io_uring_register_wait_reg(3)

💖 io_uring_register_wait_reg(3) 💖

okay bestie, this one lives in the liburing Manual, and it's lowkey one of the good ones. it's about registering wait regions — yes that sounds like a snooze but trust me, it's giving efficiency queen ✨

🌸 NAME 🌸

io_uring_register_wait_reg — register wait regions with io_uring 🎀

✨ SYNOPSIS ✨

#include <liburing.h>

int io_uring_register_wait_reg(struct io_uring *ring,
                               struct io_uring_reg_wait *reg,
                               int nr);

💅 DESCRIPTION 💅

so the io_uring_register_wait_reg(3) function registers wait regions with the io_uring instance you point at with ring. main character move.

the reg argument is a pointer to an array of struct io_uring_reg_wait with nr entries. like, an actual array, nr of them, all lined up 🫶

now here's why this slaps: wait regions let you register timeout and signal mask information that you can reuse across multiple wait operations without copying the data every single call. no repeated copying. no wasted effort. the way that this reduces overhead is honestly iconic 😭💖

it's used in conjunction with io_uring_submit_and_wait_reg(3) to reduce the overhead of wait operations — they're a duo, fr fr 👑

and if you're like "okay but where's the memory coming from" — check out io_uring_register_region(3) for registering the underlying memory region 🌈

🦋 RETURN VALUE 🦋

• Returns 0 on success. slay 🎉
• On error, a negative errno value is returned. not slay, but informative 💀

👑 SEE ALSO 👑

• io_uring_submit_and_wait_reg(3)
• io_uring_register_region(3)
• io_uring_register(2)

okay that's the whole page, you ate it, go register some wait regions 💜

this little love letter comes to you from liburing-2.9, dated January 18, 2025 — and remember, io_uring_register_wait_reg(3) is the moment, periodt 🎀✨