them? How to detect them?? For any responses I present my deep appreciation.

    Read the article

  • public class ImageHandler : IHttpHandler

    - by Ken
    cmd.Parameters.AddWithValue("@id", new system.Guid (imageid)); What using System reference would this require? Here is the handler: using System; using System.Collections.Specialized; using System.Web; using System.Web.Configuration; using System.Web.Security; using System.Globalization; using System.Configuration; using System.Data.SqlClient; using System.Data; using System.IO; using System.Web.Profile; using System.Drawing; public class ImageHandler : IHttpHandler { public void ProcessRequest(HttpContext context) { string imageid; if (context.Request.QueryString["id"] != null) imageid = (context.Request.QueryString["id"]); else throw new ArgumentException("No parameter specified"); context.Response.ContentType = "image/jpeg"; Stream strm = ShowProfileImage(imageid.ToString()); byte[] buffer = new byte[8192]; int byteSeq = strm.Read(buffer, 0, 8192); while (byteSeq > 0) { context.Response.OutputStream.Write(buffer, 0, byteSeq); byteSeq = strm.Read(buffer, 0, 8192); } //context.Response.BinaryWrite(buffer); } public Stream ShowProfileImage(String imageid) { string conn = ConfigurationManager.ConnectionStrings["MyConnectionString1"].ConnectionString; SqlConnection connection = new SqlConnection(conn); string sql = "SELECT image FROM Profile WHERE UserId = @id"; SqlCommand cmd = new SqlCommand(sql, connection); cmd.CommandType = CommandType.Text; cmd.Parameters.AddWithValue("@id", new system.Guid (imageid));//Failing Here!!!! connection.Open(); object img = cmd.ExecuteScalar(); try { return new MemoryStream((byte[])img); } catch { return null; } finally { connection.Close(); } } public bool IsReusable { get { return false; } } }

    Read the article

  • Is there any way to identify a unique user in Flash/Actionscript 3?

    - by VGambit
    I'm trying to make a vote/poll application in Flash using Actionscript 3. Is there any way to generate a specific ID that is unique to each user? The only other option I can think of is using the IP address, which is less than ideal in many cases (college campuses, shared Internet access, etc.). It needs to be the same number every time it is run on the same PC, but different for each user.

    Read the article

  • How to make my Java Swing application a Client-Server application?

    - by Jonas
    I have made a Java Swing application. Now I would like to make it a Client-Server application. All clients should be notified when data on the server is changed, so I'm not looking for a Web Service. The Client-Server application will be run on a single LAN, it's a business application. The Server will contain a database, JavaDB. What technology and library is easiest to start with? Should I implement it from scratch using Sockets, or should I use Java RMI, or maybe JMS? Or are there other alternatives that are easier to start with? And is there any server library that I should use? Is Jetty an alternative?

    Read the article

  • The way cores, processes, and threads work exactly?

    - by unknownthreat
    I need a bit of an advice for understanding how this whole procedure work exactly. If I am incorrect in any part described below, please correct me. In a single core CPU, it runs each process in the OS, jumping around from one process to another to utilize the best of itself. A process can also have many threads, in which the CPU core runs through these threads when it is running on the respective process. Now, on a multiple core CPU, Do the cores run in every process together, or can the cores run separately in different processes at one particular point of time? For instance, you have program A running two threads, can a duo core CPU run both threads of this program? I think the answer should be yes if we are using something like OpenMP. But while the cores are running in this OpenMP-embedded process, can one of the core simply switch to other process? For programs that are created for single core, when running at 100%, why the CPU utilization of each core are distributed? (ex. A duo core CPU of 80% and 20%. The utilization percentage of all cores always add up to 100% for this case.) Do the cores try help each other run each thread of each process in some ways? Frankly, I'm not sure how this works exactly. Any advice is appreciated.

    Read the article

  • How to delay shutdown of an application when user logs off or shuts down Windows?

    - by badpanda
    I am writing an application that runs in the background from startup to shutdown, and in some circumstances I need the application to display a dialogue for the user to choose whether or not to continue shutting down. This application will only be running on Windows, but may be running on any version from 2000 onward. While I have certainly done some research on the topic, the information regarding the way that windows handles application shut down (http://msdn.microsoft.com/en-us/library/ms700677(VS.85).aspx) seems to be a bit scattered. If anyone has an example of the best way to handle this, or additional knowledge regarding the topic, I would very much appreciate it (I have very little experience with C#). Thanks!! badPanda

    Read the article

  • TFS: Choose which workspace to add a solution too.

    - by Patricker
    I have a solution which I developed in VS2008 and which I am trying to add to Source Control (TFS 2010, though the issue happened in TFS 2008 as well). I have several TFS workspaces on my computer and I have access to several Team Projects. When I right click the solution in my Solution Explorer and choose the "Add Solution to Source Control" option I am never given an option of choosing which Workspace or which Team Project to add the existing solution too. VS2008 then proceeds to add it to the same team project every time. I have tried selecting an alternate workspace/team project in every window where I can see an option for it but it always adds it back to the same one. I even tried changing the name of my new workspace so that alphabetically it was the first thinking that it might be somehow related to that... no luck. I then tried goign to the Change Source Control window where you can add/remove bindings on a solution/project but that window also defaults to the same Team Project as trying to add the solution directly does... Any help would be greatly appreciated with this, maybe I'm just missing something?

    Read the article

  • Rating the Application in iphone

    - by venkat
    i am trying to build a ratings alert inside my iPhone application which I want to make it look similar to the alert view, when the application is going to be delete.But i would like to make the rating by pressing the button it should send my rating to the itunes. is it possible? Thanks in advance!

    Read the article

  • Difference between ISupportInitialize (BeginInit/EndInit) and SuspendLayout/ResumeLayout

    - by Pato
    Hello All! Could someone please explain what the difference is between using the ISupportInitialize interface methods (BeginInit/EndInit) and using SuspendLayout/ResumeLayout? Is ISupportInitialize ONLY used during construction/"initial" initialization... or can it be used later when you want to add new child controls to an existing parent control? Any particular differences? I greatly appreciate your help! Thank you, Pato

    Read the article

  • Using Visual Studio 2010 Express to create a surface I can draw to

    - by Joel
    I'm coming from a Java background and trying to port a simple version of Conway's Game of Life that I wrote to C# in order to learn the language. In Java, I drew my output by inheriting from JComponent and overriding paint(). My new canvas class then had an instance of the simulation's backend which it could read/manipulate. I was then able to get the WYSIWYG GUI editor (Matisse, from NetBeans) to allow me to visually place the canvas. In C#, I've gathered that I need to override OnPaint() to draw things, which (as far as I know) requires me to inherit from something (I chose Panel). I can't figure out how to get the Windows forms editor to let me place my custom class. I'm also uncertain about where in the generated code I need to place my class. How can I do this, and is putting all my drawing code into a subclass really how I should be going about this? The lack of easy answers on Google suggests I'm missing something important here. If anyone wants to suggest a method for doing this in WPF as well, I'm curious to hear it. Thanks

    Read the article

  • For kernel/OS is C still it

    - by Recursion
    I like operating systems and would eventually like to become a OS developer mostly working on kernels. In the future will C still be the language of choice and what else should I be trying to learn.

    Read the article

  • My Delphi 7 application halts on Application.Initialize and does not return to next line

    - by m-abdi
    I have created an application on Delphi 7. my app had running fine since yesterday. I don't know what's happened yesterday which cause my application halts on Application.Initialize line in source code and does not return to next line when i trace the program. I can't run the created executable file from widows niether while the generated file does run on another machine correctly. here is the code where the compiler stops on it: program Info_Kiosk; uses SysUtils, Forms, ... (some other units) ; {$R *.res} begin Application.Initialize; Application.CreateForm(Tfrm_Main, frm_Main); any help would be appreciated

    Read the article

  • Merging all changesets associated with a WorkItem in Team Foundation Server

    - by Rowland Shaw
    We're trailing the use of the built in bug tracking, and have written some integration into our helpdesk software that allows for escalation via workitems. One thing I haven't found out how to do, is to merge all changes associated with a work item (say to go from dev branch to main) - I appreciate you can double click on a changeset in the merge dialog to view if it is associated with a workitem, and also that I can select individual changesets, and groups of adjacent changesets; but there doesn't appear to be any way to merge changes by workitem?

    Read the article

  • .net Drawing.Graphics.FromImage() returns blank black image

    - by joox
    I'm trying to rescale uploaded jpeg in asp.net So I go: Image original = Image.FromStream(myPostedFile.InputStream); int w=original.Width, h=original.Height; using(Graphics g = Graphics.FromImage(original)) { g.ScaleTransform(0.5f, 0.5f); ... // e.g. using (Bitmap done = new Bitmap(w, h, g)) { done.Save( Server.MapPath(saveas), ImageFormat.Jpeg ); //saves blank black, though with correct width and height } } this saves a virgin black jpeg whatever file i give it. Though if i take input image stream immediately into done bitmap, it does recompress and save it fine, like: Image original = Image.FromStream(myPostedFile.InputStream); using (Bitmap done = new Bitmap(original)) { done.Save( Server.MapPath(saveas), ImageFormat.Jpeg ); } Do i have to make some magic with g? upd: i tried: Image original = Image.FromStream(fstream); int w=original.Width, h=original.Height; using(Bitmap b = new Bitmap(original)) //also tried new Bitmap(w,h) using (Graphics g = Graphics.FromImage(b)) { g.DrawImage(original, 0, 0, w, h); //also tried g.DrawImage(b, 0, 0, w, h) using (Bitmap done = new Bitmap(w, h, g)) { done.Save( Server.MapPath(saveas), ImageFormat.Jpeg ); } } same story - pure black of correct dimensions

    Read the article

< Previous Page | 181 182 183 184 185 186 187 188 189 190 191 192  | Next Page >