boost.threads Singleton initialization
hello. Is there preferred way to initialize (lazily) singleton data when using multiple threads from boost.threads? Thanks. ...
singleton
How To Create Per-Request Singleton in Pylons?
In our Pylons based web-app, we're creating a class that essentially provides some logging functionality. We need a new instance of this class for each http request that comes in, but only one per request. What is the proper way to go about this? Should we just create the object in middleware and store in in request.environ? Is there a ...
Monotouch threads, GC, WCF
Hi This is a question about best practices i guess but it applies directly to my current MT project. I'm using WCF services to communicate with the server. To do this i do the following: services.MethodToCall(params); and the asynch: services.OnMethodToCallCompleted += delegate{ //do stuff and ting }; This can lead to issue...
Call from a singleton class to a function which in turn calls that class's method
Hello, I am still looking for a way to phrase it properly (I'm not a native speaker...). So I have this class SQL which implements the singleton pattern (for obvious reasons) and I also have this function, checkUsr(), which queries the database using one of SQL's methods. Everything works fine as long as I don't call checkUsr() from w...
dao as a member of a servlet - normal?
I guess, DAO is thread safe, does not use any class members. So can it be used without any problem as a private field of a Servlet ? We need only one copy, and multiple threads can access it simultaneously, so why bother creating a local variable, right? ...
Java Singleton Pattern
Edit: Answered - error was method wasn't static I'm used the Singleton Design Pattern public class Singleton { private static final Singleton INSTANCE = new Singleton(); // Private constructor prevents instantiation from other classes private Singleton() {} public static Singleton getInstance() { return INSTANCE; ...
PHP - static DB class vs DB singleton object
I don't want to create a discussion about singleton better than static or better than global, etc. I read dozens of questions about it on SO, but I couldn't come up with an answer to this SPECIFIC question, so I hope someone could now illuminate me buy answering this question with one (or more) real simple EXAMPLES, and not theoretical d...
singleton factory connection pdo
Hey guys I am having a lot of trouble trying to understand this and I was just wondering if someone could help me with some questions. I found some code that is supposed to create a connection with pdo. The problem I was having was having my connection defined within functions. Someone suggested globals but then pointed to a 'better' sol...
How to get java singleton object manager to return any type of object?
I'm writing an interactive fiction game in java from scratch. I'm currently storing all of my game object references in a hashmap in a singleton called ObjectManager. ObjectManager has a function called get which takes an integer ID and returns the appropriate reference. The problem is that it returns a BaseObject when I need to retur...
what is the exact difference between PHP static class and singleton class
I have always used a Singleton class for a registry object in PHP. As all Singleton classes I think the main method looks like this: class registry { public static function singleton() { if( !isset( self::$instance ) ) { self::$instance = new registry(); } return self::$instance; }...
Static variables in Java for a test oObject creator
Hey, I have something like the following TestObjectCreator{ private static Person person; private static Company company; static { person = new Person() person.setName("Joe"); company = new Company(); company.setName("Apple"); } public Person createTestPerson(){ return person; } public Person createTe...
What is the best way to create a Singleton Webservice in PHP?
Hello, We have a need to access a DB that only allows one connection at a time. This screams "singleton" to me. The catch of course is that the singleton connection will be exposed (either directly or indirectly) via a web-service (most probable a SOAP based web-service - located on a separate server from the calling app(s) ) - which ...
[iphone] method created in a seperate class returns "out of scope"
Hey, I have created a Class (subclass of NSObject) which will hold all my SQLs/dbConnections etc.. in a seperate viewcontroller, i have instantiated the SQL's class and performed some actions, all went trough OK. but. one of my methods in the SQL's class is a method defined as follows: -(NSString *)queryTable:(NSUInteger *)fieldnum ...
Dependency Injection into your Singleton
I have a singleton that has a spring injected Dao (simplified below): public class MyService<T> implements Service<T> { private final Map<String, T> objects; private static MyService instance; MyDao myDao; public void set MyDao(MyDao myDao) { this. myDao = myDao; } private MyService() { this.ob...
Need advice on OOP philosophy
I'm trying to get the wheels turning on a large project in C#. My previous experience is in Delphi, where by default every form was created at applicaton startup and form references where held in (gasp) global variables. So I'm trying to adapt my thinking to a 100% object oriented environment, and my head is spinning just a little. My ...
ASP - Services static / singleton / instanciated ? Pros - Cons
Hi there. I have some problems with decisions on the design of ASP applications. The most articles i read in the last time, said that you should use instanciated services instead of static or singletons. But i get some headache, thinking about creating all services for each request i get and keep them in memory till garbage collector d...
How to create instance model that can be shared throughout a component (which can be created more than once)
I am trying to create a modular structure that will eventually live inside another actionscript/flex application. I am using cairngorm in the outside application and I'd like to create more than one instance of this new component in the inside application. Cairngorm doesn't work for creating multiple duplicate components because of the...
Using block around a static/singleton resource reference
This is interesting (to me anyway), and I'd like to see if anyone has a good answer and explanation for this behavior. Say you have a singleton database object (or static database object), and you have it stored in a class Foo. public class Foo { public static SqlConnection DBConn = new SqlConnection(ConfigurationManager.Connection...
iphone singleton object synchronization
I'm working on an iphone app but this is probably a general question. I have a singleton Model class and there would be scenarios where multiple NSOperations (threads) would exist and work with the singleton object. If they all call the same method in this object, do i need to have some locking mechanism? Or can this method be executed...
How to test Guice Singleton?
Guice Singletons are weird for me First I thought that IService ser = Guice.createInjector().getInstance(IService.class); System.out.println("ser=" + ser); ser = Guice.createInjector().getInstance(IService.class); System.out.println("ser=" + ser); will work as singleton, but it returns ser=Service2@1975b59 ser=Service2@1f934ad its...