Event-driven computing

In computing, event-driven architecture (EDA) is a software architecture pattern promoting the production, detection, consumption of, and reaction to events. An event can be defined as "a significant change in state".[1] For example, changes in data values, state transitions, external inputs, and system messages are all events.Event-driven architectures are perhaps the most prominent example of the reactive programming paradigm, and are often used when there is a need for very high performance or very low latency, such as in video games, simulations, embedded systems, trading systems, and other forms of interactive applications.

In an event-driven system, there are three basic components:

- Event producers: These are the entities that generate events, such as user input, sensors, and system messages.
- Event consumers: These are the entities that consume events and take some action in response, such as updating data values, changing states, or triggering some other action.
- Event channels: These are the channels or queues that events are routed through in order to be delivered to the appropriate consumers.

The key advantage of an event-driven architecture is that it enables different parts of the system to be loosely coupled, meaning that they can interact with each other without needing to have a direct, synchronous connection. This can make the system more scalable and easier to change, as different parts can be updated independently.

There are a few disadvantages to event-driven architectures as Why event-driven programming is used? Event-driven programming is used to process and respond to events as they occur. This type of programming is often used in web applications to handle user interactions, such as clicks and keystrokes. Event-driven programming can also be used to process data as it is received, such as from a stream or a file.

What is event-driven programming in OOP?

In event-driven programming, an event is an action or occurrence that can be detected by the program. Events can be generated by the user, by the system, or by other programs. Event-driven programming is a programming paradigm in which the flow of the program is determined by events such as user input, system events, or messages from other programs.

Event-driven programming is often used in graphical user interfaces (GUI) where user input is a major source of events. It is also used in network programming where events can be generated by network traffic.

What are event-driven programs in Cloud?

An event-driven program is a program that responds to events. An event is an occurrence that happens at a particular time and place. Examples of events include a user clicking a button, a timer going off, or a sensor detecting a change in temperature.

Event-driven programs are often used in cloud computing. For example, Amazon Simple Storage Service (S3) is an event-driven storage service. S3 can be configured to send an event to a Lambda function whenever an object is created or deleted. Lambda can then take action, such as sending a notification or performing some other task.

How does event-driven system work?

An event-driven system is a system where events are used to trigger certain actions. These events can be generated internally, externally, or both. Internally generated events are typically generated by the system itself, while externally generated events are typically generated by users or other systems.

When an event occurs, it is typically handled by an event handler. An event handler is a piece of code that is designed to handle a specific event. Event handlers are usually registered with the system in advance, so that the system knows which event handlers to call when an event occurs.

Event-driven systems are often used in GUI applications, where events such as mouse clicks or key presses are used to trigger certain actions. Event-driven systems can also be used in web applications, where events such as user requests are used to trigger certain actions.