Search results
Results From The WOW.Com Content Network
Some consider the singleton to be an anti-pattern that introduces global state into an application, often unnecessarily. This introduces a potential dependency on the singleton by other objects, requiring analysis of implementation details to determine whether a dependency actually exists. [ 7 ]
Object pool pattern: avoid expensive acquisition and release of resources by recycling objects that are no longer in use; Prototype pattern: used when the type of objects to create is determined by a prototypical instance, which is cloned to produce new objects; Singleton pattern: restrict instantiation of a class to one object
There are valid forms of the pattern, including the use of the volatile keyword in Java and explicit memory barriers in C++. [4] The pattern is typically used to reduce locking overhead when implementing "lazy initialization" in a multi-threaded environment, especially as part of the Singleton pattern. Lazy initialization avoids initializing a ...
See Singleton pattern. A singleton is also a variable that is only used once in a program, usually indicating a programming mistake. See singleton variable. From the start of the term 'Singleton pattern': In software engineering, the singleton design pattern is designed to restrict instantiation of a class to one (or a few) objects.
Singleton object: only instance of its class for the lifetime of the program; Filter object: receives a stream of data as its input and transforms it into the object's output; As an example of an object anti-pattern, the God object knows or does too much.
A primary criticism of Design Patterns is that its patterns are simply workarounds for missing features in C++, replacing elegant abstract features with lengthy concrete patterns, essentially becoming a "human compiler". Paul Graham wrote: [8] When I see patterns in my programs, I consider it a sign of trouble.
In class-based programming, a factory is an abstraction of a constructor of a class, while in prototype-based programming a factory is an abstraction of a prototype object. A constructor is concrete in that it creates objects as instances of one class, and by a specified process (class instantiation), while a factory can create objects by instantiating various classes, or by using other ...
Whereas the singleton allows only one instance of a class to be created, the multiton pattern allows for the controlled creation of multiple instances, which it manages through the use of a map. Rather than having a single instance per application (e.g. the java.lang.Runtime object in the Java programming language) the multiton pattern instead ...