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Exception Safety
Exception safety is the state of code working correctly when exceptions are thrown. To aid in ensuring exception safety, C++ standard library developers have devised a set of ''exception safety levels'', contractual guarantees of the behavior of a data structure's operations with regards to exceptions. Library implementers and clients can use these guarantees when reasoning about exception handling correctness. The exception safety levels apply equally to other languages and error-handling mechanisms. History As David Abrahams writes, "nobody ever spoke of 'error-safety' before C++ had exceptions." The term appeared as the topic of publications in JTC1/SC22/WG21, the C++ standard committee, as early as 1994. Exception safety for the C++ standard library was first formalized for STLport by Abrahams, establishing the basic safety/strong safety distinction. This was extended to the modern basic/strong/nothrow guarantees in a later proposal. Background Exceptions provide a fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exception Handling
In computing and computer programming, exception handling is the process of responding to the occurrence of ''exceptions'' – anomalous or exceptional conditions requiring special processing – during the execution of a program. In general, an exception breaks the normal flow of execution and executes a pre-registered ''exception handler''; the details of how this is done depend on whether it is a hardware or software exception and how the software exception is implemented. Exception handling, if provided, is facilitated by specialized programming language constructs, hardware mechanisms like interrupts, or operating system (OS) inter-process communication (IPC) facilities like signals. Some exceptions, especially hardware ones, may be handled so gracefully that execution can resume where it was interrupted. Definition The definition of an exception is based on the observation that each procedure has a precondition, a set of circumstances for which it will terminate "normal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
David Abrahams (computer Programmer)
David Abrahams is a computer programmer and author. He is the son of physicist Elihu Abrahams and choreographer Geulah Abrahams. He is most well known for his activities related to the C++ programming language. In particular his contributions to the language include the delineating of a theory of exceptions, sitting on the C++ Standards Committee, being a founding member of Boost and co-authoring a book on the subject of template metaprogramming. Abrahams became a member of the C++ Standards Committee in 1996 and served until 2012. During the standardization process that resulted in the first ANSI standard C++ – in 1998 – Abrahams was a principal driving force behind detailing the exception safety of the C++ Standard Library. Many of the functions and methods of the standard are specified with one of three guarantees. Together these have become known as the Abrahams guarantees. Following the standardization, Abrahams became one of the founding members of Boost.org, a comm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ISO/IEC JTC 1/SC 22
ISO/IEC JTC 1/SC 22 Programming languages, their environments and system software interfaces is a standardization subcommittee of the Joint Technical Committee ISO/IEC JTC 1 of the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC) that develops and facilitates standards within the fields of programming languages, their environments and system software interfaces. ISO/IEC JTC 1/SC 22 is also sometimes referred to as the " portability subcommittee". The international secretariat of ISO/IEC JTC 1/SC 22 is the American National Standards Institute (ANSI), located in the United States. History ISO/IEC JTC 1/SC 22 was created in 1985, with the intention of creating a JTC 1 subcommittee that would address standardization within the field of programming languages, their environments and system software interfaces. Before the creation of ISO/IEC JTC 1/SC 22, programming language standardization was addressed by ISO TC 97/SC 5. Many o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard Template Library
The Standard Template Library (STL) is a Library (computer science), software library originally designed by Alexander Stepanov for the C++ programming language that influenced many parts of the C++ Standard Library. It provides four components called ''Algorithm (C++), algorithms'', ''Container (data structure), containers'', ''Function object, functions'', and ''iterators''. The STL provides a set of common C++ classes, classes for C++, such as containers and associative arrays, that can be used with any built-in type and with any user-defined type that supports some elementary operations (such as copying and assignment). STL algorithms are independent of containers, which significantly reduces the complexity of the library. The STL achieves its results through the use of template (programming), templates. This approach provides compile-time polymorphism that is often more efficient than traditional Polymorphism in object-oriented programming, run-time polymorphism. Modern C+ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C++ Standard Library
The C standard library or libc is the standard library for the C programming language, as specified in the ISO C standard.ISO/IEC (2018). '' ISO/IEC 9899:2018(E): Programming Languages - C §7'' Starting from the original ANSI C standard, it was developed at the same time as the C library POSIX specification, which is a superset of it. Since ANSI C was adopted by the International Organization for Standardization, the C standard library is also called the ISO C library. The C standard library provides macros, type definitions and functions for tasks such as string handling, mathematical computations, input/output processing, memory management, and several other operating system services. Application programming interface Header files The application programming interface (API) of the C standard library is declared in a number of header files. Each header file contains one or more function declarations, data type definitions, and macros. After a long period of stabil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Invariant (computer Science)
In mathematics, an invariant is a property of a mathematical object (or a class of mathematical objects) which remains unchanged after operations or transformations of a certain type are applied to the objects. The particular class of objects and type of transformations are usually indicated by the context in which the term is used. For example, the area of a triangle is an invariant with respect to isometries of the Euclidean plane. The phrases "invariant under" and "invariant to" a transformation are both used. More generally, an invariant with respect to an equivalence relation is a property that is constant on each equivalence class. Invariants are used in diverse areas of mathematics such as geometry, topology, algebra and discrete mathematics. Some important classes of transformations are defined by an invariant they leave unchanged. For example, conformal maps are defined as transformations of the plane that preserve angles. The discovery of invariants is an important s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resource Leak
In computer science, a resource leak is a particular type of resource consumption by a computer program where the program does not release resources it has acquired. This condition is normally the result of a bug in a program. Typical resource leaks include memory leak and handle leak, particularly file handle leaks, though memory is often considered separately from other resources. Examples of resources available in limited numbers to the operating system include internet sockets, file handles, process table entries, and process identifiers (PIDs). Resource leaks are often a minor problem, causing at most minor slowdown and being recovered from after processes terminate. In other cases resource leaks can be a major problem, causing resource starvation and severe system slowdown or instability, crashing the leaking process, other processes, or even the system. Resource leaks often go unnoticed under light load and short runtimes, and these problems only manifest themselves under ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Memory Leak
In computer science, a memory leak is a type of resource leak that occurs when a computer program incorrectly manages memory allocations in a way that Computer memory, memory which is no longer needed is not released. A memory leak may also happen when an object (computer science), object is stored in memory but cannot be accessed by the running code (i.e. unreachable memory). A memory leak has symptoms similar to a number of other problems and generally can only be diagnosed by a programmer with access to the program's source code. A related concept is the "space leak", which is when a program consumes excessive memory but does eventually release it. Because they can exhaust available system memory as an application runs, memory leaks are often the cause of or a contributing factor to software aging. Consequences A memory leak reduces the performance of the computer by reducing the amount of available memory. Eventually, in the worst case, too much of the available memory may b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exception Handling Syntax
Exception handling syntax is the set of keywords and/or structures provided by a computer programming language to allow exception handling, which separates the handling of errors that arise during a program's operation from its ordinary processes. Syntax for exception handling varies between programming languages, partly to cover semantic differences but largely to fit into each language's overall syntactic structure. Some languages do not call the relevant concept "exception handling"; others may not have direct facilities for it, but can still provide means to implement it. Most commonly, error handling uses a try... atch...finally...] block, and errors are created via a throw statement, but there is significant variation in naming and syntax. Catalogue of exception handling syntaxes Ada ; Exception declarations Some_Error : exception; ; Raising exceptions raise Some_Error; raise Some_Error with "Out of memory"; -- specific diagnostic message ; Exception handling a ... [...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] |
Resource Leak
In computer science, a resource leak is a particular type of resource consumption by a computer program where the program does not release resources it has acquired. This condition is normally the result of a bug in a program. Typical resource leaks include memory leak and handle leak, particularly file handle leaks, though memory is often considered separately from other resources. Examples of resources available in limited numbers to the operating system include internet sockets, file handles, process table entries, and process identifiers (PIDs). Resource leaks are often a minor problem, causing at most minor slowdown and being recovered from after processes terminate. In other cases resource leaks can be a major problem, causing resource starvation and severe system slowdown or instability, crashing the leaking process, other processes, or even the system. Resource leaks often go unnoticed under light load and short runtimes, and these problems only manifest themselves under ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
