Search Results

Search found 22900 results on 916 pages for 'pascal case'.

Page 694/916 | < Previous Page | 690 691 692 693 694 695 696 697 698 699 700 701  | Next Page >

• String parsing help

  - by Click Upvote

  I have a string like the following: $string = " <paragraph>apples are red...</paragraph> <paragraph>john is a boy..</paragraph> <paragraph>this is dummy text......</paragraph> "; I would like to split this string into an array contanining the text found between the <paragraph></paragraph> tags. E.g something like this: $string = " <paragraph>apples are red...</paragraph> <paragraph>john is a boy..</paragraph> <paragraph>this is dummy text......</paragraph> "; $paragraphs = splitParagraphs($string); /* $paragraphs now contains: $paragraphs[0] = apples are red... $paragraphs[1] = john is a boy... $paragraphs[1] = this is dummy text... */ Any ideas? P.S it should be case insensitive, <paragraph>, <PARAGRAPH>, <Paragraph> should all be treated the same way.

  Read the article

• Android - need UI help/advice

  - by Donal Rafferty

  I have been working on Android for the past couple of months getting to know how various components work. One area I am completely lacking in knowledge is any sort of User Interface or graphical interface creation. As an excercise I have been asked to break down the HTC call screen into what components it contains and rebuild as close as possible. Here is a picture of the HTC call screen: From my understanding the above UI has a custom title bar where "Meteor" and the call time appears. Then the main image in the middle block along with a text view showing the called party, in this case "Voice Mail" and the number. The bottom is then a custom view maybe with three custom buttons used within it. Would I be correct in my above assumptions? So the parts I should look into start programming are a custom title bar and a custom view with three custom buttons to place at the bottom? What layout would be reccomended? I hope this question is seen as relative to Stack Overflow, if it is not then I will delete it. Thanks in advance

  Read the article

• iPhone SQLite Password Field Encryption

  - by Louis Russell

  Good Afternoon Guys and Girls, Hopefully this will be a quick and easy question. I am building an App that requires the user to input their login details for an online service that it links to. Multiple login details can be added and saved as the user may have several accounts that they would like to switch between. These details will be stored in an SQLite database and will contain their passwords. Now the questions are: 1: Should these passwords be encrypted in the database? My instinct would say yes but then I do not know how secure the device and system is and if this is necessary. 2: If they should be encrypted what should I use? I think encrypting the whole database file sounds a bit over-kill so should I just encrypt the password before saving it to the database? If this is case what could I use to achieve this? I have found reference to a "crypt(3)" but am having trouble finding much about it or how to implement it. I eagerly await your replies!

  Read the article

• Detecting duplicate values in a column of a Datatable while traversing through It

  - by Ashish Gupta

  I have a Datatable with Id(guid) and Name(string) columns. I traverse through the data table and run a validation criteria on the Name (say, It should contain only letters and numbers) and then adding the corresponding Id to a List If name passes the validation. Something like below:- List<Guid> validIds=new List<Guid>(); foreach(DataRow row in DataTable1.Rows) { if(IsValid(row["Name"]) { validIds.Add((Guid)row["Id"]); } } In addition to this validation I should also check If the name is not repeating in the whole datatable (even for the case-sensitiveness), If It is repeating, I should not add the corresponding Id in the List. Things I am thinking/have thought about:- 1) I can have another List, check for the "Name" in the same, If It exists, will add the corresponding Guild 2) I cannot use HashSet as that would treat "Test" and "test" as different strings and not duplicates. 3) Take the DataTable to another one where I have the disctict names (this I havent tried and the code might be incorrect, please correct me whereever possible) DataTable dataTableWithDistinctName = new DataTable(); dataTableWithDistinctName.CaseSensitive=true CopiedDataTable=DataTable1.DefaultView.ToTable(true,"Name"); I would loop through the original datatable and check the existence of the "Name" in the CopiedDataTable, If It exists, I wont add the Id to the List. Are there any better and optimum way to achieve the same? I need to always think of performance. Although there are many related questions in SO, I didnt find a problem similar to this. If you could point me to a question similar to this, It would be helpful. Thanks

  Read the article

• LogonUser -> CreateProcessAsUser from a system service

  - by Josh K

  I've read all the posts on Stack Overflow about CreateProcessAsUser and there are very few resolved questions, so I'm not holding my breath on this one. But it seems like I'm definitely missing something, so it might be easy. The target OS is Windows XP. I have a service running as "Local System" from which I want to create a process running as a different user. For that user, I have the username and password, so LogonUser goes fine and I get a token for the user (in this case, an Administrator account.) I then try to use that token to call CreateProcessAsUser, but it fails because that token does not come with SeAssignPrimaryTokenPrivilege - however, it does have SeIncreaseQuotaPrivilege. (I used GetTokenInformation to dump all the privileges associated with that token.) According to the MSDN page for CreateProcessAsUser, you need both privileges in order to call CreateProcessAsUser successfully. It also says you don't need the SeAssignPrimaryTokenPrivilege if the token you pass in to CreateProcessAsUser() is a "restricted version of the calling process' primary token", which I can create with CreateRestrictedToken(), but then it will be associated with the Local System user and not the target user I'm trying to run the process as. So how would I create a logon token that is both a restricted version of the calling process' primary token, AND is associated with a different user? Thanks! Note that there is no need for user interaction in here - it's all unattended - so there's no need to do stuff like grabbing WINSTA0, etc.

  Read the article

• Contributing to a Linux distribution

  - by Big Al

  I'm interested in contributing to a Linux distro, but regarding the various distro's developer communities, I'm having a bit of trouble figuring out which one I'd most like to join. What languages I know: C, C++, Lua, Python, and fairly familiar with Perl (though I wouldn't say I "know" it). In particular, I have very little experience with x86 assembly besides hacking stuff together for performance tweaks, though that will be partially rectified soon. What I'm looking for: A community that provides plenty of opportunities for developers to work on various aspects of the distribution. To be honest I'm most interested in reading and working on the kernel source (in which case the distro doesn't matter), but it's pretty daunting and I figure getting into the Linux community and working with experienced Linux developers might give me a better idea of how to jump into the guts(let me know if this is bogus, or if you have any advice regarding that). So... Which distro has the "best" developer community in terms of organization, people who are fun to work with, and opportunities to contribute? I've read various "Contributing to XXX" pages and mailing lists for distros like Ubuntu, OpenSuse, Fedora, etc. but I'd rather get a more personal testament from an actual developer.

  Read the article

• IoC and dataContext disposing in asp.net mvc 2 application

  - by zerkms

  I have the Global.asax like the code below: public class MvcApplication : System.Web.HttpApplication { public static void RegisterRoutes(RouteCollection routes) { // .... } protected void Application_Start() { AreaRegistration.RegisterAllAreas(); RegisterRoutes(RouteTable.Routes); ControllerBuilder.Current.SetControllerFactory(typeof(IOCControllerFactory)); } } public class IOCControllerFactory : DefaultControllerFactory { private readonly IKernel kernel; public IOCControllerFactory() { kernel = new StandardKernel(new NanocrmContainer()); } protected override IController GetControllerInstance(RequestContext requestContext, Type controllerType) { if (controllerType == null) return base.GetControllerInstance(requestContext, controllerType); var controller = kernel.TryGet(controllerType) as IController; if (controller == null) return base.GetControllerInstance(requestContext, controllerType); var standartController = controller as Controller; if (standartController is IIoCController) ((IIoCController)standartController).SetIoc(kernel); return standartController; } class NanocrmContainer : Ninject.Modules.NinjectModule { public override void Load() { // ... Bind<DomainModel.Entities.db>().ToSelf().InRequestScope().WithConstructorArgument("connection", "Data Source=lims;Initial Catalog=nanocrm;Persist Security Info=True;User ID=***;Password=***"); } } } In this case if somewhere it is the class, defined like: public class UserRepository : IUserRepository { private db dataContext; private IUserGroupRepository userGroupRepository; public UserRepository(db dataContext, IUserGroupRepository userGroupRepository) { this.dataContext = dataContext; this.userGroupRepository = userGroupRepository; } } then the dataContext instance is created (if no one was created in this request scope) by Ninject. So the trouble now is - where to invoke dataContext method .Dispose()?

  Read the article

• How can I improve my real-time behavior in multi-threaded app using pthreads and condition variables

  - by WilliamKF

  I have a multi-threaded application that is using pthreads. I have a mutex() lock and condition variables(). There are two threads, one thread is producing data for the second thread, a worker, which is trying to process the produced data in a real time fashion such that one chuck is processed as close to the elapsing of a fixed time period as possible. This works pretty well, however, occasionally when the producer thread releases the condition upon which the worker is waiting, a delay of up to almost a whole second is seen before the worker thread gets control and executes again. I know this because right before the producer releases the condition upon which the worker is waiting, it does a chuck of processing for the worker if it is time to process another chuck, then immediately upon receiving the condition in the worker thread, it also does a chuck of processing if it is time to process another chuck. In this later case, I am seeing that I am late processing the chuck many times. I'd like to eliminate this lost efficiency and do what I can to keep the chucks ticking away as close to possible to the desired frequency. Is there anything I can do to reduce the delay between the release condition from the producer and the detection that that condition is released such that the worker resumes processing? For example, would it help for the producer to call something to force itself to be context switched out? Bottom line is the worker has to wait each time it asks the producer to create work for itself so that the producer can muck with the worker's data structures before telling the worker it is ready to run in parallel again. This period of exclusive access by the producer is meant to be short, but during this period, I am also checking for real-time work to be done by the producer on behalf of the worker while the producer has exclusive access. Somehow my hand off back to running in parallel again results in significant delay occasionally that I would like to avoid. Please suggest how this might be best accomplished.

  Read the article

• Source Control - XCode - Visual Studio 2005/2008 / 2010

  - by Mick Walker

  My apologies if this has been asked before, I wasnt quite sure if this question should be asked on a programming forum, as it more relates to programming environment than a particular technology, so please accept my (double) appologies if I am posting this in the wrong place, my logic in this case was if it effects the code I write, then this is the place for it. At home, I do a lot of my development on a Mac Pro, I do development for the Mac, iPhone and Windows on this machine (Xcode & Visual Studio - (multiple versions installed in bootcamp, but generally I run it via Parallels)). When visiting a client, I have a similar setup, but on my MacBook Pro. What I want is a source control solution to install on the Mac Pro, that will support both XCode and multiple versions of visual studio, so that when I visit a client, I can simply grab the latest copy from source control via the MacBook Pro. Whilst visiting the client, he / she may suggest changes, and minor ones I would tend to make on site, so I need the ability to merge any modified code back into the trunk of the project / solution when I return home. At the moment, I am using no source control at all, and rely on simply coping folders and overwriting them when I return from a client- thats my 'merge'!!! I was wondering if anyone had any ideas of a source provider I could use, which would support both Windows and Mac development environments, and is cheap (free would be better).

  Read the article

• Suggestions for GUI of a multiledia messaging application in J2ME

  - by awaghad-ashish

  Hello everyone, We have developed a messaging application in j2me which adds text message, gets pictures from gallery and attaches them to the message etc and sends it over to a server after encryption, i.e. the client wants the messages to be encrypted. The app is ready but the only problem is that the GUI of the app looks miserable compared to the GUI of native messaging application on Nokia phones. Our GUI consists of a texfield for adding recipients i.e. the user clicks "options" to "add recipients" and is taken to a new form where contacts are shown. but the textfield is not in one line (like in case of native app). Also, we need the user to input the text message in a textField since we cannot have textbox inside a form (but the native app has a textbox as well as a textField ). Are there any ways to achieve such GUIs (one-line textfields, textbox like thing inside a form)? I hope you all understand what I mean, any kind of help will be appreciated. Thanks and regards, Ashish.

  Read the article

• java distributed cache for low latency, high availability

  - by Shahbaz

  I've never used distributed caches/DHTs like memcached, jboss cache, ehcache, etc. I'm wondering which, if any, is appropriate for my use. First, I'm not doing web applications (as most of these project seem to be geared towards web apps). I write servers (Order Management Systems actually) for financial trading firms. The servers themselves are not too complicated. They need to receive information (market data, orders, executions, etc.) rout them to their destination while possibly transforming some of these messages. I am looking at these products to solve the following problems: * Safe repository of the state of the server. I'd rather build the logic of my application as a bunch of transformers (similar to Apache Camel) and store the state in a 'safe' place * This repository should be distributed: in case one of these data stores crashes, one or two more should be up and I should be able to switch to them seamlessly * This repository should be fast. Single digits milliseconds count here, in other words, systems which consume/process this data are automated systems, not humans clicking on links. This system needs to have high-throughput and low latency. By sending my data outside the process, I am necessarily slowing performance, but I am trying to balance absolute raw speed and absolute protection of data. * This repository should be safe. Similar to the point about several on-line backups, this system needs to write data to disk (potentially more than one disk). I'd really like to stop writing my own 'transaction servers.' Am I correct to be looking into projects such as jboss cache, ehcache, etc.? Thanks

  Read the article

• How can I effectively test against the Windows API?

  - by Billy ONeal

  I'm still having issues justifying TDD to myself. As I have mentioned in other questions, 90% of the code I write does absolutely nothing but Call some Windows API functions and Print out the data returned from said functions. The time spent coming up with the fake data that the code needs to process under TDD is incredible -- I literally spend 5 times as much time coming up with the example data as I would spend just writing application code. Part of this problem is that often I'm programming against APIs with which I have little experience, which forces me to write small applications that show me how the real API behaves so that I can write effective fakes/mocks on top of that API. Writing implementation first is the opposite of TDD, but in this case it is unavoidable: I do not know how the real API behaves, so how on earth am I going to be able to create a fake implementation of the API without playing with it? I have read several books on the subject, including Kent Beck's Test Driven Development, By Example, and Michael Feathers' Working Effectively with Legacy Code, which seem to be gospel for TDD fanatics. Feathers' book comes close in the way it describes breaking out dependencies, but even then, the examples provided have one thing in common: The program under test obtains input from other parts of the program under test. My programs do not follow that pattern. Instead, the only input to the program itself is the system upon which it runs. How can one effectively employ TDD on such a project?

  Read the article

• How to temporarily replace one primitive type with another when compiling to different targets in c#

  - by Keith

  How to easily/quickly replace float's for doubles (for example) for compiling to two different targets using these two particular choices of primitive types? Discussion: I have a large amount of c# code under development that I need to compile to alternatively use float, double or decimals depending on the use case of the target assembly. Using something like “class MYNumber : Double” so that it is only necessary to change one line of code does not work as Double is sealed, and obviously there is no #define in C#. Peppering the code with #if #else statements is also not an option, there is just too much supporting Math operators/related code using these particular primitive types. I am at a loss on how to do this apparently simple task, thanks! Edit: Just a quick comment in relation to boxing mentioned in Kyles reply: Unfortunately I need to avoid boxing, mainly since float's are being chosen when maximum speed is required, and decimals when maximum accuracy is the priority (and taking the 20x+ performance hit is acceptable). Boxing would probably rules out decimals as a valid choice and defeat the purpose somewhat. Edit2: For reference, those suggesting generics as a possible answer to this question note that there are many issues which count generics out (at least for our needs). For an overview and further references see Using generics for calculations

  Read the article

• Text editor capable of viewing invisibles?

  - by Timo

  A recent problem* left me wondering whether there is a text editor out there that lets you see every single character of the file, even if they are invisible? Specifically, I'm not looking for hex editing capabilities, I am interested in a text editor that'll show me all of the invisible characters (not just the common whitespace / line break characters). The BOM marker is just one example, others are e.g. mathematical invisibles or possibly unsupported characters. I'm not looking for a text editor that simply supports a large variety of text encoding / translations between encodings. All text editors I've come across treat the invisible characters correctly i.e. leave them invisible (or simply get removed in the translation as in the case of the BOM marker). I'm asking this mostly out of academic interests, so I'm not particular about any specific OS. I can easily test Linux and OSX solutions, but if you recommend a Windows editor, I would appreciate if you include descriptions of how the editor handles invisibles other than whitespace / line breaks. *The incident that lead me to this question: I wrote a perl script using TextWrangler and managed to change the encoding to UTF8 BOM, which inserts te BOM marker at the start of the file. Perl (or rather the operating system) promptly misses the #! and mayhem ensues. It then took me the better part of an afternoon to figure this out since most text editors do not show the BOM marker even with various "show invisibles" options turned on. Now I've learned my lesson and will use less immediately :-).

  Read the article

• Graph colouring algorithm: typical scheduling problem

  - by newba

  Hi, I'm training code problems like UvA and I have this one in which I have to, given a set of n exams and k students enrolled in the exams, find whether it is possible to schedule all exams in two time slots. Input Several test cases. Each one starts with a line containing 1 < n < 200 of different examinations to be scheduled. The 2nd line has the number of cases k in which there exist at least 1 student enrolled in 2 examinations. Then, k lines will follow, each containing 2 numbers that specify the pair of examinations for each case above. (An input with n = 0 will means end of the input and is not to be processed). Output: You have to decide whether the examination plan is possible or not for 2 time slots. Example: Input: 3 3 0 1 1 2 2 0 9 8 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 Ouput: NOT POSSIBLE. POSSIBLE. I think the general approach is graph colouring, but I'm really a newb and I may confess that I had some trouble understanding the problem. Anyway, I'm trying to do it and then submit it. Could someone please help me doing some code for this problem? I will have to handle and understand this algo now in order to use it later, over and over. I prefer C or C++, but if you want, Java is fine to me ;) Thanks in advance

  Read the article

• Designing a fluid Javascript interface to hide callback asynchrony

  - by Anurag

  How would I design an API to hide the asynchronous nature of AJAX and HTTP requests, or basically delay it to provide a fluid interface. To show an example from Twitter's new Anywhere API: // get @ded's first 20 statuses, filter only the tweets that // mention photography, and render each into an HTML element T.User.find('ded').timeline().first(20).filter(filterer).each(function(status) { $('div#tweets').append('<p>' + status.text + '</p>'); }); function filterer(status) { return status.text.match(/photography/); } vs this (asynchronous nature of each call is clearly visible) T.User.find('ded', function(user) { user.timeline(function(statuses) { statuses.first(20).filter(filterer).each(function(status) { $('div#tweets').append('<p>' + status.text + '</p>'); }); }); }); It finds the user, gets their tweet timeline, filters only the first 20 tweets, applies a custom filter, and ultimately uses the callback function to process each tweet. I am guessing that a well designed API like this should work like a query builder (think ORMs) where each function call builds the query (HTTP URL in this case), until it hits a looping function such as each/map/etc., the HTTP call is made and the passed in function becomes the callback. An easy development route would be to make each AJAX call synchronous, but that's probably not the best solution. I am interested in figuring out a way to make it asynchronous, and still hide the asynchronous nature of AJAX.

  Read the article

• Setting nested object to null when combobox has empty value

  - by Javi

  Hello, I have a Class which models a User and another which models his country. Something like this: public class User{ private Country country; //other attributes and getter/setters } public class Country{ private Integer id; private String name; //other attributes and getter/setters } I have a Spring form where I have a combobox so the user can select his country or can select the undefined option to indicate he doen't want to provide this information. So I have something like this: <form:select path="country"> <form:option value="">-Select one-</form:option> <form:options items="${countries}" itemLabel="name" itemValue="id"/> </form:select> In my controller I get the autopopulated object with the user information and I want to have country set to null when the "-Select one-" option has been selected. So I have set a initBinder with a custom editor like this: @InitBinder protected void initBinder(WebDataBinder binder) throws ServletException { binder.registerCustomEditor(Country.class, "country", new CustomCountryEditor()); } and my editor do something like this: public class CustomCountryEditor(){ @Override public String getAsText() { //I return the Id of the country } @Override public void setAsText(String str) { //I search in the database for a country with id = new Integer(str) //and set country to that value //or I set country to null in case str == null } } When I submit the form it works because when I have country set to null when I have selected "-Select one-" option or the instance of the country selected. The problem is that when I load the form I have a method like the following one to load the user information. @ModelAttribute("user") public User getUser(){ //loads user from database } The object I get from getUser() has country set to a specific country (not a null value), but in the combobox is not selected any option. I've debugged the application and the CustomCountryEditor works good when setting and getting the text, thoughgetAsText method is called for every item in the list "countries" not only for the "country" field. Any idea? Is there a better way to set null the country object when I select no country option in the combobox? Thanks

  Read the article

• How would you answer Joel's sample programming questions?

  - by Khorkrak

  I recently interviewed a candidate for a new position here. I wish though that I'd read Joel's Guerrilla Guide to Interviewing prior to that interview - naturally I happened upon it the night afterwards :P http://www.joelonsoftware.com/articles/GuerrillaInterviewing3.html So I tried answering the easy questions myself - yeah I used the python interpreter to type stuff in and tested the results a bit - I didn't look up any solutions beforehand though and I also thought about how long it took me to come up with answers for each one and what I'd look for the next time I interview someone. I'd let them type stuff into the interpreter and see how did used python's introspection capabilities too to find out things like what's the re module's method for building a regex etc. Here are my answers - these are in python of course - what are yours in your favourite language? Do you see any issues with the answers I came up with - i.e. how could they be improved upon - what did I miss? Joel's example questions: Write a function that determines if a string starts with an upper-case letter A-Z. import re upper_regex = re.compile("^[A-Z]") def starts_with_upper(text): return upper_regex.match(text) is not None Write a function that determines the area of a circle given the radius. from math import pi def area(radius): return pi * radius**2 Add up all the values in an array. sum([1, 2, 3, 4, 5]) Harder Question: Write an example of a recursive function - so how about the classic factorial one: def factorial(num): if num > 1: return num * factorial(num - 1) else: return 1

  Read the article

• noSQL/SQL/RoR: Trying to build scalable ratings table for the game

  - by alexeypro

  I am trying to solve complex thing (as it looks to me). I have next entities: PLAYER (few of them, with names like "John", "Peter", etc.). Each has unique ID. For simplicity let's think it's their name. GAME (few of them, say named "Hide and Seek", "Jump and Run", etc.). Same - each has unique ID. For simplicity of the case let it be it's name for now. SCORE (it's numeric). So, how it works. Each PLAYER can play in multiple GAMES. He gets some SCORE in every GAME. I need to build rating table -- and not one! Table #1: most played GAMES Table #2: best PLAYERS in all games (say the total SCORE in every GAME). Table #3: best PLAYERS per GAME (by SCORE in particularly that GAME). I could be build something straight right away, but that will not work. I will have more than 10,000 players; and 15 games, which will grow for sure. Score can be as low as 0, and as high as 1,000,000 (not sure if higher is possible at this moment) for player in the game. So I really need some relative data. Any suggestions? I am planning to do it with SQL, but may be just using it for key-value storage; anything -- any ideas are welcome. Thank you!

  Read the article

• jQuery: Multiple animations with a delay on a set of divs

  - by Waleed

  Hey there, I have a group of 4 divs and I'm looking to use jQuery to animate them once, then have a delay using delay(), and then run another set of animations on them, putting the divs back to their original configuration. Here's the code that I have: //only selectors called 'option1' are affected by delay, and not 'option1 img' or 'option2' $("#option1").showOption1().delay(3000).hideOption1(); //if i don't attach to #option1, delay doesn't work, but the animations that need to happen simultaneously work $(document).showOption1().delay(3000).hideOption1(); jQuery.fn.showOption1 = function(){ $("#option2, #option3, #leftColumn").fadeOut(1000); $("#option1").css("zIndex", "5"); $("#option1").animate({ left: "370px", }, 1500); $("#option1 img").animate({ width: "500px", }, 1500, function(){ $("p.optionText").text('hello'); }); return this; } jQuery.fn.hideOption1 = function(){ $("#option1 img").animate({ width: "175px", }, 1500); $("#option1").animate({ left: "743px", }, 1500); $("#option2, #option3, #leftColumn").fadeIn(2000); $("#option1").css("zIndex", "1"); return this; } I've tried two ways of running these two functions, as seen on lines 2 and 5. In the case of line 2, showOption1() will run fine, but then only $("#option1").animate({ left: "743px", }, 1500); will work from hideOption1() after the delay. The rest of hideOption1() is fired immediately after showOption1() finishes, ignoring the delay. On the other hand, if I run line 5, all the code in hideOption1() runs simultaneously as desired, but ignores the delay entirely, running immediately after showOption1() finishes. How can I have all the code in hideOption1() run simultaneously after the delay? Thanks much in advance!

  Read the article

• Query on simple C++ threadpool implementation

  - by ticketman

  Stackoverflow has been a tremendous help to me and I'd to give something back to the community. I have been implementing a simple threadpool using the tinythread C++ portable thread library, using what I have learnt from Stackoverflow. I am new to thread programming, so not that comfortable with mutexes, etc. I have a question best asked after presenting the code (which runs quite well under Linux): // ThreadPool.h class ThreadPool { public: ThreadPool(); ~ThreadPool(); // Creates a pool of threads and gets them ready to be used void CreateThreads(int numOfThreads); // Assigns a job to a thread in the pool, but doesn't start the job // Each SubmitJob call will use up one thread of the pool. // This operation can only be undone by calling StartJobs and // then waiting for the jobs to complete. On completion, // new jobs may be submitted. void SubmitJob( void (*workFunc)(void *), void *workData ); // Begins execution of all the jobs in the pool. void StartJobs(); // Waits until all jobs have completed. // The wait will block the caller. // On completion, new jobs may be submitted. void WaitForJobsToComplete(); private: enum typeOfWorkEnum { e_work, e_quit }; class ThreadData { public: bool ready; // thread has been created and is ready for work bool haveWorkToDo; typeOfWorkEnum typeOfWork; // Pointer to the work function each thread has to call. void (*workFunc)(void *); // Pointer to work data void *workData; ThreadData() : ready(false), haveWorkToDo(false) { }; }; struct ThreadArgStruct { ThreadPool *threadPoolInstance; int threadId; }; // Data for each thread ThreadData *m_ThreadData; ThreadPool(ThreadPool const&); // copy ctor hidden ThreadPool& operator=(ThreadPool const&); // assign op. hidden // Static function that provides the function pointer that a thread can call // By including the ThreadPool instance in the void * parameter, // we can use it to access other data and methods in the ThreadPool instance. static void ThreadFuncWrapper(void *arg) { ThreadArgStruct *threadArg = static_cast<ThreadArgStruct *>(arg); threadArg->threadPoolInstance->ThreadFunc(threadArg->threadId); } // The function each thread calls void ThreadFunc( int threadId ); // Called by the thread pool destructor void DestroyThreadPool(); // Total number of threads available // (fixed on creation of thread pool) int m_numOfThreads; int m_NumOfThreadsDoingWork; int m_NumOfThreadsGivenJobs; // List of threads std::vector<tthread::thread *> m_ThreadList; // Condition variable to signal each thread has been created and executing tthread::mutex m_ThreadReady_mutex; tthread::condition_variable m_ThreadReady_condvar; // Condition variable to signal each thread to start work tthread::mutex m_WorkToDo_mutex; tthread::condition_variable m_WorkToDo_condvar; // Condition variable to signal the main thread that // all threads in the pool have completed their work tthread::mutex m_WorkCompleted_mutex; tthread::condition_variable m_WorkCompleted_condvar; }; cpp file: // // ThreadPool.cpp // #include "ThreadPool.h" // This is the thread function for each thread. // All threads remain in this function until // they are asked to quit, which only happens // when terminating the thread pool. void ThreadPool::ThreadFunc( int threadId ) { ThreadData *myThreadData = &m_ThreadData[threadId]; std::cout << "Hello world: Thread " << threadId << std::endl; // Signal that this thread is ready m_ThreadReady_mutex.lock(); myThreadData->ready = true; m_ThreadReady_condvar.notify_one(); // notify the main thread m_ThreadReady_mutex.unlock(); while(true) { //tthread::lock_guard<tthread::mutex> guard(m); m_WorkToDo_mutex.lock(); while(!myThreadData->haveWorkToDo) // check for work to do m_WorkToDo_condvar.wait(m_WorkToDo_mutex); // if no work, wait here myThreadData->haveWorkToDo = false; // need to do this before unlocking the mutex m_WorkToDo_mutex.unlock(); // Do the work switch(myThreadData->typeOfWork) { case e_work: std::cout << "Thread " << threadId << ": Woken with work to do\n"; // Do work myThreadData->workFunc(myThreadData->workData); std::cout << "#Thread " << threadId << ": Work is completed\n"; break; case e_quit: std::cout << "Thread " << threadId << ": Asked to quit\n"; return; // ends the thread } // Now to signal the main thread that my work is completed m_WorkCompleted_mutex.lock(); m_NumOfThreadsDoingWork--; // Unsure if this 'if' would make the program more efficient // if(NumOfThreadsDoingWork == 0) m_WorkCompleted_condvar.notify_one(); // notify the main thread m_WorkCompleted_mutex.unlock(); } } ThreadPool::ThreadPool() { m_numOfThreads = 0; m_NumOfThreadsDoingWork = 0; m_NumOfThreadsGivenJobs = 0; } ThreadPool::~ThreadPool() { if(m_numOfThreads) { DestroyThreadPool(); delete [] m_ThreadData; } } void ThreadPool::CreateThreads(int numOfThreads) { // Check a thread pool has already been created if(m_numOfThreads > 0) return; m_NumOfThreadsGivenJobs = 0; m_NumOfThreadsDoingWork = 0; m_numOfThreads = numOfThreads; m_ThreadData = new ThreadData[m_numOfThreads]; ThreadArgStruct threadArg; for(int i=0; i<m_numOfThreads; ++i) { threadArg.threadId = i; threadArg.threadPoolInstance = this; // Creates the thread and save in a list so we can destroy it later m_ThreadList.push_back( new tthread::thread( ThreadFuncWrapper, (void *)&threadArg ) ); // It takes a little time for a thread to get established. // Best wait until it gets established before creating the next thread. m_ThreadReady_mutex.lock(); while(!m_ThreadData[i].ready) // Check if thread is ready m_ThreadReady_condvar.wait(m_ThreadReady_mutex); // If not, wait here m_ThreadReady_mutex.unlock(); } } // Adds a job to the batch, but doesn't start the job void ThreadPool::SubmitJob(void (*workFunc)(void *), void *workData) { // Check that the thread pool has been created if(!m_numOfThreads) return; if(m_NumOfThreadsGivenJobs >= m_numOfThreads) return; m_ThreadData[m_NumOfThreadsGivenJobs].workFunc = workFunc; m_ThreadData[m_NumOfThreadsGivenJobs].workData = workData; std::cout << "Submitted job " << m_NumOfThreadsGivenJobs << std::endl; m_NumOfThreadsGivenJobs++; } void ThreadPool::StartJobs() { // Check that the thread pool has been created // and some jobs have been assigned if(!m_numOfThreads || !m_NumOfThreadsGivenJobs) return; // Set 'haveworkToDo' flag for all threads m_WorkToDo_mutex.lock(); for(int i=0; i<m_NumOfThreadsGivenJobs; ++i) m_ThreadData[i].haveWorkToDo = true; m_NumOfThreadsDoingWork = m_NumOfThreadsGivenJobs; // Reset this counter so we can resubmit jobs later m_NumOfThreadsGivenJobs = 0; // Notify all threads they have work to do m_WorkToDo_condvar.notify_all(); m_WorkToDo_mutex.unlock(); } void ThreadPool::WaitForJobsToComplete() { // Check that a thread pool has been created if(!m_numOfThreads) return; m_WorkCompleted_mutex.lock(); while(m_NumOfThreadsDoingWork > 0) // Check if all threads have completed their work m_WorkCompleted_condvar.wait(m_WorkCompleted_mutex); // If not, wait here m_WorkCompleted_mutex.unlock(); } void ThreadPool::DestroyThreadPool() { std::cout << "Ask threads to quit\n"; m_WorkToDo_mutex.lock(); for(int i=0; i<m_numOfThreads; ++i) { m_ThreadData[i].haveWorkToDo = true; m_ThreadData[i].typeOfWork = e_quit; } m_WorkToDo_condvar.notify_all(); m_WorkToDo_mutex.unlock(); // As each thread terminates, catch them here for(int i=0; i<m_numOfThreads; ++i) { tthread::thread *t = m_ThreadList[i]; // Wait for thread to complete t->join(); } m_numOfThreads = 0; } Example of usage: (this calculates pi-squared/6) struct CalculationDataStruct { int inputVal; double outputVal; }; void LongCalculation( void *theSums ) { CalculationDataStruct *sums = (CalculationDataStruct *)theSums; int terms = sums->inputVal; double sum; for(int i=1; i<terms; i++) sum += 1.0/( double(i)*double(i) ); sums->outputVal = sum; } int main(int argc, char** argv) { int numThreads = 10; // Create pool ThreadPool threadPool; threadPool.CreateThreads(numThreads); // Create thread workspace CalculationDataStruct sums[numThreads]; // Set up jobs for(int i=0; i<numThreads; i++) { sums[i].inputVal = 3000*(i+1); threadPool.SubmitJob(LongCalculation, &sums[i]); } // Run the jobs threadPool.StartJobs(); threadPool.WaitForJobsToComplete(); // Print results for(int i=0; i<numThreads; i++) std::cout << "Sum of " << sums[i].inputVal << " terms is " << sums[i].outputVal << std::endl; return 0; } Question: In the ThreadPool::ThreadFunc method, would better performance be obtained if the following if statement if(NumOfThreadsDoingWork == 0) was included? Also, I'd be grateful of criticisms and ways to improve the code. At the same time, I hope the code is of use to others.

  Read the article

• UISegmentedControl Best Practice

  - by Neal L

  Hi all, I'm trying to work out the "best" way to use a UISegmentedControl for an iPhone application. I've read a few posts here on stackoverflow and seen a few people's ideas, but I can't quite sort out the best way to do this. The posts I'm referring to are: http://stackoverflow.com/questions/1559794/changing-views-from-uisegmentedcontrol and http://stackoverflow.com/questions/1047114/how-do-i-use-a-uisegmentedcontrol-to-switch-views It would seem that the options are: Add each of the views in IB and lay them out on top of each other then show/hide them Create each of the subviews separately in IB, then create a container in the main view to populate with the subview that you need Set up one really tall or really wide UIView and animate it left/right or up/down depending on the selected segment Use a UITabBarController to swap out the subviews - seems silly For tables, reload the table and in cellForRowAtIndex and populate the table from different data sources or sections based on the segment option selected (not the case for my app) So which approach is best for subview/non-table approaches? Which is the easiest to implement? Could you share some sample code to the approach? Thanks!

  Read the article

• BITS client fails to specify HTTP Range header

  - by user256890

  Our system is designed to deploy to regions with unreliable and/or insufficient network connections. We build our own fault tolerating data replication services that uses BITS. Due to some security and maintenance requirements, we implemented our own ASP.NET file download service on the server side, instead of just letting IIS serving up the files. When BITS client makes an HTTP download request with the specified range of the file, our ASP.NET page pulls the demanded file segment into memory and serve that up as the HTTP response. That is the theory. ;) This theory fails in artificial lab scenarios but I would not let the system deploy in real life scenarios unless we can overcome that. Lab scenario: I have BITS client and the IIS on the same developer machine, so practically I have enormous network "bandwidth" and BITS is intelligent enough to detect that. As BITS client discovers the unlimited bandwidth, it gets more and more "greedy". At each HTTP request, BITS wants to grasp greater and greater file ranges (we are talking about downloading CD iso files, videos), demanding 20-40MB inside a single HTTP request, a size that I am not comfortable to pull into memory on the server side as one go. I can overcome that simply by giving less than demanded. It is OK. However, BITS gets really "confident" and "arrogant" demanding files WITHOUT specifying the download range, i.e., it wants the entire file in a single request, and this is where things go wrong. I do not know how to answer that response in the case of a 600MB file. If I just provide the starting 1MB range of the file, BITS client keeps sending HTTP requests for the same file without download range to continue, it hammers its point that it wants the entire file in one go. Since I am reluctant to provide the entire file, BITS gives up after several trials and reports error. Any thoughts?

  Read the article

• Deriving an HTMLElement Object from jQuery Object

  - by Jasconius

  I'm doing a fairly exhaustive series of DOM manipulations where a few elements (specifically form elements) have some events. I am dynamically creating (actually cloning from a source element) several boxes and assigning a change() event to them. The change event executes, and within the context of the event, "this" is the HTML Element Object. What I need to do at this point however is determine a contact for this HTML Element Object. I have these objects stored already as jQuery entities in assorted arrays, but obviously [HTMLElement Object] != [Object Object] And the trick is that I cannot cast $(this) and make a valid comparison since that would create a new object and the pointer would be different. So... I've been banging my head against this for a while. In the past I've been able to circumvent this problem by doing an innerHTML comparison, but in this case the objects I am comparing are 100% identical, just there's lots of them. Therefore I need a solid comparison. This would be easy if I could somehow derive the HTMLElement object from my originating jQuery object. Thoughts, other ideas? Help. :(

  Read the article

• JsonParseException on Valid JSON

  - by user2909602

  I am having an issue calling a RESTful service from my client code. I have written the RESTful service using CXF/Jackson, deployed to localhost, and tested using RESTClient successfully. Below is a snippet of the service code: @POST @Produces("application/json") @Consumes("application/json") @Path("/set/mood") public Response setMood(MoodMeter mm) { this.getMmDAO().insert(mm); return Response.ok().entity(mm).build(); } The model class and dao work successfully and the service itself works fine using RESTClient. However, when I attempt to call this service from Java Script, I get the error below on the server side: Caused by: org.codehaus.jackson.JsonParseException: Unexpected character ('m' (code 109)): expected a valid value (number, String, array, object, 'true', 'false' or 'null') I have copied the client side code below. To make sure it has nothing to do with the JSON data itself, I used a valid JSON string (which works using RESTClient, JSON.parse() method, and JSONLint) in the vars 'json' (string) and 'jsonData' (JSON). Below is the Java Script code: var json = '{"mood_value":8,"mood_comments":"new comments","user_id":5,"point":{"latitude":37.292929,"longitude":38.0323323},"created_dtm":1381546869260}'; var jsonData = JSON.parse(json); $.ajax({ url: 'http://localhost:8080/moodmeter/app/service/set/mood', dataType: 'json', data: jsonData, type: "POST", contentType: "application/json" }); I've seen the JsonParseException a number of times on other threads, but in this case the JSON itself appears to be valid (and tested). Any thoughts are appreciated.

  Read the article

< Previous Page | 690 691 692 693 694 695 696 697 698 699 700 701  | Next Page >