4 * IO engine that doesn't do any real IO transfers, it just pretends to.
5 * The main purpose is to test fio itself.
7 * It also can act as external C++ engine - compiled with:
9 * g++ -O2 -g -shared -rdynamic -fPIC -o cpp_null null.c -DFIO_EXTERNAL_ENGINE
13 * LD_LIBRARY_PATH=./engines ./fio examples/cpp_null.fio
30 static struct io_u *null_event(struct null_data *nd, int event)
32 return nd->io_us[event];
35 static int null_getevents(struct null_data *nd, unsigned int min_events,
36 unsigned int fio_unused max,
37 const struct timespec fio_unused *t)
49 static int null_commit(struct thread_data *td, struct null_data *nd)
52 #ifndef FIO_EXTERNAL_ENGINE
53 io_u_mark_submit(td, nd->queued);
55 nd->events = nd->queued;
62 static int null_queue(struct thread_data *td, struct null_data *nd,
65 fio_ro_check(td, io_u);
67 if (td->io_ops->flags & FIO_SYNCIO)
68 return FIO_Q_COMPLETED;
72 nd->io_us[nd->queued++] = io_u;
76 static int null_open(struct null_data fio_unused *nd,
77 struct fio_file fio_unused *f)
82 static void null_cleanup(struct null_data *nd)
90 static int null_init(struct thread_data *td, struct null_data **nd_ptr)
92 struct null_data *nd = (struct null_data *) malloc(sizeof(**nd_ptr));
94 memset(nd, 0, sizeof(*nd));
96 if (td->o.iodepth != 1) {
97 nd->io_us = (struct io_u **) malloc(td->o.iodepth * sizeof(struct io_u *));
98 memset(nd->io_us, 0, td->o.iodepth * sizeof(struct io_u *));
100 td->io_ops->flags |= FIO_SYNCIO;
108 static struct io_u *fio_null_event(struct thread_data *td, int event)
110 return null_event((struct null_data *)td->io_ops_data, event);
113 static int fio_null_getevents(struct thread_data *td, unsigned int min_events,
114 unsigned int max, const struct timespec *t)
116 struct null_data *nd = (struct null_data *)td->io_ops_data;
117 return null_getevents(nd, min_events, max, t);
120 static int fio_null_commit(struct thread_data *td)
122 return null_commit(td, (struct null_data *)td->io_ops_data);
125 static int fio_null_queue(struct thread_data *td, struct io_u *io_u)
127 return null_queue(td, (struct null_data *)td->io_ops_data, io_u);
130 static int fio_null_open(struct thread_data *td, struct fio_file *f)
132 return null_open((struct null_data *)td->io_ops_data, f);
135 static void fio_null_cleanup(struct thread_data *td)
137 null_cleanup((struct null_data *)td->io_ops_data);
140 static int fio_null_init(struct thread_data *td)
142 return null_init(td, (struct null_data **)&td->io_ops_data);
145 static struct ioengine_ops ioengine = {
147 .version = FIO_IOOPS_VERSION,
148 .queue = fio_null_queue,
149 .commit = fio_null_commit,
150 .getevents = fio_null_getevents,
151 .event = fio_null_event,
152 .init = fio_null_init,
153 .cleanup = fio_null_cleanup,
154 .open_file = fio_null_open,
155 .flags = FIO_DISKLESSIO | FIO_FAKEIO,
158 static void fio_init fio_null_register(void)
160 register_ioengine(&ioengine);
163 static void fio_exit fio_null_unregister(void)
165 unregister_ioengine(&ioengine);
170 #ifdef FIO_EXTERNAL_ENGINE
173 NullData(struct thread_data *td)
175 null_init(td, &impl_);
183 static NullData *get(struct thread_data *td)
185 return reinterpret_cast<NullData *>(td->io_ops_data);
188 io_u *fio_null_event(struct thread_data *, int event)
190 return null_event(impl_, event);
193 int fio_null_getevents(struct thread_data *, unsigned int min_events,
194 unsigned int max, const struct timespec *t)
196 return null_getevents(impl_, min_events, max, t);
199 int fio_null_commit(struct thread_data *td)
201 return null_commit(td, impl_);
204 int fio_null_queue(struct thread_data *td, struct io_u *io_u)
206 return null_queue(td, impl_, io_u);
209 int fio_null_open(struct thread_data *, struct fio_file *f)
211 return null_open(impl_, f);
214 struct null_data *impl_;
219 static struct io_u *fio_null_event(struct thread_data *td, int event)
221 return NullData::get(td)->fio_null_event(td, event);
224 static int fio_null_getevents(struct thread_data *td, unsigned int min_events,
225 unsigned int max, const struct timespec *t)
227 return NullData::get(td)->fio_null_getevents(td, min_events, max, t);
230 static int fio_null_commit(struct thread_data *td)
232 return NullData::get(td)->fio_null_commit(td);
235 static int fio_null_queue(struct thread_data *td, struct io_u *io_u)
237 return NullData::get(td)->fio_null_queue(td, io_u);
240 static int fio_null_open(struct thread_data *td, struct fio_file *f)
242 return NullData::get(td)->fio_null_open(td, f);
245 static int fio_null_init(struct thread_data *td)
247 td->io_ops_data = new NullData(td);
251 static void fio_null_cleanup(struct thread_data *td)
253 delete NullData::get(td);
256 static struct ioengine_ops ioengine;
257 void get_ioengine(struct ioengine_ops **ioengine_ptr)
259 *ioengine_ptr = &ioengine;
261 ioengine.name = "cpp_null";
262 ioengine.version = FIO_IOOPS_VERSION;
263 ioengine.queue = fio_null_queue;
264 ioengine.commit = fio_null_commit;
265 ioengine.getevents = fio_null_getevents;
266 ioengine.event = fio_null_event;
267 ioengine.init = fio_null_init;
268 ioengine.cleanup = fio_null_cleanup;
269 ioengine.open_file = fio_null_open;
270 ioengine.flags = FIO_DISKLESSIO | FIO_FAKEIO;
273 #endif /* FIO_EXTERNAL_ENGINE */
275 #endif /* __cplusplus */