Here is a singleton design pattern example. Simple Singleton Pattern: (Lazy Initialization + ThreadSafe with synchronized block) This implementation uses the same double-checkedlockingmechanism as in the previous implementation. The addedlogging statementshelp demonstrate when the instance is being created ...
Note that instead of locking ontypeof(Singleton)as some versions of this implementation do, I lock on the value of a static variable which is private to the class. Locking on objects which other classes can access and lock on (such as the type) risks performance issues and even deadlocks....
TheSingleton1implementation is bad because it is not thread-safe. Two different threads could both pass the if test when the mInstance is null, then both of them create instances, which violates the singleton pattern. The advantage of this implementation is the instance is created inside the In...
The simplest implementation of the Singleton Pattern is not thread safe, which may result in two different threads evaluate the instance value tonulland actually create two instances of the object thus completely violating the core concept of the Singleton Pattern. // This is not recommended impleme...
The question remains, where should we use the real Singleton pattern? Honestly, I’ve never used the full Gang of Four implementation in a game. To ensure single instantiation, I usually simply use a static class. If that doesn’t work, I’ll use a static flag to check at runtime ...
Singleton Design Pattern - Learn about the Singleton Design Pattern, its implementation, and use cases in software development.
I don't think you'll have a situation where you initialize an object more than once with this implementation. The second call to alloc will return nil, not the object, so you'll be calling [nil init]. If you’re a working programmer, you’ve likely used or at least heard of design...
The pattern is useful whenever you want a single global object in your application. Other uses might include a global exception handler, application security, or a single point of interface to another application.Implementation ExampleTo implement a class of this type, override the constructor and ...
This article describes the Design Pattern "Singleton" and its usage in the programming language Java. 1. The Singleton Pattern in Java 1.1. Overview In Java, the Singleton pattern ensures that only one instance of a class is created and provides a global point of access to this instance. ...
Implementation variants of the singleton design pattern[C]//On the Move to Meaningful Internet Systems: OTM 2008 Workshops. Berlin Heidelberg: Springer, 2008: 396-406.Stencel, K. and P. Wegrzynowicz, 2008. Implementation Variants of the Singleton Design Pattern, Lecture Notes in Computer Science...