blob: bf7885e92187e68488c3c5109ca52ed77cd4fd36 [file] [log] [blame]
/*
* null engine
*
* IO engine that doesn't do any real IO transfers, it just pretends to.
* The main purpose is to test fio itself.
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <assert.h>
#include "../fio.h"
struct null_data {
struct io_u **io_us;
int queued;
int events;
};
static struct io_u *fio_null_event(struct thread_data *td, int event)
{
struct null_data *nd = td->io_ops->data;
return nd->io_us[event];
}
static int fio_null_getevents(struct thread_data *td, unsigned int min_events,
unsigned int fio_unused max,
struct timespec fio_unused *t)
{
struct null_data *nd = td->io_ops->data;
int ret = 0;
if (min_events) {
ret = nd->events;
nd->events = 0;
}
return ret;
}
static int fio_null_commit(struct thread_data *td)
{
struct null_data *nd = td->io_ops->data;
if (!nd->events) {
io_u_mark_submit(td, nd->queued);
nd->events = nd->queued;
nd->queued = 0;
}
return 0;
}
static int fio_null_queue(struct thread_data *td, struct io_u *io_u)
{
struct null_data *nd = td->io_ops->data;
fio_ro_check(td, io_u);
if (td->io_ops->flags & FIO_SYNCIO)
return FIO_Q_COMPLETED;
if (nd->events)
return FIO_Q_BUSY;
nd->io_us[nd->queued++] = io_u;
return FIO_Q_QUEUED;
}
static int fio_null_open(struct thread_data fio_unused *td,
struct fio_file fio_unused *f)
{
return 0;
}
static void fio_null_cleanup(struct thread_data *td)
{
struct null_data *nd = td->io_ops->data;
if (nd) {
if (nd->io_us)
free(nd->io_us);
free(nd);
}
}
static int fio_null_init(struct thread_data *td)
{
struct null_data *nd = malloc(sizeof(*nd));
memset(nd, 0, sizeof(*nd));
if (td->o.iodepth != 1) {
nd->io_us = malloc(td->o.iodepth * sizeof(struct io_u *));
memset(nd->io_us, 0, td->o.iodepth * sizeof(struct io_u *));
} else
td->io_ops->flags |= FIO_SYNCIO;
td->io_ops->data = nd;
return 0;
}
static struct ioengine_ops ioengine = {
.name = "null",
.version = FIO_IOOPS_VERSION,
.queue = fio_null_queue,
.commit = fio_null_commit,
.getevents = fio_null_getevents,
.event = fio_null_event,
.init = fio_null_init,
.cleanup = fio_null_cleanup,
.open_file = fio_null_open,
.flags = FIO_DISKLESSIO,
};
static void fio_init fio_null_register(void)
{
register_ioengine(&ioengine);
}
static void fio_exit fio_null_unregister(void)
{
unregister_ioengine(&ioengine);
}