Task (computers)
Encyclopedia
A task is an execution path through address space
Address space
In computing, an address space defines a range of discrete addresses, each of which may correspond to a network host, peripheral device, disk sector, a memory cell or other logical or physical entity.- Overview :...

. In other words, a set of program
Computer program
A computer program is a sequence of instructions written to perform a specified task with a computer. A computer requires programs to function, typically executing the program's instructions in a central processor. The program has an executable form that the computer can use directly to execute...

 instructions that are loaded in memory
Computer storage
Computer data storage, often called storage or memory, refers to computer components and recording media that retain digital data. Data storage is one of the core functions and fundamental components of computers....

. The address registers have been loaded with the initial address of the program. At the next clock cycle, the CPU
Central processing unit
The central processing unit is the portion of a computer system that carries out the instructions of a computer program, to perform the basic arithmetical, logical, and input/output operations of the system. The CPU plays a role somewhat analogous to the brain in the computer. The term has been in...

 will start execution, in accord with the program. The sense is that some part of 'a plan is being accomplished'. As long as the program remains in this part of the address space, the task can continue, in principle, indefinitely, unless the program instructions contain a halt
Halt
Halt can refer to:* Train station § Halt, a small train station, usually unstaffed, with few facilities and normally is a request stop* A sign, meaning attention* "Hungry, Angry, Lonely, Tired" in behavioral addiction recovery...

, exit
Exit (operating system)
On many computer operating systems, a computer process terminates its execution by making an exit system call. More generally, an exit in a multithreading environment means that a thread of execution has stopped running. The operating system reclaims resources that were used by the process...

, or return.
  • In the computer field, "task" has the sense of a real-time
    Real-time computing
    In computer science, real-time computing , or reactive computing, is the study of hardware and software systems that are subject to a "real-time constraint"— e.g. operational deadlines from event to system response. Real-time programs must guarantee response within strict time constraints...

     application, as distinguished from process
    Process (computing)
    In computing, a process is an instance of a computer program that is being executed. It contains the program code and its current activity. Depending on the operating system , a process may be made up of multiple threads of execution that execute instructions concurrently.A computer program is a...

    , which takes up space (memory), and execution time. See operating system
    Operating system
    An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...

    .
    • Both "task" and "process" should be distinguished from event
      Event-driven programming
      In computer programming, event-driven programming or event-based programming is a programming paradigm in which the flow of the program is determined by events—i.e., sensor outputs or user actions or messages from other programs or threads.Event-driven programming can also be defined as an...

      , which takes place at a specific time and place, and which can be planned for in a computer program.
      • In a computer graphical user interface
        Graphical user interface
        In computing, a graphical user interface is a type of user interface that allows users to interact with electronic devices with images rather than text commands. GUIs can be used in computers, hand-held devices such as MP3 players, portable media players or gaming devices, household appliances and...

         (GUI), an event can be as simple as a mouse click or keystroke.

See also

  • Thread
    Thread (computer science)
    In computer science, a thread of execution is the smallest unit of processing that can be scheduled by an operating system. The implementation of threads and processes differs from one operating system to another, but in most cases, a thread is contained inside a process...

  • Process states
    Process states
    In a multitasking computer system, processes may occupy a variety of states. These distinct states may not actually be recognized as such by the operating system kernel, however they are a useful abstraction for the understanding of processes....

  • Process
    Process (computing)
    In computing, a process is an instance of a computer program that is being executed. It contains the program code and its current activity. Depending on the operating system , a process may be made up of multiple threads of execution that execute instructions concurrently.A computer program is a...


  • Computer multitasking
    Computer multitasking
    In computing, multitasking is a method where multiple tasks, also known as processes, share common processing resources such as a CPU. In the case of a computer with a single CPU, only one task is said to be running at any point in time, meaning that the CPU is actively executing instructions for...

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