|
Sequential Consistency
Sequential consistency is a consistency model used in the domain of concurrent computing (e.g. in distributed shared memory, distributed transactions, etc.). It is the property that "... the result of any execution is the same as if the operations of all the processors were executed in some sequential order, and the operations of each individual processor appear in this sequence in the order specified by its program." That is, the execution order of a program in the same processor (or thread) is the same as the program order, while the execution order of a program on different processors (or threads) is undefined. In an example like this: execution order between A1, B1 and C1 is preserved, that is, A1 runs before B1, and B1 before C1. The same for A2 and B2. But, as execution order between processors is undefined, B2 might run before or after C1 (B2 might physically run before C1, but the effect of B2 might be seen after that of C1, which is the same as "B2 run after C1") Conc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Consistency Model
In computer science, a consistency model specifies a contract between the programmer and a system, wherein the system guarantees that if the programmer follows the rules for operations on memory, memory will be data consistency, consistent and the results of reading, writing, or updating memory will be predictable. Consistency models are used in Distributed computing, distributed systems like distributed shared memory systems or distributed data stores (such as filesystems, databases, optimistic replication systems or web caching). Consistency is different from coherence, which occurs in systems that are cache coherence, cached or cache-less, and is consistency of data with respect to all processors. Coherence deals with maintaining a global order in which writes to a single location or single variable are seen by all processors. Consistency deals with the ordering of operations to multiple locations with respect to all processors. High level languages, such as C++ and Java (progr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Instruction Set Architecture
In computer science, an instruction set architecture (ISA) is an abstract model that generally defines how software controls the CPU in a computer or a family of computers. A device or program that executes instructions described by that ISA, such as a central processing unit (CPU), is called an ''implementation'' of that ISA. In general, an ISA defines the supported instructions, data types, registers, the hardware support for managing main memory, fundamental features (such as the memory consistency, addressing modes, virtual memory), and the input/output model of implementations of the ISA. An ISA specifies the behavior of machine code running on implementations of that ISA in a fashion that does not depend on the characteristics of that implementation, providing binary compatibility between implementations. This enables multiple implementations of an ISA that differ in characteristics such as performance, physical size, and monetary cost (among other things), but t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linearizability
In concurrent programming, an operation (or set of operations) is linearizable if it consists of an ordered list of invocation and response events, that may be extended by adding response events such that: # The extended list can be re-expressed as a sequential history (is serializable). # That sequential history is a subset of the original unextended list. Informally, this means that the unmodified list of events is linearizable if and only if its invocations were serializable, but some of the responses of the serial schedule have yet to return. In a concurrent system, processes can access a shared object at the same time. Because multiple processes are accessing a single object, a situation may arise in which while one process is accessing the object, another process changes its contents. Making a system linearizable is one solution to this problem. In a linearizable system, although operations overlap on a shared object, each operation appears to take place instantaneousl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concurrent Data Structure
In computer science, a concurrent data structure (also called shared data structure) is a data structure designed for access and modification by multiple computing threads (or processes or nodes) on a computer, for example concurrent queues, concurrent stacks etc. The concurrent data structure is typically considered to reside in an abstract storage environment known as shared memory, which may be physically implemented as either a tightly coupled or a distributed collection of storage modules. Basic principles Concurrent data structures, intended for use in parallel or distributed computing environments, differ from "sequential" data structures, intended for use on a uni-processor machine, in several ways. Most notably, in a sequential environment one specifies the data structure's properties and checks that they are implemented correctly, by providing safety properties. In a concurrent environment, the specification must also describe liveness properties which an impl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Write-back Cache
In computing, a cache ( ) is a hardware or software component that stores data so that future requests for that data can be served faster; the data stored in a cache might be the result of an earlier computation or a copy of data stored elsewhere. A cache hit occurs when the requested data can be found in a cache, while a cache miss occurs when it cannot. Cache hits are served by reading data from the cache, which is faster than recomputing a result or reading from a slower data store; thus, the more requests that can be served from the cache, the faster the system performs. To be cost-effective, caches must be relatively small. Nevertheless, caches are effective in many areas of computing because typical computer applications access data with a high degree of locality of reference. Such access patterns exhibit temporal locality, where data is requested that has been recently requested, and spatial locality, where data is requested that is stored near data that has already bee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RISC-V
RISC-V (pronounced "risk-five") is an open standard instruction set architecture (ISA) based on established reduced instruction set computer (RISC) principles. The project commenced in 2010 at the University of California, Berkeley. It transferred to the RISC-V Foundation in 2015, and from there to RISC-V International, a Swiss non-profit entity, in November 2019. Similar to several other RISC ISAs, e.g. Amber (processor), Amber (ARMv2)(2001), SuperH#J_Core, J-Core(2015), OpenRISC(2000), or OpenSPARC(2005), RISC-V is offered under royalty-free open-source licenses. The documents defining the RISC-V instruction set architecture (ISA) are offered under a Creative Commons license or a BSD licenses, BSD License. Mainline support for RISC-V was added to the Linux 5.17 kernel in 2022, along with its toolchain. In July 2023, RISC-V, in its 64-bit computing, 64-bit variant called riscv64, was included as an official architecture of Linux distribution Debian, in its Debian version histor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ARM Architecture Family
ARM (stylised in lowercase as arm, formerly an acronym for Advanced RISC Machines and originally Acorn RISC Machine) is a family of RISC instruction set architectures (ISAs) for computer processors. Arm Holdings develops the ISAs and licenses them to other companies, who build the physical devices that use the instruction set. It also designs and licenses cores that implement these ISAs. Due to their low costs, low power consumption, and low heat generation, ARM processors are useful for light, portable, battery-powered devices, including smartphones, laptops, and tablet computers, as well as embedded systems. However, ARM processors are also used for desktops and servers, including Fugaku, the world's fastest supercomputer from 2020 to 2022. With over 230 billion ARM chips produced, , ARM is the most widely used family of instruction set architectures. There have been several generations of the ARM design. The original ARM1 used a 32-bit internal structure but h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X86-64
x86-64 (also known as x64, x86_64, AMD64, and Intel 64) is a 64-bit extension of the x86 instruction set architecture, instruction set. It was announced in 1999 and first available in the AMD Opteron family in 2003. It introduces two new operating modes: 64-bit mode and compatibility mode, along with a new four-level paging mechanism. In 64-bit mode, x86-64 supports significantly larger amounts of virtual memory and physical memory compared to its 32-bit computing, 32-bit predecessors, allowing programs to utilize more memory for data storage. The architecture expands the number of general-purpose registers from 8 to 16, all fully general-purpose, and extends their width to 64 bits. Floating-point arithmetic is supported through mandatory SSE2 instructions in 64-bit mode. While the older x87 FPU and MMX registers are still available, they are generally superseded by a set of sixteen 128-bit Processor register, vector registers (XMM registers). Each of these vector registers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strict Consistency
In computer science, a consistency model specifies a contract between the programmer and a system, wherein the system guarantees that if the programmer follows the rules for operations on memory, memory will be consistent and the results of reading, writing, or updating memory will be predictable. Consistency models are used in distributed systems like distributed shared memory systems or distributed data stores (such as filesystems, databases, optimistic replication systems or web caching). Consistency is different from coherence, which occurs in systems that are cached or cache-less, and is consistency of data with respect to all processors. Coherence deals with maintaining a global order in which writes to a single location or single variable are seen by all processors. Consistency deals with the ordering of operations to multiple locations with respect to all processors. High level languages, such as C++ and Java, maintain the consistency contract by translating memory oper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concurrent Computing
Concurrent computing is a form of computing in which several computations are executed '' concurrently''—during overlapping time periods—instead of ''sequentially—''with one completing before the next starts. This is a property of a system—whether a program, computer, or a network—where there is a separate execution point or "thread of control" for each process. A ''concurrent system'' is one where a computation can advance without waiting for all other computations to complete. Concurrent computing is a form of modular programming. In its paradigm an overall computation is factored into subcomputations that may be executed concurrently. Pioneers in the field of concurrent computing include Edsger Dijkstra, Per Brinch Hansen, and C.A.R. Hoare. Introduction The concept of concurrent computing is frequently confused with the related but distinct concept of parallel computing, Pike, Rob (2012-01-11). "Concurrency is not Parallelism". ''Waza conference'', 11 Ja ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kourosh Gharachorloo
Kourosh (; also spelled as Koorosh or Kurosh), is a Persian male name common in Iran (Persia). Kourosh is composed of ''kouro''- un+ -''sh'' - roprietorial suffix meaning "Lord of the sun". It was the throne name of Cyrus the Great and some other kings of the Achaemenid dynasty, historically translated into English and Latin as "Cyrus". Etymology The name ''Cyrus'' is a Latinized form derived from the Greek Κῦρος, ''Kỹros'', itself from the Old Persian ''Kūruš''. The name and its meaning has been recorded in ancient inscriptions in different languages. The ancient Greek historians Ctesias and Plutarch noted that Cyrus was named from ''Kuros'', the Sun, a concept which has been interpreted as meaning "like the Sun" (Khurvash) by noting its relation to the Persian noun for sun, ''khouro'', while using ''-sh'' as a proprietorial suffix.; Plutarch, ''Artaxerxes'' 1. classics.mit.edu Photius, ''Epitome of Ctesias' Persica'' 5livius.org This may also point to a relations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sarita V
Sarita may refer to: Sarah”, meaning “woman of high rank, Princess, essence, speckled”. --> People * Saritha, Indian actress * Sarita Adhana (born 1987), Indian para-archer * Sarita Austin, American politician * Saritha Nair, Indian businesswoman, involved in the 2013 Kerala solar panel scam * Sarita Choudhury (born 1966), British-Indian actress * Sarita Colonia (1914–1940), Peruvian folk saint * Sarita Edgerton, American politician * Sarita Khajuria (1974–2003), British-Indian actress * Sarita Joshi (born 1941), Indian television actress * Sarita Pérez de Tagle (born 1986), Filipina actress * Sarita Schoenebeck, American computer scientist * Laishram Sarita Devi (born 1982), Indian boxer * Sarita, ring name of professional wrestler Sarah Stock (born 1979) Other uses * 796 Sarita, a minor planet * ''Saritha'' (film), a 1977 Indian film * ''Sarita'' (magazine), a Hindi magazine published by Delhi Press Group * ''Sarita'' (play), a 1984 play by Maria Ire ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
