#include <liburing.h> int io_uring_sqring_wait(struct io_uring *ring);
The function io_uring_sqring_wait(3) allows the caller to wait for space to free up in the SQ ring belonging to the ring param, which happens when the kernel side thread has consumed one or more entries. If the SQ ring is currently non-full, no action is taken.
This feature can only be used when the ring has been setup with IORING_SETUP_SQPOLL and hence is using an offloaded approach to request submissions.
On success it returns the free space. If the kernel does not support the feature, -EINVAL is returned.
io_uring_submit(3), io_uring_wait_cqe(3), io_uring_wait_cqes(3)