Idiomatic Rust bindings to liburing.
This gives users an idiomatic Rust interface for interacting with the Linux kernel's
interface for async IO. Despite being idiomatic Rust, this interface is still very low level
and some fundamental operations remain unsafe.
The core entry point to the API is the
IoUring type, which manages an
io_uring object for
interfacing with the kernel. Using this, users can submit IO events and wait for their
It is also possible to "split" an
IoUring instance into its constituent components - a
CompletionQueue, and a
Registrar - in order to operate on them
separately without synchronization.
You can prepare new IO events using the
SubmissionQueueEvent type. Once an event has been
prepared, the next call to submit will submit that event. Eventually, those events will
complete, and that a
CompletionQueueEvent will appear on the completion queue indicating that
the event is complete.
Preparing IO events is inherently unsafe, as you must guarantee that the buffers and file descriptors used for that IO are alive long enough for the kernel to perform the IO operation with them.
Some APIs allow you to time out a call into the kernel. It's important to note how this works with io_uring.
A timeout is submitted as an additional IO event which completes after the specified time.
Therefore when you create a timeout, all that happens is that a completion event will appear
after that specified time. This also means that when processing completion events, you need to
be prepared for the possibility that the completion represents a timeout and not a normal IO
CompletionQueueEvent has a method to check for this).