Event Handling vs Polling: Which is Better?

Question

Hey everyone! 👋 I'm Sarah, a CS student. I'm always getting confused about when to use event handling versus polling. 🤔 Is one always better, or does it depend? Any insights would be super helpful! 🙏

nathanielwilkerson2001 · Accepted Answer

📚 Event Handling vs. Polling: An In-Depth Comparison
When building applications that interact with external systems or respond to user actions, you'll often encounter the terms 'event handling' and 'polling'. Both are mechanisms for detecting and reacting to changes, but they differ significantly in their approach and suitability.

🔎 Defining Event Handling
Event handling is a programming paradigm where the application reacts to events as they occur. An event is a signal that something of interest has happened, such as a user clicking a button, data arriving on a network socket, or a timer expiring.  The system is 'event-driven', meaning it mostly sits idle until an event triggers a response.

📡  The system waits for events to occur.
  📜  Event handlers (also called listeners or callbacks) are registered to specific events.
  ⚙️  When an event happens, the corresponding handler is executed.

💡 Defining Polling
Polling, on the other hand, involves the application repeatedly checking the status of a system or resource to see if there has been a change.  Instead of waiting for an event to be signaled, the application actively asks, "Has something happened yet?" in a loop.

🕰️  The system periodically checks for changes.
  🔄  The application actively queries the status of a resource.
  📉  If a change is detected, the application takes appropriate action.

📊 Event Handling vs. Polling: A Detailed Comparison

Feature
   Event Handling
   Polling

Mechanism
   Reacts to events as they occur.
   Repeatedly checks for changes.

Resource Usage
   Lower when idle; higher during event processing.
   Higher overall due to constant checking.

Responsiveness
   More responsive; immediate reaction to events.
   Responsiveness depends on the polling interval; potential delay.

Complexity
   Can be more complex to set up and manage.
   Simpler to implement initially.

Real-time Suitability
   Well-suited for real-time applications.
   Less suitable for real-time applications requiring immediate responses.

Scalability
   More scalable; handles concurrent events efficiently.
   Less scalable; polling every resource becomes expensive.

Example Use Cases
   GUI applications, network programming, IoT devices.
   Checking sensor values, simple hardware status monitoring.

🔑 Key Takeaways

✅  Event handling is generally preferred when timely responses and low resource usage are critical.
  💡  Polling is simpler to implement for basic monitoring tasks, but can be inefficient and less responsive.
  ⚙️  The choice between event handling and polling depends on the specific requirements of the application.

🧭  Consider the trade-offs between responsiveness, resource usage, and complexity when making your decision.

Event Handling vs Polling: Which is Better?

1 Answers

📚 Event Handling vs. Polling: An In-Depth Comparison

🔎 Defining Event Handling

💡 Defining Polling

📊 Event Handling vs. Polling: A Detailed Comparison

🔑 Key Takeaways

Join the discussion

Feature	Event Handling	Polling
Mechanism	Reacts to events as they occur.	Repeatedly checks for changes.
Resource Usage	Lower when idle; higher during event processing.	Higher overall due to constant checking.
Responsiveness	More responsive; immediate reaction to events.	Responsiveness depends on the polling interval; potential delay.
Complexity	Can be more complex to set up and manage.	Simpler to implement initially.
Real-time Suitability	Well-suited for real-time applications.	Less suitable for real-time applications requiring immediate responses.
Scalability	More scalable; handles concurrent events efficiently.	Less scalable; polling every resource becomes expensive.
Example Use Cases	GUI applications, network programming, IoT devices.	Checking sensor values, simple hardware status monitoring.