Function test

test/poll-mshot-overflow.c:45–138

}

static int test(bool defer_taskrun)
{
	struct io_uring_cqe *cqe;
	struct io_uring_sqe *sqe;
	struct io_uring ring;
	int pipe1[2];
	int ret, i;

	if (pipe(pipe1) != 0) {
		perror("pipe");
		return T_EXIT_FAIL;
	}

	struct io_uring_params params = {
		/* cheat using SINGLE_ISSUER existence to know if this behaviour
		 * is updated
		 */
		.flags = IORING_SETUP_CQSIZE | IORING_SETUP_SINGLE_ISSUER,
		.cq_entries = 2
	};

	if (defer_taskrun)
		params.flags |= IORING_SETUP_SINGLE_ISSUER |
				IORING_SETUP_DEFER_TASKRUN;

	ret = io_uring_queue_init_params(2, &ring, &params);
	if (ret)
		return T_EXIT_SKIP;

	sqe = io_uring_get_sqe(&ring);
	if (!sqe) {
		fprintf(stderr, "get sqe failed\n");
		return T_EXIT_FAIL;
	}
	io_uring_prep_poll_multishot(sqe, pipe1[0], POLLIN);
	io_uring_sqe_set_data64(sqe, 1);

	if (io_uring_cq_ready(&ring)) {
		fprintf(stderr, "unexpected cqe\n");
		return T_EXIT_FAIL;
	}

	for (i = 0; i < 2; i++) {
		sqe = io_uring_get_sqe(&ring);
		io_uring_prep_nop(sqe);
		io_uring_sqe_set_data64(sqe, 2);
		io_uring_submit(&ring);
	}

	do {
		errno = 0;
		ret = write(pipe1[1], "foo", 3);
	} while (ret == -1 && errno == EINTR);

	if (ret <= 0) {
		fprintf(stderr, "write failed: %d\n", errno);
		return T_EXIT_FAIL;
	}