Monitor

The word monitor, depending on context, may have one of the following meanings:

A computer display
A speaker used on stage or in a studio to enable musicians to hear what is being recorded or broadcasted
A concurrent programming language construct which encapsulates variables, access procedures and initialisation code within an abstract data type. The monitor's variable may only be accessed via its access procedures and only one process may be actively accessing the monitor at any one time. The access procedures are critical sections. A monitor may have a queue of processes which are waiting to access it. Monitors in this sense were invented by C. A. R. Hoare.
A hardware device that measures electrical events such as pulses or voltage levels in a digital computer.
To oversee a program during execution. For example, the monitor function in the Unix C library enables profiling of a certain range of code addresses. A histogram is produced showing how often the program counter was found to be at each position and how often each profiled function was called.
A control program within the operating system that manages the allocation of system resources to active programs.
A machine code monitor used by programmers to modify computer memory contents, including entering and modifying machine language programs.
A program that measures software performance.
USS Monitor, the ironclad warship of the American civil war.
A monitor warship type of ship based on the USS Monitor and built by several navies for coastal defence in the 1860s and 1870s. It reappeared in a different form during the First World War.
Monitor lizards are a family of large tropical lizards (Varanidae).
A popular NBC radio program which aired from 1955 to 1975.

This is a disambiguation page; that is, one that points to other pages that might otherwise have the same name. If you followed a link here, you might want to go back and fix that link to point to the appropriate specific page.

The original version of this page was based on monitor at the Free On-line Dictionary of Computing (FOLDOC), and is used with permission under the GFDL.