Code Archaeology

Nov 14, 2025 · Backend Development

Netty 4.2 IoUring Zero-Copy Send: Two CQEs Explained

This article explains how Netty 4.2 leverages Linux io_uring's zero-copy send (IORING_OP_SEND_ZC) to avoid user-kernel data copies, detailing the two completion queue events (CQEs) — I/O completion and buffer release notification — and Netty's handling logic with code examples.