/*

 * posixaio engine

 *

 * IO engine that uses the posix defined aio interface.

 *

 */

#include <stdio.h>

#include <stdlib.h>

#include <unistd.h>

#include <errno.h>

#include <fcntl.h>

#include "../fio.h"

struct posixaio_data {

	struct io_u **aio_events;

	unsigned int queued;

};

static int fill_timespec(struct timespec *ts)

{

#ifdef CONFIG_CLOCK_GETTIME

#ifdef CONFIG_CLOCK_MONOTONIC

	clockid_t clk = CLOCK_MONOTONIC;

#else

	clockid_t clk = CLOCK_REALTIME;

#endif

	if (!clock_gettime(clk, ts))

		return 0;

	perror("clock_gettime");

	return 1;

#else

	struct timeval tv;

	gettimeofday(&tv, NULL);

	ts->tv_sec = tv.tv_sec;

	ts->tv_nsec = tv.tv_usec * 1000;

	return 0;

#endif

}

static unsigned long long ts_utime_since_now(struct timespec *t)

{

	long long sec, nsec;

	struct timespec now;

	if (fill_timespec(&now))

		return 0;

	sec = now.tv_sec - t->tv_sec;

	nsec = now.tv_nsec - t->tv_nsec;

	if (sec > 0 && nsec < 0) {

		sec--;

		nsec += 1000000000;

	}

	sec *= 1000000;

	nsec /= 1000;

	return sec + nsec;

}

static int fio_posixaio_cancel(struct thread_data fio_unused *td,

			       struct io_u *io_u)

{

	struct fio_file *f = io_u->file;

	int r = aio_cancel(f->fd, &io_u->aiocb);

	if (r == AIO_ALLDONE || r == AIO_CANCELED)

		return 0;

	return 1;

}

static int fio_posixaio_prep(struct thread_data fio_unused *td,

			     struct io_u *io_u)

{

	os_aiocb_t *aiocb = &io_u->aiocb;

	struct fio_file *f = io_u->file;

	aiocb->aio_fildes = f->fd;

	aiocb->aio_buf = io_u->xfer_buf;

	aiocb->aio_nbytes = io_u->xfer_buflen;

	aiocb->aio_offset = io_u->offset;

	aiocb->aio_sigevent.sigev_notify = SIGEV_NONE;

	io_u->seen = 0;

	return 0;

}

#define SUSPEND_ENTRIES	8

static int fio_posixaio_getevents(struct thread_data *td, unsigned int min,

				  unsigned int max, const struct timespec *t)

{

	struct posixaio_data *pd = td->io_ops_data;

	os_aiocb_t *suspend_list[SUSPEND_ENTRIES];

	struct timespec start;

	int have_timeout = 0;

	int suspend_entries;

	struct io_u *io_u;

	unsigned int r;

	int i;

	if (t && !fill_timespec(&start))

		have_timeout = 1;

	else

		memset(&start, 0, sizeof(start));

	r = 0;

restart:

	memset(suspend_list, 0, sizeof(suspend_list));

	suspend_entries = 0;

	io_u_qiter(&td->io_u_all, io_u, i) {

		int err;

		if (io_u->seen || !(io_u->flags & IO_U_F_FLIGHT))

			continue;

		err = aio_error(&io_u->aiocb);

		if (err == EINPROGRESS) {

			if (suspend_entries < SUSPEND_ENTRIES) {

				suspend_list[suspend_entries] = &io_u->aiocb;

				suspend_entries++;

			}

			continue;

		}

		io_u->seen = 1;

		pd->queued--;

		pd->aio_events[r++] = io_u;

		if (err == ECANCELED)

			io_u->resid = io_u->xfer_buflen;

		else if (!err) {

			ssize_t retval = aio_return(&io_u->aiocb);

			io_u->resid = io_u->xfer_buflen - retval;

		} else

			io_u->error = err;

	}

	if (r >= min)

		return r;

	if (have_timeout) {

		unsigned long long usec;

		usec = (t->tv_sec * 1000000) + (t->tv_nsec / 1000);

		if (ts_utime_since_now(&start) > usec)

			return r;

	}

	/*

	 * must have some in-flight, wait for at least one

	 */

	aio_suspend((const os_aiocb_t * const *)suspend_list,

							suspend_entries, t);

	goto restart;

}

static struct io_u *fio_posixaio_event(struct thread_data *td, int event)

{

	struct posixaio_data *pd = td->io_ops_data;

	return pd->aio_events[event];

}

static enum fio_q_status fio_posixaio_queue(struct thread_data *td,

					    struct io_u *io_u)

{

	struct posixaio_data *pd = td->io_ops_data;

	os_aiocb_t *aiocb = &io_u->aiocb;

	int ret;

	fio_ro_check(td, io_u);

	if (io_u->ddir == DDIR_READ)

		ret = aio_read(aiocb);

	else if (io_u->ddir == DDIR_WRITE)

		ret = aio_write(aiocb);

	else if (io_u->ddir == DDIR_TRIM) {

		if (pd->queued)

			return FIO_Q_BUSY;

		do_io_u_trim(td, io_u);

		return FIO_Q_COMPLETED;

	} else {

#ifdef CONFIG_POSIXAIO_FSYNC

		ret = aio_fsync(O_SYNC, aiocb);

#else

		if (pd->queued)

			return FIO_Q_BUSY;

		do_io_u_sync(td, io_u);

		return FIO_Q_COMPLETED;

#endif

	}

	if (ret) {

		int aio_err = errno;

		/*

		 * At least OSX has a very low limit on the number of pending

		 * IOs, so if it returns EAGAIN, we are out of resources

		 * to queue more. Just return FIO_Q_BUSY to naturally

		 * drop off at this depth.

		 */

		if (aio_err == EAGAIN)

			return FIO_Q_BUSY;

		io_u->error = aio_err;

		td_verror(td, io_u->error, "xfer");

		return FIO_Q_COMPLETED;

	}

	pd->queued++;

	return FIO_Q_QUEUED;

}

static void fio_posixaio_cleanup(struct thread_data *td)

{

	struct posixaio_data *pd = td->io_ops_data;

	if (pd) {

		free(pd->aio_events);

		free(pd);

	}

}

static int fio_posixaio_init(struct thread_data *td)

{

	struct posixaio_data *pd = malloc(sizeof(*pd));

	memset(pd, 0, sizeof(*pd));

	pd->aio_events = malloc(td->o.iodepth * sizeof(struct io_u *));

	memset(pd->aio_events, 0, td->o.iodepth * sizeof(struct io_u *));

	td->io_ops_data = pd;

	return 0;

}

static struct ioengine_ops ioengine = {

	.name		= "posixaio",

	.version	= FIO_IOOPS_VERSION,

	.flags		= FIO_ASYNCIO_SYNC_TRIM,

	.init		= fio_posixaio_init,

	.prep		= fio_posixaio_prep,

	.queue		= fio_posixaio_queue,

	.cancel		= fio_posixaio_cancel,

	.getevents	= fio_posixaio_getevents,

	.event		= fio_posixaio_event,

	.cleanup	= fio_posixaio_cleanup,

	.open_file	= generic_open_file,

	.close_file	= generic_close_file,

	.get_file_size	= generic_get_file_size,

};

static void fio_init fio_posixaio_register(void)

{

	register_ioengine(&ioengine);

}

static void fio_exit fio_posixaio_unregister(void)

{

	unregister_ioengine(&ioengine);

}