Function io_uring_load_sq_head

src/include/liburing.h:1708–1720

Read the kernel's SQ head index with appropriate memory ordering */

/* Read the kernel's SQ head index with appropriate memory ordering */
IOURINGINLINE unsigned io_uring_load_sq_head(const struct io_uring *ring)
	LIBURING_NOEXCEPT
{
	/*
	 * Without acquire ordering, we could overwrite a SQE before the kernel
	 * finished reading it. We don't need the acquire ordering for
	 * non-SQPOLL since then we drive updates.
	 */
	if (ring->flags & IORING_SETUP_SQPOLL)
		return io_uring_smp_load_acquire(ring->sq.khead);

	return *ring->sq.khead;
}

/*
 * Returns number of unconsumed (if SQPOLL) or unsubmitted entries exist in