#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <sys/types.h>
#include <errno.h>
#include <assert.h>
#include <sys/eventfd.h>
#include <libaio.h>

int
main(int argc, char **argv)
{
#define SIZE	(256*1024*1024)
	char *buf;
	struct io_event io_event;
	struct iocb iocb;
	struct iocb *iocbs[] = { &iocb };
	int rwfd, efd;
	int res;
	io_context_t	io_ctx;

	efd = eventfd(0, 0);
	if (efd < 0) {
		perror("eventfd");
		exit(1);
	}

	rwfd = open("rwfile", O_RDWR|O_DIRECT);		assert(rwfd != -1);
	if (posix_memalign((void **)&buf, getpagesize(), SIZE) < 0) {
		perror("posix_memalign");
		exit(1);
	}
	memset(buf, 0x42, SIZE);

	/* Write test. */
	res = io_queue_init(1024, &io_ctx);		assert(res == 0);
	io_prep_pwrite(&iocb, rwfd, buf, SIZE, 0);
	io_set_eventfd(&iocb, efd);
	res = io_submit(io_ctx, 1, iocbs);		assert(res == 1);

	/* Now close the eventfd so that AIO has the last reference */
	close(efd);

	/* Keep this process around so that the aio subsystem does not hold
	 * the last reference on the rwfd, otherwise the really_put_req will
	 * be called from process context */
	res = io_getevents(io_ctx, 1, 1, &io_event, NULL);
	if (res != 1) {
		if (res < 0) {
			errno = -res;
			perror("io_getevents");
		} else
			printf("io_getevents did not return 1 event after "
			       "closing eventfd\n");
		exit(1);
	}
	assert(io_event.res == SIZE);
	printf("eventfd write test [SUCCESS]\n");

	return 0;
}