Search Results

Search found 19878 results on 796 pages for 'multiple dispatch'.

Page 701/796 | < Previous Page | 697 698 699 700 701 702 703 704 705 706 707 708  | Next Page >

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

  - by Michael E

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

  Read the article

• How to test a Grails Service that utilizes a criteria query (with spock)?

  - by user569825

  I am trying to test a simple service method. That method mainly just returns the results of a criteria query for which I want to test if it returns the one result or not (depending on what is queried for). The problem is, that I am unaware of how to right the corresponding test correctly. I am trying to accomplish it via spock, but doing the same with any other way of testing also fails. Can one tell me how to amend the test in order to make it work for the task at hand? (BTW I'd like to keep it a unit test, if possible.) The EventService Method public HashSet<Event> listEventsForDate(Date date, int offset, int max) { date.clearTime() def c = Event.createCriteria() def results = c { and { le("startDate", date+1) // starts tonight at midnight or prior? ge("endDate", date) // ends today or later? } maxResults(max) order("startDate", "desc") } return results } The Spock Specification package myapp import grails.plugin.spock.* import spock.lang.* class EventServiceSpec extends Specification { def event def eventService = new EventService() def setup() { event = new Event() event.publisher = Mock(User) event.title = 'et' event.urlTitle = 'ut' event.details = 'details' event.location = 'location' event.startDate = new Date(2010,11,20, 9, 0) event.endDate = new Date(2011, 3, 7,18, 0) } def "list the Events of a specific date"() { given: "An event ranging over multiple days" when: "I look up a date for its respective events" def results = eventService.listEventsForDate(searchDate, 0, 100) then: "The event is found or not - depending on the requested date" numberOfResults == results.size() where: searchDate | numberOfResults new Date(2010,10,19) | 0 // one day before startDate new Date(2010,10,20) | 1 // at startDate new Date(2010,10,21) | 1 // one day after startDate new Date(2011, 1, 1) | 1 // someday during the event range new Date(2011, 3, 6) | 1 // one day before endDate new Date(2011, 3, 7) | 1 // at endDate new Date(2011, 3, 8) | 0 // one day after endDate } } The Error groovy.lang.MissingMethodException: No signature of method: static myapp.Event.createCriteria() is applicable for argument types: () values: [] at myapp.EventService.listEventsForDate(EventService.groovy:47) at myapp.EventServiceSpec.list the Events of a specific date(EventServiceSpec.groovy:29)

  Read the article

• Prototyping Qt/C++ in Python

  - by tstenner

  I want to write a C++ application with Qt, but build a prototype first using Python and then gradually replace the Python code with C++. Is this the right approach, and what tools (bindings, binding generators, IDE) should I use? Ideally, everything should be available in the Ubuntu repositories so I wouldn't have to worry about incompatible or old versions and have everything set up with a simple aptitude install. Is there any comprehensive documentation about this process or do I have to learn every single component, and if yes, which ones? Right now I have multiple choices to make: Qt Creator, because of the nice auto completion and Qt integration. Eclipse, as it offers support for both C++ and Python. Eric (haven't used it yet) Vim PySide as it's working with CMake and Boost.Python, so theoretically it will make replacing python code easier. PyQt as it's more widely used (more support) and is available as a Debian package. Edit: As I will have to deploy the program to various computers, the C++-solution would require 1-5 files (the program and some library files if I'm linking it statically), using Python I'd have to build PyQt/PySide/SIP/whatever on every platform and explain how to install Python and everything else.

  Read the article

• Scalability 101: How can I design a scalable web application using PHP?

  - by Legend

  I am building a web-application and have a couple of quick questions. From what I learnt, one should not worry about scalability when initially building the app and should only start worrying when the traffic increases. However, this being my first web-application, I am not quite sure if I should take an approach where I design things in an ad-hoc manner and later "fix" them. I have been reading stories about how people start off with an app that gets millions of users in a week or two. Not that I will face the same situation but I can't help but wonder, how do these people do it? Currently, I bought a shared hosting account on Lunarpages and that got me started in building and testing the application. However, I am interested in learning how to build the same application in a scalable-manner using the cloud, for instance, Amazon's EC2. From my understanding, I can see a couple of components: There is a load balancer that first receives requests and then decides where to route each request This request is then handled by a server replica that then processes the request and updates (if required) the database and sends back the response to the client If a similar request comes in, then a caching mechanism like memcached kicks into picture and returns objects from the cache A blackbox that handles database replication Specifically, I am trying to do the following: Setting up a load balancer (my homework revealed that HAProxy is one such load balancer) Setting up replication so that databases can be synchronized Using memcached Configuring Apache to work with multiple web servers Partitioning application to use Amazon EC2 and Amazon S3 (my application is something that will need great deal of storage) Finally, how can I avoid burning myself when using Amazon services? Because this is just a learning phase, I can probably do with 2-3 servers with a simple load balancer and replication but until I want to avoid paying loads of money accidentally. I am able to find resources on individual topics but am unable to find something that starts off from the big picture. Can someone please help me get started?

  Read the article

• Client Side Only Cookies

  - by Mike Jones

  I need something like a cookie, but I specifically don't want it going back to the server. I call it a "client side session cookie" but any reasonable mechanism would be great. Basically, I want to store some data encrypted on the server, and have the user type a password into the browser. The browser decrypts the data with the password (or creates and encrypts the data with the password) and the server stores only encrypted data. To keep the data secure on the server, the server should not store and should never receive the password. Ideally there should be a cookie session expiration to clean up. Of course I need it be available on multiple pages as the user walks through the web site. The best I can come up with is some sort of iframe mechanism to store the data in javascript variables, but that is ugly. Does anyone have any ideas how to implement something like this? FWIW, the platform is ASP.NET, but I don't suppose that matters. It needs to support a broad range of browsers, including mobile. In response to one answer below, let me clarify. My question is not how to achieve the crypto, that isn't a problem. The question is where to store the password so that it is persistent from page to page, but not beyond a session, and in such a way that the server doesn't see it.

  Read the article

• Jquery Parent Item of Div containing X content.

  - by fighella

  I need to add a CSS class to the TR (or multiple TR's) of the parent of a TD containing some specific text. Because of the CMS I can't control the code, but I can add some Jquery and CSS. I've tried a few things, but I've had no luck. Here is an example of what I had in mind. <style> tr.highlight { background: Blue;} </style> <table> <tr> <td> Pet </td> <td> Number of Legs </td> </tr> <tr> <td> Cat </td> <td> 4 </td> </tr> <tr> <td> Doggie </td> <td> 4 </td> </tr> </table> And I essentially want the jquery to add that class (highlight) to the offending TR. ** I know this is not an ideal approach, but desperate times call for desperate measures. ** Thanks for your help.

  Read the article

• Dojo: Setting a CheckBox label programmatically

  - by Mitchell Flaherty

  Let me preface by saying that I saw this other question on the subject of CheckBox labels that was asked and answered well over a year ago. I was confused by the answers and am hoping that someone can clarify or that there has been new dojo functionality introduced since then that allows me to do this without resorting to HTML. So without further ado, I would like to know how to programmatically create labels for check boxes. I have a check box like so: this.pubBoxId = new dijit.form.CheckBox({ label: "IdChannel", checked: false, channel: that.idChannel }, that.name + "_PBI"); As you can see I've tried to edit the "label" field, but the label never actually shows up on the page. I have multiple CheckBoxes that I am adding to a ContentPane and simply want a label to the left or right of the check box. Is there any way I can do this without having to write separate HTML? Also, making a separate ContentPane for each individual label would be a big pain because of how many CheckBoxes I plan to have. Thank you for reading, and let me know if further clarification is needed!

  Read the article

• Web Applications Development: Security practices for Application design

  - by Shyam

  Hi, As I am creating more web applications that are targeted for multiple users, I figured out that I have to start thinking about user management and security. At a glance and in my ideal world, all users belong to a group. Permissions and access is thus defined per group (and inherited by the users of that group). Logically, I have my group of administrators, which are identified with a level "7" (integer) clearance. A group of webusers have for example level "1". This in generally all works great for me, but I need some kind of list that I have to keep in mind how I secure my system, and some general practices. I am not looking for a specific environment; I want to learn the why's and how's. An example is privilege escalation. If someone would be able to "push" themselves inside a group with higher privileges, for example the Administration, how can I prevent this, or what measures should I take to have some sort of precaution? I don't like in that case to walk into a caveat. My question is basically: where can I find a good resource, list, policy, book that explains the security of web applications, the why's, the how's and readable if you don't have any experience in the realm of advanced security? I prefer a free resource, as I believe I couldn't be the first one who thought about this. Thank you for your answers, comments and feedback.

  Read the article

• JSR-299 (CDI) configuration at runtime

  - by nsn

  I need to configure different @Alternatives, @Decorators and @Injectors for different runtime environments (think testing, staging and production servers). Right now I use maven to create three wars, and the only difference between those wars are in the beans.xml files. Is there a better way to do this? I do have @Alternative @Stereotypes for the different environments, but even then I need to alter beans.xml, and they don't work for @Decorators (or do they?) Is it somehow possible to instruct CDI to ignore the values in beans.xml and use a custom configuration source? Because then I could for example read a system property or other environment variable. The application exclusively runs in containers that use Weld, so a weld-specific solution would be ok. I already tried to google this but can't seem to find good search terms, and I asked the Weld-Users-Forums, but to no avail. Someone over there suggested to write my own custom extension, but I can't find any API to actually change the container configuration at runtime. I think it would be possible to have some sort of @ApplicationScoped configuration bean and inject that into all @Decorators which could then decide themselves whether they should be active or not and then in order to configure @Alternatives write @Produces methods for every interface with multiple implementations and inject the config bean there too. But this seems to me like a lot of unnecessary work to essentially duplicate functionality already present in CDI?

  Read the article

• Catch a PHP Object Instantiation Error

  - by Rob Wilkerson

  It's really irking me that PHP considers the failure to instantiate an object a Fatal Error (which can't be caught) for the application as a whole. I have set of classes that aren't strictly necessary for my application to function--they're really a convenience. I have a factory object that attempts to instantiate the class variant that's indicated in a config file. This mechanism is being deployed for message storage and will support multiple store types: DatabaseMessageStore FileMessageStore MemcachedMessageStore etc. A MessageStoreFactory class will read the application's preference from a config file, instantiate and return an instance of the appropriate class. It might be easy enough to slap a conditional around the instantiation to ensure that class_exists(), but MemcachedMessageStore extends PHP's Memcached class. As a result, the class_exists() test will succeed--though instantiation will fail--if the memcached bindings for PHP aren't installed. Is there any other way to test whether a class can be instantiated properly? If it can't, all I need to do is tell the user which features won't be available to them, but let them continue one with the application. Thanks.

  Read the article

• Connection Pool Strategy: Good, Bad or Ugly?

  - by Drew

  I'm in charge of developing and maintaining a group of Web Applications that are centered around similar data. The architecture I decided on at the time was that each application would have their own database and web-root application. Each application maintains a connection pool to its own database and a central database for shared data (logins, etc.) A co-worker has been positing that this strategy will not scale because having so many different connection pools will not be scalable and that we should refactor the database so that all of the different applications use a single central database and that any modifications that may be unique to a system will need to be reflected from that one database and then use a single pool powered by Tomcat. He has posited that there is a lot of "meta data" that goes back and forth across the network to maintain a connection pool. My understanding is that with proper tuning to use only as many connections as necessary across the different pools (low volume apps getting less connections, high volume apps getting more, etc.) that the number of pools doesn't matter compared to the number of connections or more formally that the difference in overhead required to maintain 3 pools of 10 connections is negligible compared to 1 pool of 30 connections. The reasoning behind initially breaking the systems into a one-app-one-database design was that there are likely going to be differences between the apps and that each system could make modifications on the schema as needed. Similarly, it eliminated the possibility of system data bleeding through to other apps. Unfortunately there is not strong leadership in the company to make a hard decision. Although my co-worker is backing up his worries only with vagueness, I want to make sure I understand the ramifications of multiple small databases/connections versus one large database/connection pool.

  Read the article

• Providing downloads on ASP.net website

  - by Dave

  I need to provide downloads of large files (upwards of 2 GB) on an ASP.net website. It has been some time since I've done something like this (I've been in the thick-client world for awhile now), and was wondering on current best practices for this. Ideally, I would like: To be able to track download statistics: # of downloads is essential; actual bytes sent would be nice. To provide downloads in a way that "plays nice" with third-party download managers. Many of our users have unreliable internet connections, and being able to resume a download is a must. To allow multiple users to download the same file simultaneously. My download files are not security-sensitive, so providing a direct link ("right-click to download...") is a possibility. Is just providing a direct link sufficient, letting IIS handle it, and then using some log analyzer service (any recommendations?) to compile and report the statistics? Or do I need to intercept the download request, store some info in a database, then send a custom Response? Or is there an ASP.net user control (built-in or third party) that does this? I appreciate all suggestions.

  Read the article

• LNK2019 Against CArray Add, GetAt, GetSize, all includes are present

  - by David J

  I'm having some issues trying to Compile a DLL, but I just can't see where this linking error is coming from. My LNK2019 is: Exports.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: int __thiscall CArray<struct HWND__ *,struct HWND__ *>::Add(struct HWND__ *)" (__imp_?Add@? $CArray@PAUHWND__@@PAU1@@@QAEHPAUHWND__@@@Z) referenced in function "int __stdcall _Disable(struct HWND__ *,long)" (?_Disable@@YGHPAUHWND__@@J@Z) Disable(...) is... static BOOL CALLBACK _Disable(HWND hwnd, LPARAM lParam) { CArray<HWND, HWND>* pArr = (CHWndArray*)lParam; if(::IsWindowEnabled(hwnd) && ::IsWindowVisible(hwnd)) { pArr->Add(hwnd); ::Enable(hwnd, FALSE); } } This is the first function in Exports.cpp; right above it is #include <afxtempl.h> I have the Windows 7.1 SDK installed (and have tried reinstalling both that and VS2010). The exact same project compiles perfectly fine on other machines, so it can't be the code itself.. I've spent countless errors researching, which led to desperate attempts of just changing random values in the solution file, including different Windows headers, etc. My last resort is getting to be just reinstalling the OS completely (assuming it's actually a problem with the Windows SDK being incorrect or something). Any suggestions at all would be a huge help. EDIT: I've added /showIncludes on the cpp giving issues, and I do see afxtempl.h being included. It's being included multiple times due to other headers including it, but it is there (and it is from the same directory every time): 1> Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\atlmfc\include\afxtempl.h

  Read the article

• Log in to subdomain via main domain

  - by Mattias

  I have a website, available through multiple domainnames. like www.domain1.com .... www.domain5.com All my customers have their own subdomain. like: customer1.domain1.com customer2.domain1.com .... customer351.domain4.com Currently i dont use SSL, each customer log in their own account via their sub domain. I want to change this, and make all customers log in on a central log in page, that would use SSL, for example. https://login.domain1.com And somehow redirect each user to the correct sub domain adress. (Sub domain that don't use SSL) How do I do this, and maintain security? One idea i had: Login - add random value somewhere in the database, Redirect to subdomain, with querystring the randomvalue. And after that the session takes care of it, Each value can be used once only.. But how secure is that? I guess someone would ask the question "why?" to me. Because SSL costs money. And unfortunately i dont have a lot of it. :D Thanks for your time!

  Read the article

• How should I link two items with MouseMovementListeners?

  - by user1708810

  I'm working on a program that will display two "views" of the same set of items. So I need to have something set up so that when the top down view is changed, the side view is updated (and vice versa). Here's a brief outline of the relevant code so you can get an idea of my structure so far: public class DraggableComponent extends JComponent { //Contains code for MouseMovementListener that makes the item draggable } public class ItemGraphic extends DraggableComponent { //Code to render the graphic } public class Item { private ItemGraphic topGraphic; private ItemGraphic sideGraphic; } I'm able to get each graphic to display fine in my GUI. I can also independently drag each graphic. I'm missing the "linking." Some ideas I've been thinking about: Have one listener for the whole GUI. Loop through each Item and if the cursor is within the bounds of either graphic, move the other graphic. I'm concerned about the efficiency of this method. Multiple "paired" listeners (not quite sure how this would work, but the idea is that each graphic would have a listener for the other paired graphic)

  Read the article

• Multithreading using pthread in C++ with shared variables

  - by Saviour Self

  I'm new to threading (and C/C++ for that matter), and I'm attempting to use multiple threads to access shared variables. In the main, I've created a variable char inputarray[100]; Thread 1: This thread will be reading data from stdin in 2 byte bursts, and appending them to the inputarray. (input by feeding a file in) Thread 2: This thread will be reading data 1 byte at a time, performing a calculation, and putting its data into an output array. Thread 3: This thread will be outputting data from the output array in 2 byte bursts. (stdout) I've attempted the input part and got it working by passing a struct, but would like to do it without using a struct, but it has been giving me problems. If I can get input down, I'm sure I'll be able to use a similar strategy to complete output. Any help would be greatly appreciated. Below is a rough template for the input thread. #include <stdio.h> #include <pthread.h> using namespace std; void* input(void* arg) { char reading[3]; fread(reading,1,2,stdin); //append to char inputarray[]..??? } int main() { char inputarray[100]; pthread_t t1; pthread_create(&t1, NULL, &input, &inputarray); void *result; pthread_join(t1,&result); return 0; }

  Read the article

• What is the best way to remove flickering from a fast series of image loads in Flash?

  - by msandbot

  Hi, working on making a flash program that loads about 1000 jpegs and then plays them like a movie. Have all the buttons and stuff working but the time it takes for an image to load is so high that the movie can't be played at 30 fps. I've tried multiple ways of fixing this using 1 scrollpane and changing its source ever 30 ms. This one is the worst but simplest. Flickers cause strobing and it is unwatchable. used 2 scrollpanes that were duplicates of each other until I had to load. I would then make that one invisible, load it , then make it visible. Then load the background one. Works but same problem as the first at high speeds, just less severe. used 1 scrollpane per image . This works great, except that it fails miserably on any more than 100 of them due to the number of objects. Has anyone else experienced/solved/wants to help me solve this? None of my fixes have worked. Currently using action script 3, but will change if its not possible in that. Also, I want to be able to zoom in and then scroll around the window hence the scrollpanes, but if that's not possible its a sacrifice I'm willing to make

  Read the article

• How should I handle header files in a bundle?

  - by ldiqual

  I want to develop a program that relies on plugins (here: loadable bundles) to work. Multiple plugins are asked to use the same AFNetworking ressource to make network requests. However, I don't know where to put AFNetworking and CustomPluginProtocol headers. Here is how my program structure looks like for now: MyApp.xcodeproj - AFNetworking - Header.h - Plugins - Plugin1.xcodeproj - PrincipalClass.m - Plugin2.xcodeproj - PrincipalClass.m - Classes - CustomPluginProtocol.h - MainClass.m Of course, every principalClass from PluginN complies to the CustomPluginProtocol. Do the headers have to be copied in each bundle ? Can I just include the main program AFNetworking headers from my plugins ? If so (and that's what I do for now), I don't have any completion. How can I get it ? Edit Ok, so maybe I wasn't clear in my question. I want my plugins to use sources from the main application, let's say CommonClass.m and CommonClass.h. Do the plugins need CommonClass.h in their bundle, and if not, how do I enable completion when I'm in the plugin scope ?

  Read the article

• Appropriate use of die()?

  - by letseatfood

  I create pages in my current PHP project by using the following template: <?php include 'bootstrap.php'; head(); ?> <!-- Page content here --> <?php foot(); ?> Is the following example an appropriate use of die()? Also, what sort of problems might this cause for me, if any? <?php include 'bootstrap.php'; head(); try { //Simulate throwing an exception from some class throw new Exception('Something went wrong!'); } catch(Exception $e) { ?> <p>Please fix the following errors:</p> <p><?php echo $e->getMessage(); ?></p> <?php foot(); die(); } //If no exception is thrown above, continue script doSomething(); doSomeOtherThing(); foot(); ?> ?> <?php foot(); ?> Basically, I have a script with multiple tasks on it and I am trying to set up a graceful way to notify the user of input errors while preventing the remaining portion of the script from executing. Thanks!

  Read the article

• How can I change jtable height at runtime

  - by wniroshan

  I hava a JFrame with multiple JPanels of similar width aligned one below other. I use one of these JPanels to display a JTable which is the last JPanel of the lot. This JPanel has a JScrollpane as a child component. This is where I try to add my table dynamically. Initial height of this JScrollpane is set to 40. I designed above template using Netbeans 6.8 Now I'm trying to add the table to the JPanel. When a button is pressed below code snippet is called. The class which includes this code extends javax.swing.JFrame class. I am expecting below code would adjust table height according to the row count and display the table. SearchTable = new JTable(RowData, DisplayNames) { @Override public boolean isCellEditable(int rowIndex, int vColIndex) { return false; } }; // if row count is less than 10 then display all the rows without a scroll bar if (SearchTable.getRowCount() < 10) { pnl_tblpanel.setPreferredSize(new Dimension(625, SearchTable.getRowHeight() * (SearchTable.getRowCount() + 4))); scr_tblholder.setPreferredSize(new Dimension(625, SearchTable.getRowHeight() * (SearchTable.getRowCount() + 4))); } else {// if row count is more than 10 display first 10 rows and add a scroll bar pnl_tblpanel.setPreferredSize(new Dimension(625, SearchTable.getRowHeight() * (10 + 2))); scr_tblholder.setAutoscrolls(true); } //pnl_tblpanel.add(scr_tblholder); scr_tblholder.setViewportView(SearchTable); //pnl_tblpanel.repaint(); pnl_tblpanel.validate(); this.validate(); //this.repaint(); pnl_tblpanel.setVisible(true); this.pack(); The table displays, but the table height is not changed according to the row count. It stays its default value. I have been trying many combinations of validate and repaint but nothing worked. (More in desperation) Can anyone shed some light on this Thank you

  Read the article

• Haskell quiz: a simple function

  - by levy

  I'm not a Haskell programmer, but I'm curious about the following questions. Informal function specification: Let MapProduct be a function that takes a function called F and multiple lists. It returns a list containing the results of calling F with one argument from each list in each possible combination. Example: Call MapProduct with F being a function that simply returns a list of its arguments, and two lists. One of the lists contains the integers 1 and 2, the other one contains the strings "a" and "b". It should return a list that contains the lists: 1 and "a", 1 and "b", 2 and "a", 2 and "b". Questions: How is MapProduct implemented? What is the function's type? What is F's type? Can one guess what the function does just by looking at its type? Can you handle inhomogeneous lists as input? (e.g. 1 and "a" in one of the input lists) What extra limitation (if any) do you need to introduce to implement MapProduct?

  Read the article

• Is it bad practise to initialise fields outside of an explicit constructor

  - by MrTortoise

  So its monday and we are arguing about coding practises. The examples here are a litttle too simple, but the real deal has several constructors. In order to initialise the simple values (eg dates to their min value) I have moved the code out of the constructors and into the field definitions. public class ConstructorExample { string _string = "John"; } public class ConstructorExample2 { string _string; public ConstructorExample2() { _string = "John"; } } How should it be done by the book. I tend to be very case by case and so am maybe a little lax abotu this kind of thing. However i feel that accams razor tells me to move the initialisation out of multiple constructors. Of course I could always move this shared initialisation into a private method. The question is essentially ... is initialising fields where they are defined as opposed to the constructor bad in any way? The argument I am facing is one of error handling, but i do not feel it is relevant as there are no possible exceptions that won't be picked up at compile time.

  Read the article

• 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

• iPhone Development - CoreData runtime error

  - by Mustafa

  I'm facing a strange CoreData issue. Here's the log: 2010-04-07 15:59:36.913 MyProject[263:207] <MyEntity: 0x180370> (entity: MyEntity; id: 0x17e890 <x-coredata://0F55C533-41BD-4F09-9CCA-0CB304CAB065/MyEntity/p380> ; data: <fault>) 2010-04-07 15:59:36.918 MyProject[263:207] *** Terminating app due to uncaught exception 'NSObjectInaccessibleException', reason: 'The NSManagedObject with ID:0x17e890 <x-coredata://0F55C533-41BD-4F09-9CCA-0CB304CAB065/MyEntity/p380> has been invalidated.' I have a hierarchy of UITableViewControllers that use NSFetchedResultsController to populate the table, and when a particular row is selected, the detail view is shown. UITableView (MyMainEntity) UITableView (MyEntity) UITableView (MyEntity) detail view Both MyMainEntity UITableView and MyEntity UITableView use NSFetchedResultsController to show the records. Sometimes it crashes when i'm scrolling the tableView, and sometimes it crashes when i try to open the detail view. I can navigate to the MyEntity detail view multiple times before application crashes. What does this error mean? and how can i fix it!?

  Read the article

• The way cores, processes, and threads work exactly?

  - by unknownthreat

  I need a bit of an advice for understanding how this whole procedure work exactly. If I am incorrect in any part described below, please correct me. In a single core CPU, it runs each process in the OS, jumping around from one process to another to utilize the best of itself. A process can also have many threads, in which the CPU core runs through these threads when it is running on the respective process. Now, on a multiple core CPU, Do the cores run in every process together, or can the cores run separately in different processes at one particular point of time? For instance, you have program A running two threads, can a duo core CPU run both threads of this program? I think the answer should be yes if we are using something like OpenMP. But while the cores are running in this OpenMP-embedded process, can one of the core simply switch to other process? For programs that are created for single core, when running at 100%, why the CPU utilization of each core are distributed? (ex. A duo core CPU of 80% and 20%. The utilization percentage of all cores always add up to 100% for this case.) Do the cores try help each other run each thread of each process in some ways? Frankly, I'm not sure how this works exactly. Any advice is appreciated.

  Read the article

< Previous Page | 697 698 699 700 701 702 703 704 705 706 707 708  | Next Page >