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Virtual Threads
In computer programming, a virtual thread is a Thread (computing), thread that is managed by a runtime library or virtual machine (VM) and made to resemble "real" operating system thread to code executing on it, while requiring substantially fewer resources than the latter. Virtual threads allows for tens of millions of preemptive tasks and events on a 2021 consumer-grade computer, compared to low thousands of operating system threads. Preemptive execution is important to performance gains through parallelism and fast preemptive response times for tens of millions of events. Earlier constructs that are not or not always preemptive, such as coroutines, green threads or the largely single-threaded Node.js, introduce delays in responding to asynchronous events such as every incoming request in a server application. Definition Virtual threads are preemptive * Important for response performance, a virtual thread can react to events without programmer intervention or before concl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Programming
Computer programming or coding is the composition of sequences of instructions, called computer program, programs, that computers can follow to perform tasks. It involves designing and implementing algorithms, step-by-step specifications of procedures, by writing source code, code in one or more programming languages. Programmers typically use high-level programming languages that are more easily intelligible to humans than machine code, which is directly executed by the central processing unit. Proficient programming usually requires expertise in several different subjects, including knowledge of the Domain (software engineering), application domain, details of programming languages and generic code library (computing), libraries, specialized algorithms, and Logic#Formal logic, formal logic. Auxiliary tasks accompanying and related to programming include Requirements analysis, analyzing requirements, Software testing, testing, debugging (investigating and fixing problems), imple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Async/await
In computer programming, the async/await pattern is a syntactic feature of many programming languages that allows an asynchronous, non-blocking function to be structured in a way similar to an ordinary synchronous function. It is semantically related to the concept of a coroutine and is often implemented using similar techniques, and is primarily intended to provide opportunities for the program to execute other code while waiting for a long-running, asynchronous task to complete, usually represented by promises or similar data structures. The feature is found in C#, C++, Python, F#, Hack, Julia, Dart, Kotlin, Rust, Nim, JavaScript, and Swift. History F# added asynchronous workflows with await points in version 2.0 in 2007. This influenced the async/await mechanism added to C#. Microsoft first released a version of C# with async/await in the Async CTP (2011). It was later officially released in C# 5 (2012). Haskell lead developer Simon Marlow created the async pack ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protothreads
A protothread is a low-overhead mechanism for concurrent programming. Protothreads function as Call stack, stackless, lightweight Thread (computer science), threads, or coroutines, providing a blocking context cheaply using minimal memory per protothread (on the order of single bytes). Protothreads are used to accomplish a Preemption (computing), non-preempted form of concurrency (computer science), concurrency known as cooperative multitasking and, therefore, do not incur context switch when yielding to another thread. Within a protothread, yielding is accomplished by utilizing Duff's device within a thread's function and an external variable used in within the switch statement. This allows jumping (resuming) from a yield upon another function call. In order to Blocking (computing), block threads, these yields may be guarded by a Conditional (computer programming), conditional so that successive calls to the same function will yield unless the guard conditional is true. A feature ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GNU Portable Threads
GNU Pth (Portable Threads) is a POSIX/ANSI- C based user space thread library for UNIX platforms that provides priority-based scheduling for multithreading applications. GNU Pth targets for a high degree of portability. It is part of the GNU Project. Pth also provides API emulation for POSIX threads for backward compatibility. GNU Pth uses an N:1 mapping to kernel-space threads, i.e., the scheduling is done completely by the GNU Pth library and the kernel itself is not aware of the N threads in user-space. Because of this there is no possibility to utilize SMP as kernel dispatching would be necessary. See also *Fiber Fiber (spelled fibre in British English; from ) is a natural or artificial substance that is significantly longer than it is wide. Fibers are often used in the manufacture of other materials. The strongest engineering materials often inco ... References External links *Downloads {{DEFAULTSORT:Gnu Portable Threads Application programming interf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fiber (computer Science)
In computer science, a fiber is a particularly lightweight thread of execution. Like threads, fibers share address space. However, fibers use cooperative multitasking while threads use preemptive multitasking. Threads often depend on the kernel's thread scheduler to preempt a busy thread and resume another thread; fibers yield themselves to run another fiber while executing. Threads, fibers and coroutines The key difference between fibers and kernel threads is that fibers use cooperative context switching, instead of preemptive time-slicing. In effect, fibers extend the concurrency taxonomy: * on a single computer, multiple processes can run * within a single process, multiple threads can run * within a single thread, multiple fibers can run Fibers (sometimes called stackful coroutines or user mode cooperatively scheduled threads) and stackless coroutines (compiler synthesized state machines) represent two distinct programming facilities with vast performance and funct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Global Interpreter Lock
A global interpreter lock (GIL) is a mechanism used in computer-language Interpreter (computing), interpreters to synchronize the execution of Threads (computer science), threads so that only one native thread (per process) can execute basic operations (such as memory allocation and reference counting) at a time. As a general rule, an interpreter that uses GIL will see only one thread to execute at a time, even if it runs on a multi-core processor, although some implementations provide for CPU-bound, CPU intensive code to release the GIL, allowing multiple threads to use multiple cores. Some popular interpreters that have a GIL are CPython and Ruby MRI. Technical background concepts A global interpreter lock (GIL) is a mutual exclusion, mutual-exclusion lock (computer science), lock held by a programming language interpreter (computing), interpreter Thread (computer science), thread to avoid sharing code that is not thread-safe with other threads. In implementations with a GIL, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coroutine
Coroutines are computer program components that allow execution to be suspended and resumed, generalizing subroutines for cooperative multitasking. Coroutines are well-suited for implementing familiar program components such as cooperative tasks, exceptions, event loops, iterators, infinite lists and pipes. They have been described as "functions whose execution you can pause". Melvin Conway coined the term ''coroutine'' in 1958 when he applied it to the construction of an assembly program. The first published explanation of the coroutine appeared later, in 1963. Definition and types There is no single precise definition of coroutine. In 1980 Christopher D. Marlin summarized two widely-acknowledged fundamental characteristics of a coroutine: # the values of data local to a coroutine persist between successive calls; # the execution of a coroutine is suspended as control leaves it, only to carry on where it left off when control re-enters the coroutine at some later s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light-weight Process
In computer operating systems, a light-weight process (LWP) is a means of achieving multitasking. In the traditional meaning of the term, as used in Unix System V and Solaris, a LWP runs in user space on top of a single kernel thread and shares its address space and system resources with other LWPs within the same process. Multiple user-level threads, managed by a thread library, can be placed on top of one or many LWPs - allowing multitasking to be done at the user level, which can have some performance benefits. In some operating systems, there is no separate LWP layer between kernel threads and user threads. This means that user threads are implemented directly on top of kernel threads. In those contexts, the term "light-weight process" typically refers to kernel threads and the term "threads" can refer to user threads. On Linux, user threads are implemented by allowing certain processes to share resources, which sometimes leads to these processes to be called "light wei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Global Interpreter Lock
A global interpreter lock (GIL) is a mechanism used in computer-language Interpreter (computing), interpreters to synchronize the execution of Threads (computer science), threads so that only one native thread (per process) can execute basic operations (such as memory allocation and reference counting) at a time. As a general rule, an interpreter that uses GIL will see only one thread to execute at a time, even if it runs on a multi-core processor, although some implementations provide for CPU-bound, CPU intensive code to release the GIL, allowing multiple threads to use multiple cores. Some popular interpreters that have a GIL are CPython and Ruby MRI. Technical background concepts A global interpreter lock (GIL) is a mutual exclusion, mutual-exclusion lock (computer science), lock held by a programming language interpreter (computing), interpreter Thread (computer science), thread to avoid sharing code that is not thread-safe with other threads. In implementations with a GIL, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thread (computing)
In computer science, a thread of execution is the smallest sequence of programmed instructions that can be managed independently by a scheduler, which is typically a part of the operating system. In many cases, a thread is a component of a process. The multiple threads of a given process may be executed concurrently (via multithreading capabilities), sharing resources such as memory, while different processes do not share these resources. In particular, the threads of a process share its executable code and the values of its dynamically allocated variables and non- thread-local global variables at any given time. The implementation of threads and processes differs between operating systems. History Threads made an early appearance under the name of "tasks" in IBM's batch processing operating system, OS/360, in 1967. It provided users with three available configurations of the OS/360 control system, of which Multiprogramming with a Variable Number of Tasks (MVT) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parallel Computing
Parallel computing is a type of computing, computation in which many calculations or Process (computing), processes are carried out simultaneously. Large problems can often be divided into smaller ones, which can then be solved at the same time. There are several different forms of parallel computing: Bit-level parallelism, bit-level, Instruction-level parallelism, instruction-level, Data parallelism, data, and task parallelism. Parallelism has long been employed in high-performance computing, but has gained broader interest due to the physical constraints preventing frequency scaling.S.V. Adve ''et al.'' (November 2008)"Parallel Computing Research at Illinois: The UPCRC Agenda" (PDF). Parallel@Illinois, University of Illinois at Urbana-Champaign. "The main techniques for these performance benefits—increased clock frequency and smarter but increasingly complex architectures—are now hitting the so-called power wall. The computer industry has accepted that future performance inc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Node
In general, a node is a localized swelling (a "knot") or a point of intersection (a vertex). Node may refer to: In mathematics * Vertex (graph theory), a vertex in a mathematical graph *Vertex (geometry), a point where two or more curves, lines, or edges meet. * Node (autonomous system), behaviour for an ordinary differential equation near a critical point * Singular point of an algebraic variety, a type of singular point of a curve In science and engineering Spherical geometry * node, the points where a great circle crosses a plane of reference, or the equator of a sphere Astronomy * Orbital node, the points where an orbit crosses a plane of reference ** Lunar node, where the orbits of the Sun and Moon intersect ** Longitude of the ascending node, how orbital nodes are parameterized Biology * Lymph node, an immune system organ used to store white blood cells * Node of Ranvier, periodic gaps in the insulating myelin sheaths of myelinated axons *Sinoatrial node and atrioven ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
