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Finalizer
In computer science, a finalizer or finalize method is a special method that performs finalization, generally some form of cleanup. A finalizer is executed during object destruction, prior to the object being deallocated, and is complementary to an initializer, which is executed during object creation, following allocation. Finalizers are strongly discouraged by some, due to difficulty in proper use and the complexity they add, and alternatives are suggested instead, mainly the dispose pattern (see problems with finalizers). The term ''finalizer'' is mostly used in object-oriented and functional programming languages that use garbage collection, of which the archetype is Smalltalk. This is contrasted with a '' destructor'', which is a method called for finalization in languages with deterministic object lifetimes, archetypically C++. These are generally exclusive: a language will have either finalizers (if automatically garbage collected) or destructors (if manually memory manage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Object Destruction
In object-oriented programming (OOP), the object lifetime (or life cycle) of an object is the time between an object's creation and its destruction. Rules for object lifetime vary significantly between languages, in some cases between implementations of a given language, and lifetime of a particular object may vary from one run of the program to another. In some cases, object lifetime coincides with variable lifetime of a variable with that object as value (both for static variables and automatic variables), but in general, object lifetime is not tied to the lifetime of any one variable. In many cases – and by default in many object-oriented languages, particularly those that use garbage collection (GC) – objects are allocated on the heap, and object lifetime is not determined by the lifetime of a given variable: the value of a variable holding an object actually corresponds to a ''reference'' to the object, not the object itself, and destruction of the variable just des ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Object Creation
In object-oriented programming (OOP), the object lifetime (or life cycle) of an object is the time between an object's creation and its destruction. Rules for object lifetime vary significantly between languages, in some cases between implementations of a given language, and lifetime of a particular object may vary from one run of the program to another. In some cases, object lifetime coincides with variable lifetime of a variable with that object as value (both for static variables and automatic variables), but in general, object lifetime is not tied to the lifetime of any one variable. In many cases – and by default in many object-oriented languages, particularly those that use garbage collection (GC) – objects are allocated on the heap, and object lifetime is not determined by the lifetime of a given variable: the value of a variable holding an object actually corresponds to a ''reference'' to the object, not the object itself, and destruction of the variable just dest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manual Memory Management
In computer science, manual memory management refers to the usage of manual instructions by the programmer to identify and deallocate unused objects, or garbage. Up until the mid-1990s, the majority of programming languages used in industry supported manual memory management, though garbage collection has existed since 1959, when it was introduced with Lisp. Today, however, languages with garbage collection such as Java are increasingly popular and the languages Objective-C and Swift provide similar functionality through Automatic Reference Counting. The main manually managed languages still in widespread use today are C and C++ – see C dynamic memory allocation. Description Many programming languages use manual techniques to determine when to ''allocate'' a new object from the free store. C uses the malloc function; C++ and Java use the new operator; and many other languages (such as Python) allocate all objects from the free store. Determining when an object ought to be cr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Object Pool
The object pool pattern is a software creational design pattern that uses a set of initialized objects kept ready to use – a "pool" – rather than allocating and destroying them on demand. A client of the pool will request an object from the pool and perform operations on the returned object. When the client has finished, it returns the object to the pool rather than destroying it; this can be done manually or automatically. Object pools are primarily used for performance: in some circumstances, object pools significantly improve performance. Object pools complicate object lifetime, as objects obtained from and returned to a pool are not actually created or destroyed at this time, and thus require care in implementation. Description When it is necessary to work with numerous objects that are particularly expensive to instantiate and each object is only needed for a short period of time, the performance of an entire application may be adversely affected. An object pool desig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C++/CLI
C++/CLI is a variant of the C++ programming language, modified for Common Language Infrastructure. It has been part of Visual Studio 2005 and later, and provides interoperability with other .NET languages such as C#. Microsoft created C++/CLI to supersede Managed Extensions for C++. In December 2005, Ecma International published C++/CLI specifications as the ECMA-372 standard. Syntax changes C++/CLI should be thought of as a language of its own (with a new set of keywords, for example), instead of the C++ superset-oriented Managed C++ (MC++) (whose non-standard keywords were styled like or ). Because of this, there are some major syntactic changes, especially related to the elimination of ambiguous identifiers and the addition of .NET-specific features. Many conflicting syntaxes, such as the multiple versions of operator in MC++, have been split: in C++/CLI, .NET reference types are created with the new keyword (i.e. garbage collected new()). Also, C++/CLI has introduced the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Destructor (computer Programming)
In object-oriented programming, a destructor (sometimes abbreviated dtor) is a method which is invoked mechanically just before the memory of the object is released. It can happen when its lifetime is bound to scope and the execution leaves the scope, when it is embedded in another object whose lifetime ends, or when it was allocated dynamically and is released explicitly. Its main purpose is to free the resources (memory allocations, open files or sockets, database connections, resource locks, etc.) which were acquired by the object during its life and/or deregister from other entities which may keep references to it. Use of destructors is needed for the process of Resource Acquisition Is Initialization (RAII). With most kinds of automatic garbage collection algorithms, the releasing of memory may happen a long time after the object becomes unreachable, making destructors (called finalizers in this case) unsuitable for most purposes. In such languages, the freeing of resources i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Method (computer Programming)
A method in object-oriented programming (OOP) is a procedure associated with a message and an object. An object consists of ''state data'' and ''behavior''; these compose an ''interface'', which specifies how the object may be utilized by any of its various consumers. A method is a behavior of an object parametrized by a consumer. Data is represented as properties of the object, and behaviors are represented as methods. For example, a Window object could have methods such as open and close, while its state (whether it is open or closed at any given point in time) would be a property. In class-based programming, methods are defined within a class, and objects are instances of a given class. One of the most important capabilities that a method provides is ''method overriding'' - the same name (e.g., area) can be used for multiple different kinds of classes. This allows the sending objects to invoke behaviors and to delegate the implementation of those behaviors to the receiving o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dispose Pattern
In object-oriented programming, the dispose pattern is a design pattern for resource management. In this pattern, a resource is held by an object, and released by calling a conventional method – usually called close, dispose, free, release depending on the language – which releases any resources the object is holding onto. Many programming languages offer language constructs to avoid having to call the dispose method explicitly in common situations. The dispose pattern is primarily used in languages whose runtime environment have automatic garbage collection (see motivation below). Motivation Wrapping resources in objects Wrapping resources in objects is the object-oriented form of encapsulation, and underlies the dispose pattern. Resources are typically represented by handles (abstract references), concretely usually integers, which are used to communicate with an external system that provides the resource. For example, files are provided by the operating system (spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reference Counting
In computer science, reference counting is a programming technique of storing the number of references, pointers, or handles to a resource, such as an object, a block of memory, disk space, and others. In garbage collection algorithms, reference counts may be used to deallocate objects that are no longer needed. Advantages and disadvantages The main advantage of the reference counting over tracing garbage collection is that objects are reclaimed ''as soon as'' they can no longer be referenced, and in an incremental fashion, without long pauses for collection cycles and with clearly defined lifetime of every object. In real-time applications or systems with limited memory, this is important to maintain responsiveness. Reference counting is also among the simplest forms of memory management to implement. It also allows for effective management of non-memory resources such as operating system objects, which are often much scarcer than memory (tracing garbage collection systems us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Java (programming Language)
Java is a high-level, class-based, object-oriented programming language that is designed to have as few implementation dependencies as possible. It is a general-purpose programming language intended to let programmers ''write once, run anywhere'' ( WORA), meaning that compiled Java code can run on all platforms that support Java without the need to recompile. Java applications are typically compiled to bytecode that can run on any Java virtual machine (JVM) regardless of the underlying computer architecture. The syntax of Java is similar to C and C++, but has fewer low-level facilities than either of them. The Java runtime provides dynamic capabilities (such as reflection and runtime code modification) that are typically not available in traditional compiled languages. , Java was one of the most popular programming languages in use according to GitHub, particularly for client–server web applications, with a reported 9 million developers. Java was originally developed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inheritance (object-oriented Programming)
In object-oriented programming, inheritance is the mechanism of basing an object or class upon another object ( prototype-based inheritance) or class ( class-based inheritance), retaining similar implementation. Also defined as deriving new classes ( sub classes) from existing ones such as super class or base class and then forming them into a hierarchy of classes. In most class-based object-oriented languages, an object created through inheritance, a "child object", acquires all the properties and behaviors of the "parent object" , with the exception of: constructors, destructor, overloaded operators and friend functions of the base class. Inheritance allows programmers to create classes that are built upon existing classes, to specify a new implementation while maintaining the same behaviors ( realizing an interface), to reuse code and to independently extend original software via public classes and interfaces. The relationships of objects or classes through inheritance give ris ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common Language Infrastructure
The Common Language Infrastructure (CLI) is an open specification and technical standard originally developed by Microsoft and standardized by ISO/IEC (ISO/IEC 23271) and Ecma International (ECMA 335) that describes executable code and a runtime environment that allows multiple high-level languages to be used on different computer platforms without being rewritten for specific architectures. This implies it is platform agnostic. The .NET Framework, .NET and Mono are implementations of the CLI. The metadata format is also used to specify the API definitions exposed by the Windows Runtime. Overview Among other things, the CLI specification describes the following four aspects: ;The Common Type System (CTS) :A set of data types and operations that are shared by all CTS-compliant programming languages. ;The Metadata :Information about program structure is language-agnostic, so that it can be referenced between languages and tools, making it easy to work with code written in a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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