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
27 static struct io_u *null_event(struct null_data *nd, int event)
29 return nd->io_us[event];
32 static int null_getevents(struct null_data *nd, unsigned int min_events,
33 unsigned int fio_unused max,
34 const struct timespec fio_unused *t)
46 static int null_commit(struct thread_data *td, struct null_data *nd)
49 #ifndef FIO_EXTERNAL_ENGINE
50 io_u_mark_submit(td, nd->queued);
52 nd->events = nd->queued;
59 static int null_queue(struct thread_data *td, struct null_data *nd,
62 fio_ro_check(td, io_u);
64 if (td->io_ops->flags & FIO_SYNCIO)
65 return FIO_Q_COMPLETED;
69 nd->io_us[nd->queued++] = io_u;
73 static int null_open(struct null_data fio_unused *nd,
74 struct fio_file fio_unused *f)
79 static void null_cleanup(struct null_data *nd)
87 static struct null_data *null_init(struct thread_data *td)
89 struct null_data *nd = (struct null_data *) malloc(sizeof(*nd));
91 memset(nd, 0, sizeof(*nd));
93 if (td->o.iodepth != 1) {
94 nd->io_us = (struct io_u **) malloc(td->o.iodepth * sizeof(struct io_u *));
95 memset(nd->io_us, 0, td->o.iodepth * sizeof(struct io_u *));
97 td->io_ops->flags |= FIO_SYNCIO;
104 static struct io_u *fio_null_event(struct thread_data *td, int event)
106 return null_event(td->io_ops_data, event);
109 static int fio_null_getevents(struct thread_data *td, unsigned int min_events,
110 unsigned int max, const struct timespec *t)
112 struct null_data *nd = td->io_ops_data;
113 return null_getevents(nd, min_events, max, t);
116 static int fio_null_commit(struct thread_data *td)
118 return null_commit(td, td->io_ops_data);
121 static int fio_null_queue(struct thread_data *td, struct io_u *io_u)
123 return null_queue(td, td->io_ops_data, io_u);
126 static int fio_null_open(struct thread_data *td, struct fio_file *f)
128 return null_open(td->io_ops_data, f);
131 static void fio_null_cleanup(struct thread_data *td)
133 null_cleanup(td->io_ops_data);
136 static int fio_null_init(struct thread_data *td)
138 td->io_ops_data = null_init(td);
139 assert(td->io_ops_data);
143 static struct ioengine_ops ioengine = {
145 .version = FIO_IOOPS_VERSION,
146 .queue = fio_null_queue,
147 .commit = fio_null_commit,
148 .getevents = fio_null_getevents,
149 .event = fio_null_event,
150 .init = fio_null_init,
151 .cleanup = fio_null_cleanup,
152 .open_file = fio_null_open,
153 .flags = FIO_DISKLESSIO | FIO_FAKEIO,
156 static void fio_init fio_null_register(void)
158 register_ioengine(&ioengine);
161 static void fio_exit fio_null_unregister(void)
163 unregister_ioengine(&ioengine);
168 #ifdef FIO_EXTERNAL_ENGINE
171 NullData(struct thread_data *td)
173 impl_ = null_init(td);
182 static NullData *get(struct thread_data *td)
184 return reinterpret_cast<NullData *>(td->io_ops_data);
187 io_u *fio_null_event(struct thread_data *, int event)
189 return null_event(impl_, event);
192 int fio_null_getevents(struct thread_data *, unsigned int min_events,
193 unsigned int max, const struct timespec *t)
195 return null_getevents(impl_, min_events, max, t);
198 int fio_null_commit(struct thread_data *td)
200 return null_commit(td, impl_);
203 int fio_null_queue(struct thread_data *td, struct io_u *io_u)
205 return null_queue(td, impl_, io_u);
208 int fio_null_open(struct thread_data *, struct fio_file *f)
210 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 */