Non-Blocking IO

Definitions

1. An I/O model in which system calls like `read()` and `write()` return immediately — either with available data or an EAGAIN/EWOULDBLOCK status — instead of suspending the thread until data is ready. Typically used with multiplexing mechanisms like epoll, kqueue, or io_uring to handle thousands of concurrent connections on a single thread.

   In plain English: A technique where reading from or writing to files and networks never pauses your program — it checks what's available and moves on.

   Example: "Node.js handles 10k concurrent WebSocket connections on one thread because libuv does non-blocking IO with epoll under the hood."

Related Terms

• Mutex
• Greenthread
• NAT
• DHCP
• subnet
• reverse proxy
• asyncio
• Rendezvous
• Lightweight Thread
• Run Loop