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Ravenscar Profile
The Ravenscar profile is a subset of the Ada tasking features designed for safety-critical hard real-time computing. It was defined by a separate technical report in Ada 95; it is now part of the Ada 2012 Standard. It has been named after the English village of Ravenscar, the location of the 8th International Real-Time Ada Workshop (IRTAW 8). Restrictions of the profile A Ravenscar Ada application uses the following compiler directive: pragma Profile (Ravenscar); This is the same as writing the following set of configuration pragmas: pragma Task_Dispatching_Policy (FIFO_Within_Priorities); pragma Locking_Policy (Ceiling_Locking); pragma Detect_Blocking; pragma Restrictions ( No_Abort_Statements, No_Calendar, No_Dynamic_Attachment, No_Dynamic_Priorities, No_Implicit_Heap_Allocations, No_Local_Protected_Objects, No_Local_Timing_Events, No_Protect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ada (programming Language)
Ada is a structured, statically typed, imperative, and object-oriented high-level programming language, extended from Pascal and other languages. It has built-in language support for '' design by contract'' (DbC), extremely strong typing, explicit concurrency, tasks, synchronous message passing, protected objects, and non-determinism. Ada improves code safety and maintainability by using the compiler to find errors in favor of runtime errors. Ada is an international technical standard, jointly defined by the International Organization for Standardization (ISO), and the International Electrotechnical Commission (IEC). , the standard, called Ada 2012 informally, is ISO/IEC 8652:2012. Ada was originally designed by a team led by French computer scientist Jean Ichbiah of CII Honeywell Bull under contract to the United States Department of Defense (DoD) from 1977 to 1983 to supersede over 450 programming languages used by the DoD at that time. Ada was named after Ada Lovelace ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Safety-critical
A safety-critical system (SCS) or life-critical system is a system whose failure or malfunction may result in one (or more) of the following outcomes: * death or serious injury to people * loss or severe damage to equipment/property * environmental harm A safety-related system (or sometimes safety-involved system) comprises everything (hardware, software, and human aspects) needed to perform one or more safety functions, in which failure would cause a significant increase in the safety risk for the people or environment involved. Safety-related systems are those that do not have full responsibility for controlling hazards such as loss of life, severe injury or severe environmental degradation, environmental damage. The malfunction of a safety-involved system would only be that hazardous in conjunction with the failure of other systems or human error. Some safety organizations provide guidance on safety-related systems, for example the Health and Safety Executive (HSE) in the Un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Real-time Computing
Real-time computing (RTC) is the computer science term for hardware and software systems subject to a "real-time constraint", for example from event to system response. Real-time programs must guarantee response within specified time constraints, often referred to as "deadlines". Ben-Ari, Mordechai; "Principles of Concurrent and Distributed Programming", ch. 16, Prentice Hall, 1990, , page 164 Real-time responses are often understood to be in the order of milliseconds, and sometimes microseconds. A system not specified as operating in real time cannot usually ''guarantee'' a response within any timeframe, although ''typical'' or ''expected'' response times may be given. Real-time processing ''fails'' if not completed within a specified deadline relative to an event; deadlines must always be met, regardless of system load. A real-time system has been described as one which "controls an environment by receiving data, processing them, and returning the results sufficiently quic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ravenscar, North Yorkshire
Ravenscar is a coastal village in the Scarborough district of North Yorkshire, England. It is within the civil parish of Staintondale and the North York Moors National Park, and is north of Scarborough. A National Trail, the Cleveland Way, passes through Ravenscar, which is also the eastern terminus of the Lyke Wake Walk. The official end of the walk is at a point where the path meets the coast road. History Ravenscar was the location of a late 4th century Roman signal station, part of a chain that extended along the Yorkshire coast. To the north of the village is the old Peak alum works, now a National Trust site, but once an important part of the dyeing industry. The last alum works at Ravenscar closed down in 1871 after the invention of a synthetic dye fixer. At the edge of the village is a disused windmill, Peak Mill, which dates from 1858. Until the early 20th century Ravenscar was known as 'Peak' or 'The Peak'. At the turn of the 19th–20th century, plans were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Directive (programming)
In computer programming, a directive or pragma (from "pragmatic") is a language construct that specifies how a compiler (or other translator) should process its input. Directives are not part of the grammar of a programming language, and may vary from compiler to compiler. They can be processed by a preprocessor to specify compiler behavior, or function as a form of in-band parameterization. In some cases directives specify global behavior, while in other cases they only affect a local section, such as a block of programming code. In some cases, such as some C programs, directives are optional compiler hints, and may be ignored, but normally they are prescriptive, and must be followed. However, a directive does not perform any action in the language itself, but rather only a change in the behavior of the compiler. This term could be used to refer to proprietary third party tags and commands (or markup) embedded in code that result in additional executable processing that extend t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High Integrity Software
High-integrity software is software whose failure may cause serious damage with possible "life-threatening consequences." “Integrity is important as it demonstrates the safety, security, and maintainability of… code.” Examples of high-integrity software are nuclear reactor control, avionics software, and process control software. A number of standards are applicable to high-integrity software, including: * DO-178C, Software Considerations in Airborne Systems and Equipment Certification * CENELEC EN 50128, Railway applications - Communication, signalling and processing systems - Software for railway control and protection systems * IEC 61508, Functional Safety of Electrical/Electronic/Programmable Electronic Safety-related Systems (E/E/PE, or E/E/PES) See also * Safety-critical system * High availability software * Formal methods * Software of unknown pedigree SOUP stands for software of unknown (or uncertain) pedigree (or provenance), and is a term often used in the context ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SPARK (programming Language)
SPARK is a formally defined computer programming language based on the Ada programming language, intended for the development of high integrity software used in systems where predictable and highly reliable operation is essential. It facilitates the development of applications that demand safety, security, or business integrity. Originally, there were three versions of the SPARK language (SPARK83, SPARK95, SPARK2005) based on Ada 83, Ada 95 and Ada 2005 respectively. A fourth version of the SPARK language, SPARK 2014, based on Ada 2012, was released on April 30, 2014. SPARK 2014 is a complete re-design of the language and supporting verification tools. The SPARK language consists of a well-defined subset of the Ada language that uses contracts to describe the specification of components in a form that is suitable for both static and dynamic verification. In SPARK83/95/2005, the contracts are encoded in Ada comments and so are ignored by any standard Ada compiler, but are p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ACM SIGAda Ada Letters
ACM or A.C.M. may refer to: Aviation * AGM-129 ACM, 1990–2012 USAF cruise missile * Air chief marshal * Air combat manoeuvring or dogfighting * Air cycle machine * Arica Airport (Colombia) (IATA: ACM), in Arica, Amazonas, Colombia Computing * Abstract Control Model, for USB to act as a serial port * Association for Computing Machinery, a US-based international learned society for computing * Asynchronous communication mechanism * Audio Compression Manager, Microsoft Windows codec manager Education * Allegany College of Maryland * Associated Colleges of the Midwest * Association for College Management Music * Academy of Contemporary Music, in Guildford, England, UK * Academy of Country Music * Association for Contemporary Music, in the Russian Federation Organizations or businesses * Alliance for Community Media * American Center for Mobility * American Ceylon Mission * Anaconda Copper Mining Company * Anti-Coalition Militia, anti-NATO Taliban in Afghanistan * Anti-cult move ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
