| 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 | * It also can act as external C++ engine - compiled with: |
| 8 | * |
| 9 | * g++ -O2 -g -shared -rdynamic -fPIC -o null.so null.c -DFIO_EXTERNAL_ENGINE |
| 10 | * |
| 11 | */ |
| 12 | #include <stdio.h> |
| 13 | #include <stdlib.h> |
| 14 | #include <unistd.h> |
| 15 | #include <errno.h> |
| 16 | #include <assert.h> |
| 17 | |
| 18 | #include "../fio.h" |
| 19 | |
| 20 | struct null_data { |
| 21 | struct io_u **io_us; |
| 22 | int queued; |
| 23 | int events; |
| 24 | }; |
| 25 | |
| 26 | static struct io_u *fio_null_event(struct thread_data *td, int event) |
| 27 | { |
| 28 | struct null_data *nd = (struct null_data *) td->io_ops_data; |
| 29 | |
| 30 | return nd->io_us[event]; |
| 31 | } |
| 32 | |
| 33 | static int fio_null_getevents(struct thread_data *td, unsigned int min_events, |
| 34 | unsigned int fio_unused max, |
| 35 | const struct timespec fio_unused *t) |
| 36 | { |
| 37 | struct null_data *nd = (struct null_data *) td->io_ops_data; |
| 38 | int ret = 0; |
| 39 | |
| 40 | if (min_events) { |
| 41 | ret = nd->events; |
| 42 | nd->events = 0; |
| 43 | } |
| 44 | |
| 45 | return ret; |
| 46 | } |
| 47 | |
| 48 | static int fio_null_commit(struct thread_data *td) |
| 49 | { |
| 50 | struct null_data *nd = (struct null_data *) td->io_ops_data; |
| 51 | |
| 52 | if (!nd->events) { |
| 53 | #ifndef FIO_EXTERNAL_ENGINE |
| 54 | io_u_mark_submit(td, nd->queued); |
| 55 | #endif |
| 56 | nd->events = nd->queued; |
| 57 | nd->queued = 0; |
| 58 | } |
| 59 | |
| 60 | return 0; |
| 61 | } |
| 62 | |
| 63 | static int fio_null_queue(struct thread_data *td, struct io_u *io_u) |
| 64 | { |
| 65 | struct null_data *nd = (struct null_data *) td->io_ops_data; |
| 66 | |
| 67 | fio_ro_check(td, io_u); |
| 68 | |
| 69 | if (td->io_ops->flags & FIO_SYNCIO) |
| 70 | return FIO_Q_COMPLETED; |
| 71 | if (nd->events) |
| 72 | return FIO_Q_BUSY; |
| 73 | |
| 74 | nd->io_us[nd->queued++] = io_u; |
| 75 | return FIO_Q_QUEUED; |
| 76 | } |
| 77 | |
| 78 | static int fio_null_open(struct thread_data fio_unused *td, |
| 79 | struct fio_file fio_unused *f) |
| 80 | { |
| 81 | return 0; |
| 82 | } |
| 83 | |
| 84 | static void fio_null_cleanup(struct thread_data *td) |
| 85 | { |
| 86 | struct null_data *nd = (struct null_data *) td->io_ops_data; |
| 87 | |
| 88 | if (nd) { |
| 89 | free(nd->io_us); |
| 90 | free(nd); |
| 91 | } |
| 92 | } |
| 93 | |
| 94 | static int fio_null_init(struct thread_data *td) |
| 95 | { |
| 96 | struct null_data *nd = (struct null_data *) malloc(sizeof(*nd)); |
| 97 | |
| 98 | memset(nd, 0, sizeof(*nd)); |
| 99 | |
| 100 | if (td->o.iodepth != 1) { |
| 101 | nd->io_us = (struct io_u **) malloc(td->o.iodepth * sizeof(struct io_u *)); |
| 102 | memset(nd->io_us, 0, td->o.iodepth * sizeof(struct io_u *)); |
| 103 | } else |
| 104 | td->io_ops->flags |= FIO_SYNCIO; |
| 105 | |
| 106 | td->io_ops_data = nd; |
| 107 | return 0; |
| 108 | } |
| 109 | |
| 110 | #ifndef __cplusplus |
| 111 | static struct ioengine_ops ioengine = { |
| 112 | .name = "null", |
| 113 | .version = FIO_IOOPS_VERSION, |
| 114 | .queue = fio_null_queue, |
| 115 | .commit = fio_null_commit, |
| 116 | .getevents = fio_null_getevents, |
| 117 | .event = fio_null_event, |
| 118 | .init = fio_null_init, |
| 119 | .cleanup = fio_null_cleanup, |
| 120 | .open_file = fio_null_open, |
| 121 | .flags = FIO_DISKLESSIO | FIO_FAKEIO, |
| 122 | }; |
| 123 | |
| 124 | static void fio_init fio_null_register(void) |
| 125 | { |
| 126 | register_ioengine(&ioengine); |
| 127 | } |
| 128 | |
| 129 | static void fio_exit fio_null_unregister(void) |
| 130 | { |
| 131 | unregister_ioengine(&ioengine); |
| 132 | } |
| 133 | |
| 134 | #else |
| 135 | |
| 136 | #ifdef FIO_EXTERNAL_ENGINE |
| 137 | extern "C" { |
| 138 | static struct ioengine_ops ioengine; |
| 139 | void get_ioengine(struct ioengine_ops **ioengine_ptr) |
| 140 | { |
| 141 | *ioengine_ptr = &ioengine; |
| 142 | |
| 143 | ioengine.name = "cpp_null"; |
| 144 | ioengine.version = FIO_IOOPS_VERSION; |
| 145 | ioengine.queue = fio_null_queue; |
| 146 | ioengine.commit = fio_null_commit; |
| 147 | ioengine.getevents = fio_null_getevents; |
| 148 | ioengine.event = fio_null_event; |
| 149 | ioengine.init = fio_null_init; |
| 150 | ioengine.cleanup = fio_null_cleanup; |
| 151 | ioengine.open_file = fio_null_open; |
| 152 | ioengine.flags = FIO_DISKLESSIO | FIO_FAKEIO; |
| 153 | } |
| 154 | } |
| 155 | #endif /* FIO_EXTERNAL_ENGINE */ |
| 156 | |
| 157 | #endif /* __cplusplus */ |