What is io-uring?

This library gives Rust programmers direct access to io_uring, a modern Linux feature for handling input and output operations (like reading and writing files) very efficiently. The main benefit is speed: instead of waiting for each file operation to finish before starting the next one, a program can queue up many operations at once and let the operating system process them in bulk. Under the hood, it works through a pair of shared queues between the program and the kernel. The program submits tasks into one queue (submission), and the kernel reports completed tasks back through a second queue (completion). The README demonstrates this with a file-read example: the code builds a "read" request, drops it into the submission queue, waits for the result, and checks that it completed successfully. The developer is responsible for making sure submitted requests reference valid files and memory buffers, which is why that step is marked unsafe. The people who would reach for this are typically building high-performance systems in Rust, think database engines, web servers, or file-intense applications that need to squeeze maximum throughput out of Linux. If you are writing a service that reads thousands of files simultaneously or handles heavy network traffic, this library lets you tap into a kernel mechanism designed specifically for that workload. A notable constraint is that some operations require a relatively recent Linux kernel (version 5.6 or newer for the read example shown). The README does not go into detail on which features work on older kernels or what fallbacks exist. It is also explicitly a low-level interface, meaning the developer handles safety guarantees and queue management manually rather than getting a simpler, higher-level API. The project is dual-licensed under MIT and Apache 2.0, so users can choose either. It includes built-in test and benchmark packages for measuring and validating performance.