#include <assert.h>
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/epoll.h>
#include <sys/timerfd.h>

int main(int argc, char *argv[])
{
	int pipe, timerfd, epoll;
	struct epoll_event ev[2];
	struct itimerspec it;
	int ret;

	assert(argc == 2);
	pipe = open(argv[1], O_RDONLY);
	assert(pipe >= 0);

	timerfd = timerfd_create(CLOCK_MONOTONIC, 0);
	assert(timerfd >= 0);
	it.it_value.tv_sec = 0;
	it.it_value.tv_nsec = 1;
	it.it_interval.tv_sec = 0;
	it.it_interval.tv_nsec = 50000;
	ret = timerfd_settime(timerfd, 0, &it, NULL);
	assert(ret == 0);

	epoll = epoll_create1(0);
	assert(epoll >= 0);

	ev[0].events = EPOLLIN;
	ev[0].data.fd = pipe;
	ret = epoll_ctl(epoll, EPOLL_CTL_ADD, pipe, &ev[0]);
	assert(ret == 0);

	ev[1].events = EPOLLIN;
	ev[1].data.fd = timerfd;
	ret = epoll_ctl(epoll, EPOLL_CTL_ADD, timerfd, &ev[1]);
	assert(ret == 0);

	printf("starting loop\n");
	while (1) {
		struct epoll_event event;
		char buffer[8];
		size_t size;

		ret = epoll_wait(epoll, &event, 1, -1);
		assert(ret == 1);
		if (event.data.fd == timerfd)
			size = 8;
		else
			size = 1;
		ret = read(event.data.fd, buffer, size);
		assert(ret == size);
	}
}