Search Results

Search found 1055 results on 43 pages for 'thomas g mayfield'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 21/43 | < Previous Page | 17 18 19 20 21 22 23 24 25 26 27 28  | Next Page >

  • C# 4: conflicting overloaded methods with optional parameters

    - by Thomas
    I have two overloaded methods, one with an optional parameter. void foo(string a) { } void foo(string a, int b = 0) { } now I call: foo("abc"); interestingly the first overload is called. why not the second overload with optional value set to zero? To be honest, I would have expect the compiler to bring an error, at least a warning to avoid unintentional execution of the wrong method. What's the reason for this behaviour? Why did the C# team define it that way? Thanks for your opinions!

    Read the article

  • Linux: How to find all serial devices (ttyS, ttyUSB and others)?

    - by Thomas Tempelmann
    What is the proper way to get a list of all available serial ports/devices on a Linux system? In other words, when I iterate over all devices in /dev/, how do I tell which ones are serial ports in the classic way, i.e. those usually supporting baud rates and RTS/CTS flow control? The solution would be coded in C. I ask because I am using a 3rd party library that does this clearly wrong: It appears to only iterate over /dev/ttyS*. The problem is that there are, for instance, serial ports over USB (provided by USB-RS232 adapters), and those are listed under /dev/ttyUSB*. And reading the Serial-HOWTO at Linux.org, I get the idea that there'll be other name spaces as well, as time comes. So I need to find the official way to detect serial devices. Problem is that there appears none documented, or I can't find it. I imagine one way would be to open all files from /dev/tty* and call a specific ioctl() on them that is only available on serial devices. Would that be a good solution, though?

    Read the article

  • Lightweight spinlocks built from GCC atomic operations?

    - by Thomas
    I'd like to minimize synchronization and write lock-free code when possible in a project of mine. When absolutely necessary I'd love to substitute light-weight spinlocks built from atomic operations for pthread and win32 mutex locks. My understanding is that these are system calls underneath and could cause a context switch (which may be unnecessary for very quick critical sections where simply spinning a few times would be preferable). The atomic operations I'm referring to are well documented here: http://gcc.gnu.org/onlinedocs/gcc-4.4.1/gcc/Atomic-Builtins.html Here is an example to illustrate what I'm talking about. Imagine a RB-tree with multiple readers and writers possible. RBTree::exists() is read-only and thread safe, RBTree::insert() would require exclusive access by a single writer (and no readers) to be safe. Some code: class IntSetTest { private: unsigned short lock; RBTree<int>* myset; public: // ... void add_number(int n) { // Aquire once locked==false (atomic) while (__sync_bool_compare_and_swap(&lock, 0, 0xffff) == false); // Perform a thread-unsafe operation on the set myset->insert(n); // Unlock (atomic) __sync_bool_compare_and_swap(&lock, 0xffff, 0); } bool check_number(int n) { // Increment once the lock is below 0xffff u16 savedlock = lock; while (savedlock == 0xffff || __sync_bool_compare_and_swap(&lock, savedlock, savedlock+1) == false) savedlock = lock; // Perform read-only operation bool exists = tree->exists(n); // Decrement savedlock = lock; while (__sync_bool_compare_and_swap(&lock, savedlock, savedlock-1) == false) savedlock = lock; return exists; } }; (lets assume it need not be exception-safe) Is this code indeed thread-safe? Are there any pros/cons to this idea? Any advice? Is the use of spinlocks like this a bad idea if the threads are not truly concurrent? Thanks in advance. ;)

    Read the article

  • Why does Clojure hang after hacing performed my calculations?

    - by Thomas
    Hi all, I'm experimenting with filtering through elements in parallel. For each element, I need to perform a distance calculation to see if it is close enough to a target point. Never mind that data structures already exist for doing this, I'm just doing initial experiments for now. Anyway, I wanted to run some very basic experiments where I generate random vectors and filter them. Here's my implementation that does all of this (defn pfilter [pred coll] (map second (filter first (pmap (fn [item] [(pred item) item]) coll)))) (defn random-n-vector [n] (take n (repeatedly rand))) (defn distance [u v] (Math/sqrt (reduce + (map #(Math/pow (- %1 %2) 2) u v)))) (defn -main [& args] (let [[n-str vectors-str threshold-str] args n (Integer/parseInt n-str) vectors (Integer/parseInt vectors-str) threshold (Double/parseDouble threshold-str) random-vector (partial random-n-vector n) u (random-vector)] (time (println n vectors (count (pfilter (fn [v] (< (distance u v) threshold)) (take vectors (repeatedly random-vector)))))))) The code executes and returns what I expect, that is the parameter n (length of vectors), vectors (the number of vectors) and the number of vectors that are closer than a threshold to the target vector. What I don't understand is why the programs hangs for an additional minute before terminating. Here is the output of a run which demonstrates the error $ time lein run 10 100000 1.0 [null] 10 100000 12283 [null] "Elapsed time: 3300.856 msecs" real 1m6.336s user 0m7.204s sys 0m1.495s Any comments on how to filter in parallel in general are also more than welcome, as I haven't yet confirmed that pfilter actually works.

    Read the article

  • Could an ontology suitably replace an RDBMS for a web app?

    - by Thomas
    I'm considering storing the content of a web app in an RDF or OWL ontology instead of an RDBMS. However, when I research ontologies they seem to always exist in the context of publicly accessible data stores serving as the backbone of the semantic web. I've never heard of them being used as the content engine behind a web app. Is it reasonable to use an ontology instead of an RDBMS for such an application? (Again, this is just for content. User data, commerce and stuff like that will stay in a database as I see no need to reinvent the wheel there.)

    Read the article

  • Can I check wheter Linq 2 SQL's DataContext is tracking entities?

    - by Thomas Jespersen
    We want to throw an exception, if a user calls DataContext.SubmitChanges() and the DataContext is not tracking anything. That is... it is OK to call SubmitChanges if there are no inserts, updates or deletes. But we want to ensure that the developer didn't forget to attach the entity to the DataContext. Even better... is it possible to get a collection of all entities that the DataContext is tracking (including those that are not changed)? PS: The last question I asked were answered with: "do it this way instead"... please don't :-)

    Read the article

  • Symfony app - how to add calculated fields to Propel objects?

    - by Thomas Kohl
    What is the best way of working with calculated fields of Propel objects? Say I have an object "Customer" that has a corresponding table "customers" and each column corresponds to an attribute of my object. What I would like to do is: add a calculated attribute "Number of completed orders" to my object when using it on View A but not on Views B and C. The calculated attribute is a COUNT() of "Order" objects linked to my "Customer" object via ID. What I can do now is to first select all Customer objects, then iteratively count Orders for all of them, but I'd think doing it in a single query would improve performance. But I cannot properly "hydrate" my Propel object since it does not contain the definition of the calculated field(s). How would you approach it?

    Read the article

  • how to redirect terminal contents to a jtextpane?

    - by sonu thomas
    hi.. I was trying to run a java class file using java code.The aim was to direct the executing sequence of the terminal of fedora 10 into a frame with a textpane. My code is: import java.io.DataInputStream; import java.io.IOException; import javax.swing.JDialog; import javax.swing.JFrame; import javax.swing.JOptionPane; import javax.swing.JPanel; import javax.swing.JTextArea; import javax.swing.JTextPane; //import sun.reflect.ReflectionFactory.GetReflectionFactoryAction; public class file { /** * @param args */ /** * @param args * @throws IOException */ public static void main(String[] args) throws IOException{ // TODO Auto-generated method stub JDialog jj = new JDialog(); jj.setTitle("helllo"); String sssub1,sssub2,sssub3; String ss="C:/Users/sonu/Desktop/ourIDE/src/src/nn.java"; JPanel n = new JPanel(); jj.setContentPane(n); JTextPane tpn2=new JTextPane(); jj.getContentPane().add(tpn2); jj.setVisible(true); Runtime runtime; Process process; if(ss.indexOf(" ")==-1) { try { runtime= Runtime.getRuntime(); sssub1="/home/ss/Desktop/src/"; sssub2="nn"; process=runtime.exec("sh jrun.sh "+sssub1+" "+sssub2); DataInputStream data=new DataInputStream(process.getInputStream()); DataInputStream data_data=new DataInputStream(process.getErrorStream()); String s="",t=""; int ch; while((ch=data.read())!=-1){ s=s+(char)ch; } data.close(); while((ch=data_data.read())!=-1){ t=t+(char)ch; } data_data.close(); if(t.equals("")) { s+="\nNormal Termination."; tpn2.setText(s); } else tpn2.setText(t); }catch(Exception e){ System.out.println("Error executing file==>"+e);} } } } The content of **jrun.sh** is cd $1 java $2 When the content of **nn.java** was this: import java.io.*; class nn { public static void main(String[] ar)throws IOException { int i=90; BufferedReader dt = new BufferedReader(new InputStreamReader(System.in)); System.out.println("Enter"); //i=Integer.parseInt(dt.readLine()); line--notable System.out.println("i="+i); } } It worked smoothly But when I remove the comment on line--notable,it gave me Textpane with no content. The problem is : I cant read an input from nn.java Kindly give me a solution... If i am able to: get the terminal pop up with executing the nn.class,and i am able to enter the input,then it will do... Thanks in advance...

    Read the article

  • How do I localize the jQuery DatePicker?

    - by Thomas Eyde
    I really need a localized dropdown calendar. An English calendar doesn't exactly communicate excellence on a Norwegian website ;-) I have experimented with the jQuery DatePicker, their website says it can be localized, however that doesn't seem to work. I am using ASPNET.MVC, and I really want to stick to one javascript library. In this case jQuery. The ajax toolkit calendar would be acceptable, if only it too would display Norwegian names. Update: Awesome! I see I am missing the language files, a not so minor detail :-)

    Read the article

  • How to bind a table in a dataset to a WPF datagrid in C# and XAML

    - by Jim Thomas
    I have been searching to hours for something very simple: bind a WPF datagrid to a datatable in order to see the columns at design-time. I can’t get any of the examples to work for me. Here is the C# code to populate the datatable InfoWork inside the dataset info: info = new Info(); InfoTableAdapters.InfoWorkTableAdapter adapter = new InfoTableAdapters.InfoWorkTableAdapter(); adapter.Fill(info.InfoWork); The problem is no matter how I declare ‘info’ or ‘infoWork’ Visual Studio/XAML can’t find it. I have tried: <Window.Resources> <ObjectDataProvider x:Key="infoWork" ObjectType="{x:Type local:info}" /> </Window.Resources> I have also tried this example from wpf.codeplex, but XAML doesn’t even like the “local:” keyword! <Window.Resources> <local:info x:Key="infoWork"/> </Window.Resources> There are really two main questions here: 1) How do I declare the table InfoWork in C# so that XAML can see it? I tried declaring it Public in the window class that XAML exists in with no success. 2) How do I declare the windows resource in XAML, specifcally the datatable inside the dataset? Out of curiosity, is there a reason that ItemsSource just doesn't show up as a property that be set in the properties design window?

    Read the article

  • Is the Silverstripe CMS as easy to deploy, maintain, and develop on as it appears?

    - by Thomas Owens
    Although I haven't thought about deploying it on my own site, someone I know sent me a link to a CMS called SilverStripe that I've never heard of before. I read their site, looked at and played around with their demo, and so on. It looks like it's a CMS backed by a custom PHP framework that they call Sapphire. And from what I can gather on their website and using their demo, it potentially might be as good and easy as they say (once you get past any learning curve, which appears to be small, considering it looks a lot like other PHP frameworks and CMSes). Has anyone here ever deployed, maintained, or developed a CMS using SilverStripe? If so, could you shed some light on it, from a developer's point-of-view? I also found this earlier question about SilverStripe here on StackOverflow, but I'm more interested from a development point of view than a user or administrator point of view.

    Read the article

  • Applying Domain Model on top of Linq2Sql entities

    - by Thomas
    I am trying to practice the model first approach and I am putting together a domain model. My requirement is pretty simple: UserSession can have multiple ShoppingCartItems. I should start off by saying that I am going to apply the domain model interfaces to Linq2Sql generated entities (using partial classes). My requirement translates into three database tables (UserSession, Product, ShoppingCartItem where ProductId and UserSessionId are foreign keys in the ShoppingCartItem table). Linq2Sql generates these entities for me. I know I shouldn't even be dealing with the database at this point but I think it is important to mention. The aggregate root is UserSession as a ShoppingCartItem can not exist without a UserSession but I am unclear on the rest. What about Product? It is defiently an entity but should it be associated to ShoppingCartItem? Here are a few suggestion (they might all be incorrect implementations): public interface IUserSession { public Guid Id { get; set; } public IList<IShoppingCartItem> ShoppingCartItems{ get; set; } } public interface IShoppingCartItem { public Guid UserSessionId { get; set; } public int ProductId { get; set; } } Another one would be: public interface IUserSession { public Guid Id { get; set; } public IList<IShoppingCartItem> ShoppingCartItems{ get; set; } } public interface IShoppingCartItem { public Guid UserSessionId { get; set; } public IProduct Product { get; set; } } A third one is: public interface IUserSession { public Guid Id { get; set; } public IList<IShoppingCartItemColletion> ShoppingCartItems{ get; set; } } public interface IShoppingCartItemColletion { public IUserSession UserSession { get; set; } public IProduct Product { get; set; } } public interface IProduct { public int ProductId { get; set; } } I have a feeling my mind is too tightly coupled with database models and tables which is making this hard to grasp. Anyone care to decouple?

    Read the article

  • Automatically install and launch a code-signed application from Safari

    - by Thomas Jung
    Is it possible and if so what are the steps necessary to package (or build) a Mac OS X application and code-sign it so that it can be downloaded with Safari and automatically launch? ... possibly after the user responds to some sort of dialog explaining that it is a signed application and the publisher has been verified. An example of the user experience I am trying to create is "installing Google Chrome for the first time on Windows", which is a 3-click, less-than-a-minute process. For the concerned among you: I am not trying to create a drive-by download. I am fine with some sort of intermittent user step approving the download. I just want to make the installation as quick and painless as possible and not require the user drag the app from a mounted DMG into the application folder. This may not 100% jibe with established Mac OS X user interaction guidelines, but it would work better for the not-power users. I only need the high-level steps or pointers to resources ... my google-fu was weak on this one.

    Read the article

  • Get children count via HQL

    - by Thomas Lötzer
    Hi, I have a one-to-many mapping between a parent entity and child entities. Now I need to find the number of children associated with each parent for a list of parents. I am trying to do this with HQL but I am not sure how I can get the list of parents in there. Also, I don't know how I can return the entity itself and not just its ID. My current HQL query is: select new map(parent.id as parentId, count(*) as childCount) from Parent parent left join parent.children children group by parent.id but this only returns the ID and does not filter on specific parents. EDIT Based on Pascal's answer I have modified the query to select new map(parent as parent, count(elements(parent.children)) as childCount) from Parent parent group by parent That does work, but is prohibitively slow: 30 seconds instead of 400 ms on the same database.

    Read the article

  • std::map operator[] and automatically created new objects

    - by thomas-gies
    I'm a little bit scared about something like this: std::map<DWORD, DWORD> tmap; tmap[0]+=1; tmap[0]+=1; tmap[0]+=1; Since DWORD's are not automatically initialized, I'm always afraid of tmap[0] being a random number that is incremented. How does the map know hot to initialize a DWORD if the runtime does not know how to do it? Is it guaranteed, that the result is always tmap[0] == 3?

    Read the article

  • SQL Server Compact with Visual Studio 2008

    - by Thomas
    I am running SQL server 2008 and Visual Studio 2008 on Vista. I downloaded SQL server compact 3.5 SP1 from Microsofts website and ran the install. When I open the server explorer for any windows application that I'm working on with VS 2008 and right click on data connections and then on add a connection a dialog comes up with available data providers. The problem is that SQL compact is not one of the options. Any idea why SQL compact is not showing up as a data provider in VS 2008?

    Read the article

  • Is it possible to easily convert SqlCommand to T-SQL string ?

    - by Thomas Wanner
    I have a populated SqlCommand object containing the command text and parameters of various database types along with their values. What I need is a T-SQL script that I could simply execute that would have the same effect as calling the ExecuteNonQuery method on the command object. Is there an easy way to do such "script dump" or do I have to manually construct such script from the command object ?

    Read the article

  • Database tables - how many database?

    - by Thomas
    How many databases are needed for a social website? I have my tech team working on developing a social site but all their tables are in 1 database. I wanted to create separate table sets for user data, temporary tables, etc and thinking maybe have one separate database only for critical data, etc but I am not a tech person and now sure how this works? The site is going to be a local reviews website.

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 17 18 19 20 21 22 23 24 25 26 27 28  | Next Page >