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  • a class function with if(this==NULL) test got compiled?

    - by James
    I saw this code snippet during our lab and it actually compiles in MSVC2008 and G++. void LinkList< class T ::Insert(T n) { if (this == NULL) // some code here } As far as I know the this must not be null since you cannot call a class functions in c++ if it wasn't instantiated. Is this a valid code? if so what's the reason behind and where it can be useful?

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  • Double request from mod-rewrite

    - by Dave
    I've written a module that sets Apache environment variables to be used by mod-rewrite. It hooks into ap_hook_post_read_request() and that works fine, but if mod-rewrite matches a RewriteRule then it makes a second call to my request handler with the rewritten URL. This looks like a new request to me in that the environment variables are no longer set and therefore I have to execute my (expensive) code twice for each hit. What am I doing wrong, or is there a work around for this? Thanks

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  • How to keep current selection for jqGrid pulldown edit

    - by WildBill
    When editing cells in jqGrid, specifically using a select pull-down to edit a cell, how does one make the current selection the current choice for that cell? In my page I have a cell where edittype:'select' is set but when one clicks on that row the value for that cells automatically changes to the first entry that my AJAX call returns. Is there something within JQGrid that needs to be set or does the object I send to jqGrid have to be of a certain format to do so?

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  • javascript function document.location working incorrectly

    - by john
    When I change on proxy-server page from cnn.com (I add javascript, that call document.location), result of the document.location is some url of advertisement: http://ads.cnn.com/html.ng/site=cnn_international&cnn_intl_pagetype=mmst&cnn_intl_position=336x850_rgt&cnn_intl_rollup=asia&page.allowcompete=yes&params.styles=fs&tile=5656033441721&domId=894131 and not current url:http://edition.cnn.com/2010/WORLD/asiapcf/04/13/soccer.world.cup.pakistan/index.html?hpt=C1 Do you know, where can be problem?

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  • Monitoring UDP socket in glib(mm) eats up CPU time

    - by Gyorgy Szekely
    Hi, I have a GTKmm Windows application (built with MinGW) that receives UDP packets (no sending). The socket is native winsock and I use glibmm IOChannel to connect it to the application main loop. The socket is read with recvfrom. My problem is: this setup eats 25% percent CPU time on a 3GHz workstation. Can somebody tell me why? The application is idle in this case, and if I remove the UDP code, CPU usage drops down to almost zero. As the application has to perform some CPU intensive tasks, I could image better ways to spend that 25% Here are some code excerpts: (sorry for the printf's ;) ) /* bind */ void UDPInterface::bindToPort(unsigned short port) { struct sockaddr_in target; WSADATA wsaData; target.sin_family = AF_INET; target.sin_port = htons(port); target.sin_addr.s_addr = 0; if ( WSAStartup ( 0x0202, &wsaData ) ) { printf("WSAStartup failed!\n"); exit(0); // :) WSACleanup(); } sock = socket( AF_INET, SOCK_DGRAM, 0 ); if (sock == INVALID_SOCKET) { printf("invalid socket!\n"); exit(0); } if (bind(sock,(struct sockaddr*) &target, sizeof(struct sockaddr_in) ) == SOCKET_ERROR) { printf("failed to bind to port!\n"); exit(0); } printf("[UDPInterface::bindToPort] listening on port %i\n", port); } /* read */ bool UDPInterface::UDPEvent(Glib::IOCondition io_condition) { recvfrom(sock, (char*)buf, BUF_SIZE*4, 0, NULL, NULL); /* process packet... */ } /* glibmm connect */ Glib::RefPtr channel = Glib::IOChannel::create_from_win32_socket(udp.sock); Glib::signal_io().connect( sigc::mem_fun(udp, &UDPInterface::UDPEvent), channel, Glib::IO_IN ); I've read here in some other question, and also in glib docs (g_io_channel_win32_new_socket()) that the socket is put into nonblocking mode, and it's "a side-effect of the implementation and unavoidable". Does this explain the CPU effect, it's not clear to me? Whether or not I use glib to access the socket or call recvfrom() directly doesn't seem to make much difference, since CPU is used up before any packet arrives and the read handler gets invoked. Also glibmm docs state that it's ok to call recvfrom() even if the socket is polled (Glib::IOChannel::create_from_win32_socket()) I've tried compiling the program with -pg and created a per function cpu usage report with gprof. This wasn't usefull because the time is not spent in my program, but in some external glib/glibmm dll.

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  • Experiences with IKVM.NET

    - by Kottan
    Is IKVM.NET a good way to use Java Code or Java Libs in .NET applications ? Has anybody experiences with this tool ? Are there alternatives ? Are there possibilities to call Java functions / code in COM-based applications like Visual Basic 6 or Classical ASP ?

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  • Hi, how to verify if file exists on windows bat file?

    - by CuSS
    Hi, i have to create a bat file that does this: 1 - If "C:\myprogram\sync\data.handler" exists, exit; 2 - If "C:\myprogram\html\data.sql" doesn't exists, exit; 3 - In "C:\myprogram\sync\" delete all files and folders except ('test','test3' and 'test2') 4 - Copy "C:\myprogram\html\data.sql" to "C:\myprogram\sync\" 5 - Call other bat file w/ option "sync.bat myprogram.ini". If it was in bash enviroment it was easy for me, but i don't know how to test if a file or folder exists and if it is a file or folder :/ Thanks

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  • how can i access a value on a cell in tableview from different class?

    - by ahmet732
    I can hold the value of touched cell but I cannot pass that value to another class or call from that class. SearchTableViewController.m **deneme= [[NSMutableArray alloc]init]; deneme=[tableData objectAtIndex:indexPath.row]; NSLog(@"my row = %@", deneme); //I can hold one of the selected or touched rows in table HistoryTableViewController.m **SearchTableViewController *obj = (SearchTableViewController *)[self.tabBarController.viewControllers objectAtIndex:11]; NSLog(@"my 2nd row= %@", [obj deneme]); //It doesn't retrieve here

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  • Windows service porting to linux

    - by Sirish Kumar
    I am porting an application which runs as a background service in windows at startup, we are porting the application to linux(SUSE Enterprise server), I'am completely new to linux. Can somebody help me on how to proceed with this. Like Should I build the linux executable After builiding the binary, what changes should I make to linux startup files to run this executable How my service can register call back function to modify or change or send commands to my service while it is running

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  • Implementing Skip List in C++

    - by trikker
    [SOLVED] So I decided to try and create a sorted doubly linked skip list... I'm pretty sure I have a good grasp of how it works. When you insert x the program searches the base list for the appropriate place to put x (since it is sorted), (conceptually) flips a coin, and if the "coin" lands on a then that element is added to the list above it(or a new list is created with element in it), linked to the element below it, and the coin is flipped again, etc. If the "coin" lands on b at anytime then the insertion is over. You must also have a -infinite stored in every list as the starting point so that it isn't possible to insert a value that is less than the starting point (meaning that it could never be found.) To search for x, you start at the "top-left" (highest list lowest value) and "move right" to the next element. If the value is less than x than you continue to the next element, etc. until you have "gone too far" and the value is greater than x. In this case you go back to the last element and move down a level, continuing this chain until you either find x or x is never found. To delete x you simply search x and delete it every time it comes up in the lists. For now, I'm simply going to make a skip list that stores numbers. I don't think there is anything in the STL that can assist me, so I will need to create a class List that holds an integer value and has member functions, search, delete, and insert. The problem I'm having is dealing with links. I'm pretty sure I could create a class to handle the "horizontal" links with a pointer to the previous element and the element in front, but I'm not sure how to deal with the "vertical" links (point to corresponding element in other list?) If any of my logic is flawed please tell me, but my main questions are: How to deal with vertical links and whether my link idea is correct Now that I read my class List idea I'm thinking that a List should hold a vector of integers rather than a single integer. In fact I'm pretty positive, but would just like some validation. I'm assuming the coin flip would simply call int function where rand()%2 returns a value of 0 or 1 and if it's 0 then a the value "levels up" and if it's 0 then the insert is over. Is this incorrect? How to store a value similar to -infinite? Edit: I've started writing some code and am considering how to handle the List constructor....I'm guessing that on its construction, the "-infinite" value should be stored in the vectorname[0] element and I can just call insert on it after its creation to put the x in the appropriate place.

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  • How does the proc in the caches_action if clause get execute

    - by Sid
    I have a newbie kind of question which I cant get my head around. How does the Proc in the if condition of the caches_action get executed for the caches_action method. for example caches_action :show, :if=Proc.new{|x| something} what i dont get its how does this get called. I know i can execute a proc defined as proc= Proc.new by proc.call so i dont understand how this gets called. Second how do I pass conditions like if logged_in? I'd appreciate any help on this

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  • Javascript/jQuery HasLoaded or equivalent?

    - by maxp
    I know in jquery it is possible to call the javascript/jquery onload()/load() functions on, for example an image (<img>). However, if in jquery if i use .html(htmlString) to insert an image after the dom has loaded, how can i add a listener to handle the images onload event? Is there a property I can check to see various images and if they have loaded?

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  • Calling and writing jquery/javascript functions

    - by Ankur
    I think I have not got the syntax correct for writing a javascript function and calling it to assign its return value to a variable. My function is: getObjName(objId){ var objName =""; $.ajax( { type : "GET", url : "Object", dataType: 'json', data : "objId="+objId, success : function(data) { objName = data; } }); return objName; } I am trying to call it and assign it to a variable with: var objName = getObjName(objId); However Eclipse is telling me that "the function getObjName(any) is undefined"

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  • Agile Uploader error code 2101?

    - by adamwstl
    I'm trying to install Agile Uploader, but keep running into an error code 2101 (no other message besides that.) Any idea what error code "2101" means? Whenever I try to submit/upload (when I call agileUploaderSubmit()), nothing seems to happen and with Firebug mode on, all the log prints out is that code. I can't find anything that tells me what it means. Thanks

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  • [Ruby on Rails] Data Structure

    - by siulamvictor
    I am building a online form, with about 20 multiple choice checkboxes. I can get the nested data with this command. raise params.to_yaml I need to store these data and call them again later. I want to sort out which user chose which specific checkbox, i.e. who chose checkbox no.2? What's the best way to store these data in database?

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  • When is the onPreExecute called on an AsyncTask running parallely or concurrently?

    - by Debarshi Dutta
    I am using Android HoneyComb.I need to execute some tasks parallely and I am using AsyncTask's public final AsyncTask executeOnExecutor (Executor exec, Params... params) method.In each separate thread I am computing some values and I need to store then in an ArrayList.I must then sort all the values in the arrayList and then display it in the UI.Now my question is if one of the thread gets completed earlier than the other then will it immediately call the onPostExecute method or onPostExecute method will be called after all the background threads have been completed?MY program implementation depends on what occurs here.

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  • Should a g_object_new have a matching g_object_unref?

    - by legends2k
    I'm using libnotify to show desktop notifications in my application; notify_notification_new() returns a NotifyNotification*, which should be passed as the first param to further function calls of the notification library. There is no notify_notification_free() which frees the pointer it returns. I looked up the source of notify_notification_new() and internally it does a g_object_new(), gets a GObject* and returns it as a NotfiyNotification*, so when my application does the clean up, should I call a g_object_unref() on the pointer returned by notify_notification_new()?

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  • How do I set an ABPeoplePickerNavigationController's prompt?

    - by mverzilli
    This is the code I'm using to call the people picker, but the prompt label text doesn't change: ABPeoplePickerNavigationController *picker = [[ABPeoplePickerNavigationController alloc] init]; picker.peoplePickerDelegate = self; picker.displayedProperties = [NSArray arrayWithObjects: [NSNumber numberWithInt:kABPersonEmailProperty], nil]; picker.navigationItem.prompt = @"Choose a contact to..."; [self presentModalViewController:picker animated:YES];

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  • How would you implement this "WorkerChain" functionality in .NET?

    - by Dan Tao
    Sorry for the vague question title -- not sure how to encapsulate what I'm asking below succinctly. (If someone with editing privileges can think of a more descriptive title, feel free to change it.) The behavior I need is this. I am envisioning a worker class that accepts a single delegate task in its constructor (for simplicity, I would make it immutable -- no more tasks can be added after instantiation). I'll call this task T. The class should have a simple method, something like GetToWork, that will exhibit this behavior: If the worker is not currently running T, then it will start doing so right now. If the worker is currently running T, then once it is finished, it will start T again immediately. GetToWork can be called any number of times while the worker is running T; the simple rule is that, during any execution of T, if GetToWork was called at least once, T will run again upon completion (and then if GetToWork is called while T is running that time, it will repeat itself again, etc.). Now, this is pretty straightforward with a boolean switch. But this class needs to be thread-safe, by which I mean, steps 1 and 2 above need to comprise atomic operations (at least I think they do). There is an added layer of complexity. I have need of a "worker chain" class that will consist of many of these workers linked together. As soon as the first worker completes, it essentially calls GetToWork on the worker after it; meanwhile, if its own GetToWork has been called, it restarts itself as well. Logically calling GetToWork on the chain is essentially the same as calling GetToWork on the first worker in the chain (I would fully intend that the chain's workers not be publicly accessible). One way to imagine how this hypothetical "worker chain" would behave is by comparing it to a team in a relay race. Suppose there are four runners, W1 through W4, and let the chain be called C. If I call C.StartWork(), what should happen is this: If W1 is at his starting point (i.e., doing nothing), he will start running towards W2. If W1 is already running towards W2 (i.e., executing his task), then once he reaches W2, he will signal to W2 to get started, immediately return to his starting point and, since StartWork has been called, start running towards W2 again. When W1 reaches W2's starting point, he'll immediately return to his own starting point. If W2 is just sitting around, he'll start running immediately towards W3. If W2 is already off running towards W3, then W2 will simply go again once he's reached W3 and returned to his starting point. The above is probably a little convoluted and written out poorly. But hopefully you get the basic idea. Obviously, these workers will be running on their own threads. Also, I guess it's possible this functionality already exists somewhere? If that's the case, definitely let me know!

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  • ASP.NET LINQ to SQL SubmitChanges() doesn't update the database

    - by Alex
    In my 2nd ASP.NET MVC project I'm facing a very weird problem: when I call the SubmitChanges method of the DataContext class, nothing updates in the database. It's weird because everything works fine with my first project. I'm using a remote database created in Sql Server Management Studio, I tried doing some queries there and in Visual Studio 2010 (where I have the connection to the database), they all work. Where might the problem be hidden?

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