Search Results

Search found 9067 results on 363 pages for 'big fizzy'.

Page 300/363 | < Previous Page | 296 297 298 299 300 301 302 303 304 305 306 307  | Next Page >

• How expensive is a context switch? Is it better to implement a manual task switch than to rely on OS

  - by Vilx-

  The title says it all. Imagine I have two (three, four, whatever) tasks that have to run in parallel. Now, the easy way to do this would be to create separate threads and forget about it. But on a plain old single-core CPU that would mean a lot of context switching - and we all know that context switching is big, bad, slow, and generally simply Evil. It should be avoided, right? On that note, if I'm writing the software from ground up anyway, I could go the extra mile and implement my own task-switching. Split each task in parts, save the state inbetween, and then switch among them within a single thread. Or, if I detect that there are multiple CPU cores, I could just give each task to a separate thread and all would be well. The second solution does have the advantage of adapting to the number of available CPU cores, but will the manual task-switch really be faster than the one in the OS core? Especially if I'm trying to make the whole thing generic with a TaskManager and an ITask, etc?

  Read the article

• Faster Insertion of Records into a Table with SQLAlchemy

  - by Kyle Brandt

  I am parsing a log and inserting it into either MySQL or SQLite using SQLAlchemy and Python. Right now I open a connection to the DB, and as I loop over each line, I insert it after it is parsed (This is just one big table right now, not very experienced with SQL). I then close the connection when the loop is done. The summarized code is: log_table = schema.Table('log_table', metadata, schema.Column('id', types.Integer, primary_key=True), schema.Column('time', types.DateTime), schema.Column('ip', types.String(length=15)) .... engine = create_engine(...) metadata.bind = engine connection = engine.connect() .... for line in file_to_parse: m = line_regex.match(line) if m: fields = m.groupdict() pythonified = pythoninfy_log(fields) #Turn them into ints, datatimes, etc if use_sql: ins = log_table.insert(values=pythonified) connection.execute(ins) parsed += 1 My two questions are: Is there a way to speed up the inserts within this basic framework? Maybe have a Queue of inserts and some insertion threads, some sort of bulk inserts, etc? When I used MySQL, for about ~1.2 million records the insert time was 15 minutes. With SQLite, the insert time was a little over an hour. Does that time difference between the db engines seem about right, or does it mean I am doing something very wrong?

  Read the article

• How to accommodate for the different screen resolution of iPhone 4?

  - by mystify

  This is a programming question! Read on before you vote to close! According to Apple, iPhone 4 has a new screen resolution: 3.5-inch (diagonal) widescreen Multi-Touch display 960-by-640-pixel resolution at 326 ppi This little detail affects our apps in a heavy way. Most of the demo apps on the net have one thing in common: They position views in the believe that the screen has a fixed size of 320 x 480 pixels. So what most -if not all- developers do is: They designed everything in such a way, that a touchable area is -for example- 50 x 50 pixels big. Just enough to tap it. Things have been positioned relative to the upper left, to reach a specific position on screen - let's say the center, or somewhere at the bottom. Edit: It seems Apple has integrated an switch that allows to tell if an app is highRes or not. Nice. When we develop high-resolution apps, probably they won't work on older devices. And if they did, they would suffer a lot from 4-times the size of any image, having to scale them down in memory. This is community wiki. Just add anything that you think is relevant to this huge problem (constant screen res was one of the main reasons why I didn't go for Android!!).

  Read the article

• How can I keep the the logic to translate a ViewModel's values to a Where clause to apply to a linq query out of My Controller?

  - by Mr. Manager

  This same problem keeps cropping up. I have a viewModel that doesn't have any persistent backing. It is just a ViewModel to generate a search input form. I want to build a large where clause from the values the user entered. If the Action Accepts as a parameter SearchViewModel How do I do this without passing my viewModel to my service layer? Service shouldn't know about ViewModels right? Oh and if I serialize it, then it would be a big string and the key/values would be strongly typed. SearchViewModel this is just a snippet. [Display(Name="Address")] public string AddressKeywords { get; set; } /// <summary> /// Gets or sets the census. /// </summary> public string Census { get; set; } /// <summary> /// Gets or sets the lot block sub. /// </summary> public string LotBlockSub { get; set; } /// <summary> /// Gets or sets the owner keywords. /// </summary> [Display(Name="Owner")] public string OwnerKeywords { get; set; } In my controller action I was thinking of something like this. but I would think all this logic doesn't belong in my Controller. ActionResult GetSearchResults(SearchViewModel model){ var query = service.GetAllParcels(); if(model.Census != null){ query = query.Where(x=>x.Census == model.Census); } if (model.OwnerKeywords != null){ query = query.Where(x=>x.Owners == model.OwnerKeywords); } return View(query.ToList()); }

  Read the article

• best web database solution for scala for a high traffic site?

  - by egervari

  I am in charge of a rebuilding a website that gets about 250,000 visitors a day. We'd like to use Scala, but it does not work very well with Spring (in some minor cases) and Hibernate (there is a major and very annoying mismatch here if you want to use scala collections, which we do). The application itself is going to have about 40-50 tables. Other than Hibernate, is there an ORM that works awesome with Scala and is as performant and reliable as Hibernate? Does it also have the same capabilities, or are we going to run into leaky-abstractions if we don't use Hibernate? It would be a big risk for us to go with a framework that is newer and doesn't seem to have a lot of industry backing... and at the same time, Hibernate is a real pain to program against when using Scala. 1) The Java Collection <- Scala Collection is absolutely painful. There is a lot more boilerplate and crap to write. 2) The IDE doesn't import JavaConversions and java interfaces automatically... so we this needs to be done manually. Optimizing Imports in IDEA is going to destroy all the manual work. 3) There is also a performance cost to converting back and forth all the time in your domain objects and your dao classes. 4) Not to mention there needs to be a lot of casting, which produces code ugly as sin. I actually would love to write my own orm that is 100% tailored to scala, but obviously this is really outside of the scope of our project for now. So what is the best approach?

  Read the article

• Re-usable Obj-C classes with custom values: The right way

  - by Prairiedogg

  I'm trying to reuse a group of Obj-C clases between iPhone applications. The values that differ from app to app have been isolated and I'm trying to figure out the best way to apply these custom values to the classes on an app-to-app basis. Should I hold them in code? // I might have 10 customizable values for each class, that's a long signature! CarController *controller = [[CarController alloc] initWithFontName:@"Vroom" engine:@"Diesel" color:@"Red" number:11]; Should I store them in a big settings.plist? // Wasteful! I sometimes only use 2-3 of 50 settings! AllMyAppSettings *settings = [[AllMyAppSettings alloc] initFromDisk:@"settings.plist"]; MyCustomController *controller = [[MyCustomController alloc] initWithSettings:settings]; [settings release]; Should I have little, optional n_settings.plists for each class? // Sometimes I customize CarControllerSettings *carSettings = [[CarControllerSettings alloc] initFromDisk:@"car_settings.plist"]; CarController *controller = [[CarController alloc] initWithSettings:carSettings]; [carSettings release]; // Sometimes I don't, and CarController falls back to internally stored, reasonable defaults. CarController *controller = [[CarController alloc] initWithSettings:nil]; Or is there an OO solution that I'm not thinking of at all that would be better?

  Read the article

• Creating a network adapter - how hard is it?

  - by Vilx-

  I'm interested in building a little (commercial) device on top of Arduino. I want it to be able to interface with network. Network as in standard Ethernet, Cat5, RJ-45, etc. I know that there is an Ethernet Shield, but it costs even more than the Arduino itself, and it's pretty big. Naturally, I want my device to be as small and as cheap as possible. So I'm thinking about recreating an Ethernet module myself. The problem is - I haven't got any experience with Ethernet, nor do I have a good idea where to start looking. Thus I can't even say if my ideas are feasible. Ultimately I would like the device to have three ports - one for incoming signal, two for outgoing, so the device is essentially a little switch where it is plugged in itself as well. The switching capabilities need not be very fast - the volume of data will be low. 10Mbit is more than enough, can be even slower. If that is not possible, a single port for controlling the device itself will also do. Another possibility I'm considering is power line communications - sending information through power lines. That's another area I've no experience with. What hardware should I be looking at, and where can I find information about the necessary software? So - can anyone tell me if these ideas are feasible, and if yes - where should I start looking?

  Read the article

• controlling css with javascript works with mozilla but not with webkit based browsers

  - by GlassGhost

  Im having problems with applying css text variable in this javascript with webkit based browsers(Chrome & Safari) but it works in firefox 3.6 the function: function addGlobalStyle(sCss) { var head = document.getElementsByTagName('head')[0]; if( !head || head == null ) { return false; } var oStyle = document.createElement('style'); oStyle.type = 'text/css'; oStyle.rel = 'stylesheet'; oStyle.media = 'screen'; if ( is_gecko ) { // firefox WORKING !!! oStyle.href = 'FireFox.css'; oStyle.innerHTML = sCss; head.appendChild(oStyle); return true; } else {//nothing but firefox works oStyle.href = 'FireFox.css'; oStyle.innerHTML = sCss; head.appendChild(oStyle); return true; } } the use of the function: var NewSyleText = //The page styling "h1, h2, h3, h4, h5 {font-family: 'Verdana','Helvetica',sans-serif; font-style: normal; font-weight:normal;}" + "body, b {background: #fbfbfb; font-style: normal; font-family: 'Cochin','GaramondNo8','Garamond','Big Caslon','Georgia','Times',serif;font-size: 11pt;}" + "p { margin: 0pt; text-indent:2.5em; margin-top: 0.3em; }" + "a { text-decoration: none; color: Navy; background: none;}" + "a:visited { color: #500050;}" + "a:active { color: #faa700;}" + "a:hover { text-decoration: underline;}"; addGlobalStyle(NewSyleText);//inserts the page styling

  Read the article

• mysql_affected_rows() returns 0 for UPDATE statement even when an update actually happens

  - by Alex Moore

  I am trying to get the number of rows affected in a simple mysql update query. However, when I run this code below, PHP's mysql_affected_rows() always equals 0. No matter if foo=1 already (in which case the function should correctly return 0, since no rows were changed), or if foo currently equals some other integer (in which case the function should return 1). $updateQuery = "UPDATE myTable SET foo=1 WHERE bar=2"; mysql_query($updateQuery); if (mysql_affected_rows() > 0) { echo "affected!"; } else { echo "not affected"; // always prints not affected } The UPDATE statement itself works. The INT gets changed in my database. I have also double-checked that the database connection isn't being closed beforehand or anything funky. Keep in mind, mysql_affected_rows doesn't necessarily require you to pass a connection link identifier, though I've tried that too. Details on the function: mysql_affected_rows Any ideas? SOLUTION The part I didn't mention turned out to be the cause of my woes here. This PHP file was being called ten times consecutively in an AJAX call, though I was only looking at the value returned on the last call, ie. a big fat 0. My apologies!

  Read the article

• Fix N+1 query in "declarative_authorization" gem using gem "bullet"

  - by makaroni4

  Currently I am working on one big web application and to make it work faster I decided to refactor all N+1 queries (to decrease number of requests to database, http://rails-bestpractices.com/posts/29-fix-n-1-queries). So I installed gem "bullet" which doesn`t work with Rails 3.1.1 now (you can use fork from https://github.com/flyerhzm/bullet). When using declarative_authorization gem on each page I get same alerts: N+1 Query detected Role => [:permissions] Add to your finder: :include => [:permissions] N+1 Query detected Permission => [:permission_rules] Add to your finder: :include => [:permission_rules] CACHE (0.0ms) SELECT "roles".* FROM "roles" CACHE (0.0ms) SELECT "permissions".* FROM "permissions" WHERE "permissions"."role_id" = 1 CACHE (0.0ms) SELECT "permissions".* FROM "permissions" WHERE "permissions"."role_id" = 2 CACHE (0.0ms) SELECT "permissions".* FROM "permissions" WHERE "permissions"."role_id" = 3 CACHE (0.0ms) SELECT "permissions".* FROM "permissions" WHERE "permissions"."role_id" = 4 CACHE (0.0ms) SELECT "permissions".* FROM "permissions" WHERE "permissions"."role_id" = 6 CACHE (0.0ms) SELECT "permissions".* FROM "permissions" WHERE "permissions"."role_id" = 7 CACHE (0.0ms) SELECT "permissions".* FROM "permissions" WHERE "permissions"."role_id" = 8 CACHE (0.0ms) SELECT "permission_rules".* FROM "permission_rules" INNER JOIN "permission_rules_permissions" ON "permission_rules"."id" = "permission_rules_permissions"."permission_rule_id" WHERE "permission_rules_permissions"."permission_id" = 30 CACHE (0.0ms) SELECT "permission_rules".* FROM "permission_rules" INNER JOIN "permission_rules_permissions" ON "permission_rules"."id" = "permission_rules_permissions"."permission_rule_id" WHERE "permission_rules_permissions"."permission_id" = 31 ... Could you please help me with that and to make this queries faster?

  Read the article

• optimize output value using a class and public member

  - by wiso

  Suppose you have a function, and you call it a lot of times, every time the function return a big object. I've optimized the problem using a functor that return void, and store the returning value in a public member: #include <vector> const int N = 100; std::vector<double> fun(const std::vector<double> & v, const int n) { std::vector<double> output = v; output[n] *= output[n]; return output; } class F { public: F() : output(N) {}; std::vector<double> output; void operator()(const std::vector<double> & v, const int n) { output = v; output[n] *= n; } }; int main() { std::vector<double> start(N,10.); std::vector<double> end(N); double a; // first solution for (unsigned long int i = 0; i != 10000000; ++i) a = fun(start, 2)[3]; // second solution F f; for (unsigned long int i = 0; i != 10000000; ++i) { f(start, 2); a = f.output[3]; } } Yes, I can use inline or optimize in an other way this problem, but here I want to stress on this problem: with the functor I declare and construct the output variable output only one time, using the function I do that every time it is called. The second solution is two time faster than the first with g++ -O1 or g++ -O2. What do you think about it, is it an ugly optimization?

  Read the article

• Adapting the width of a Flexs 3 DataGridColumn to the content of its ItemRenderer ?

  - by phtrivier

  I have the following scenario : A Flex 3 DataGrid is sitting here At runtime, a column is added to this grid The column has a custom ItemRenderer The ItemRenderer inherits from HBox, and adds a few items to the HBOx dynamically My problem is that the width of the column doesn't change. As a consequence, my column stays small, and an ugly horizontal scrollbar is displayed in the line, instead of my content (which is completely unreadable). I would like the column to adapt its width to the content of the HBox in the ItemRenderer. I tried the following : Setting the 'percentWidth' of the ItemRenderer to '100' Invalidating the properties of the ItemRenderer after adding the items The only thing that has a "visible" effect it to force the width of the DataGridColumn. Obviously this is not acceptable since I'm dynamically adding components to the ItemRenderer, and I don't know how many or how big they are. Besides, when I am in the ItemRenderer, I have no access to the column itself (or do I ?) so I cannot force the size of the column from here. So is there a way around this ? Would AdvancedDataGrid help here (notwhistanding the fact that I cannot really use it for other reasons ...) Thanks PH

  Read the article

• Who needs singletons?

  - by sexyprout

  Imagine you access your MySQL database via PDO. You got some functions, and in these functions, you need to access the database. The first thing I thought of is global, like: $db = new PDO('mysql:host=127.0.0.1;dbname=toto', 'root', 'pwd'); function some_function() { global $db; $db->query('...'); } But it's considered as a bad practice. So, after a little search, I ended up with the Singleton pattern, which "applies to situations in which there needs to be a single instance of a class." According to the example of the manual, we should do this: class Database { private static $instance, $db; private function __construct(){} static function singleton() { if(!isset(self::$instance)) self::$instance = new __CLASS__; return self:$instance; } function get() { if(!isset(self::$db)) self::$db = new PDO('mysql:host=127.0.0.1;dbname=toto', 'user', 'pwd') return self::$db; } } function some_function() { $db = Database::singleton(); $db->get()->query('...'); } some_function(); But I just can't understand why you need that big class when you can do it merely with: class Database { private static $db; private function __construct(){} static function get() { if(!isset(self::$rand)) self::$db = new PDO('mysql:host=127.0.0.1;dbname=toto', 'user', 'pwd'); return self::$db; } } function some_function() { Database::get()->query('...'); } some_function(); This last one works perfectly and I don't need to worry about $db anymore. But maybe I'm forgetting something. So, who's wrong, who's right?

  Read the article

• Time complexity of a powerset generating function

  - by Lirik

  I'm trying to figure out the time complexity of a function that I wrote (it generates a power set for a given string): public static HashSet<string> GeneratePowerSet(string input) { HashSet<string> powerSet = new HashSet<string>(); if (string.IsNullOrEmpty(input)) return powerSet; int powSetSize = (int)Math.Pow(2.0, (double)input.Length); // Start at 1 to skip the empty string case for (int i = 1; i < powSetSize; i++) { string str = Convert.ToString(i, 2); string pset = str; for (int k = str.Length; k < input.Length; k++) { pset = "0" + pset; } string set = string.Empty; for (int j = 0; j < pset.Length; j++) { if (pset[j] == '1') { set = string.Concat(set, input[j].ToString()); } } powerSet.Add(set); } return powerSet; } So my attempt is this: let the size of the input string be n in the outer for loop, must iterate 2^n times (because the set size is 2^n). in the inner for loop, we must iterate 2*n times (at worst). 1. So Big-O would be O((2^n)*n) (since we drop the constant 2)... is that correct? And n*(2^n) is worse than n^2. if n = 4 then (4*(2^4)) = 64 (4^2) = 16 if n = 100 then (10*(2^10)) = 10240 (10^2) = 100 2. Is there a faster way to generate a power set, or is this about optimal?

  Read the article

• Stop Rewrite htaccess create random pages

  - by Vistol

  Recently I saw in my Webmaster tools that some random sites are linking to my site. Actually this is not an big issue. The issue comes when the pages that are linked are not real pages because of my httaccess file. This is the htaccess code that Im running: <pre> #Options +FollowSymLinks RewriteEngine on RewriteRule ^([^/\.]+)/?$ index.php?id=$1 [L] RewriteRule ^([0-9]+)/(.*)$ index.php?id=$1 [L] </pre> So the real URLs would be: mysite.com/folder/999/TITLE-OR-NAME But cecause I only check the 1st folder ($1) which is an I numberD, this htaccess file is allowing hackers linking to my site with random URLs like: mysite.com/folder/999/TITLE-OR-NAME1 mysite.com/folder/999/TITLE-OR-NAME2 mysite.com/folder/999/TITLE-OR-NAME3 mysite.com/folder/999/TITLE-OR-NAME4 mysite.com/folder/999/TITLE-OR-NAME5 The worst part comes when google tells me that I am duplicating content!!! Actually I am not duplicating content, the htaccess is duplicating it for me. And yes I know, Im a bad newbie programmer but Id really appreciate your help with this cause Im struggling to find a solution but it never. Thank you very much for all your support to this newbie :)

  Read the article

• I have data about deadlocks, but I can't understand why they occur

  - by Alex

  I am receiving a lot of deadlocks in my big web application. http://stackoverflow.com/questions/2941233/how-to-automatically-re-run-deadlocked-transaction-asp-net-mvc-sql-server Here I wanted to re-run deadlocked transactions, but I was told to get rid of the deadlocks - it's much better, than trying to catch the deadlocks. So I spent the whole day with SQL Profiler, setting the tracing keys etc. And this is what I got. There's a Users table. I have a very high usable page with the following query (it's not the only query, but it's the one that causes troubles) UPDATE Users SET views = views + 1 WHERE ID IN (SELECT AuthorID FROM Articles WHERE ArticleID = @ArticleID) And then there's the following query in ALL pages: User = DB.Users.SingleOrDefault(u => u.Password == password && u.Name == username); That's where I get User from cookies. Very often a deadlock occurs and this second Linq-to-SQL query is chosen as a victim, so it's not run, and users of my site see an error screen. I read a lot about deadlocks... And I don't understand why this is causing a deadlock. So obviously both of this queries run very often. At least once a second. Maybe even more often (300-400 users online). So they can be run at the same time very easily, but why does it cause a deadlock? Please help. Thank you

  Read the article

• Error monitoring/handling on webservers

  - by Industrial

  Hi everybody, We have a web server that we're about to launch a number of applications onto. They will all share database and memcached servers, but each application has it's own mySQL database and all memcached keys per application, is prefixed. Possible scenario: If a memcached server in our cluster goes boom, we want someone (operative system admin) to be automatically contacted by email/iphone push notification or in any other appropriate way. If we we're about to install 150 identical applications for our customers on our servers, and a memcached server dies - all 150 applications will individually find this out and contact our system admin, which most certainly is going to think about getting a new job where he or she isn't about to be woken up by getting 150 messages sent 4:15 in the morning. Possible solution: One idea is to set up an external server for error handling that gets a $_POST or cURL request sent, and handles storage of the error message depending on the seriousness of the actual error message. It would of course check upon receiving the error call, that if the same memcached server have already been reported as offline, there would be no need to spam the system admin with additional reminders... The questions: What's a good approach on how to handle errors? How does the big guys in the industry handle this? Thanks!

  Read the article

• How to save errors with the handleError in CakePHP 2.0?

  - by jags1988cr

  I have a big problem. Well, I'm trying to save the errors that happen in my web application. For example (only a example), if I make a division by zero, or happens an error in a query or something like that. So, I wanna catch that and save it in the database. But the handleError of CakePHP is static, so I can't use $this-MyModel-saveError(...). In my /app/Lib/AppError.php I have this: class AppError extends ErrorHandler { public $uses = array('Errors.Error'); public static function handleError($code, $description, $file = null, $line = null, $context = null) { //This print the error: echo "Code: ".$code." Description: ".$description." File: ".$file." Line: ".$line."<br>"; //I want to do this, (save to the database): $this->Error->saveError($code, $description, $file, $line); } } Without the $this-Error-saveError($code, $description, $file, $line); it works but I not only want to show the error. I think need an example or something like that. Please help me. Regards and thank you. Thanks... P.D.: Sorry for the English, I'm an english student...

  Read the article

• Building argv and argc

  - by Wylie Coyote SG.

  I'm a student programmer using Qt to build a GUI application for work. The primary purpose of this application is to open some of our old style files, allows better editing and then save the file in a new format and file extension. Recently I have been asked to allow this conversion to take place from a terminal. While I do know what argv and argc are along with what they represent I am unsure how to accomplish what they want. For instance how to handle relative paths vs. absolute... maybe how to get absolute from relative; perhaps none of that is even needed. My programming experience has been primarily with guis so this is a little new to me. Users would like the following to be ran from the terminal application -o /fileLocation /fileDestination template(to determine new format) I began to use for loops and if statements to begin accomplishing this when I relized that I might be taking the worng approach to all of this. I WOULD ALSO BE REALLY INTERESTED IF QT HAS SOMETHING FOR THIS! Here is what I have began coming up with: int main(int argc, char *argv[]) { if(argc > 1) { for(int i = 0; i < argc; i++) { if(argv[i] == "-c") { QString fileName = QString::fromStdString(argv[i+1]); QString fileDestination = QString::fromStdString(argv[i+2]); QString templateName = QString::fromStdString(argv[i+3]); QFile fileToConvert(fileName); if(fileToConvert.open(QFile::ReadOnly)) { //do stuff Thanks for reading my post and a big thanks for any contributions you make to helping me overcome this issue.

  Read the article

• Ajax request not receiving xml from Django

  - by amougeot

  I have a Django server which handles requests to a URL which will return some HTML for use in an image gallery. I can navigate to the URL and the browser will display the HTML that is returned, but I can't get that same HTML by doing an AJAX call (using jQuery) to the same URL. This is the view that generates the response: def gallery_images(request, gallery_name): return render_to_response('galleryimages.html', {'images': get_images_of_gallery(gallery_name)}, mimetype='text/xml') This is the 'galleryimages.html' template: {% for image in images %} <div id="{{image.name}}big"> <div class="actualImage" style="background-image:url({{image.image.name}});"> <h1>{{image.caption|safe}}</h1> </div> </div> {% endfor %} This is the jQuery call I am making: $("#allImages").load("http://localhost:8000/galleryimages/Web"); However, this loads nothing into my #allImages div. I've used firebug and ran jQuery's Ajax method .get("http://localhost:8000/galleryimages/Web") and firebug says that the response text is completely empty. When I check my Django server log, this is the entry I see for when I navigate to the URL manually, through my browser: [16/Jan/2010 17:34:10] "GET /galleryimages/Web HTTP/1.1" 200 215 This is the entry in the server log for when I make the AJAX call: [16/Jan/2010 17:36:19] "OPTIONS /galleryimages/Web HTTP/1.1" 200 215 Why does the AJAX request not get the xml that my Django page is serving?

  Read the article

• Strange results while measuring delta time on Linux

  - by pachanga

  Folks, could you please explain why I'm getting very strange results from time to time using the the following code: #include <unistd.h> #include <sys/time.h> #include <time.h> #include <stdio.h> int main() { struct timeval start, end; long mtime, seconds, useconds; while(1) { gettimeofday(&start, NULL); usleep(2000); gettimeofday(&end, NULL); seconds = end.tv_sec - start.tv_sec; useconds = end.tv_usec - start.tv_usec; mtime = ((seconds) * 1000 + useconds/1000.0) + 0.5; if(mtime > 10) printf("WTF: %ld\n", mtime); } return 0; } (You can compile and run it with: gcc test.c -o out -lrt && ./out) What I'm experiencing is sporadic big values of mtime variable almost every second or even more often, e.g: $ gcc test.c -o out -lrt && ./out WTF: 14 WTF: 11 WTF: 11 WTF: 11 WTF: 14 WTF: 13 WTF: 13 WTF: 11 WTF: 16 How can this be possible? Is it OS to blame? Does it do too much context switching? But my box is idle( load average: 0.02, 0.02, 0.3). Here is my Linux kernel version: $ uname -a Linux kurluka 2.6.31-21-generic #59-Ubuntu SMP Wed Mar 24 07:28:56 UTC 2010 i686 GNU/Linux

  Read the article

• What's best choice career-wise, to know a little about a lot or a lot about a little?

  - by nimo

  I work as a developer at a rather small company and we are providing a web application that is used by a big base of customers. Because we are so small everyone have to be able to do a lot of different tasks. It ranges from advanced support, developing the product (programming: c/c++, c#, php, sql, javascript, html, css), handle network configuration and network related issues and even sometimes go on sales meetings with potential customers. My concern is that I don't really specialize in any specific area. I know and learn little about a lot. I have graduated from school two years ago and this is my first real employment and when I look at other positions out there they always require so and so many years of experience in a specific area (for example 5 years of C#). For me to get that kind of specialized experience will be really hard at my current job. My question for you is what is, in your opinion, best choice career-wise, to know a little about a lot or a lot about a little? What path did you take? pros and cons that comes with that choice.

  Read the article

• In Java, is there a gain in using interfaces for complex models?

  - by Gnoupi

  The title is hardly understandable, but I'm not sure how to summarize that another way. Any edit to clarify is welcome. I have been told, and recommended to use interfaces to improve performances, even in a case which doesn't especially call for the regular "interface" role. In this case, the objects are big models (in a MVC meaning), with many methods and fields. The "good use" that has been recommended to me is to create an interface, with its unique implementation. There won't be any other class implementing this interface, for sure. I have been told that this is better to do so, because it "exposes less" (or something close) to the other classes which will use methods from this class, as these objects are referring to the object from its interface (all public method from the implementation being reproduced in the interface). This seems quite strange to me, as it seems like a C++ use to me (with header files). There I see the point, but in Java? Is there really a point in making an interface for such unique implementation? I would really appreciate some clarifications on the topic, so I could justify not following such kind of behavior, and the hassle it creates from duplicating all declarations.

  Read the article

• Cross-Origin Resource Sharing (CORS) - am I missing something here?

  - by David Semeria

  I was reading about CORS (https://developer.mozilla.org/en/HTTP_access_control) and I think the implementation is both simple and effective. However, unless I'm missing something, I think there's a big part missing from the spec. As I understand, it's the foreign site that decides, based on the origin of the request (and optionally including credentials), whether to allow access to its resources. This is fine. But what if malicious code on the page wants to POST a user's sensitive information to a foreign site? The foreign site is obviously going to authenticate the request. Hence, again if I'm not missing something, CORS actually makes it easier to steal sensitive information. I think it would have made much more sense if the original site could also supply an immutable list of servers its page is allowed to access. So the expanded sequence would be: 1) Supply a page with list of acceptable CORS servers (abc.com, xyz.com, etc) 2) Page wants to make an XHR request to abc.com - the browser allows this because it's in the allowed list and authentication proceeds as normal 3) Page wants to make an XHR request to malicious.com - request rejected locally (ie by the browser) because the server is not in the list. I know that malicious code could still use JSONP to do its dirty work, but I would have thought that a complete implementation of CORS would imply the closing of the script tag multi-site loophole. I also checked out the official CORS spec (http://www.w3.org/TR/cors) and could not find any mention of this issue.

  Read the article

• Schema for storing "binary" values, such as Male/Female, in a database

  - by latentflip

  Intro I am trying to decide how best to set up my database schema for a (Rails) model. I have a model related to money which indicates whether the value is an income (positive cash value) or an expense (negative cash value). I would like separate column(s) to indicate whether it is an income or an expense, rather than relying on whether the value stored is positive or negative. Question: How would you store these values, and why? Have a single column, say Income, and store 1 if it's an income, 0 if it's an expense, null if not known. Have two columns, Income and Expense, setting their values to 1 or 0 as appropriate. Something else? I figure the question is similar to storing a person's gender in a database (ignoring aliens/transgender/etc) hence my title. My thoughts so far Lookup might be easier with a single column, but there is a risk of mistaking 0 (false, expense) for null (unknown). Having seperate columns might be more difficult to maintain (what happens if we end up with a 1 in both columns? Maybe it's not that big a deal which way I go, but it would be great to have any concerns/thoughts raised before I get too far down the line and have to change my code-base because I missed something that should have been obvious! Thanks, Philip

  Read the article

< Previous Page | 296 297 298 299 300 301 302 303 304 305 306 307  | Next Page >