Search Results

Search found 33247 results on 1330 pages for 'anonymous access'.

Page 566/1330 | < Previous Page | 562 563 564 565 566 567 568 569 570 571 572 573  | Next Page >

• I've registered my oath about 5 times now, but... (twitteR package R)

  - by user2985989

  I'm attempting to mine twitter data in R, and am having trouble getting started. I created a twitter account, an app in twitter developers, changed the settings to read, write, and access, created my access token, and followed instructions to the letter in registering it: My code: > library(twitteR) > download.file(url="http://curl.haxx.se/ca/cacert.pem", + destfile="cacert.pem") > requestURL <- "https://api.twitter.com/oauth/request_token" > accessURL <- "https://api.twitter.com/oauth/access_token" > authURL <- "https://api.twitter.com/oauth/authorize" > consumerKey <-"my key" #took this part out for privacy's sake > consumerSecret <- "my secret" #this too > twitCred <- OAuthFactory$new(consumerKey=consumerKey, consumerSecret = consumerSecret, requestURL = requestURL, accessURL = accessURL, authURL = authURL) > twitCred$handshake(cainfo="cacert.pem") To enable the connection, please direct your web browser to: https://api.twitter.com/oauth/authorize?oauth_token=zxgHXJkYAB3wQ2IVAeyJjeyid7WK6EGPfouGmlx1c When complete, record the PIN given to you and provide it here: 0010819 > registerTwitterOAuth(twitCred) [1] TRUE > save(list="twitCred", file="twitteR_credentials") And yet, this: > s <- searchTwitter('#United', cainfo="cacert.pem") [1] "Unauthorized" Error in twInterfaceObj$doAPICall(cmd, params, "GET", ...) : Error: Unauthorized I'm about to have a temper tantrum. I'd be extremely grateful if someone could explain to me what is going wrong, or, better yet, how to fix it. Thank you.

  Read the article

• How to create a separate thread to do some operation periodically and update UI in WPF?I'm stack

  - by black sensei

  Hello Experts! I'm trying to do a periodic separated thread operation let's say check for internet connection or check for user's info via web service and update the user interface. i've tried with quartz.net to implement that.So i created an inner class for the window i need to update.That inner class does what is meant for but the problem is that i don't know how to access parent's(window class) members form the child(inner class). for example public partial class Window2 : Window { private int i; public Window2() { InitializeComponent(); } public string doMyOperation() { //code here return result; } public class Myclass :IJob { public void Execute(JobExecutionContext context) { string result = doMyOperation(); //Now here i could be able to call a label of name lblNotif //lblNotif.Content = result; } } } Well the whole idea works but i'm stacked at here i need to access a controls of Window2 Since i'm stacked i tried Spring.Net way of implementing Quartz hoping that i could use MethodInvokingJobDetailFactoryObject and rather have the Operation done on Window2 itself.But for some reason i'm having an exception Cannot resolve type [System.Windows.Window2,System.Windows];, could not load type from string value System.Windows.Window2,System.Windows and the wiring is done so <object name="UpdateLabelJob" type="System.Windows.Window2,System.Windows"/> What i'm i doing wrong here?Is that a way round? thanks for reading and for helping out

  Read the article

• Using multiple Qt (SQL) Models

  - by radix07

  I have a near real-time application that I am using Qt and an SQLite database to run. I am curious if it is safe to have two separate models access a database at once. I know 2 separate views can access a model just fine, but I can't find any document addressing this. I also realize that SQLite is thread safe for reading, so I don't see a real issue to doing this from the SQLite part of things... Basically I want to use a QSqlTableModel to do the real-time read and write in the background and at the same time use a QSqlQueryModel to give the user desired data. Since I may be doing lots of filtering in the background using the table model I can't use it as the main view as well. I have gotten this to work for the most part, but am not sure if this is the best way to do this. If the models act like multiple SQL queries I don't believe this should be an issue, but I would like to know from someone I bit more knowledgeable about this stuff since this is pretty new to me. Thanks

  Read the article

• How to use the Zend_Log instance that was created using the Zend_Application_Resource_Log in a model

  - by Alex

  Our Zend_Log is initialized by only adding the following lines to application.ini resources.log.stream.writerName = "Stream" resources.log.stream.writerParams.mode = "a" So Zend_Application_Resource_Log will create the instance for us. We are already able to access this instance in controllers via the following: public function getLog() { $bootstrap = $this->getInvokeArg('bootstrap'); //if (is_null($bootstrap)) return false; if (!$bootstrap->hasPluginResource('Log')) { return false; } $log = $bootstrap->getResource('Log'); return $log; } So far, so good. Now we want to use the same log instance in model classes, where we can not access the bootstrap. Our first idea was to register the very same Log instance in Zend_Registry to be able to use Zend_Registry::get('Zend_Log') everywhere we want: in our Bootstrap class: protected function _initLog() { if (!$this->hasPluginResource('Log')) { throw new Zend_Exception('Log not enabled'); } $log = $this->getResource('Log'); assert( $log != null); Zend_Registry::set('Zend_Log', $log); } Unfortunately this assertion fails == $log IS NULL --- but why?? It is clear that we could just initialize the Zend_Log manually during bootstrapping without using the automatism of Zend_Application_Resource_Log, so this kind of answers will not be accepted.

  Read the article

• [c++] accessing the hidden 'this' pointer

  - by Kyle

  I have a GUI architecture wherein elements fire events like so: guiManager->fireEvent(BUTTON_CLICKED, this); Every single event fired passes 'this' as the caller of the event. There is never a time I dont want to pass 'this', and further, no pointer except for 'this' should ever be passed. This brings me to a problem: How can I assert that fireEvent is never given a pointer other than 'this', and how can I simplify (and homogenize) calls to fireEvent to just: guiManager->fireEvent(BUTTON_CLICKED); At this point, I'm reminded of a fairly common compiler error when you write something like this: class A { public: void foo() {} }; class B { void oops() { const A* a = new A; a->foo(); } }; int main() { return 0; } Compiling this will give you ../src/sandbox.cpp: In member function ‘void B::oops()’: ../src/sandbox.cpp:7: error: passing ‘const A’ as ‘this’ argument of ‘void A::foo()’ discards qualifiers because member functions pass 'this' as a hidden parameter. "Aha!" I say. This (no pun intended) is exactly what I want. If I could somehow access the hidden 'this' pointer, it would solve both issues I mentioned earlier. The problem is, as far as I know you can't (can you?) and if you could, there would be outcries of "but it would break encapsulation!" Except I'm already passing 'this' every time, so what more could it break. So, is there a way to access the hidden 'this', and if not are there any idioms or alternative approaches that are more elegant than passing 'this' every time?

  Read the article

• "Permission denied" with Internet Explorer and jQuery

  - by rallex

  I try to do an AJAX call with jQuery and $.post in Internet Explorer, but all I get is an error saying "Permission denied". The problem is kinda weird since it occurs only when I access a page after I was on any other page. For instance I type the URL in the adress line and let IE load the page. Then I click on a button so the script should start loading JSON data. (The script providing the data lies on the same server and I access it with a relative URL, so using a different domain is not the problem here. Even tried to use a absolute URL with the same host part.) But when I refresh the page then and try it again it works! Same thing when I come to that page from another page. At first nothing works, but when I click "refresh" everything is fine. IE gives me the error message "Permission denied" while in every other browser I don't notice this behaviour. Since I have tried many things and still cannot imagine where the problem lies I'd like to ask you what you think the problem might be?

  Read the article

• How security of the systems might be improved using database procedures?

  - by Centurion

  The usage of Oracle PL/SQL procedures for controlling access to data often emphasized in PL/SQL books and other sources as being more secure approach. I'v seen several systems where all business logic related with data is performed through packages, procedures and functions, so application code becomes quite "dumb" and is only responsible for visualization part. I even heard some devs call such approaches and driving architects as database nazi :) because all logic code resides in database. I do know about DB procedure performance benefits, but now I'm interested in a "better security" when using thick client model. I assume such design mostly used when Oracle (and maybe MS SQL Server) databases are used. I do agree such approach improves security but only if there are not much users and every system user has a database account, so we might control and monitor data access through standard database user security. However, how such approach could increase the security for an average web system where thick clients are used: for example one database user with DML grants on all tables, and other users are handled using "users" and"user_rights" tables? We could use DB procedures, save usernames into context use that for filtering but vulnerability resides at the root - if the main database account is compromised than nothing will help. Of course in a real system we might consider at least several main users (for example frontend_db_user, backend_db_user).

  Read the article

• Do I need to using locking against integers in c++ threads

  - by Shane MacLaughlin

  The title says it all really. If I am accessing a single integer type (e.g. long, int, bool, etc...) in multiple threads, do I need to use a synchronisation mechanism such as a mutex to lock them. My understanding is that as atomic types, I don't need to lock access to a single thread, but I see a lot of code out there that does use locking. Profiling such code shows that there is a significant performance hit for using locks, so I'd rather not. So if the item I'm accessing corresponds to a bus width integer (e.g. 4 bytes on a 32 bit processor) do I need to lock access to it when it is being used across multiple threads? Put another way, if thread A is writing to integer variable X at the same time as thread B is reading from the same variable, is it possible that thread B could end up a few bytes of the previous value mixed in with a few bytes of the value being written? Is this architecture dependent, e.g. ok for 4 byte integers on 32 bit systems but unsafe on 8 byte integers on 64 bit systems? Edit: Just saw this related post which helps a fair bit.

  Read the article

• Sharepoint page menu items gone?

  - by Richard

  I'm running MOSS 2007 and have created a new site under an existing one using sitemanager.aspx. I've done this on two machines. on one of those everything works correctly, while on the other some of the menu items for pages in the site seem to be gone. Also on the faulty site I get "Access denied" when I click "Version history". The permissions on both sites should be the same. I attach a screenshot of how the menus differ from each other. The one to the right (the faulty one) is unfortunately not in English but the items appearing on it are "Open link in a new window", "Copy", "Edit page settings" and "Version history". "View properties" and some more items are missing! What could have caused this? Screenshot: I'm running MOSS 2007 and have created a new site under an existing one using sitemanager.aspx. I've done this on two machines. on one of those everything works correctly, while on the other some of the menu items for pages in the site seem to be gone. Also on the faulty site I get "Access denied" when I click "Version history". The permissions on both sites should be the same. I attach a screenshot of how the menus differ from each other. The one to the right (the faulty one) is unfortunately not in English but the items appearing on it are "Open link in a new window", "Copy", "Edit page settings" and "Version history". "View properties" and some more items are missing! What could have caused this? Screenshot: hxxp://i40.tinypic.com/302naxx.jpg

  Read the article

• How to ensure nginx serves a request from an external IP?

  - by Matt

  I have a strange situation, where my nginx setup stopped handling external requests. I'm pretty stuck. If I hit the domain without a subdomain, I properly get redirected, however, if I request the full url, that fails and doesn't log anything, anywhere. I am able to curl localhost on the server itself, however when I attempt to curl from an external machine, it fails with: curl: (7) couldn't connect to host I've also noticed that bots can get through, I've seen Google hit the log every now and then. My nginx.conf file: upstream mongrels { server 127.0.0.1:5000; } server { listen 80; server_name culini.com; rewrite ^/(.*) http://www.culini.com/$1 permanent; } # the server directive is nginx's virtual host directive. server { # port to listen on. Can also be set to an IP:PORT listen 80; # Set the max size for file uploads to 50Mb client_max_body_size 50M; # sets the domain[s] that this vhost server requests for server_name www.culini.com; # doc root root /var/www/culini/current/public; log_format app '$remote_addr - $remote_user [$time_local] ' '"$request" $status $body_bytes_sent "$http_referer" ' '"$http_user_agent" "$http_x_forwarded_for" [$upstream_addr $upstream_response_time $upstream_status]'; # vhost specific access log access_log /var/www/culini/current/log/nginx.access.log app; error_log /var/www/culini/current/log/nginx.error.log debug; location / { proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_set_header Host $http_host; proxy_redirect false; proxy_max_temp_file_size 0; proxy_intercept_errors on; proxy_ignore_client_abort on; if (-f $request_filename) { break; } if (!-f $request_filename) { proxy_pass http://mongrels; break; } } } Please, please, any help would be greatly appreciated.

  Read the article

• Thread-Safe lazy instantiating using MEF

  - by Xaqron

  // Member Variable private static readonly object _syncLock = new object(); // Now inside a static method foreach (var lazyObject in plugins) { if ((string)lazyObject.Metadata["key"] = "something") { lock (_syncLock) { // It seems the `IsValueCreated` is not up-to-date if (!lazyObject.IsValueCreated) lazyObject.value.DoSomething(); } return lazyObject.value; } } Here I need synchronized access per loop. There are many threads iterating this loop and based on the key they are looking for, a lazy instance is created and returned. lazyObject should not be created more that one time. Although Lazy class is for doing so and despite of the used lock, under high threading I have more than one instance created (I track this with a Interlocked.Increment on a volatile static int and log it somewhere). The problem is I don't have access to definition of Lazy and MEF defines how the Lazy class create objects. I should notice the CompositionContainer has a thread-safe option in constructor which is already used. My questions: 1) Why the lock doesn't work ? 2) Should I use an array of locks instead of one lock for performance improvement ?

  Read the article

• Error while setting UserAcces permission for WebForms?

  - by ksg

  I've created a class named BaseClass.cs and I've written a function in its constructor. Here's how it looks public class BasePage:Page { public BasePage() { setUserPermission(); } private void setUserPermission() { String strPathAndQuery = HttpContext.Current.Request.Url.PathAndQuery; string strulr = strPathAndQuery.Replace("/SGERP/", "../"); Session["Url"] = strulr; GEN_FORMS clsForm = new GEN_FORMS(); clsForm.Form_Logical_Name = Session["Url"].ToString(); clsForm.User_ID = Convert.ToInt32(Session["User_ID"]); DataSet dsPermission = clsForm.RETREIVE_BUTTON_PERMISSIONS(); if (dsPermission.Tables.Count > 0) { if (dsPermission.Tables[1].Rows.Count > 0) { Can_Add = Convert.ToBoolean(dsPermission.Tables[1].Rows[0]["Can_Add"].ToString()); Can_Delete = Convert.ToBoolean(dsPermission.Tables[1].Rows[0]["Can_Delete"].ToString()); Can_Edit = Convert.ToBoolean(dsPermission.Tables[1].Rows[0]["Can_Edit"].ToString()); Can_Print = Convert.ToBoolean(dsPermission.Tables[1].Rows[0]["Can_Print"].ToString()); Can_View = Convert.ToBoolean(dsPermission.Tables[1].Rows[0]["Can_Print"].ToString()); } } } } I've inherited this class on my webform so that when the page loads, the setUserPermission function is executed. My webpage looks like this public partial class Setting_CompanyDetails : BasePage My problem is that I cannot access Session["Url"] in my BasePage. I'm getting the following error Session state can only be used when enableSessionState is set to true, either in a configuration file or in the Page directive. Please also make sure that System.Web.SessionStateModule or a custom session state module is included in the <configuration>\<system.web>\<httpModules> section in the application configuration. How can I solve this issue? Is this the right way to set UserPermission access?

  Read the article

• Windows service: Listening on socket while running as LocalSystem

  - by Socob

  I'm writing a small server-like program in C for Windows (using MinGW/GCC, testing on Windows 7) which is eventually supposed to run as a service with the LocalSystem account. I am creating a socket, and using Windows Sockets bind(), listen() and accept() to listen for incoming connections. If I run the application from the command line (i.e. not as a service, but as a normal user), I have no problems connecting to it from external IPs. However, if I run the program as a service with the LocalSystem account, I can only connect to the service from my own PC, either with 127.0.0.1 or my local address, 192.168.1.80 (I'm behind a router in a small local network). Neither external IPs nor other PCs in the same local network, using my local address, can connect now, even though there were no problems without running as a service. Now, I've heard that networking is handled differently or even not accessible (?) when running as LocalSystem or LocalService or that services cannot access both the desktop and the network (note: my service is not interactive) at the same time due to security considerations. Essentially, I need to find out what's going wrong/how to listen for connections in a service. Is running as NetworkService the same as running as LocalSystem, but with network access? Surely there must be servers that can run as background services, so how do they do it?

  Read the article

• Passing additional data value to strongly typed partial views in ASP.NET MVC

  - by fearofawhackplanet

  I have an OrderForm domain class, which has property subclasses, something like: interface IOrderForm { int OrderId { get; } ICustomerDetails CustomerDetails { get; set; } IDeliveryDetails DeliveryDetails{ get; set; } IPaymentsDetails PaymentsDetails { get; set; } IOrderDetails OrderDetails { get; set; } } My "Details" view is strongly typed inheriting from IOrderForm. I then have a strongly type partial for rendering each section: <div id="CustomerDetails"> <% Html.RenderPartial("CustomerDetails", Model.CustomerDetails); %> </div> <div id="DeliveryDetails"> <% Html.RenderPartial("DeliveryDetails", Model.DeliveryDetails); %> </div> ... etc This works ok up to this point, but I'm trying to add some nice ajax bits for updating some parts of the order form, and I've realised that each of my partial views also needs access to the IOrderForm.OrderId. Whats the easiest way to give my partials access to this value?

  Read the article

• Writing my own implementation of stl-like Iterator in C++.

  - by Negai

  Good evening everybody, I'm currently trying to understand the intrinsics of iterators in various languages i.e. the way they are implemented. For example, there is the following class exposing the list interface. template<class T> class List { public: virtual void Insert( int beforeIndex, const T item ) throw( ListException ) =0 ; virtual void Append( const T item ) =0; virtual T Get( int position ) const throw( ListException ) =0; virtual int GetLength() const =0; virtual void Remove( int position ) throw( ListException ) =0; virtual ~List() =0 {}; }; According to GoF, the best way to implement an iterator that can support different kinds of traversal is to create the base Iterator class (friend of List) with protected methods that can access List's members. The concrete implementations of Iterator will handle the job in different ways and access List's private and protected data through the base interface. From here forth things are getting confusing. Say, I have class LinkedList and ArrayList, both derived from List, and there are also corresponding iterators, each of the classes returns. How can I implement LinkedListIterator? I'm absolutely out of ideas. And what kind of data can the base iterator class retrieve from the List (which is a mere interface, while the implementations of all the derived classes differ significantly) ? Sorry for so much clutter. Thanks.

  Read the article

• Is OpenID too complicated?

  - by John Leidegren

  I'm beginning to seriously doubt the OpenID community despite that fact that it works. I'm in the process of currently evaluating OpenID as an authentication service for 'this' site and while the promises are great, I just can't get it to work. And I'm really lost. I ask of the SO community to help me out here. Give me answers and show me examples so I can leverage this in the way it was meant to be. My scenario is very typical. I want to authenticate users through a specific Google Apps domain. If you have access to this Google Apps domain, then you have access to my web application. Where I get lost, is all the prerequisites and dependencies involved. What is XRD? What is Yadis? Why do I need XRD and Yadis? What do I need to do to deploy OpenID authentication on my website? Also, this is really important to me. When I login to SO, I use my Google Account. When I click the login button I'm presented with this confirmation page. Where I'm granting SO the right to use my Google Account credentials. Somehow, Google knows that it's "Stackoverflow.com" that's asking me if it's okay to login. And I wish to know what manner of control I have over this little text. I intend to deploy OpenID on several different domains but I would prefer if they would all work without having to be individually configured with special parameters, such as secret API keys and what not. However, I don't know for sure if this is a prerequisite of OpenID, that or the Federated Login API that Google provides.

  Read the article

• Automate Field Entry in outside site

  - by JClaspill

  I am attempting to automate the entry of data into form fields. The problem is that this data (user/pass) is not known by the user. I'm not expressly hiding it from them, but they also don't need to know it. This is used to automate logins on several of our outside partner websites, who do not want our agents knowing their passwords. Sadly, most of these sites do not have any APIs I can work with... so I have to get the user logged in. I tried using an iframe and javascript, but I ran into the issue of security permissions denying it access. And sadly, our clients do not have access to add our domain to their sites(they seem to be 3rd party). Requirements: - Display webpage - Automatically enter data into fields Would be nice: - Automate signin similar to form.submit() - Flash/AJAX support. These seem to give the VB app issues. Is there a way to do this via javascript/html, and if not, do you have any recommendations for C#/php/asp.net options? PS: I am not sure what this techinque is called, so google isn't helping me it seems. Please set me straight on the terminology of what I am actually trying to accomplish.

  Read the article

• Generating a zend form with dynamic data?

  - by meder

  I need to access my session and based on the session property I need to grab stuff from the database to use as options in my dropdown. $_SESSION is: [sess_name] => Array( [properties] => Array( 1=> Hotel A, 2=> Hotel B ), [selected] => 1 ) I need to grab Hotel A from selected, and then access all accounts under Hotel A from the database: id title hotel_id ------------------------------ 1 Hotel A Twitter Account 1 2 Hotel B Facebook Account 2 3 Hotel A Facebook Account 1 I need ids 1 and 3 because my hotel_id is 1 in the context of: $this->addElement( 'select', 'account', array( 'multioptions' => $NEED_IT_HERE )); Here's my query / session grabbing code: $cs = new Zend_Session_Namespace( SESS_NAME ); $model = new Model_DbTable_Social; $s = " SELECT social_accounts.* FROM social_accounts LEFT JOIN social_media_outlets ON social_media_outlets.id = social_accounts.property WHERE social_accounts.property=".(int)$cs->selectedclient; I have this code in my form page, but I need to move it into my model now.

  Read the article

• Best practice when removing entity regarding mappedBy collections?

  - by Daniel Bleisteiner

  I'm still kind of undecided which is the best practice to handle em.remove(entity) with this entity being in several collections mapped using mappedBy in JPA. Consider an entity like a Property that references three other entities: a Descriptor, a BusinessObject and a Level entity. The mapping is defined using @ManyToOne in the Property entity and using @OneToMany(mappedBy...) in the other three objects. That inverse mapping is defined because there are some situations where I need to access those collections. Whenever I remove a Property using em.remove(prop) this element is not automatically removed from managed entities of the other three types. If I don't care about that and the following page load (webapp) doesn't reload those entities the Property is still found and some decisions might be taken that are no longer true. The inverse mappings may become quite large and though I don't want to use something like descriptor.getProperties().remove(prop) because it will load all those properties that might have been lazy loaded until then. So my currently preferred way is to refresh the entity if it is managed: if (em.contains(descriptor)) em.refresh(descriptor) - which unloads a possibly loaded collection and triggers a reload upon the next access. Is there another feasible way to handle all those mappedBy collections of already loaded entites?

  Read the article

• Doesn't this defeat the whole purpose of having read-only properties?

  - by flockofcode

  I know how to use properties and I understand that they implicitly call underlying get and set accessors, depending on whether we are writing to or reading from a property. static void Main(string[] args) { A a = new A(); (a.b).i = 100; } class A { private B _b = new B(); public B b { get { return _b; } } } class B { public int i; } What code (a.b).i = 100; essentially does is that first property’s get accessor returns a reference to an object _b, and once we have this reference, we are able to access _b’s members and change their values. Thus, in our example, having read only property only prevents outside code from changing the value of a reference variable _b, but it doesn’t prevent outside code from accessing _b’s members. So it seems that property can only detect whether we are trying to read from or write to a variable ( in our case variable _b ) located on the stack, while it’s not able to detect whether we’re trying to also write to members of an object to which the variable on the stack ( assuming this variable is of reference type ) points to. a) But doesn’t that defeat the whole purpose of having read-only properties? Wouldn’t it be more effective if properties had the ability to also detect whether we’re trying to access members of an object returned by get accessor( assuming backing field is of a reference type )? thank you

  Read the article

• Hot to set class variable to be visible to its public static methods?

  - by RCola

  Why I can noy access my variable p in mull form iterate method? How to resolve a problem? Hot to set class variable to be visible to its public static methods? public class mull { public static void main(String[] args) throws InterruptedException { final JPanel p = createAndShowGUI(); Timer timer = new Timer(1000, new MyTimerActionListener()); timer.start(); try { Thread.sleep(10000); } catch (InterruptedException e) { } timer.stop(); public static void iterate(){ for (int i = 0; i < 55; i++){ // "p cannot be resolved" p.moveSquare(i*10, i*10); p.setParamsRing(i*5, i*7, 200, 200); // p.repaint(); } } } class MyPanel extends JPanel { .... } How to access variable set in another method (in this example main())? Why Eclipse forces me to use this ((MyPanel) p).setParamsRing(i*5, i*7, 200, 200); instead of this p.setParamsRing(i*5, i*7, 200, 200);?

  Read the article

• Are programming languages and methods ineffective? (assembler and C knowledge needed)

  - by b-gen-jack-o-neill

  Hi, for a long time, I am thinking and studying output of C language compiler in asemlber form, as well as CPU architecture. I know this may be silly to you, but it seems to me that something is very ineffective. Please, don´t be angry if I am wrong, and there is some reason I do not see for all these principles. I will be very glad if you tell me why is it designed this way. I actually trully believe I am wrong, I know the genius minds of people which get PCs together knew a reason to do so. What exactly, do you ask? I´ll tell you right away, I use C as a example: 1, Stack local scope memory allocation: So, typical local memory allocation uses stack. Just copy esp to ebp and than allocate all the memory via ebp. OK, I would understand this if you explicitly need allocate RAM by default stack values, but if I do understand it correctly, modern OS use paging as a translation layer between application and physical RAM, when adress you desire is further translated before reaching actuall RAM byte. So why don´t just say 0x00000000 is int a,0x00000004 is int b and so? And access them just by mov 0x00000000,#10? Becouse you wont actually access memory blocks 0x00000000 and 0x00000004 but those your OS set the paging tables to. Actually, since memory allocation by ebp and esp use indirect adressing, "my" way would be even faster. 2, Variable allocation duplicitly: When you run aaplication, Loader load its code into RAM. When you create variable, or string, compiler generates code that pushes these values on the top o stack when created in main. So there is actuall instruction for do so, and that actuall number in memory. So, there are 2 entries of the same value in RAM. One in fomr of instruction, second in form of actuall bytes in the RAM. But why? Why not to just when declaring variable count at which memory block it would be, than when used, just insert this memory location?

  Read the article

• File being used by another process. Reason, and solution?

  - by pstar

  The process cannot access the file 'abc.log' because it is being used by another process. Hi, I've seen this exception from my application occationaly but I am still trying to fix that, hope I will get some insight from stackoverflow. In my application I've have defined a WriteToLog function which will write to a log file. Also the mainForm of my application will launch a backgroundWorker do some job which also calls the WriteToLog. Maybe two threads access a file will cause a problem? But in my code I 've already do my best to write flush and close the text file (I think), and here is my code from WriteToLog: StreamWriter sw = null; string newText = ""; try { //populate the content for newText sw = File.AppendText(LOG_FILE); sw.Write(newText); sw.Flush(); sw.Close(); } catch (IOException ex) { MessageBox.Show("Failed to write to log!\n\t" + ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error); } finally { if (sw != null) { sw.Close(); } } I think as long as I flush and close the streamWriter, I should be able call the WriteToLog multi-times and in multi-threads isn't it? Or if I am wrong, could I simple make the file open shared, or there are other reason/solutions?

  Read the article

• Processor, OS : 32bit, 64 bit

  - by Sandbox

  I am new to programming and come from a non-CS background (no formal degree). I mostly program winforms using C#. I am confused about 32 bit and 64 bit.... I mean, have heard about 32 bit OS, 32 bit processor and based on which a program can have maximum memory. How it affects the speed of a program. There are lot more questions which keep coming to mind. I tried to go through some Computer Organization and Architecture books. But, either I am too dumb to understand what is written in there or the writers assume that the reader has some CS background. Can someone explain me these things in a plain simple English or point me to something which does that. EDIT: I have read things like In 32-bit mode, they can access up to 4GB memory; in 64-bit mode, they can access much much more....I want to know WHY to all such things. BOUNTY: Answers below are really good....esp one by Martin. But, I am looking at a thorough explanation, but in plain simple English.

  Read the article

• Virtual functions - base class pointer

  - by user980411

  I understood why a base class pointer is made to point to a derived class object. But, I fail to understand why we need to assign to it, a base class object, when it is a base class object by itself. Can anyone please explain that? #include <iostream> using namespace std; class base { public: virtual void vfunc() { cout << "This is base's vfunc().\n"; } }; class derived1 : public base { public: void vfunc() { cout << "This is derived1's vfunc().\n"; } }; int main() { base *p, b; derived1 d1; // point to base p = &b; p->vfunc(); // access base's vfunc() // point to derived1 p = &d1; p->vfunc(); // access derived1's vfunc() return 0; }

  Read the article

< Previous Page | 562 563 564 565 566 567 568 569 570 571 572 573  | Next Page >