Explain the mechanism of the event processing loop in asynchronous applications.

The event loop in asynchronous applications is responsible for managing task execution without blocking the main thread. In Flutter, which uses Dart, the event loop works as follows:

1. All asynchronous operations (e.g., network requests, timers) are placed in the event queue.
2. The event loop sequentially retrieves events from the queue and executes the corresponding handlers.
3. If a handler initiates new asynchronous operations, they are added to the queue.
4. The event loop continues to run until the queue is empty.

This allows the UI to remain responsive, as long operations do not block the main thread but are executed as they become ready.

Example: when a button is pressed, an asynchronous function is launched that makes a request to the server. The event loop places this request in the queue and continues processing other events until it receives a response and calls the callback.