Search Results

Search found 15591 results on 624 pages for 'problems'.

Page 374/624 | < Previous Page | 370 371 372 373 374 375 376 377 378 379 380 381  | Next Page >

• What division operator symbol would you pick?

  - by Mackenzie

  I am currently designing and implementing a small programming language as an extra-credit project in a class I'm taking. My problem is that the language has three numeric types: Long, Double, and Fraction. Fractions can be written in the language as proper or improper fractions (e.g. "2 1/3" or "1/2"). This fact leads to problems such as "2/3.5" (Long/Double) and "2/3"(Long/Long) not being handled correctly by the lexer.The best solution that I see is to change the division operator. So far, I think "\" is the best solution since "//" starts comments. Would you pick "\", if you were designing the language? Would you pick something else? If so, what? Note: changing the way fractions are written is not possible. Thanks in advance for your help,

  Read the article

• How should I delete a child object from within a parent's slot? Possibly boost::asio specific.

  - by kaliatech

  I have written a network server class that maintains a std::set of network clients. The network clients emit a signal to the network server on disconnect (via boost::bind). When a network client disconnects, the client instance needs to be removed from the Set and eventually deleted. I would think this is a common pattern, but I am having problems that might, or might not, be specific to ASIO. I've tried to trim down to just the relevant code: /** NetworkServer.hpp **/ class NetworkServices : private boost::noncopyable { public: NetworkServices(void); ~NetworkServices(void); private: void run(); void onNetworkClientEvent(NetworkClientEvent&); private: std::set<boost::shared_ptr<const NetworkClient>> clients; }; /** NetworkClient.cpp **/ void NetworkServices::run() { running = true; boost::asio::io_service::work work(io_service); //keeps service running even if no operations // This creates just one thread for the boost::asio async network services boost::thread iot(boost::bind(&NetworkServices::run_io_service, this)); while (running) { boost::system::error_code err; try { tcp::socket* socket = new tcp::socket(io_service); acceptor->accept(*socket, err); if (!err) { NetworkClient* networkClient = new NetworkClient(io_service, boost::shared_ptr<tcp::socket>(socket)); networkClient->networkClientEventSignal.connect(boost::bind(&NetworkServices::onNetworkClientEvent, this, _1)); clients.insert(boost::shared_ptr<NetworkClient>(networkClient)); networkClient->init(); //kicks off 1st asynch_read call } } // etc... } } void NetworkServices::onNetworkClientEvent(NetworkClientEvent& evt) { switch(evt.getType()) { case NetworkClientEvent::CLIENT_ERROR : { boost::shared_ptr<const NetworkClient> clientPtr = evt.getClient().getSharedPtr(); // ------ THIS IS THE MAGIC LINE ----- // If I keep this, the io_service hangs. If I comment it out, // everything works fine (but I never delete the disconnected NetworkClient). // If actually deleted the client here I might expect problems because it is the caller // of this method via boost::signal and bind. However, The clientPtr is a shared ptr, and a // reference is being kept in the client itself while signaling, so // I would the object is not going to be deleted from the heap here. That seems to be the case. // Never-the-less, this line makes all the difference, most likely because it controls whether or not the NetworkClient ever gets deleted. clients.erase(clientPtr); //I should probably put this socket clean-up in NetworkClient destructor. Regardless by doing this, // I would expect the ASIO socket stuff to be adequately cleaned-up after this. tcp::socket& socket = clientPtr->getSocket(); try { socket.shutdown(boost::asio::socket_base::shutdown_both); socket.close(); } catch(...) { CommServerContext::error("Error while shutting down and closing socket."); } break; } default : { break; } } } /** NetworkClient.hpp **/ class NetworkClient : public boost::enable_shared_from_this<NetworkClient>, Client { NetworkClient(boost::asio::io_service& io_service, boost::shared_ptr<tcp::socket> socket); virtual ~NetworkClient(void); inline boost::shared_ptr<const NetworkClient> getSharedPtr() const { return shared_from_this(); }; boost::signal <void (NetworkClientEvent&)> networkClientEventSignal; void onAsyncReadHeader(const boost::system::error_code& error, size_t bytes_transferred); }; /** NetworkClient.cpp - onAsyncReadHeader method called from io_service.run() thread as result of an async_read operation. Error condition usually result of an unexpected client disconnect.**/ void NetworkClient::onAsyncReadHeader( const boost::system::error_code& error, size_t bytes_transferred) { if (error) { //Make sure this instance doesn't get deleted from parent/slot deferencing //Alternatively, somehow schedule for future delete? boost::shared_ptr<const NetworkClient> clientPtr = getSharedPtr(); //Signal to service that this client is disconnecting NetworkClientEvent evt(*this, NetworkClientEvent::CLIENT_ERROR); networkClientEventSignal(evt); networkClientEventSignal.disconnect_all_slots(); return; } I believe it's not safe to delete the client from within the slot handler because the function return would be ... undefined? (Interestingly, it doesn't seem to blow up on me though.) So I've used boost:shared_ptr along with shared_from_this to make sure the client doesn't get deleted until all slots have been signaled. It doesn't seem to really matter though. I believe this question is not specific to ASIO, but the problem manifests in a peculiar way when using ASIO. I have one thread executing io_service.run(). All ASIO read/write operations are performed asynchronously. Everything works fine with multiple clients connecting/disconnecting UNLESS I delete my client object from the Set per the code above. If I delete my client object, the io_service seemingly deadlocks internally and no further asynchronous operations are performed unless I start another thread. I have try/catches around the io_service.run() call and have not been able to detect any errors. Questions: Are there best practices for deleting child objects, that are also signal emitters, from within parent slots? Any ideas as to why the io_service is hanging when I delete my network client object?

  Read the article

• Where to start on creating finger swipe navigation trough a list.

  - by Thomas Stock

  Lets say I want to make a control to select any integer number by dragging on a "bar" with numbers: (156 is selected) Mousedown on "159" and dragging towards the left and then doing mouseup changes the control to this: (160 is selected) I've been experimenting for the past 3 hours but I'm inexperienced in Silverlight so I'm having problems getting started. My current guess is I should seperate this into 2 steps: Step 1: Build this control without swiping behavior. Just 2 buttons to go up a number or go down a number Step 2: Replace the buttons by handling mouse events. With my limited knowledge I think I would manage building a crappy control that does this, with very messy xaml and c# and lots of headaches when trying to apply styling and fancy state transitions, but I was hoping some xaml wizards could get me started with the basic approach? Edit: This is an implementation of what I'm trying to achieve in Silverlight: Iphone's datepicker:

  Read the article

• Left outer join null using VB.NET and LINQ

  - by jvcoach23

  I've got what I think is a working left outer join LINQ query, but I'm having problems with the select because of null values in the right hand side of the join. Here is what I have so far Dim Os = From e In oExcel Group Join c In oClassIndexS On c.tClassCode Equals Mid(e.ClassCode, 1, 4) Into right1 = Group _ From c In right1.DefaultIfEmpty I want to return all of e and one column from c called tClassCode. I was wondering what the syntax would be. As you can see, I'm using VB.NET. Update... Here is the query doing join where I get the error: _message = "Object reference not set to an instance of an object." Dim Os = From e In oExcel Group Join c In oClassIndexS On c.tClassCode Equals Mid(e.ClassCode, 1, 4) Into right1 = Group _ From c In right1.DefaultIfEmpty Select e, c.tClassCode If I remove the c.tClassCode from the select, the query runs without error. So I thought perhaps I needed to do a select new, but I don't think I was doing that correctly either.

  Read the article

• MySQL locking problem

  - by teehoo

  I have a simple setup of a set of writers and a set of readers working with a MySQL ISAM table. The writers are only inserting rows while the readers are only checking for new rows. OK, so I know that I don't need a lock in this situation, since I'm not modifying existing rows. However my Writers are accessing one more table that does need a lock. I piece of information seems irrelevant except for the following limitation stated in the MySQL documentation: A session that requires locks must acquire all the locks that it needs in a single LOCK TABLES statement. While the locks thus obtained are held, the session can access only the locked tables. For example, in the following sequence of statements, an error occurs for the attempt to access t2 because it was not locked in the LOCK TABLES statement: So to access the table I want to insert rows into, I NEED to lock it, which is causing me performance problems. Any suggestions of how to get around this?

  Read the article

• Deleting orphans with JPA

  - by homaxto

  I have a one-to-one relation where I use CascadeType.PERSIST. This has over time build up a huge amount of child records that has not been deleted, to such an extend that it is reflected in the performance. Now I wish to add some code that cleans up the database removing all the child records that are not referenced by a parent. At the moment we are talking 400K+ records, at I need to run the code on all customer installations just to be sure they do not run into the same problem. I think the best solution would be to run a named query (because we support two databases) that deletes the necessary records, and this is where I get into problems, because how should I write it in JPQL? The result I want can be defined like the following sql statement, which unfortunaltely does not run on MySQL. DELETE FROM child c1 WHERE c1.pk NOT IN (SELECT DISTINCT p.pk FROM child c2 JOIN parent p ON p.child = c2.pk);

  Read the article

• Changing folder names in Visual Studio when using SVN

  - by Piers Myers

  I am using VS2008/VS2010 with Resharper 5, TortoiseSVN 1.6.8.19260-x64, and AnkhSVN 2.1.8420.8. Most operations I do in Visual Studio are reflected fine in SVN, however, renaming folders in a project can cause problems when I try to submit my changes. Also all the namespaces in the C# source files under the renamed folder need to be updated to reflect the name change. What is the best way to rename the main project folder or any sub folders and ensure there are no issues with SVN? Should it be done outside Visual Studio? What is the best way to update all the namespace changes? Is search/replace the only way? Are there any best practices regarding folder names and their contents?

  Read the article

• Rails Cache Sweeper and Model Callback Firing

  - by Topher Fangio

  Hey guys, I have the following classes: class Vigil < ActiveRecord::Base after_update :do_something_cool private def do_something_cool # Sweet code here end end class NewsFeedObserver < ActionController::Caching::Sweeper observe Vigil def after_update # Create a news feed entry end end Everything works as expected. The after_update in the sweeper requires that the do_something_cool method in the model has finished before it can run properly. The problem is that the after_update in the sweeper is being called before (or perhaps at the same time as) the do_something_cool callback and it's causing problems. Does anyone know how to force the after_update in the sweeper to fire after the model callback? Is there better way to achieve this?

  Read the article

• Autmatically create table on MySQL server based on date?

  - by Anthony

  Is there an equivalent to cron for MySQL? I have a PHP script that queries a table based on the month and year, like: SELECT * FROM data_2010_1 What I have been doing until now is, every time the script executes it does a query for the table, and if it exists, does the work, if it doesn't it creates the table. I was wondering if I can just set something up on the MySQL server itself that will create the table (based on a default table) at the stroke of midnight on the first of the month. Update Based on the comments I've gotten, I'm thinking this isn't the best way to achieve my goal. So here's two more questions: If I have a table with thousands of rows added monthly, is this potentially a drag on resources? If so, what is the best way to partition this table, since the above is verboten? What are the potential problems with my home-grown method I originally thought up?

  Read the article

• Why does Perl's Crypt::SSLeay timeout on Intel Mac OS X machines?

  - by Joe

  A have a Perl cron job that recently started having its HTTPS connections start failing with an error of "500 SSL read timeout". I've tracked that the error is being thrown as part of an alarm in Crypt::SSLeay, but I don't know if this is simply something taking too long to respond. So far, I've adjusted the timeout from the default 30 seconds to 10 minutes and it still times out. I've moved the script to other machines, and those on Intel Mac OS X systems all time out, while those under Linux, or on PPC Mac OS X systems run fine, so I don't think it's changes on the network or remote server. When the process started having problems does not coincide with any software updates or reboots on the machine, and I've contacted the server I'm connecting to, and everyone claims that they haven't changed anything. Does anyone have recommendations on trying to debug HTTPS, or have you ever seen this behavior and give recommendations on something I might've overlooked at that could've caused this problem?

  Read the article

• urlrewriter.net page not executed

  - by peter

  Hello, I'm having some problems with the module urlrewriter.net for ASP.NET. I have a multilingual site with a URL like this; ~/home.aspx To support languages I use this rewrite rule; <rewrite url="~/de-DE/(.*)" to="~/$1"></rewrite> Then in my code I get the de-DE part and set the right culture for the current thread. All of this works well. After I login on the website I get a message "Hello, user x" to show i'm logged in. When navigating to another page, it doesn't display this message anymore and it seems like the page comes from the cache or something with the old (not logged in) data. Also, when I attach the debugger, nothing is executed for this request. If I visit the page like ~/home.aspx instead of ~/de-DE/home.aspx, does problem does not occur. What could be the problem here? Thanks

  Read the article

• Really new to XCode. Why won't the thing run?

  - by Matt W

  Hi, I'm trying to follow the April 2009 and Winter 2010 Stanford iPhone app development videos and I'm running up against the same problems with both. First, they don't appear to be using the latest version of XCode - the Outlets and Actions panels are in a different window and there is little info on the net about this (other than one other post on S.O.F.) Second, having got to the point where I've managed to connect the slider, label and changedLabelText connections, I save, build and run the app - the simulator loads, the app loads and then promptly closes again. What's going on? I have not written any code yet and I still have an app which, while it compiles, does not behave! Is there a better starting point for an XCode noob than the Stanford vids? Thanks, Matt.

  Read the article

• Browser popup blocker blocking jasper reports generated from flex

  - by pietervn

  Hi all, I have a flex application that uses navigateToURL() to call a servlet. The servlet in turn generates a JasperReport and then uses exportReport() to show the report in a new browser tab. Now, my problem is this. I want to generate multiple reports at once, each opening in its own tab. It all works fine except that in Firefox the built in browser pop-up blocker sees every new tab that is opened after the first report tab as a pop-up. It blocks this and is giving me endless headaches. I also tried this in IE8, Safari, Chrome and Opera with no problems. Any help as to how I can get past the Firefox pop-up blocker would be much appreciated. Pieter

  Read the article

• Entity framework, adding custom entity to diagram

  - by molgan

  Hello I'm using the entity framework that comes with 3.5sp1, and I'm trying to add a custom entity that I will propulate with searchresults from a stored procedure. But I have problems with the designer....... when I pick "Add + Entity" and give it a name, and hit save, the whole diagram stops working...... blah entities namespace could not be found..... all the other entities have lost its reference or summet. Works when I add a "table" to it that exists in database. But when custom it screws everything up. How should I fix this? I've imported the function, I just need to add an entity for it... I've read http://blogs.microsoft.co.il/blogs/gilf/archive/2009/03/13/mapping-stored-procedure-results-to-a-custom-entity-in-entity-framework.aspx but I cant get to step 3 since of all the errors when saving on step 2. /M

  Read the article

• PayPal IPN & ASP.NET MVC

  - by Wayne

  Hello - I have a strange problem that somebody can hopefully help me with. For a while now I have been using PayPal's IPN service for our website. In order to test it I have a port opened up on our firewall pointing to my machine. This has been working great with no problems at all. I recently upgraded to the RTM release of ASP.NET MVC and now things are not working. I can navigate to my IPN handler from the outside world so I know it's not my connection or a firewall issue. It simply refuses to recieve any PayPal IPN messages. I am puzzled why the page can be accessed yet the PayPal IPN server wont connect to it. I realize there could be a 1000 different reasons for this, but I am hoping somebody out there can point me in the right direction!

  Read the article

• Python regex on list

  - by Peter Nielsen

  Hi there I am trying to build a parser and save the results as an xml file but i have problems.. For instance i get a TypeError: expected string or buffer when i try to run the code.. Would you experts please have a look at my code ? import urllib2, re from xml.dom.minidom import Document from BeautifulSoup import BeautifulSoup as bs osc = open('OSCTEST.html','r') oscread = osc.read() soup=bs(oscread) doc = Document() root = doc.createElement('root') doc.appendChild(root) countries = doc.createElement('countries') root.appendChild(countries) findtags1 = re.compile ('<h1 class="title metadata_title content_perceived_text(.*?)</h1>', re.DOTALL | re.IGNORECASE).findall(soup) findtags2 = re.compile ('<span class="content_text">(.*?)</span>', re.DOTALL | re.IGNORECASE).findall(soup) for header in findtags1: title_elem = doc.createElement('title') countries.appendChild(title_elem) header_elem = doc.createTextNode(header) title_elem.appendChild(header_elem) for item in findtags2: art_elem = doc.createElement('artikel') countries.appendChild(art_elem) s = item.replace('<P>','') t = s.replace('</P>','') text_elem = doc.createTextNode(t) art_elem.appendChild(text_elem) print doc.toprettyxml()

  Read the article

• How can match end-of-line multiple times in a regex without interpolation?

  - by harschware

  Hi, if I have a input with new lines in it like: [INFO] xyz [INFO] How can I pull out the xyz part? I tried a pattern like /^\[INFO\]$(.*?)$\[INFO\]/ms, but perl gives me: Use of uninitialized value $\ in regexp compilation at scripts\t.pl line 6. I've been trying things to get interpolation to stop like using qr// but alas, no love. EDIT: The key is that the end-of-line anchor is a dollar sign but at times it may be necessary to intersperse the end-of-line anchor through the pattern. If the pattern is interpolating then you might get problems such as uninitialized $\. For instance an acceptable solution here is /^\[INFO\]\s*^(.*?)\s*^\[INFO\]/ms but that does not solve the crux of the first problem. I've changed the anchors to be ^ so there is no interpolation going on, and with this input I'm free to do that. But what about when I really do want to reference EOL with $ in my pattern? How do I get the regex to compile?

  Read the article

• Nike + iPod app like customisation ?

  - by Madhup

  Hi, I am very much curious about Nike + iPod app look and feel. They have selected uitabbar buttons red in color The tableviewcell selection style as red in color. The disclosure indicator is also red in color. The solution in my mind for two of these is: I can use a red colored arrow image to use it as accessory view. I can flip between a red colored and white colored view with animation for having the selection style But I am clueless of how the tabbar thing is to be done. I am very curious to know the tricks behind this, I also accept that I may be wrong with my other two solutions. So please suggest the solution for any of the problems. I think all are worth knowing for the developers. Thanks, Madhup

  Read the article

• Java: I am trying to server a zip file through a link, but the file comes out as being empty

  - by Ankur

  I am trying to server a zip file through a link, but the file comes out as being empty. My app takes a number of files and zips them up, then presents the user with a link to the file so he/she can download it. On the server I can see that the zip file is being created correctly, but when I download it from the server through the normal HTML link provided no data is downloaded i.e. a zip file is created locally but it has file size 0kb. The file names are of the form XPCS.2010-03-09.15.13.42.165.zip - will the dots cause problems?

  Read the article

• C# Class Instantiation Overflow

  - by Goober

  Scenario I have a C# Win Forms App, where the Main Form contains a loop that creates 3000 Instances of another form (Form B). Inside Form B there are a large number of properties and fields and a bunch of methods that do a fair amount of processing. Question Will the creation of 3000 of these classes give me problems? I'm thinking along the lines of memory exceptions? I've had 1 or 2 already, and I've also had an exception that says something along the lines of "Something went bang and this is usually a sign of corrupt memory somewhere else". Setup I'm using a DevExpress Ribbon Form and I haven't implemented Dispose on anything....Do I need to? Help greatly appreciated.

  Read the article

• How to make distributed builds using XCode 3.2 on OS X 10.6

  - by Sorin Sbarnea

  After I upgraded using a clean install from OS X 10.5 to 10.6.2 and upgraded the XCode to 3.2.1 I wasn't able to use distributed builds feature anymore. There are several issues that I detected: In most cases Bonjour is not detecting the other computers even they are on the same switch. I added a custom 'set' where I added manually the IP addreses of each computer. Even so I still get status: "unreachable" on them.BTW, ping does work without problems. Both share my computer for shared workgroup builds (distcc) and distribute builds via shared workgroup builds options are checked.

  Read the article

• Need help on how to begin learning website development

  - by Golfy

  OK for the past 10 days I have been trying to figure out where to begin learning website development a dynamic one, So far everyone told me you should start with computer science and I am like What the @#$% how am I suppose to learn computer science without going to school and get a degree but I don't want a degree I just want to learn how to devlope websites. So now I am here and confused about how to put together a website. I get HTML and CSS but still have some problems designing the site now on the other had I am having trouble trying to figure out how php and database mysql is used to put together a website. I have seen videos from lynda.com and still have no Idea after I have watched the video the basic one, one that teach you the Variables, Loops, Strings ext... ok than what happens, how do you build the website with it, that is the question I am real not understand the answer to. Any help will be appreciated.

  Read the article

• vector<vector<largeObject>> vs. vector<vector<largeObject>*> in c++

  - by Leif Andersen

  Obviously it will vary depending on the compiler you use, but I'm curious as to the performance issues when doing vector<vector<largeObject>> vs. vector<vector<largeObject>*>, especially in c++. In specific: let's say that you have the outer vector full, and you want to start inserting elements into first inner vector. How will that be stored in memory if the outer vector is just storing pointers, as apposed to storing the whole inner vector. Will the whole outer vector have to be moved to gain more space, or will the inner vector be moved (assuming that space wasn't pre-allocated), causing problems with the outer vector? Thank you

  Read the article

• Problem in VS2010 IDE in analog monitor in a dual-monitor setup

  - by Samik R.

  I am using VS2010 Premium with a dual-window setup. One of the monitors is on a digital (DVI) cable and other one is on an analog (VGA) cable. I have noticed that when I put VS2010 in the analog monitor, there are garbled texts and refresh problems while coding and/or scrolling. This does not seem to be the case when I put VS2010 in the digital monitor. Note that, I am not expanding VS IDE to use 2 screens, just making it 1 full screen, either analog or digital. Has anyone else experienced this problem? I also work with VS2008 and have not seen this problem in either screen. VS IDE has started using WPF from the 2010 release, not sure if this has something to do with it.

  Read the article

• MySQL ALTER TABLE on very large table - is it safe to run it?

  - by Timothy Mifsud

  I have a MySQL database with one particular MyISAM table of above 4 million rows. I update this table about once a week with about 2000 new rows. After updating, I then perform the following statement: ALTER TABLE x ORDER BY PK DESC i.e. I order the table in question by the primary key field in descending order. This has not given me any problems on my development machine (Windows with 3GB memory), but, even though 3 times I have tried it successfully on the production Linux server (with 512MB RAM - and achieving the resulted sorted table in about 6 minutes each time), the last time I tried it I had to stop the query after about 30 minutes and rebuild the database from a backup. I have started to wonder whether a 512MB server can cope with that statement (on such a large table) as I have read that a temporary table is created to perform the ALTER TABLE command?! And, if it can be safely run, what should be the expected time for the alteration of the table? Thanks in advance, Tim

  Read the article

< Previous Page | 370 371 372 373 374 375 376 377 378 379 380 381  | Next Page >