monitor

n 1: someone who supervises (an examination) [syn: {proctor}]

2: someone who gives a warning so that a mistake can be avoided

[syn: {admonisher}, {reminder}]

3: a device that takes signals from a computer and displays

them on a CRT screen

4: equipment that is used to check the quality or content of

electronic transmissions

5: a piece of electronic equipment that keeps track of the

operation of a system continuously and warns of trouble

6: any of various large tropical carnivorous lizards of Africa

Asia and Australia; fabled to warn of crocodiles [syn: {monitor

lizard}, {varan}]

v : keep tabs on; keep an eye on; keep under surveillance [syn:

{supervise}, {ride herd on}]

monitor

1. A {cathode-ray tube} and associated electronics connected

to a computer's video output. A monitor may be either

{monochrome} (black and white) or colour ({RGB}). Colour

monitors may show either digital colour (each of the red,

green and blue signals may be either on or off, giving eight

possible colours: black, white, red, green, blue, cyan,

magenta and yellow) or analog colour (red, green and blue

signals are continuously variable allowing any combination to

be displayed). Digital monitors are sometimes known as {TTL}

because the voltages on the red, green and blue inputs are

compatible with TTL logic chips.

See also {gamut}, {multisync}, {visual display unit}.

2. A 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 section}s. A monitor may have a

queue of processes which are waiting to access it.

3. A hardware device that measures electrical events such as

pulses or voltage levels in a digital computer.

4. 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.

{Unix} {man} page: monitor(3).

5. A control program within the {operating system} that

manages the allocation of system resources to active

programs.

6. A program that measures software performance.