IOCP (I/O Completion Ports)

I/O Completion Ports (IOCP) is a high-performance asynchronous I/O mechanism in Windows, designed to efficiently handle large numbers of concurrent network connections. It is widely used in server-side game development to optimize networking performance, making it ideal for MMORPGs and real-time multiplayer games. Unlike select or WSA-Poll, IOCP uses a thread pool and a queue-based event system to process completed I/O operations asynchronously, minimizing CPU overhead and improving scalability. By leveraging IOCP, game servers can efficiently handle thousands of connections with minimal latency, making it the preferred choice for high-performance Windows-based game networking.