In computer science, a thread of execution is the smallest sequence of programmed instructions that can be managed independently by an operating system scheduler. A thread is a light-weight process. The implementation of threads and processes differs from one operating system to another, but in most cases, a thread is contained inside a process. Multiple threads can exist within the same process and share resources such as memory, while different processes do not share these resources. In particular, the threads of a process share the latter's instructions (its code) and its context (the values that its variables reference at any given moment).
On a single processor, multithreading generally occurs by time-division multiplexing (as in multitasking): the processor switches between different threads. This context switching generally happens frequently enough that the user perceives the threads or tasks as running at the same time. On a multiprocessor (including multi-core system), the threads or tasks will actually run at the same time, with each processor or core running a particular thread or task.
Many modern operating systems directly support both time-sliced and multiprocessor threading with a process scheduler. The kernel of an operating system allows programmers to manipulate threads via the system call interface. Some implementations are called a kernel thread, whereas a lightweight process (LWP) is a specific type of kernel thread that shares the same state and information.
Programs can have user-space threads when threading with timers, signals, or other methods to interrupt their own execution, performing a sort of ad-hoc time-slicing.
Read more about Thread (computing): How Threads Differ From Processes, Multithreading, Processes, Kernel Threads, User Threads, and Fibers, Programming Language Support
Other articles related to "threads":
... from concurrently interpreting the applications code on two or more threadsat the same time, which effectively limits the concurrency on multiple core systems (most ... have a different threading model which supports extremely large numbers of threads(for modeling hardware) ...
Famous quotes containing the word thread:
“One sought not absolute truth. One sought only a spool on which to wind the thread of history without breaking it.”
—Henry Brooks Adams (18381918)