The Reactor Pattern in Node.js is a design pattern used to handle asynchronous Input/Output (I/O) operations efficiently and without blocking the execution of the application. This pattern is crucial in Node.js due to its single-threaded nature, which could otherwise lead to performance bottlenecks if I/O operations were handled synchronously.
This component is responsible for handling I/O requests by blocking on all resources until an I/O operation completes. When an I/O operation is ready, the Event Demultiplexer collects these events and pushes them into the Event Queue[1][2][4].
Event Queue:
The Event Queue acts as a repository where events collected by the Event Demultiplexer are queued. These events are associated with their respective handlers, which are meant to process the events[1][2][4].
Event Loop:
The Event Loop is the heart of the Reactor Pattern. It continuously checks the Event Queue for new events and dispatches them to their corresponding handlers for processing. The loop ensures that the application remains responsive by processing events asynchronously and non-blockingly[1][2][4].
Request Handlers (Application):
These are the actual application-specific handlers that are executed to process the events. Each handler is associated with an event and is responsible for handling the event when it is dispatched by the Event Loop[1][2][4].
How It Works
The application starts by submitting an I/O request to the Event Demultiplexer.
The Event Demultiplexer, which operates non-blockingly, immediately returns control to the application while it waits for the I/O operation to compl...
