#include <unistd.h>
#include <sys/signalfd.h>
#include <sys/poll.h>
#include <sys/time.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>

#include <liburing.h>

#define SFD_TASK	00000001

int main(int argc, char *argv[])
{
	struct __kernel_timespec ts;
	struct io_uring_sqe *sqe;
	struct io_uring_cqe *cqe;
	struct io_uring ring;
	struct itimerval itv;
	sigset_t mask;
	int sfd, ret;

	sigemptyset(&mask);
	sigaddset(&mask, SIGALRM);
	sigprocmask(SIG_BLOCK, &mask, NULL);

	sfd = signalfd(-1, &mask, SFD_CLOEXEC | SFD_TASK);
	if (sfd < 0) {
		if (errno == EINVAL) {
			printf("Not supported\n");
			return 0;
		}
		perror("signalfd");
		return 1;
	}

	memset(&itv, 0, sizeof(itv));
	itv.it_value.tv_sec = 0;
	itv.it_value.tv_usec = 100000;
	setitimer(ITIMER_REAL, &itv, NULL);

	io_uring_queue_init(32, &ring, 0);
	sqe = io_uring_get_sqe(&ring);
	io_uring_prep_poll_add(sqe, sfd, POLLIN);
	io_uring_submit(&ring);

	ts.tv_sec = 1;
	ts.tv_nsec = 0;
	ret = io_uring_wait_cqe_timeout(&ring, &cqe, &ts);
	if (ret < 0) {
		fprintf(stderr, "Timed out waiting for cqe\n");
		ret = 1;
	} else {
		if (cqe->res < 0) {
			fprintf(stderr, "cqe failed with %d\n", cqe->res);
			ret = 1;
		} else if (!(cqe->res & POLLIN)) {
			fprintf(stderr, "POLLIN not set in result mask?\n");
			ret = 1;
		} else {
			ret = 0;
		}
	}
	io_uring_cqe_seen(&ring, cqe);

	io_uring_queue_exit(&ring);
	close(sfd);
	return ret;
}