io_uring_submit_and_wait(3)

✨ io_uring_submit_and_wait(3) ✨

okay bestie, welcome to liburing's manual pages, you're gonna slay this 🫶

🌸 NAME 🌸

io_uring_submit_and_wait — drop your requests into the submission queue and hang around for the completion, all in one go 💅

🎀 SYNOPSIS 🎀

#include <liburing.h>

int io_uring_submit_and_wait(struct io_uring *ring,
                             unsigned wait_nr);

🦋 DESCRIPTION 🦋

so, io_uring_submit_and_wait(3) does exactly what it says on the tin, no cap: it submits the next requests sitting in the submission queue of the ring you pass in, and then it waits for wait_nr completion events. two jobs, one function call, iconic behaviour honestly.

the flow is like this: first you grab a submission queue entry (an SQE) with io_uring_get_sqe(3), you prep it however you need it, and then you ship it off with io_uring_submit_and_wait(3). that's the whole vibe ✨

💖 pro move: this thing is ideally used with a ring that was set up with IORING_SETUP_SINGLE_ISSUER|IORING_SETUP_DEFER_TASKRUN, because that combo greatly reduces the number of context switches your application will see when it's waiting on a bunch of requests at once. fewer context switches = happier app, periodt.

👑 RETURN VALUE 👑

• on success, io_uring_submit_and_wait(3) returns the number of submitted submission queue entries 🎉
• on failure, it returns -errno 😭

🔥 SEE ALSO 🔥

• io_uring_queue_init_params(3)
• io_uring_get_sqe(3)
• io_uring_submit(3)
• io_uring_submit_and_wait_timeout(3)

and that's the tea 🍓 this page is from liburing-2.1, dated November 15, 2021, and it lives in the liburing manual. go forth and submit responsibly, bestie 💜🧚