Function setup_buffer_pool

examples/io_uring-udp.c:47–89

}

static int setup_buffer_pool(struct ctx *ctx)
{
	int ret, i;
	void *mapped;
	struct io_uring_buf_reg reg = { .ring_addr = 0,
					.ring_entries = BUFFERS,
					.bgid = 0 };

	ctx->buf_ring_size = (sizeof(struct io_uring_buf) + buffer_size(ctx)) * BUFFERS;
	mapped = mmap(NULL, ctx->buf_ring_size, PROT_READ | PROT_WRITE,
		      MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
	if (mapped == MAP_FAILED) {
		fprintf(stderr, "buf_ring mmap: %s\n", strerror(errno));
		return -1;
	}
	ctx->buf_ring = (struct io_uring_buf_ring *)mapped;

	io_uring_buf_ring_init(ctx->buf_ring);

	reg = (struct io_uring_buf_reg) {
		.ring_addr = (unsigned long)ctx->buf_ring,
		.ring_entries = BUFFERS,
		.bgid = 0
	};
	ctx->buffer_base = (unsigned char *)ctx->buf_ring +
			   sizeof(struct io_uring_buf) * BUFFERS;

	ret = io_uring_register_buf_ring(&ctx->ring, &reg, 0);
	if (ret) {
		fprintf(stderr, "buf_ring init failed: %s\n"
				"NB This requires a kernel version >= 6.0\n",
				strerror(-ret));
		return ret;
	}

	for (i = 0; i < BUFFERS; i++) {
		io_uring_buf_ring_add(ctx->buf_ring, get_buffer(ctx, i), buffer_size(ctx), i,
				      io_uring_buf_ring_mask(BUFFERS), i);
	}
	io_uring_buf_ring_advance(ctx->buf_ring, BUFFERS);

	return 0;
}

static int setup_context(struct ctx *ctx)
{