What is Real Time Computing?
In computer science, real-time computing (RTC) also known as reactive computing refers to the level of computer’s responsiveness deemed immediately sufficient by the user. Real-time computing functions within a specified time restrain i.e. the computer system (software or hardware) must guarantee response within a given time constraint, often reefed to as ‘deadlines’. Real time responses are often measured in milliseconds or microseconds.
In other words RTC is a term for computing practices functioning within specified time constraints often measured in the order of milliseconds or sometimes microseconds as well. Real time computing has to be carried out within a time frame often impalpable to end users. A system on the other hand not specified as operating in real time is under no pressure as such to generate response within the given deadline, although they usually function within the realm of actual and expected timeframe. Also, other types of systems are not compelled to provide information within the stipulated time frame. Computing can be done on delayed basis i.e. collection and storage of data for processing at some other time.
Real-time computing is generally applied to systems used for mission critical applications. A good example could that be of anti-lock brakes on a motor vehicle which are used for maximum deceleration but at intermittent interval to prevent the vehicle from skidding. Real time metric in another words is a metric which needs close attention of developers or programs when they are deciding upon as to how a program will work. They need to carefully assess what part of the program will be subject to real time computing i.e. what functions will immediately come into play in response to users’ command.
Real-time systems, as well as their deadlines, are classified according to the way deadlines are missed. Hard refers to total failure, firm refers to infrequent propensity to miss deadlines (tolerable to a certain extent) and soft refers to the usefulness of a result degrades after its deadline.