Search Results

Search found 102826 results on 4114 pages for 'question about the problem'.

Page 90/4114 | < Previous Page | 86 87 88 89 90 91 92 93 94 95 96 97  | Next Page >

• Threadpool design question

  - by ZeroVector

  I have a design question. I want some feedback to know if a ThreadPool is appropriate for the client program I am writing. I am having a client running as a service processing database records. Each of these records contains connection information to external FTP sites [basically it is a queue of files to transfer]. A lot of them are to the same host, just moving different files. Therefore, I am grouping them together by host. I want to be able to create a new thread per host. I really don't care when the transfers finish, they just need to do all the work (or try to do) they were assigned, and then terminate once they are finished, cleaning up all resources they used in the process. I anticipate no more than 10-25 connections to be established. Once the transfer queue is empty, the program will simply wait until there are records in the queue again. Is the ThreadPool a good candidate for this or should I use a different approach? Edit: For the most part, this is the only significant custom application running on the server.

  Read the article

• PHP Object Access Syntax Question with the $

  - by ImperialLion

  I've been having trouble searching for this answer because I am not quite sure how to phrase it. I am new to PHP and still getting my feet on the ground. I was writing a page with a class in it that had the property name. When I originally wrote the page there was no class so I just had a variable called $name. When I went to encapsulate it in a class I accidental changed it to be $myClass->$name. It tool me a while to realize that the syntax I needed was $myClass->name. The reason it took so long was the error I kept getting was "Attempt to access a null property" or something along those lines. The error lead me to believe it was a data population error. My question is does $myClass->$name have a valid meaning? In other words is there a time you would use this and a reason why it doesn't create a syntax error? If so what is the semantic meaning of that code? When would I use it if it is valid? If its not valid, is there a reason that it doesn't create a syntax error?

  Read the article

• Simple question about the lunarlander example.

  - by Smills

  I am basing my game off the lunarlander example. This is the run loop I am using (very similar to what is used in lunarlander). I am getting considerable performance issues associated with my drawing, even if I draw almost nothing. I noticed the below method. Why is the canvas being created and set to null each cycle? @Override public void run() { while (mRun) { Canvas c = null; try { c = mSurfaceHolder.lockCanvas();//null synchronized (mSurfaceHolder) { updatePhysics(); doDraw(c); } } finally { // do this in a finally so that if an exception is thrown // during the above, we don't leave the Surface in an // inconsistent state if (c != null) { mSurfaceHolder.unlockCanvasAndPost(c); } } } } Most of the times I have read anything about canvases it is more along the lines of: mField = new Bitmap(...dimensions...); Canvas c = new Canvas(mField); My question is: why is Google's example done that way (null canvas), what are the benefits of this, and is there a faster way to do it?

  Read the article

• C++ design question, container of instances and pointers

  - by Tom

  Hi all, Im wondering something. I have class Polygon, which composes a vector of Line (another class here) class Polygon { std::vector<Line> lines; public: const_iterator begin() const; const_iterator end() const; } On the other hand, I have a function, that calculates a vector of pointers to lines, and based on those lines, should return a pointer to a Polygon. Polygon* foo(Polygon& p){ std::vector<Line> lines = bar (p.begin(),p.end()); return new Polygon(lines); } Here's the question: I can always add a Polygon (vector Is there a better way that dereferencing each element of the vector and assigning it to the existing vector container? //for line in vector<Line*> v //vcopy is an instance of vector<Line> vcopy.push_back(*(v.at(i)) I think not, but I dont really like that approach. Hopefully, I will be able to convince the author of the class to change it, but I cant base my coding right now to that fact (and i'm scared of a performance hit). Thanks in advance.

  Read the article

• C++ design question, container of instances and pointers

  - by Tom

  Hi all, Im wondering something. I have class Polygon, which composes a vector of Line (another class here) class Polygon { std::vector<Line> lines; public: const_iterator begin() const; const_iterator end() const; } On the other hand, I have a function, that calculates a vector of pointers to lines, and based on those lines, should return a pointer to a Polygon. Polygon* foo(Polygon& p){ std::vector<Line> lines = bar (p.begin(),p.end()); return new Polygon(lines); } Here's the question: I can always add a Polygon (vector Is there a better way that dereferencing each element of the vector and assigning it to the existing vector container? //for line in vector<Line*> v //vcopy is an instance of vector<Line> vcopy.push_back(*(v.at(i)) I think not, but I dont really like that approach. Hopefully, I will be able to convince the author of the class to change it, but I cant base my coding right now to that fact (and i'm scared of a performance hit). Thanks in advance.

  Read the article

• C++ design question, container of instances and pointers

  - by Tom

  Hi all, Im wondering something. I have class Polygon, which composes a vector of Line (another class here) class Polygon { std::vector<Line> lines; public: const_iterator begin() const; const_iterator end() const; } On the other hand, I have a function, that calculates a vector of pointers to lines, and based on those lines, should return a pointer to a Polygon. Polygon* foo(Polygon& p){ std::vector<Line> lines = bar (p.begin(),p.end()); return new Polygon(lines); } Here's the question: I can always add a Polygon (vector Is there a better way that dereferencing each element of the vector and assigning it to the existing vector container? //for line in vector<Line*> v //vcopy is an instance of vector<Line> vcopy.push_back(*(v.at(i)) I think not, but I dont really like that approach. Hopefully, I will be able to convince the author of the class to change it, but I cant base my coding right now to that fact (and i'm scared of a performance hit). Thanks in advance.

  Read the article

• Problem in mutiple :dependent=> :destroy when multiple polymorphic is true

  - by piemesons

  I have four models question, answer, comment and vote.Consider it same as stackoverflow. Question has_many comments Answers has_many comments Questions has_many votes answers has_many votes comments has_many votes Here are the models (only relevant things) class Comment < ActiveRecord::Base belongs_to :commentable, :polymorphic => true has_many :votes, :as => :votable, :dependent => :destroy end class Question < ActiveRecord::Base has_many :comments, :as => :commentable, :dependent => :destroy has_many :answers, :dependent => :destroy has_many :votes, :as => :votable, :dependent => :destroy end class Vote < ActiveRecord::Base belongs_to :votable, :polymorphic => true end class Answer < ActiveRecord::Base belongs_to :question, :counter_cache => true has_many :comments, :as => :commentable , :dependent => :destroy end Now the problem is whenever i am trying to delete any question/answer/comment its giving me an error NoMethodError in QuestionsController#destroy undefined method `each' for 0:Fixnum if i remove this line from any of the model (question/answer/comment) has_many :votes, :as => :votable, :dependent => :destroy then it works perfectly. It seems there is a problem while deleting the records active record is not able to find out the proper path because of multiple joins within the tables.

  Read the article

• Database design question

  - by Lijo

  Hi Team, I have an interesting database design problem that I formulated while travelling by a bus, coming back from my home. Design a normalized database for a bus ticketing system (not reservation system). In each trip, the conductor of the bus will give tickets to its passengers after collecting fare from them. Passengers travel from a various source places to various destination places. The system must be able to give a report of the places for which the number of passengers was more than 2. Suppose the stops for the bus are L1,L2, L3 and L4 Suppose passenger P1 travels from L1 to L4. P2 travels from L2 to L4. P3 travels from L3 to L4. The report should list only (L3-L4) for which it has more than 2 travelers. Can you please help me to solve the following problems 1) Design a normalized database 2) Write a query for the report 3) Is there any site that gives these kinds of interesting database design questions and answers? Thanks Lijo

  Read the article

• Objective-C++ visibility question

  - by John Smith

  I have linked a library with my program. It works fine. The only problem is that there visibility errors/warnings (thousands of them). They are all of the form: newlib::method() has different visibility (default) in newlib.a and (hidden) in AppDelegate.o It is always with AppDelegate.o. I have tried to set the visibility for both the library and the main app in several ways: the visibility checkmark in XCode, and -fvisibility. Non seem to have worked. Is there somethin special about AppDelegate.mm?

  Read the article

• C# Reflection Question

  - by Jimbo

  This is a scenario created to help understand what Im trying to achieve. I am trying to create a method that returns the specified property of a generic object e.g. public object getValue<TModel>(TModel item, string propertyName) where TModel : class{ PropertyInfo p = typeof(TModel).GetProperty(propertyName); return p.GetValue(item, null); } The code above works fine if you're looking for a property on the TModel item e.g. string customerName = getValue<Customer>(customer, "name"); However, if you want to find out what the customer's group's name is, it becomes a problem: e.g. string customerGroupName = getValue<Customer>(customer, "Group.name"); Hoping someone can give me some insight on this way out scenario - thanks.

  Read the article

• Simple iPhone tally method question

  - by Rob

  Just trying to create a simple method that counts up 1 on the tally when the button is pressed. My knowledge is extremely limited and I am pretty sure that my problem is somewhere in the method implementation: -(IBAction) updateTally:(id) sender { NSString *text; int total = 0; total = total + 1; text=[[NSString alloc] initWithFormat: @"%i", total]; lblTally.text = text; } I have done the necessary interface declarations for the lblTally UILabel and the updateTally method. I suspect that there is some sort of an NSString/int/%i/%@ mixup that I am making but I'm not sure how to fix it. When I run the program as it currently is it displays a 0 in the lblTally label field on the iphone. When I press the button it then displays a 1 in that field. However, if I continue to press the button - nothing happens.

  Read the article

• load balancer question c# asp.net

  - by Migs

  The place where I work has 2 servers and a load balancer. The setup is horrible since I have to manually make sure both servers have the same files. I know there are ways to automate this but it has not been implemented, hopefully soon (I have no control over this). I wrote an application that collects a bunch of information from a user, then creates a folder named after the email of the user in one of the servers. The problem is that I can't control in which server the folder gets created in, so let say a user goes in.. fills his stuff and his folder gets created in server 1, user goes away for a while and goes back to the site but this time the load balancer throws the user into server 2, now the user does something that needs to be saved into his folder but since it didn't created in this server an error occurs. What can I do about this? any suggestions? Thanks

  Read the article

• StringBufferInputStream Question in Java

  - by JJG

  I want to read an input string and return it as a UTF8 encoded string. SO I found an example on the Oracle/Sun website that used FileInputStream. I didn't want to read a file, but a string, so I changed it to StringBufferInputStream and used the code below. The method parameter jtext, is some Japanese text. Actually this method works great. The question is about the deprecated code. I had to put @SuppressWarnings because StringBufferInputStream is deprecated. I want to know is there a better way to get a string input stream? Is it ok just to leave it as is? I've spent so long trying to fix this problem that I don't want to change anything now I seem to have cracked it. @SuppressWarnings("deprecation") private String readInput(String jtext) { StringBuffer buffer = new StringBuffer(); try { StringBufferInputStream sbis = new StringBufferInputStream (jtext); InputStreamReader isr = new InputStreamReader(sbis, "UTF8"); Reader in = new BufferedReader(isr); int ch; while ((ch = in.read()) > -1) { buffer.append((char)ch); } in.close(); return buffer.toString(); } catch (IOException e) { e.printStackTrace(); return null; } }

  Read the article

• opengl: question about glutMainLoop()

  - by lego69

  can somebody explain how does glutMainLoop work? and second question, why glClearColor(0.0f, 0.0f, 1.0f, 1.0f); defined after glutDisplayFunc(RenderScene); cause firstly we call glClear(GL_COLOR_BUFFER_BIT); and only then define glClearColor(0.0f, 0.0f, 1.0f, 1.0f); int main(int argc, char* argv[]) { glutInit(&argc, argv); glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB); glutInitWindowSize(800, 00); glutInitWindowPosition(300,50); glutCreateWindow("GLRect"); glutDisplayFunc(RenderScene); glutReshapeFunc(ChangeSize); glClearColor(0.0f, 0.0f, 1.0f, 1.0f); <-- glutMainLoop(); return 0; } void RenderScene(void) { // Clear the window with current clearing color glClear(GL_COLOR_BUFFER_BIT); // Set current drawing color to red // R G B glColor3f(1.0f, 0.0f, 1.0f); // Draw a filled rectangle with current color glRectf(0.0f, 0.0f, 50.0f, -50.0f); // Flush drawing commands glFlush(); }

  Read the article

• string in c++,question

  - by user189364

  Hi, I created a program in C++ that remove commas (') from a given integer. i.e. 2,00,00 would return 20000. I am not using any new space. Here is the program i created void removeCommas(string& str1,int len) { int j=0; for(int i=0;i<len;i++) { if(str1[i] == ',') continue; else { str1[j] =str1[i]; j++; } } str1[j] = '\0'; } void main() { string str1; getline(cin,str1); int i = str1.length(); removeCommas(str1,i); cout<<"the new string "<<str1<<endl; } Here is the result i get : Input : 2,000,00 String length =8 Output = 200000 0 Length = 8 My question is that why does it show the length has 8 in output and shows the rest of string when i did put a null character. It should show output as 200000 and length has 6.

  Read the article

• javacript question related to use of ' and "

  - by vatismarty

  my_window.document.write(' function redirect(linkid) { opener.location.href=linkid; window.close(); } Hello Thank you.If you accidentally closed our website click here to go back to our website '); This is my piece of code to close a already opened pop up window by redirecting it to google.com. I think there is some problem with matching the apostrophes ' and "... how to code with (' (" (' ') ") ')... is this correct... please help me with this.

  Read the article

• Twitter OAuth question

  - by Squall

  Hi there, I'm making a Twitter client in Java, and I've came to a problem I don't know how to solve it. How the hell I store open auth for twitter? I mean it doesn't make very sense for a person to allow an application every time he wants to use the client. I've been look at the Twitter documentation, but I must say, it's really poor in terms of Java. So do you guy have some idea to solve this? Thanks in advance!

  Read the article

• .htaccess redirect question

  - by russp

  I have a slight problem with .htaccess redirect. I have a dynamic site with 2 levels of variables - content="type -(alpha)" and ID="number" but this is very not seo friendly what I really would like to create is a rewrite rule that generates a "friendly" url for serach engines & users alike. Very much like WordPress does. Each ID is already unique (obviously) and on creation is creating a unique "permalink" field so for example ID=1 has a "permalink field" as "2009/10/27/page title" and ID=100 would be "2010/10/27 page title". I would like folder/wall.php?content=type&ID=number to redirect to folder/permalink.php/html/htm (don't mind a non dynamic extension) Any clues? - this is not right (I know) but it also "breaks" my css file RewriteEngine On RewriteRule wall/content/(.*)/ID/(.*)/ wall.php?content=$1&ID=$2 RewriteRule wall/content/(.*)/ID/(.*) wall.php?content=$1&ID=$2

  Read the article

• Python to C/C++ const char question

  - by tsukemonoki

  I am extending Python with some C++ code. One of the functions I'm using has the following signature: int PyArg_ParseTupleAndKeywords(PyObject *arg, PyObject *kwdict, char *format, char **kwlist, ...); (link: http://docs.python.org/release/1.5.2p2/ext/parseTupleAndKeywords.html) The parameter of interest is kwlist. In the link above, examples on how to use this function are given. In the examples, kwlist looks like: static char *kwlist[] = {"voltage", "state", "action", "type", NULL}; When I compile this using g++, I get the warning: warning: deprecated conversion from string constant to ‘char*’ So, I can change the static char* to a static const char*. Unfortunately, I can't change the Python code. So with this change, I get a different compilation error (can't convert char** to const char**). Based on what I've read here, I can turn on compiler flags to ignore the warning or I can cast each of the constant strings in the definition of kwlist to char *. Currently, I'm doing the latter. What are other solutions? Sorry if this question has been asked before. I'm new.

  Read the article

• css position question: layers with z-index?

  - by user239831

  hey guys, i have a probably rather simpel problem: my website has two layers: 1) a drag&drop navigation on top which should be positioned absolute, so scrolling doesn't affect the bars. 2) a content area in the back behind the navigation which should be scrollable. you can see what i mean right here: http://jsfiddle.net/Pghqv/ however now, i cannot click links in my content-area in the back. any ideas or solutions how i can still have the same position result and the links in the back are working? thank you very much.

  Read the article

• Redirection Still not working (updated on earlier question)

  - by NoviceCoding

  So earlier I asked this question: JQuery Login Redirect. Code Included The php file is sending the following: $return['error'] = false; $return['msg'] = 'You have successfully logged in!!'; I've tried all the suggestions, quoting the error on php and ajax end, 2 equals instead of 3, I've also tried DNE true which should be the same as an else statement: $(document).ready(function(){ $('#submit').click(function() { $('#waiting').show(500); $('#empty').show(500); $('#reg').hide(0); $('#message').hide(0); $.ajax({ type : 'POST', url : 'logina.php', dataType : 'json', data: { type : $('#typeof').val(), login : $('#login').val(), pass : $('#pass').val(), }, success : function(data){ $('#waiting').hide(500); $('#empty').show(500); $('#message').removeClass().addClass((data.error === true) ? 'error' : 'success') .text(data.msg).show(500) if(data.error != true) window.location.replace("http://blahblah.com/usercp.php"); if (data.error === true) $('#reg').show(500); $('#empty').hide() }, error : function(XMLHttpRequest, textStatus, errorThrown) { $('#waiting').hide(500); $('#message').removeClass().addClass('error') .text("There was an Error. Please try again.").show(500); $('#reg').show(500); $('#empty').hide(); Recaptcha.reload(); } }); return false; }); And it still wont work. Any ideas on how to make a redirection work if login is successful and error returns false? Also while I am asking, can I put a .delay(3000) 3s at the end of window.location.replace("http://blahblah.com/usercp.php")?

  Read the article

• css3 nth child question

  - by JCHASE11

  Hello. I am designing a 960px wide layout with an unordered list. Each list item is 240px wide, so 4 list items fit horizontally in a row. I have about 20 rows on the page.... I want every other list item to have a background of #ececec, so my css would be: ul li:nth-child(2n+2){ background-color:#ececec; } This works. The only problem is because there are 4 items in a row (an even #), the next row would be identical, thus rendering background colors on every 1st and 3rd list items in a row. This is not the effect I am looking to achieve. I want the background colors to alternate, creating a grid-like effect. What is the correct css to do so (think a checker board). Thanks!

  Read the article

• To NOLOCK or NOT to NOLOCK, that is the question

  - by Limey

  Hi all, This is really more of a discussion than a specific question about nolock. I took over an app recently that almost every query (and there are lots of them) has the nolock option on them. Now I am pretty new to SQL server (used Oracle for 10 years) but yet I find this pretty disturbing. So this weekend I was talking with one of my friends who runs a rather large ecommerce site (name will be withheld to protect the guilty) and he says he has to do this with all of his SQL servers cause he will always end in deadlocks. Is this just a huge short fall with SQL server? Is this just a failure in the DB design (mine is not 3rd level, but its close) Is anybody out there running an SQL server app without nolocks? These are issues that Oracle handles better with more grandulare recordlocks. Is SQL server just not able to handle big loads? Is there some better workaround than reading uncommited data? I would love to hear what people think. Thanks

  Read the article

• Simple question about javascript history.go

  - by Camran

  I have a classifieds website. In every classified, there is a back link which simply takes the browser back one step. This is because when users search classifieds, and click on one to view it, they can easily go back with a link also (instead of only the browser back button). Here is the problem, if the classified is entered directly into the adress bar of a browser, or if somebody bookmarked a classified, then this back-link would take them someplace else... Is there any way of making sure that the previous page is a certain page (index.php in my case)? This way I would only display the back link if the previous page was index.php... Thanks

  Read the article

• Grid related UI design question

  - by younevertell

  Grid related UI design question I want some 16-grid (4 rows and 4 columns) user interface, and fill the grid with some round shapes. I also want to use the MouseOver, mouse left button down, and Mouse Left Button Up events to set the state of grids as selected or not selected. My questions: 1. How fill the grid with some round shapes? by SetColumn and SetRow? 2. How to make the grids respond to the mouse please? Thanks <Grid.ColumnDefinitions> <ColumnDefinition /> <ColumnDefinition /> <ColumnDefinition /> <ColumnDefinition /> </Grid.ColumnDefinitions> <Grid.RowDefinitions> <RowDefinition /> <RowDefinition /> <RowDefinition /> <RowDefinition /> </Grid.RowDefinitions>

  Read the article

< Previous Page | 86 87 88 89 90 91 92 93 94 95 96 97  | Next Page >