Search Results

Search found 22641 results on 906 pages for 'use case'.

Page 718/906 | < Previous Page | 714 715 716 717 718 719 720 721 722 723 724 725  | Next Page >

• Regular expression for finding non-breaking string names in code and then breaking them up for SQL q

  - by Rob Segal

  I am trying to devlop a regex for finding camel case strings in several code files I am working with so I can break them up into separate words for use in a SQL query. I have strings of the form... EmailAddress FirstName MyNameIs And I want them like this... Email Address First Name My Name Is An example SQL query which I currently have is... select FirstName, MyNameIs from MyTables I need the queries in the form... select FirstName as 'First Name', MyNameIs as 'My Name Is' from MyTables Any time a new capital letter appears that should be a new grouping which I can pick out of the matched string. I currently have the following regex... ([A-Z][a-z]+)+ Which does match the cases I have shown above but when I want to perform a replace I need to define groups. Currently I have tried... (([A-Z])([a-z]+))+ Which sort of works. It will pick out "Address" as the first grouping from "EmailAddress" as opposed to "Email" which is what I was expecting. No doubt there is something I'm misunderstanding here so any help is greatly appreciated.

  Read the article

• Android getting XML values

  - by Nils

  Hello, I have the following XML code, which I got by a UPnP device and like to get the res value - the RTSP URL. In this case rtsp://10.42.0.103:554/live.sdp How can I do this? I heard that Android has some built-in support for reading XML. Is that true? <DIDL-Lite xmlns="urn:schemas-upnp-org:metadata-1-0/DIDL-Lite/" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:upnp="urn:schemas-upnp-org:metadata-1-0/upnp/"> <item id="11" parentID="1" restricted="1"> <dc:title>Network Camera Stream 1</dc:title> <upnp:class>object.item.videoItem</upnp:class> <res protocolInfo="rtsp-rtp-udp:*:video/mpeg4-generic:*" resolution="640x480">rtsp://10.42.0.103:554/live.sdp</res> </item> <item id="12" parentID="1" restricted="1"> <dc:title>Network Camera Stream 2</dc:title> <upnp:class>object.item.videoItem</upnp:class> <res protocolInfo="rtsp-rtp-udp:*:video/mpeg4-generic:*" resolution="176x144">rtsp://10.42.0.103:554/live2.sdp</res> </item> </DIDL-Lite>

  Read the article

• function objects versus function pointers

  - by kumar_m_kiran

  Hi All, I have two questions related to function objects and function pointers, Question : 1 When I read the different uses sort algorithm of STL, I see that the third parameter can be a function objects, below is an example class State { public: //... int population() const; float aveTempF() const; //... }; struct PopLess : public std::binary_function<State,State,bool> { bool operator ()( const State &a, const State &b ) const { return popLess( a, b ); } }; sort( union, union+50, PopLess() ); Question : Now, How does the statement, sort(union, union+50,PopLess()) work? PopLess() must be resolved into something like PopLess tempObject.operator() which would be same as executing the operator () function on a temporary object. I see this as, passing the return value of overloaded operation i.e bool (as in my example) to sort algorithm. So then, How does sort function resolve the third parameter in this case? Question : 2 Question Do we derive any particular advantage of using function objects versus function pointer? If we use below function pointer will it derive any disavantage? inline bool popLess( const State &a, const State &b ) { return a.population() < b.population(); } std::sort( union, union+50, popLess ); // sort by population PS : Both the above references(including example) are from book "C++ Common Knowledge: Essential Intermediate Programming" by "Stephen C. Dewhurst". I was unable to decode the topic content, thus have posted for help. Thanks in advance for your help.

  Read the article

• What are the options for overriding Django's cascading delete behaviour?

  - by Tom

  Django models generally handle the ON DELETE CASCADE behaviour quite adequately (in a way that works on databases that don't support it natively.) However, I'm struggling to discover what is the best way to override this behaviour where it is not appropriate, in the following scenarios for example: ON DELETE RESTRICT (i.e. prevent deleting an object if it has child records) ON DELETE SET NULL (i.e. don't delete a child record, but set it's parent key to NULL instead to break the relationship) Update other related data when a record is deleted (e.g. deleting an uploaded image file) The following are the potential ways to achieve these that I am aware of: Override the model's delete() method. While this sort of works, it is sidestepped when the records are deleted via a QuerySet. Also, every model's delete() must be overridden to make sure Django's code is never called and super() can't be called as it may use a QuerySet to delete child objects. Use signals. This seems to be ideal as they are called when directly deleting the model or deleting via a QuerySet. However, there is no possibility to prevent a child object from being deleted so it is not usable to implement ON CASCADE RESTRICT or SET NULL. Use a database engine that handles this properly (what does Django do in this case?) Wait until Django supports it (and live with bugs until then...) It seems like the first option is the only viable one, but it's ugly, throws the baby out with the bath water, and risks missing something when a new model/relation is added. Am I missing something? Any recommendations?

  Read the article

• Is it normal for C++ static initialization to appear twice in the same backtrace?

  - by Joseph Garvin

  I'm trying to debug a C++ program compiled with GCC that freezes at startup. GCC mutex protects function's static local variables, and it appears that waiting to acquire such a lock is why it freezes. How this happens is rather confusing. First module A's static initialization occurs (there are __static_init functions GCC invokes that are visible in the backtrace), which calls a function Foo(), that has a static local variable. The static local variable is an object who's constructor calls through several layers of functions, then suddenly the backtrace has a few ??'s, and then it's is in the static initialization of a second module B (the __static functions occur all over again), which then calls Foo(), but since Foo() never returned the first time the mutex on the local static variable is still set, and it locks. How can one static init trigger another? My first theory was shared libraries -- that module A would be calling some function in module B that would cause module B to load, thus triggering B's static init, but that doesn't appear to be the case. Module A doesn't use module B at all. So I have a second (and horrifying) guess. Say that: Module A uses some templated function or a function in a templated class, e.g. foo<int>::bar() Module B also uses foo<int>::bar() Module A doesn't depend on module B at all At link time, the linker has two instances of foo<int>::bar(), but this is OK because template functions are marked as weak symbols... At runtime, module A calls foo<int>::bar, and the static init of module B is triggered, even though module B doesn't depend on module A! Why? Because the linker decided to go with module B's instance of foo::bar instead of module A's instance at link time. Is this particular scenario valid? Or should one module's static init never trigger static init in another module?

  Read the article

• How to create databinding over two xaml files?

  - by BionicGecko

  Hello, I am trying to come to a working understanding of how databinding works, but even after several tutorials I only have a basic understanding of how databinding works. Thus this question might seem fundamental to those more familiar with silverlight. Even if it is trivial, please point me to some tutorial that deals with this problem. All that I could find simply solved this via adding the data binding on a parent page.xaml (that i must not use in my case). For the sake of this example let us assume, that we have 5 files: starter.cs button1.xaml + codeBehind button2.xaml + codeBehind The two buttons are generated in code in the starter(.cs) file, and then added to some MapLayer button1 my_button1 = new button1(); button2 my_button1 = new button2(); someLayer.Children.Add(my_button1); someLayer.Children.Add(my_button2); My aim is to connect the two buttons, so that they always display the same "text" (i.e. my_button1.content==my_button2.content = true;). Thus when something changes my_button1.content this change should be propagated to the other button (two way binding). At the moment my button1.xaml looks like this: <Grid x:Name="LayoutRoot"> <Button x:Name="x_button1" Margin="0,0,0,0" Content="{Binding ElementName=x_button2, Path=Content}" ClickMode="Press" Click="button1_Click"/> </Grid> But everthing that i get out of that is a button with no content at all, it is just blank as the binding silently fails. How could I create the databinding in the context I described? Preferably in code and not XAML ;) Thanks in advance

  Read the article

• NULL-keys for key/value table

  - by user72185

  (Using Oracle) I have a table with key/value pairs like this: create table MESSAGE_INDEX ( KEY VARCHAR2(256) not null, VALUE VARCHAR2(4000) not null, MESSAGE_ID NUMBER not null ) I now want to find all the messages where key = 'someKey' and value is 'val1', 'val2' or 'val3' - OR value is null in which case there will be no entry in the table at all. This is to save space; there would be a large number of keys with null values if I stored them all. I think this works: SELECT message_id FROM message_index idx WHERE ((key = 'someKey' AND value IN ('val1', 'val2', 'val3')) OR NOT EXISTS (SELECT 1 FROM message_index WHERE key = 'someKey' AND idx.message_id = message_id)) But is is extremely slow. Takes 8 seconds with 700K records in message_index and there will be many more records and more search criteria when moving outside of my test environment. Primary key is key, value, message_id: add constraint PK_KEY_VALUE primary key (KEY, VALUE, MESSAGE_ID) And I added another index for message_id, to speed up searching for missing keys: create index IDX_MESSAGE_ID on MESSAGE_INDEX (MESSAGE_ID) I will be doing several of these key/value lookups in every search, not just one as shown above. So far I am doing them nested, where output id's of one level is the input to the next. E.g.: SELECT message_id from message_index WHERE (key/value compare) AND message_id IN ( SELECT ... and so on ) What can I do to speed this up?

  Read the article

• Does pressing Back always cause Activity to finish()?

  - by stormin986

  I've heard that pressing the back button will essentially cause the current Activity to finish(). Is this always the case? Seems like it would be with the way it pops the Activity off the stack. The one situation I'm not so sure about is when the root Activity in a Task has back pressed. I'm currently experiencing a very weird effect, described as follows: On loading my application, the first Activity is for initialization, and once it finishes, it calls my main Activity (a TabActivity). This first init activity has android:noHistory="true" set in the Manifest so pressing Back from my main Activity won't go back to that. It goes to the Launcher. When I click on my App in the Launcher a second time, the initialization activity loads again, and loads the main Activity when done. Almost immediately after, it loads a second instance of my main Activity. But ONLY after the Application has already been run once, and was exited by pressing BACK from the main Activity. It does it every subsequent time until I force quit the app or load a new version from the IDE. Based on this, I am suspecting some kind of Activity instance is lying around and being reused, since it only happens on the second+ time I run the application (and exit with BACK -- using HOME just returns to the last state of the app, no big deal). Anyone have any thoughts??

  Read the article

• Retrieve a TextBox element dinamically created and Focus it

  - by user335444

  Hi, I have a collection (VariableValueCollection) of custom type VariableValueViewModel objects binded with a ListView. WPF Follow: <ListView ItemsSource="{Binding VariableValueCollection}" Name="itemList"> <ListView.Resources> <DataTemplate DataType="{x:Type vm:VariableValueViewModel}"> <Grid> <Grid.ColumnDefinitions> <ColumnDefinition Width="180"></ColumnDefinition> </Grid.ColumnDefinitions> <TextBox TabIndex="{Binding Path=Index, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}" Grid.Column="0" Name="tbValue" Focusable="True" LostFocus="tbValue_LostFocus" GotFocus="tbValue_GotFocus" KeyDown="tbValue_KeyDown"> <TextBox.Text> <Binding Path="Value" UpdateSourceTrigger="PropertyChanged" Mode="TwoWay"> <Binding.ValidationRules> <ExceptionValidationRule></ExceptionValidationRule> </Binding.ValidationRules> </Binding> </TextBox.Text> </TextBox> </Grid> </DataTemplate> </ListView.Resources> </ListView> My Goal is to add a new row when I press "enter" on last row, and Focus the new row. To do that, I check that row is the last row and add a new row in that case. But I don't know how to focus the new TextBox... Here the KeyPressed method: private void tbValue_KeyDown(object sender, KeyEventArgs e) { if (e.Key == System.Windows.Input.Key.Enter) { DependencyObject obj = itemList.ContainerFromElement((sender as TextBox)); int index = itemList.ItemContainerGenerator.IndexFromContainer(obj); if( index == (VariableValueCollection.Count - 1) ) { // Create a VariableValueViewModel object and add to collection. In binding, that create a new list item with a new TextBox ViewModel.AddNewRow(); // How to set cursor and focus last row created? } } } Thank's in advance...

  Read the article

• libxml2 on iPhone

  - by mellkord

  I'm trying to parse HTML file with libxml2. Usually this works fine, but not in this case: <p> <b>Titles</b> (Some Text) <table> <tr> <td valign="top"> …Something1... </td> <td align="right" valign="top"> …Something2... </td> </tr> </table> </p> I do this query to get the first <td> //p[b='Titles']/table/tr/td[0] but nothing is returned because libxml think that <table> tag is not a child of a tag <p> and following him. And finally the question WHY?

  Read the article

• How can I create a properly sizing QWebView?

  - by chacham15

  I want to make a QWebView appear expanding to the width and height so that ideally it will have no scroll bars. Some websites may have fixed widths that wont allow this, but I am not concerned with those. In any case, I cannot do as I wish because QWebView implements sizeHint as follows: QSize QWebView::sizeHint() const { return QSize(800, 600); // ####... } This is incorrect on a number of levels. 1. It doesnt at all take into account the size of the actual web page. 2. It doesnt take into account that the height and width are related to each other. (To prove #2 think about text in web pages that wraps to the next line.) As a simple fix I tried to do (where QResizingWebView extends QWebView): QSize QResizingWebView::sizeHint() const{ return this-page()-mainFrame()-contentsSize(); } While this is closer to the result, it also has 2 flaws. 1. It doesnt take into account the relation between the displayed width/height. 2. this->page()->mainFrame()->contentsSize() is inaccurate from what I can tell from my preliminary testing (it has returned heights larger than it should under many cases, although this may be related to #1). Does anyone have any tips to fix this?

  Read the article

• Destructors not called when native (C++) exception propagates to CLR component

  - by Phil Nash

  We have a large body of native C++ code, compliled into DLLs. Then we have a couple of dlls containing C++/CLI proxy code to wrap the C++ interfaces. On top of that we have C# code calling into the C++/CLI wrappers. Standard stuff, so far. But we have a lot of cases where native C++ exceptions are allowed to propagate to the .Net world and we rely on .Net's ability to wrap these as System.Exception objects and for the most part this works fine. However we have been finding that destructors of objects in scope at the point of the throw are not being invoked when the exception propagates! After some research we found that this is a fairly well known issue. However the solutions/ workarounds seem less consistent. We did find that if the native code is compiled with /EHa instead of /EHsc the issue disappears (at least in our test case it did). However we would much prefer to use /EHsc as we translate SEH exceptions to C++ exceptions ourselves and we would rather allow the compiler more scope for optimisation. Are there any other workarounds for this issue - other than wrapping every call across the native-managed boundary in a (native) try-catch-throw (in addition to the C++/CLI layer)?

  Read the article

• How do you make a static sprite be a child of another sprite in cocos2D while using SpaceManager

  - by JJBigThoughts

  I have two static (STATIC_MASS) SpaceManager sprites. One is a child of the other - by which I mean that one sort of builds up the other one, but although the child's images shows up in the right place, the child doesn't seem to exists in the chipmunk physics engine, like I would expect. In my case, I have a backboard (rectangular sprite) and a hoop (a circular sprite). Since I might want to move the backboard, I'd like to attach the hoop to backboard so that the hoop automatically moves right along with the backboard. Here, we see a rotating backboard with attached hoop. It looks OK on the screen, but other objects only bounce off the backboard but pass right through the hoop (in a bad sense of the term). What doesn't my child sprite seem to exist in the physics engine? // Add Backboard cpShape *shapeRect = [smgr addRectAt:cpvWinCenter mass:STATIC_MASS width:200 height:10 rotation:0.0f ];// We're upgrading this cpCCSprite * cccrsRect = [cpCCSprite spriteWithShape:shapeRect file:@"rect_200x10.png"]; [self addChild:cccrsRect]; // Spin the static backboard: http://stackoverflow.com/questions/2691589/how-do-you-make-a-sprite-rotate-in-cocos2d-while-using-spacemanager // Make static object update moves in chipmunk // Since Backboard is static, and since we're going to move it, it needs to know about spacemanager so its position gets updated inside chipmunk. // Setting this would make the smgr recalculate all static shapes positions every step // cccrsRect.integrationDt = smgr.constantDt; // cccrsRect.spaceManager = smgr; // Alternative method: smgr.rehashStaticEveryStep = YES; smgr.rehashStaticEveryStep = YES; // Spin the backboard [cccrsRect runAction:[CCRepeatForever actionWithAction: [CCSequence actions: [CCRotateTo actionWithDuration:2 angle:180], [CCRotateTo actionWithDuration:2 angle:360], nil] ]]; // Add the hoop cpShape *shapeHoop = [smgr addCircleAt:ccp(100,-45) mass:STATIC_MASS radius: 50 ]; cpCCSprite * cccrsHoop = [cpCCSprite spriteWithShape:shapeHoop file:@"hoop_100x100.png"]; [cccrsRect addChild:cccrsHoop]; This is only half working for me. Note: SpaceManager is a toolkit for working with cocos2D-iphone

  Read the article

• How to detect a WCF session crash before calling a contract method?

  - by brain_pusher

  I am using a session mode for my WCF service. The problem is the following: if session is broken and no longer exists, client can't know it before calling a contract. For example, if the service has been restarted, the client's session id is invalid, because that session has been closed on the server side. I check the channel state before calling the contract and its value is CommunicationState.Opened even if session is already broken. So, when I call the contract after this check I get a CommunicationException with this message: The remote endpoint no longer recognizes this sequence. This is most likely due to an abort on the remote endpoint. The value of wsrm:Identifier is not a known Sequence identifier. The reliable session was faulted. Is there any workaround? I need a way to get an appropriate session state before calling a contract so that I can restore it without getting an exception. P.S. The CommunicationException type is general, so I can't detect a session crash by catching this exception. P.P.S. I have asked the similar question here, but in that case I didn't know the reason, now I don't know how to evade it.

  Read the article

• SocialAuth.NET is not working

  - by Alen Joy

  I'm trying to use SocialAuth.NET for extract contacts from gmail and yahoo for my web application but when I run the WebformDemo the following error occurs Server Error in '/Demo' Application. Configuration Error Description: An error occurred during the processing of a configuration file required to service this request. Please review the specific error details below and modify your configuration file appropriately. Parser Error Message: Unrecognized attribute 'targetFramework'. Note that attribute names are case-sensitive. Source Error: Line 76: </authentication>--> Line 77: <!--<authentication mode="None"/>--> Line 78: <compilation debug="true" targetFramework="4.0"> Line 79: <assemblies> Line 80: <add assembly="Microsoft.IdentityModel, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" /> Source File: D:\test\SocialAuth-net-2.3\WebFormsDemo\web.config Line: 78 Version Information: Microsoft .NET Framework Version:2.0.50727.3053; ASP.NET Version:2.0.50727.3053 I'm using Windows XP and Visual Studio 2010. Any help?

  Read the article

• super light software development process

  - by Walty

  hi, For the development process I have involved so far, most have teams of SINGLE member, or occasionally two. We used python + django for the major development, the development process is actually very fast, and we do have code reviews, design pattern discussions, and constant refactoring. Though team size is small, I do think there are some development processes / best practices that could be enforced. For example, using svn would be definitely better than regular copy backup. I did read some articles & books about Agile, XP & continuous integration, I think they are nice, but still too heavy for this case (team of 1 or 2, and fast coding). For example, IMHO, with nice design pattern, and iterative development + refactoring, the TDD MIGHT be an overkill, or at least the overhead does not out-weight the advantages. And so is the pair programming. The automated testing is a nice idea, but it seems not technically feasible for every project. our current practices are: svn + milestone + code review I wonder if there are development processes / best practices specifically targeted on such super light teams? thanks.

  Read the article

• Single developer, project organization

  - by poke

  I am looking for a good (and free) way to organize some of my personal projects. I am saying "organize" because I'm not sure, if the standard project management software solutions are exactly what I am looking for and especially something what I, as a single developer, need. In general, I just want to keep my progress of my projects organized in some way. I would like to be able to keep track of milestones and split those into multiple smaller tasks, so I can keep track of my progress. So some task/issue based system would probably be good, especially as I also want to keep track of issues/bugs with specific versions (although I alone will create those issues). I am and will be the only developer on those projects, so it doesn't matter if the software is offline or online, and I also don't need any collaboration features (like commenting on things, or assigning tasks to other developers etc). But if there is a good software that fits my needs, and in addition it has those things, I don't really care. After all it's easy enough to not use available features. Many online solutions also offer integrated code hosting. I am using git internally, but I don't plan to push any of the code, so such a feature is not needed either. In case of online solutions however I would like the projects to be closed to the public (some of the online utilities only offer open source projects for free and require payments for private projects). I have looked at some project management solutions already, I also read some similar questions here on SO. But given that I'm a single developer, my focus is probably a bit different as when others ask for a huge distributed software that supports many developers and different collaboration features. Some standard answers such as Trac (which also only supports one project), Redmine and FogBUGZ look interesting, but are a bit off my interest (although you may change my mind on that :P). Currently, I'm looking at Indefero which doesn't look too bad. But what do you think?

  Read the article

• How should i organize authority code?

  - by acidzombie24

  I have users that fall into the following Not logged in Not Verified Verified Moderator Admin All code that only admin and moderators can access (like banning) is in ModeratorUser which inherits from verified which inherits from BaseUser. Some pages are accessible to all users such as public profiles. If a user is logged in he can leave a comment. To check this i use if (IsVerifiedUser). Now here is the problem. To avoid problems if a user is banned he is not recognized as a verified user. However in the rare case i need to know if he is verified i can use usertype & Verified. Should i not be doing this? I have a bunch of code in my VerifiedUser class and find i am moving tons of it to BaseUser. Is this something i help because a not logged in user can access the page? Should i handle the ban user in a different way and allow IsVerifiedUser to be true even if the user is banned?

  Read the article

• keep HTMLformat after replace some text (using PHP and JS)

  - by Sadi

  I would like modify HTML like I am <b>Sadi, novice</b> programmer. to I am <b>Sadi, learner</b> programmer. To do it I will search using a string "novice programmer". How can I do it please? Any idea? Thank you Sadi More clarification: I get some nice reply with possible solution. But please keep posting if you have any idea in mind. I would like to more clarify the problem just in case anyone missed it. Main post shows the problem as an example scenario. 1) Now the problem is find and replace some string without considering the tags. The tags may shows up within a single word. String may contain multiple word. Tag only appear in the content string or the document. The search phrase never contain any tags. We can easily remove all tags and do some text operation. But here the another problem shows up. 2) The tags must be preserve, even after replacing the text. That is what the example shows. Thank you Again for helping

  Read the article

• MySQL FULLTEXT aggravation

  - by southof40

  Hi - I'm having problems with case-sensitivity in MySQL FULLTEXT searches. I've just followed the FULLTEXT example in the MySQL doco at http://dev.mysql.com/doc/refman/5.1/en/fulltext-boolean.html . I'll post it here for ease of reference ... CREATE TABLE articles ( id INT UNSIGNED AUTO_INCREMENT NOT NULL PRIMARY KEY, title VARCHAR(200), body TEXT, FULLTEXT (title,body) ); INSERT INTO articles (title,body) VALUES ('MySQL Tutorial','DBMS stands for DataBase ...'), ('How To Use MySQL Well','After you went through a ...'), ('Optimizing MySQL','In this tutorial we will show ...'), ('1001 MySQL Tricks','1. Never run mysqld as root. 2. ...'), ('MySQL vs. YourSQL','In the following database comparison ...'), ('MySQL Security','When configured properly, MySQL ...'); SELECT * FROM articles WHERE MATCH (title,body) AGAINST ('database' IN NATURAL LANGUAGE MODE); ... my problem is that the example shows that SELECT returning the first and fifth rows ('..DataBase..' and '..database..') but I only get one row ('database') ! The example doesn't demonstrate what collation the table in the example had but I have ended up with latin1_general_cs on the title and body columns of my example table. My version of MySQL is 5.1.39-log and the connection collation is utf8_unicode_ci . I'd be really grateful is someone could suggest why my experience differs from the example in the manual ! Be grateful for any advice.

  Read the article

• ConcurrentLinkedQueue$Node remains in heap after remove()

  - by action8

  I have a multithreaded app writing and reading a ConcurrentLinkedQueue, which is conceptually used to back entries in a list/table. I originally used a ConcurrentHashMap for this, which worked well. A new requirement required tracking the order entries came in, so they could be removed in oldest first order, depending on some conditions. ConcurrentLinkedQueue appeared to be a good choice, and functionally it works well. A configurable amount of entries are held in memory, and when a new entry is offered when the limit is reached, the queue is searched in oldest-first order for one that can be removed. Certain entries are not to be removed by the system and wait for client interaction. What appears to be happening is I have an entry at the front of the queue that occurred, say 100K entries ago. The queue appears to have the limited number of configured entries (size() == 100), but when profiling, I found that there were ~100K ConcurrentLinkedQueue$Node objects in memory. This appears to be by design, just glancing at the source for ConcurrentLinkedQueue, a remove merely removes the reference to the object being stored but leaves the linked list in place for iteration. Finally my question: Is there a "better" lazy way to handle a collection of this nature? I love the speed of the ConcurrentLinkedQueue, I just cant afford the unbounded leak that appears to be possible in this case. If not, it seems like I'd have to create a second structure to track order and may have the same issues, plus a synchronization concern.

  Read the article

• gethostbyname fails for local hostname after resuming from hibernate (Vista+7?)

  - by John

  Just wondering if anyone else has spotted this: On some user's machines running our software, occasionally the call to Win32 winsock gethostbyname fails with error code 11004. For the argument to gethostbyname, I'm passing in the result from gethostname. Now the docs say 11004 is WSANO_DATA. None of the descriptions seem to be relevant (it occurs if you pass in an IP6 address, but as I say, I'm passing in a hostname). Even more interesting is that the MSDN suggests that this combination (gethostname followed by gethostbyname) should never fail, not even if there is no IP address (in that case it would just return empty list of IPs). Here is the quote from the gethostname MSDN entry: ...it is guaranteed that the name returned will be successfully parsed by gethostbyname and WSAAsyncGetHostByName. It only ever happens after resuming from hibernate, in that short period when the network is restarting, and only on Vista/7 (well I've only seen it on Vista and 7). One theory I had was that it related to IP6. Maybe for a short period the network reports an IP6 address but not the corresponging IP4 address (I'm pretty sure that all the client machines are dual IP stack, but I could be wrong). I tried to reproduce by turning off my network card (to force no IP addresses) and couldn't reproduce. Anyone seen this before? Any ideas? John

  Read the article

• Core Data: Deleting causes 'NSObjectInaccessibleException' from NSOperation with a reference to a deleted object

  - by Bryan Irace

  My application has NSOperation subclasses that fetch and operate on managed objects. My application also periodically purges rows from the database, which can result in the following race condition: An background operation fetches a bunch of objects (from a thread-specific context). It will iterate over these objects and do something with their properties. A bunch of rows are deleted in the main managed object context. The background operation accesses a property on an object that was deleted from the main context. This results in an 'NSObjectInaccessibleException', reason: 'CoreData could not fulfill a fault' Ideally, the objects that are fetched by the NSOperation can be operated on even if one is deleted in the main context. The best way I can think to achieve this is either to: Call [request setReturnsObjectsAsFaults:NO] to ensure that Core Data won't try to fulfill a fault for an object that no longer exists in the main context. The problem here is I may need to access the object's relationships, which (to my understanding) will still be faulted. Iterate through the managed objects up front and copy the properties I will need into separate non-managed objects. The problem here is that (I think) I will need to synchronize/lock this part, in case an object is deleted in the main context before I can finish copying. Am I missing something obvious? It doesn't seem like what I'm trying to accomplish is too out of the ordinary. Thanks for your help.

  Read the article

• Database and logic layer for ASP.NET MVC application

  - by Ismail

  I'm going to start a new project which is going to be small initially but may grow to big over the years. I'm strongly convinced that I'm going to use ASP.NET MVC with jQuery for UI. I want to go for MySQL as database for some reasons but worried on few things. I've a good years of experience working on SQL Server databases and on one project I've had a bad experience creating and managing stored procedures on MySQL database. I'm totally new to Linq but I see that it is easier to use once you are familiar with it. First thing is that accessing data should be easy. So I thought I should use MySQL to Linq but somewhere I read that it is not directly supported but MySQL .NET connector adds support for EntityFramework. I don't know what are the pros and cons of it. I would love if I can implement repository pattern as it allows to apply filter in logic layer rather than in data access layer. Will it be possible if I use Entity Framework? I'm not clear on how I should go about all this or I should just forget every thing and directly use SQL to Linq on SQL Server. I'm also concerned about the performance. Someone told me that if we use Entity framework it fetches lot of data and then filter it. Is that right? So questions basically are - Is MySQL to Linq possible? If yes where can I get more details on it? Pros and cons of using EntityFramework with MySQL? Will it be easy to access data using EntityFramework with MySQL? Will I be able to implement repository patter which allows applying filter in logic layer rather than data access layer (when I use EntityFramework with MySQL) Does it fetches hell lot of data from database and then apply filter on it? If it sounds too many questions from my side in that case, if you can just let me know what you will do (with a considerable reason) in this situation as an experienced person in this area, that should answer my question.

  Read the article

• Apache module, is it possible to have asynchronous processing

  - by prashant2361

  Hi, I have a requirement where I need to send continous updates to my clients. Client is browser in this case. We have some data which updates every sec, so once client connects to our server, we maintain a persistent connection and keep pushing data to the client. I am looking for suggestions of this implementation at the server end. Basically what I need is this: 1. client connects to server. I maintain the socket and metadata about the socket. metadata contains what updates need to be send to this client 2. server process now waits for new client connections 3. One other process will have the list of all the sockets opened and will go through each of them and send the updates if required. Can we do something like this in apache module: 1. apache process gets the new connection. It maintains the state for the connection. It keeps the state in some global memory and returns back to root process to signify that it is done so that it can accept the new connection 2. the apache process though has returned the status to root process but it is also executing parallely where it going through its global store and sending updates to the client, if any. So can a apache process do these things: 1. Have more than one connection associated with it 2. Asynchronously waiting for new connection and at the same time processing the previous connections? Regards Prashant

  Read the article

< Previous Page | 714 715 716 717 718 719 720 721 722 723 724 725  | Next Page >