Eventgesteuerte

Eventgesteuerte describes a programming and system design paradigm in which the flow of control is determined by events. In this approach, components react to events such as user input, sensor readings, messages, or timers via event handlers or listeners. Event sources generate events, and an event dispatcher routes these events to registered handlers. The processing model is typically asynchronous, allowing the system to continue work while waiting for events.

Core concepts include event sources, event buses or queues, event handlers, and an event loop or dispatcher. In many frameworks, events are dispatched on a single thread (the event loop) or across multiple threads using concurrency primitives. Event-driven systems are common in graphical user interfaces, web front-ends, server backends (for example Node.js and other asynchronous servers), and embedded or IoT applications.

Examples and patterns: in GUI frameworks, interacting with widgets emits events that trigger logic. In web development, browser events drive user interactions and asynchronous requests. In backend architectures, message queues (such as RabbitMQ or Apache Kafka) enable decoupled event publishing and consumption, supporting event-driven microservices and streaming pipelines. Reactive programming and pub/sub are related paradigms that emphasize asynchronous data flows.

Advantages include responsiveness, scalability through non-blocking I/O, and loose coupling between components. Challenges include complexity in tracing event paths, potential for race conditions, debugging difficulties, and testing in distributed environments.

Historically, event-driven concepts emerged from graphical interfaces and evolved to cover networked and distributed systems. The term Eventgesteuerte is commonly used in German-language discussions of event-driven programming and architecture.