For non-file engines, set ->real_file_size if total size is known
[fio.git] / engines / null.c
... / ...
CommitLineData
1/*
2 * null engine
3 *
4 * IO engine that doesn't do any real IO transfers, it just pretends to.
5 * The main purpose is to test fio itself.
6 *
7 */
8#include <stdio.h>
9#include <stdlib.h>
10#include <unistd.h>
11#include <errno.h>
12#include <assert.h>
13
14#include "../fio.h"
15
16struct null_data {
17 struct io_u **io_us;
18 int queued;
19 int events;
20};
21
22static struct io_u *fio_null_event(struct thread_data *td, int event)
23{
24 struct null_data *nd = td->io_ops->data;
25
26 return nd->io_us[event];
27}
28
29static int fio_null_getevents(struct thread_data *td, int min_events,
30 int fio_unused max, struct timespec fio_unused *t)
31{
32 struct null_data *nd = td->io_ops->data;
33 int ret = 0;
34
35 if (min_events) {
36 ret = nd->events;
37 nd->events = 0;
38 }
39
40 return ret;
41}
42
43static int fio_null_commit(struct thread_data *td)
44{
45 struct null_data *nd = td->io_ops->data;
46
47 if (!nd->events) {
48 nd->events = nd->queued;
49 nd->queued = 0;
50 }
51
52 return 0;
53}
54
55static int fio_null_queue(struct thread_data fio_unused *td, struct io_u *io_u)
56{
57 struct null_data *nd = td->io_ops->data;
58
59 if (td->io_ops->flags & FIO_SYNCIO)
60 return FIO_Q_COMPLETED;
61 if (nd->events)
62 return FIO_Q_BUSY;
63
64 nd->io_us[nd->queued++] = io_u;
65 return FIO_Q_QUEUED;
66}
67
68static int fio_null_setup(struct thread_data *td)
69{
70 struct fio_file *f;
71 unsigned int i;
72
73 for_each_file(td, f, i) {
74 if (td->o.size)
75 f->real_file_size = td->o.size / td->o.nr_files;
76 else
77 f->real_file_size = -1ULL;
78 }
79
80 return 0;
81}
82
83static int fio_null_open(struct thread_data fio_unused *td,
84 struct fio_file fio_unused *f)
85{
86 return 0;
87}
88
89static void fio_null_cleanup(struct thread_data *td)
90{
91 struct null_data *nd = td->io_ops->data;
92
93 if (nd) {
94 if (nd->io_us)
95 free(nd->io_us);
96 free(nd);
97 td->io_ops->data = NULL;
98 }
99}
100
101static int fio_null_init(struct thread_data *td)
102{
103 struct null_data *nd = malloc(sizeof(*nd));
104
105 memset(nd, 0, sizeof(*nd));
106
107 if (td->o.iodepth != 1) {
108 nd->io_us = malloc(td->o.iodepth * sizeof(struct io_u *));
109 memset(nd->io_us, 0, td->o.iodepth * sizeof(struct io_u *));
110 } else
111 td->io_ops->flags |= FIO_SYNCIO;
112
113 td->io_ops->data = nd;
114 return 0;
115}
116
117static struct ioengine_ops ioengine = {
118 .name = "null",
119 .version = FIO_IOOPS_VERSION,
120 .setup = fio_null_setup,
121 .queue = fio_null_queue,
122 .commit = fio_null_commit,
123 .getevents = fio_null_getevents,
124 .event = fio_null_event,
125 .init = fio_null_init,
126 .cleanup = fio_null_cleanup,
127 .open_file = fio_null_open,
128 .flags = FIO_DISKLESSIO,
129};
130
131static void fio_init fio_null_register(void)
132{
133 register_ioengine(&ioengine);
134}
135
136static void fio_exit fio_null_unregister(void)
137{
138 unregister_ioengine(&ioengine);
139}