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  • Java: Tracking a user login session - Session EJBs vs HTTPSession

    - by bguiz
    If I want to keep track of a conversational state with each client using my web application, which is the better alternative - a Session Bean or a HTTP Session - to use? Using HTTP Session: //request is a variable of the class javax.servlet.http.HttpServletRequest //UserState is a POJO HttpSession session = request.getSession(true); UserState state = (UserState)(session.getAttribute("UserState")); if (state == null) { //create default value .. } String uid = state.getUID(); //now do things with the user id Using Session EJB: In the implementation of ServletContextListener registered as a Web Application Listener in WEB-INF/web.xml: //UserState NOT a POJO this this time, it is //the interface of the UserStateBean Stateful Session EJB @EJB private UserState userStateBean; public void contextInitialized(ServletContextEvent sce) { ServletContext servletContext = sce.getServletContext(); servletContext.setAttribute("UserState", userStateBean); ... In a JSP: public void jspInit() { UserState state = (UserState)(getServletContext().getAttribute("UserState")); ... } Elsewhere in the body of the same JSP: String uid = state.getUID(); //now do things with the user id It seems to me that the they are almost the same, with the main difference being that the UserState instance is being transported in the HttpRequest.HttpSession in the former, and in a ServletContext in the case of the latter. Which of the two methods is more robust, and why?

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  • Determining selected state of jQuery Buttons

    - by lloydphillips
    I've got two radio buttons in a .net page which are being transformed to jQuery buttons a la http://jqueryui.com/demos/button/#radio When the page is loaded I have button 2 as checked. When clicking the buttons I'm firing the postback event. Problem is you can click on that button that is selected by default on the initial load i.e. Button 2, the postback is fired but the event handler isn't called in the .net code behind because the radio button is already classed as selected (and in normal circumstances wouldn't allow the postback to fire). To get around this I've added the e.PreventDefault() method BUT this is causing issues when Button 1 is clicked because before the click handler is called the button is set to selected. Therefore, in every case in the following code e.PreventDefault() is called: $(document).ready(function(){ $("[id*='rbPayable']").click(function(e){ if ($("[id*='rbPayable']").attr("checked")) e.preventDefault(); else setTimeout('__doPostBack(\'this.id\',\'\')', 0) }) $("[id*='rbReceivable']").click(function(e){ if ($("[id*='rbReceivable']").attr("checked")) e.preventDefault(); else setTimeout('__doPostBack(\'this.id\',\'\')', 0) }) }); What is the best way for me to load the page and effectively be able to do the following: 'If rbReceivable is checked then don't do anything otherwise do a postback.'

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  • Need help extrapolating Java code

    - by Berlioz
    If anyone familiar with Rebecca Wirfs-Brock, she has a piece of Java code found in her book titled, Object Design: Roles, Responsibilities, and Collaborations. Here is the quote Applying Double Dispatch to a Specific Problem To implement the game Rock, Paper, Scissors we need to write code that determines whether one object “beats” another. The game has nine possible outcomes based on the three kinds of objects. The number of interactions is the cross product of the kinds of objects. Case or switch statements are often governed by the type of data that is being operated on. The object-oriented language equivalent is to base its actions on the class of some other object. In Java, it looks like this Here is the piece of Java code on page 16 ' import java.util.*; import java.lang.*; public class Rock { public static void main(String args[]) { } public static boolean beats(GameObject object) { if (object.getClass.getName().equals("Rock")) { result = false; } else if (object.getClass.getName().equals("Paper")) { result = false; } else if(object.getClass.getName().equals("Scissors")) { result = true; } return result; } }' ===This is not a very good solution. First, the receiver needs to know too much about the argument. Second, there is one of these nested conditional statements in each of the three classes. If new kinds of objects could be added to the game, each of the three classes would have to be modified. Can anyone share with me how to get this "less than optimal" piece of code to work in order to see it 'working'. She proceeds to demonstrate a better way, but I will spare you. Thanks

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  • Entity Framework one-to-one relationship mapping flattened in code

    - by Josh Close
    I have a table structure like so. Address: AddressId int not null primary key identity ...more columns AddressContinental: AddressId int not null primary key identity foreign key to pk of Address County State AddressInternational: AddressId int not null primary key identity foreign key to pk of Address ProvinceRegion I don't have control over schema, this is just the way it is. Now, what I want to do is have a single Address object. public class Address { public int AddressId { get; set; } public County County { get; set; } public State State { get; set } public ProvinceRegion { get; set; } } I want to have EF pull it out of the database as a single entity. When saving, I want to save the single entity and have EF know to split it into the three tables. How would I map this in EF 4.1 Code First? I've been searching around and haven't found anything that meets my case yet. UPDATE An address record will have a record in Address and one in either AddressContinental or AddressInternational, but not both.

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  • Why is passing a string literal into a char* argument only sometimes a compiler error?

    - by Brian Postow
    I'm working in a C, and C++ program. We used to be compiling without the make-strings-writable option. But that was getting a bunch of warnings, so I turned it off. Then I got a whole bunch of errors of the form "Cannot convert const char* to char* in argmuent 3 of function foo". So, I went through and made a whole lot of changes to fix those. However, today, the program CRASHED because the literal "" was getting passed into a function that was expecting a char*, and was setting the 0th character to 0. It wasn't doing anything bad, just trying to edit a constant, and crashing. My question is, why wasn't that a compiler error? In case it matters, this was on a mac compiled with gcc-4.0. EDIT: added code: char * host = FindArgDefault("EMailLinkHost", ""); stripCRLF(linkHost, '\n'); where: char *FindArgDefault(char *argName, char *defVal) {// simplified char * val = defVal; return(val); } and void stripCRLF(char *str, char delim) { char *p, *q; for (p = q = str; *p; ++p) { if (*p == 0xd || *p == 0xa) { if (p[1] == (*p ^ 7)) ++p; if (delim == -1) *p = delim; } *q++ = *p; } *q = 0; // DIES HERE } This compiled and ran until it tried to set *q to 0...

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  • Fortran pointer as an argument to interface procedure

    - by icarusthecow
    Im trying to use interfaces to call different subroutines with different types, however, it doesnt seem to work when i use the pointer attribute. for example, take this sample code MODULE ptr_types TYPE, abstract :: parent INTEGER :: q END TYPE TYPE, extends(parent) :: child INTEGER :: m END TYPE INTERFACE ptr_interface MODULE PROCEDURE do_something END INTERFACE CONTAINS SUBROUTINE do_something(atype) CLASS(parent), POINTER :: atype ! code determines that this allocation is correct from input ALLOCATE(child::atype) WRITE (*,*) atype%q END SUBROUTINE END MODULE PROGRAM testpass USE ptr_types CLASS(child), POINTER :: ctype CALL ptr_interface(ctype) END PROGRAM This gives error Error: There is no specific subroutine for the generic 'ptr_interface' at (1) however if i remove the pointer attribute in the subroutine it compiles fine. Now, normally this wouldnt be a problem, but for my use case i need to be able to treat that argument as a pointer, mainly so i can allocate it if necessary. Any suggestions? Mind you I'm new to fortran so I may have missed something edit: forgot to put the allocation in the parents subroutine, the initial input is unallocated EDIT 2 this is my second attempt, with caller side casting MODULE ptr_types TYPE, abstract :: parent INTEGER :: q END TYPE TYPE, extends(parent) :: child INTEGER :: m END TYPE TYPE, extends(parent) :: second INTEGER :: meow END TYPE CONTAINS SUBROUTINE do_something(this, type_num) CLASS(parent), POINTER :: this INTEGER type_num IF (type_num == 0) THEN ALLOCATE (child::this) ELSE IF (type_num == 1) THEN ALLOCATE (second::this) ENDIF END SUBROUTINE END MODULE PROGRAM testpass USE ptr_types CLASS(child), POINTER :: ctype SELECT TYPE(ctype) CLASS is (parent) CALL do_something(ctype, 0) END SELECT WRITE (*,*) ctype%q END PROGRAM however this still fails. in the select statement it complains that parent must extend child. Im sure this is due to restrictions when dealing with the pointer attribute, for type safety, however, im looking for a way to convert a pointer into its parent type for generic allocation. Rather than have to write separate allocation functions for every type and hope they dont collide in an interface or something. hopefully this example will illustrate a little more clearly what im trying to achieve, if you know a better way let me know

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  • I need to recover an instance of an activity

    - by Bilthon
    Well.. the title is pretty descriptive, I have a bunch of tab activities (which I implemented myself, didn't want to use the tabviews with activities inside them), so It's basically 5 activities calling each other every time the user clicks on the tabs displayed as a row of LinearLayouts at the bottom of the screen. The thing is that the way I do it now, everytime the user jumps from one activity to another, a new activity is created and launched. Of course, I can see I'm wasting resources this way. So what I would like to do is to create every activity only once; and then if the user wants to go back to the previous (or any one that was already created and is probably paused) just check on some kind of list or array to see if the activity can be recovered and only in the case it can't; to lauch a new one. My question is, how can I check this? should I save the intents? and how to recover the activities afterwards? I'm kind of new with java. Greetings Nelson R. Perez

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  • How long is the time frame between context switches on Windows?

    - by mattcodes
    Reading CLR via C# 2.0 (I dont have 3.0 with me at the moment) Is this still the case: If there is only one CPU in a computer, only one thread can run at any one time. Windows has to keep track of the thread objects, and every so often, Windows has to decide which thread to schedule next to go to the CPU. This is additional code that has to execute once every 20 milliseconds or so. When Windows makes a CPU stop executing one thread's code and start executing another thread's code, we call this a context switch. A context switch is fairly expensive because the operating system has to: So circa CLR via C# 2.0 lets say we are on Pentium 4 2.4ghz 1 core non-HT, XP. Every 20 milliseconds? Where a CLR thread or Java thread is mapped to an OS thread only a maximum of 50 threads per second may get a chance to to run? I've read that context switching is very fast in mircoseconds here on SO, but how often roughly (magnitude style guesses) will say a modest 5 year old server Windows 2003 Pentium Xeon single core give the OS the opportunity to context switch? 20ms in the right area? I dont need exact figures I just want to be sure that's in the right area, seems rather long to me.

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  • Differences in accessing resources between Simulator and Device?

    - by Tony
    Is there some difference between the way that bundle resources can be accessed on the iPhone simulator versus a device (in my case, an iPad)? I am able to access a file on the former, but not the latter. NSString *filePath = [NSString stringWithFormat:@"%@%@",[[NSBundle mainBundle] bundlePath], @"/AppResources/html/pages/quickHelp.html"]; BOOL fileExists = [[NSFileManager defaultManager] fileExistsAtPath:filePath]; // fileExists == YES in the debugger on both the simulator and the device NSString *path = [NSString stringWithFormat:@"AppResources/html/pages/%@", contentsFileName]; NSString *pathForURL = [[NSBundle mainBundle] pathForResource:path ofType:@"html"]; NSURL *url = [NSURL fileURLWithPath:pathForURL isDirectory:NO]; The code above works fine in the simulator, but on the device pathForResource:path returns nil, so the last line throws a 'nil string parameter' exception. Am I missing something obvious? edit: Of course, in the above @"quickHelp" is being passed in the contentsFileName var. edit2: if it makes any difference, in my build settings "Base SDK" is set to "iPhone Device 4.0", and "iPhone OS Deployment Target" is set to "iPhone OS 3.1.3". Any other settings that might have an influence?

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  • Scalable Full Text Search With Per User Result Ordering

    - by jeremy
    What options exist for creating a scalable, full text search with results that need to be sorted on a per user basis? This is for PHP/MySQL (Symfony/Doctrine as well, if relevant). In our case, we have a database of workouts that have been performed by users. The workouts that the user has done before should appear at the top of the results. The more frequently they've done the workout, the higher it should appear in search matches. If it helps, you can assume we know the number of times a user has done a workout in advance. Possible Solutions Sphinx - Use Sphinx to implement full text search, do all the querying and sorting in MySQL. This seems promising (and there's a Symfony Plugin!) but I don't know much about it. Lucene - Use Lucene to perform full text search and put the users' completions into the query. As is suggested in this Stack Overflow thread. Alternatively, use Lucene to retrieve the results, then reorder them in PHP. However, both solutions seem clunky and potentially unscalable as a user may have completed hundreds of workouts. Mysql - No native full text support (InnoDB), so we'd have use LIKE or REGEX, which isn't scalable.

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  • How to handle build rule with unknown targets in OMake when target list generator is built

    - by Michael E
    I have a project which uses OMake for its build system, and I am trying to handle a rather tough corner case. I have some definition files and a tool which can take these definition files and create GraphViz files. There are two problems, though: Each definition file can produce multiple graphs, and the list of graphs it can produce is encoded in the file. My dump tool does have a -list option which lists all the graphs a definition file will produce. This dump tool is built in the source tree. I want this list available in the OMakefile so I can use other rules to convert the DOT files to SVG, and have a phony target depend on all the SVGs (goal: a single build command which builds SVG descriptions of all my graphs). If I only had the first problem, it would be easy - I would run the tool to build a list, and then use that list to build a target which invokes the dumper to output the GraphViz files. However, I am rather stuck on forcing the dump tool to be built before it is needed. If this were make, I would just run make recursively to build the dump tool. OMake does not allow recursive invocation, however, and the build function is only usable from osh. Any suggestions for a good solution to this problem?

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  • How to call a method after asynchronous task is complete

    - by doctordoder
    I have a class called WikiWebView which is a subclass of UIWebView which loads Wikipedia subjects and is designed to fetch all the links of the webpage, in order to create a sort of site map for the subject. My problem is that I can only create the links once the web page has loaded, but the loading isn't done right after [self loadRequest:requestObj] is called. - (void)loadSubject:(NSString *)subject { // load the actual webpage NSString *wiki = @"http://www.wikipedia.org/wiki/"; NSString *fullURL = [wiki stringByAppendingString:subject]; NSURL *url = [NSURL URLWithString:fullURL]; NSURLRequest *requestObj = [NSURLRequest requestWithURL:url]; [self loadRequest:requestObj]; // [self createLinks]; // need this to be called after the view has loaded } - (void)createLinks { NSString *javascript = @"var string = \"\";" "var arr = document.getElementsByClassName(\"mw-redirect\");" "for (var i = 0; i < arr.length; ++i)" "{" "var redirectLink = arr[i].href;" "string = string + redirectLink + \" \";" "}" "string;"; NSString *links = [self stringByEvaluatingJavaScriptFromString:javascript]; self.links = [links componentsSeparatedByString:@" "]; } I tried the normal delegation technique, which lead to this code being added: - (id)init { if (self = [super init]) { self.delegate = self; // weird } return self; } #pragma mark - UIWebViewDelegate - (void)webViewDidStartLoad:(UIWebView *)webView { ++_numProcesses; } - (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error { --_numProcesses; } - (void)webViewDidFinishLoad:(UIWebView *)webView { --_numProcesses; if (_numProcesses == 0) { [self createLinks]; } } However, the delegate methods are never called.. I've seen similar questions where the answers are to use blocks, but how would I do that in this case?

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  • Problem with derived ControlTemplates in WPF

    - by Frank Fella
    The following xaml code works: <Window x:Class="DerivedTemplateBug.Window1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:local="clr-namespace:DerivedTemplateBug" Title="Window1" Height="300" Width="300"> <Button> <Button.Template> <ControlTemplate> <Border BorderBrush="Black" BorderThickness="2"> <TextBlock>Testing!</TextBlock> </Border> </ControlTemplate> </Button.Template> </Button> </Window> Now, if you define the following data template: using System.Windows.Controls; namespace DerivedTemplateBug { public class DerivedTemplate : ControlTemplate { } } And then swap the ControlTemplate for the derived class: <Window x:Class="DerivedTemplateBug.Window1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:local="clr-namespace:DerivedTemplateBug" Title="Window1" Height="300" Width="300"> <Button> <Button.Template> <local:DerivedTemplate> <Border BorderBrush="Black" BorderThickness="2"> <TextBlock>Testing!</TextBlock> </Border> </local:DerivedTemplate> </Button.Template> </Button> </Window> You get the following error: Invalid ContentPropertyAttribute on type 'DerivedTemplateBug.DerivedTemplate', property 'Content' not found. Can anyone tell me why this is the case?

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  • Are these saml request-response good enough?

    - by Ashwin
    I have set up a single sign on(SSO) for my services. All the services confirm the identity of the user using the IDPorvider(IDP). In my case I am also the IDP. In my saml request, I have included the following: 1. the level for which auth. is required. 2. the consumer url 3. the destination service url. 4. Issuer Then, encrypting this message with the SP's(service provider) private key and then with the IDP's Public key. Then I am sending this request. The IDP on receiving the request, first decrypts with his own private key and then with SP's public key. In the saml response: 1. destination url 2. Issuer 3. Status of the response Is this good enough? Please give your suggestions?

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  • Listening socket

    - by hoodoos
    I got a strange problem, I never actually expirienced this before, here is the code of the server (client is firefox in this case), the way I create it: _Socket = new Socket( AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp ); _Socket.Bind( new IPEndPoint( Settings.IP, Settings.Port ) ); _Socket.Listen( 1000 ); _Socket.Blocking = false; the way i accept connection: while( _IsWorking ) { if( listener.Socket.Poll( -1, SelectMode.SelectRead ) ) { Socket clientSocket = listener.Socket.Accept(); clientSocket.Blocking = false; clientSocket.SetSocketOption( SocketOptionLevel.Tcp, SocketOptionName.NoDelay, true ); } } So I'm expecting it hang on listener.Socket.Poll till new connection comes, but after first one comes it hangs on poll forever. I tried to poll it constantly with smaller delay, let's say 10 microseconds, then it never goes in SelectMode.SelectRead. I guess it maybe somehow related on client's socket reuse? Maybe I don't shutdown client socket propertly and client(firefox) decides to use an old socket? I disconnect client socket this way: Context.Socket.Shutdown( SocketShutdown.Both ); // context is just a wrapper around socket Context.Socket.Close(); What may cause that problem?

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  • `enable_shared_from_this` has a non-virtual destructor

    - by Shtééf
    I have a pet project with which I experiment with new features of the upcoming C++0x standard. While I have experience with C, I'm fairly new to C++. To train myself into best practices, (besides reading a lot), I have enabled some strict compiler parameters (using GCC 4.4.1): -std=c++0x -Werror -Wall -Winline -Weffc++ -pedantic-errors This has worked fine for me. Until now, I have been able to resolve all obstacles. However, I have a need for enable_shared_from_this, and this is causing me problems. I get the following warning (error, in my case) when compiling my code (probably triggered by -Weffc++): base class ‘class std::enable_shared_from_this<Package>’ has a non-virtual destructor So basically, I'm a bit bugged by this implementation of enable_shared_from_this, because: A destructor of a class that is intended for subclassing should always be virtual, IMHO. The destructor is empty, why have it at all? I can't imagine anyone would want to delete their instance by reference to enable_shared_from_this. But I'm looking for ways to deal with this, so my question is really, is there a proper way to deal with this? And: am I correct in thinking that this destructor is bogus, or is there a real purpose to it?

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  • Meteor: how to update DOM via Javascript without a page refresh?

    - by strack
    UPDATE: It looks like this script may be the catalyst I'm looking for. Will test it and answer/close this question if so. I'm sure I'll find the answer to this eventually, but I'm putting it out there now, in case someone else knows it right off... I am using RaphaelJS to manipulate the DOM (adds a bunch of SVG tags to an identified DIV), and I want to re-render those specific DOM parts, if there's an update to the MongoDB collection. As an example: -Let's say that I have a collection called PiePieces. -When the page is first rendered/ called, let's pretend that the number of pieces in the collection is 4. -I programmatically add a pie piece using console: PiePieces.insert({...}) -I want the page to update like it would for a standard handlebars binding situation, but the problem is, the new entry needs to go through the Raphael script, which performs direct DOM manipulation. So, the logic would go something like this: MongoDB collection update event - Client function call to manipulate DOM - DOM modified/ page updated without a refresh. I've tried implementing this by reading values from the DOM itself, and I can get the updated DOM, but the entire page refreshes and/or I have to manually refresh the page, OR the DOM tree isn't completed yet, and so it's blank until I refresh. Can you point me in the right direction, maybe with a small code snippet/example? (if something similar already exists, just tell me where and I'll go digging) Thanks in advance! (I am LOVING Meteor so far...)

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  • .htaccess - alias all www-only requests to subdirectory

    - by CodeMoose
    Trying to install the wonderful Concrete5 CMS to use as my main site engine - the problem is it has about 15 different files and directories, and they clutter up my root. I'd really like to move it to a /_concrete/ subdirectory, and still maintain it in the domain root. htaccess has never been my strong suit - after a lot of research and learning, and a lot of error 500s, my frustration is overriding my pride and I'm posting here. Here's exactly what I'm trying to accomplish: Any requests that come through www.domain.com are forwarded to www.domain.com/_concrete/, except in the case of an existing file. The end-user URL shouldn't change - they will still see the site as www.domain.com, even though they're being served www.domain.com/_concrete/. Multiple subdomains exist on this site as sub-folders within the root - thus, only requests coming through www.domain.com should be redirected. Here's the closest I got with my htaccess, which produces an error 500: RewriteEngine On RewriteCond %{HTTP_HOST} ^(www\.)?domain\.com [NC] RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !^_concrete RewriteRule ^(.*)$ _concrete/$1 [L,QSA] This is the result of 4 hours of sweat and blood (mostly blood), so I have to be close. I'm hoping one of your fine minds can point out a stupid mistake and put this thing to rest swiftly. Thanks for your time! Addendum: I previously posted .htaccess - alias domain root to subfolder a while ago, which got me started. Please don't fall into the trap of thinking it's a duplicate.

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  • throwing exception from APCProc crashes program

    - by lazy_banana
    I started to do some research on how terminate a multithreaded application properly and I found those 2 post(first, second) about how to use QueueUserAPC to signal other threads to terminate. I thought I should give it a try, and the application keeps crashing when I throw the exception from the APCProc. Code: #include <stdio.h> #include <windows.h> class ExitException { public: char *desc; DWORD exit_code; ExitException(char *desc,int exit_code): desc(desc), exit_code(exit_code) {} }; //I use this class to check if objects are deconstructed upon termination class Test { public: char *s; Test(char *s): s(s) { printf("%s ctor\n",s); } ~Test() { printf("%s dctor\n",s); } }; DWORD CALLBACK ThreadProc(void *useless) { try { Test t("thread_test"); SleepEx(INFINITE,true); return 0; } catch (ExitException &e) { printf("Thread exits\n%s %lu",e.desc,e.exit_code); return e.exit_code; } } void CALLBACK exit_apc_proc(ULONG_PTR param) { puts("In APCProc"); ExitException e("Application exit signal!",1); throw e; return; } int main() { HANDLE thread=CreateThread(NULL,0,ThreadProc,NULL,0,NULL); Sleep(1000); QueueUserAPC(exit_apc_proc,thread,0); WaitForSingleObject(thread,INFINITE); puts("main: bye"); return 0; } My question is why does this happen? I use mingw for compilation and my OS is 64bit. Can this be the reason?I read that you shouldn't call QueueApcProc from a 32bit app for a thread which runs in a 64bit process or vice versa, but this shouldn't be the case.

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  • Immutability and shared references - how to reconcile?

    - by davetron5000
    Consider this simplified application domain: Criminal Investigative database Person is anyone involved in an investigation Report is a bit of info that is part of an investigation A Report references a primary Person (the subject of an investigation) A Report has accomplices who are secondarily related (and could certainly be primary in other investigations or reports These classes have ids that are used to store them in a database, since their info can change over time (e.g. we might find new aliases for a person, or add persons of interest to a report) If these are stored in some sort of database and I wish to use immutable objects, there seems to be an issue regarding state and referencing. Supposing that I change some meta-data about a Person. Since my Person objects immutable, I might have some code like: class Person( val id:UUID, val aliases:List[String], val reports:List[Report]) { def addAlias(name:String) = new Person(id,name :: aliases,reports) } So that my Person with a new alias becomes a new object, also immutable. If a Report refers to that person, but the alias was changed elsewhere in the system, my Report now refers to the "old" person, i.e. the person without the new alias. Similarly, I might have: class Report(val id:UUID, val content:String) { /** Adding more info to our report */ def updateContent(newContent:String) = new Report(id,newContent) } Since these objects don't know who refers to them, it's not clear to me how to let all the "referrers" know that there is a new object available representing the most recent state. This could be done by having all objects "refresh" from a central data store and all operations that create new, updated, objects store to the central data store, but this feels like a cheesy reimplementation of the underlying language's referencing. i.e. it would be more clear to just make these "secondary storable objects" mutable. So, if I add an alias to a Person, all referrers see the new value without doing anything. How is this dealt with when we want to avoid mutability, or is this a case where immutability is not helpful?

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  • Send Special Keys to Gtk.VteTerminal

    - by Ubersoldat
    Hi I have this OSS Project called Monocaffe connections manager which uses the Gtk.VteTerminal widget from PyGTK. A nice feature is that it allows the users to send commands to different servers' consoles (cluster mode) using a Gtk.TextView for the input. The way I send key strokes to each Gtk.VteTerminal is by using the feed_child method. For common keys there's no problem: I simply feed what the TextView receives to all the terminals, but when doing so with special keys I get into a little trouble. For "Return" I catch the event and feed the terminal a '\n'. For back-space is the same, catch the event and feed a '\b'. def cluster_backspace(self, widget): return self.cluster_send_key('\b') The problem comes with other keys like Tab, Arrows, Esc which I don't know how to feed as str to the terminal to recognize them. In the case of Esc is a real pain, because the users can edit the same file on different servers using vi, but cannot escape insert mode. Anyway, I'm not looking for a complete solution, just ideas since I've ran out of them. Thanks.

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  • I expect to see in the browswer "http://path/some_page.html" but instead it identifies with "http:/

    - by indiehacker
    I am developing with app engine SDK. I have a feeling this is much too basic a question so apologies ahead of time... A simple submit button doesnt work instead of just showing an alert box as expected it continues on afterwards and redirects me to the latest http-request, and I think this is because I dont understand how to tell the browser to recognize the proper URLs. Why does my browser say I am at the most recent http-request http://localhost:8080/putProjectInDB rather than the somepage.html that was actually served to the browser that I am currently looking at? How can I get the browser to recognize and show in its url spot the normal expected http://somepage.html ? Just in case, here are details of the specific problem which you might be able to ignore for answering the question: This hasnt been mattered for me until I just wanted to put into my .html a simple button that changes some stuff of the page without needing the server. The below code after displaying the alert box redirects me to the last server request http://localhost:8080/putProjectInDB instead of just staying in the same html page. in header: function MyFormCommands() { alert('Some Text'); } in body: <form onSubmit="MyFormCommands()" ><input type=submit ></form >

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  • How to validate DataReader is actually closed using FxCop custom rule?

    - by tanmay
    I have written couple of custom rules in for FxCop 1.36. I have written code to find weather an opened DataReader is closed or not. But it does not check which DataReader object is calling the Close() method so I can't be sure if all opened DataReader objects are closed!! 2nd: If I am a DataReader in an 'if/else' like if 1=2 dr = cmd.ExecuteReader(); else dr = cmd2.ExecuteReader(); end if In this case it will search for 2 DataReader objects to be closed. I am putting my code for more clarity. public override ProblemCollection Check(Member member) { Method method = member as Method; int countCatch =0; int countErrLog = 0; Instruction objInstr = null; if (method != null) { for (int i = 0; i < method.Instructions.Count; i++) { objInstr = method.Instructions[i]; if (objInstr.Value != null) { if (objInstr.Value.ToString() .Contains("System.Data.SqlClient.SqlDataReader")) { countCatch += 1; } if (countCatch>0) { if (objInstr.Value.ToString().Contains( "System.Data.SqlClient.SqlDataReader.Close")) { countErrLog += 1; } } } } } if (countErrLog!=countCatch) { Resolution resolu = GetResolution(new string[] { method.ToString() }); Problems.Add(new Problem(resolu)); } return Problems; }

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  • Efficient (basic) regular expression implementation for streaming data

    - by Brendan Dolan-Gavitt
    I'm looking for an implementation of regular expression matching that operates on a stream of data -- i.e., it has an API that allows a user to pass in one character at a time and report when a match is found on the stream of characters seen so far. Only very basic (classic) regular expressions are needed, so a DFA/NFA based implementation seems like it would be well-suited to the problem. Based on the fact that it's possible to do regular expression matching using a DFA/NFA in a single linear sweep, it seems like a streaming implementation should be possible. Requirements: The library should try to wait until the full string has been read before performing the match. The data I have really is streaming; there is no way to know how much data will arrive, it's not possible to seek forward or backward. Implementing specific stream matching for a couple special cases is not an option, as I don't know in advance what patterns a user might want to look for. For the curious, my use case is the following: I have a system which intercepts memory writes inside a full system emulator, and I would like to have a way to identify memory writes that match a regular expression (e.g., one could use this to find the point in the system where a URL is written to memory). I have found (links de-linkified because I don't have enough reputation): stackoverflow.com/questions/1962220/apply-a-regex-on-stream stackoverflow.com/questions/716927/applying-a-regular-expression-to-a-java-i-o-stream www.codeguru.com/csharp/csharp/cs_data/searching/article.php/c14689/Building-a-Regular-Expression-Stream-Search-with-the-NET-Framework.htm But all of these attempt to convert the stream to a string first and then use a stock regular expression library. Another thought I had was to modify the RE2 library, but according to the author it is architected around the assumption that the entire string is in memory at the same time. If nothing's available, then I can start down the unhappy path of reinventing this wheel to fit my own needs, but I'd really rather not if I can avoid it. Any help would be greatly appreciated!

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  • Loading specific files from arbitrary directories?

    - by Haydn V. Harach
    I want to load foo.txt. foo.txt might exist in the data/bar/ directory, or it might exist in the data/New Folder/ directory. There might be a different foo.txt in both of these directories, in which case I would want to either load one and ignore the other according to some order that I've sorted the directories by (perhaps manually, perhaps by date of creation), or else load them both and combine the results somehow. The latter (combining the results of both/all foo.txt files) is circumstantial and beyond the scope of this question, but something I want to be able to do in the future. I'm using SDL and boost::filesystem. I want to keep my list of dependencies as small as possible, and as cross-platform as possible. I'm guessing that my best bet would be to get a list of every directory (within the data/ folder), sort/filter this list, then when I go to load foo.txt, I search for it in each potential directory? This sounds like it would be very inefficient, if I have dozens of potential directories to search through every time. What's the best way to go about accomplishing this? Bonus: What if I want some of the directories to be archives? ie. considering both data/foo/ and data/bar.zip to both be valid, and pull foobar.txt from either one without caring.

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