| 1 | /* |
| 2 | * lttng-ust-abi.c |
| 3 | * |
| 4 | * Copyright 2010-2011 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 5 | * |
| 6 | * LTTng UST ABI |
| 7 | * |
| 8 | * Mimic system calls for: |
| 9 | * - session creation, returns an object descriptor or failure. |
| 10 | * - channel creation, returns an object descriptor or failure. |
| 11 | * - Operates on a session object descriptor |
| 12 | * - Takes all channel options as parameters. |
| 13 | * - stream get, returns an object descriptor or failure. |
| 14 | * - Operates on a channel object descriptor. |
| 15 | * - stream notifier get, returns an object descriptor or failure. |
| 16 | * - Operates on a channel object descriptor. |
| 17 | * - event creation, returns an object descriptor or failure. |
| 18 | * - Operates on a channel object descriptor |
| 19 | * - Takes an event name as parameter |
| 20 | * - Takes an instrumentation source as parameter |
| 21 | * - e.g. tracepoints, dynamic_probes... |
| 22 | * - Takes instrumentation source specific arguments. |
| 23 | * |
| 24 | * Dual LGPL v2.1/GPL v2 license. |
| 25 | */ |
| 26 | |
| 27 | #include <ust/lttng-ust-abi.h> |
| 28 | #include <urcu/compiler.h> |
| 29 | #include <urcu/list.h> |
| 30 | #include <ust/lttng-events.h> |
| 31 | #include <ust/usterr-signal-safe.h> |
| 32 | #include "ust/core.h" |
| 33 | #include "ltt-tracer.h" |
| 34 | |
| 35 | /* |
| 36 | * Object descriptor table. Should be protected from concurrent access |
| 37 | * by the caller. |
| 38 | */ |
| 39 | |
| 40 | struct obj; |
| 41 | |
| 42 | struct objd_ops { |
| 43 | long (*cmd)(int objd, unsigned int cmd, unsigned long arg); |
| 44 | int (*release)(int objd); |
| 45 | }; |
| 46 | |
| 47 | struct obj { |
| 48 | union { |
| 49 | struct { |
| 50 | void *private_data; |
| 51 | const struct objd_ops *ops; |
| 52 | int f_count; |
| 53 | } s; |
| 54 | int freelist_next; /* offset freelist. end is -1. */ |
| 55 | } u; |
| 56 | }; |
| 57 | |
| 58 | struct objd_table { |
| 59 | struct obj *array; |
| 60 | unsigned int len, allocated_len; |
| 61 | int freelist_head; /* offset freelist head. end is -1 */ |
| 62 | }; |
| 63 | |
| 64 | static struct objd_table objd_table = { |
| 65 | .freelist_head = -1, |
| 66 | }; |
| 67 | |
| 68 | static |
| 69 | int objd_alloc(void *private_data, const struct objd_ops *ops) |
| 70 | { |
| 71 | struct obj *obj; |
| 72 | |
| 73 | if (objd_table.freelist_head != -1) { |
| 74 | obj = &objd_table.array[objd_table.freelist_head]; |
| 75 | objd_table.freelist_head = obj->u.freelist_next; |
| 76 | goto end; |
| 77 | } |
| 78 | |
| 79 | if (objd_table.len >= objd_table.allocated_len) { |
| 80 | unsigned int new_allocated_len, old_allocated_len; |
| 81 | struct obj *new_table, *old_table; |
| 82 | |
| 83 | old_allocated_len = objd_table.allocated_len; |
| 84 | old_table = objd_table.array; |
| 85 | if (!old_allocated_len) |
| 86 | new_allocated_len = 1; |
| 87 | else |
| 88 | new_allocated_len = old_allocated_len << 1; |
| 89 | new_table = zmalloc(sizeof(struct obj) * new_allocated_len); |
| 90 | if (!new_table) |
| 91 | return -ENOMEM; |
| 92 | memcpy(new_table, old_table, |
| 93 | sizeof(struct obj) * old_allocated_len); |
| 94 | free(old_table); |
| 95 | objd_table.array = new_table; |
| 96 | objd_table.allocated_len = new_allocated_len; |
| 97 | } |
| 98 | obj = &objd_table.array[objd_table.len]; |
| 99 | objd_table.len++; |
| 100 | end: |
| 101 | obj->u.s.private_data = private_data; |
| 102 | obj->u.s.ops = ops; |
| 103 | obj->u.s.f_count = 1; |
| 104 | return obj - objd_table.array; |
| 105 | } |
| 106 | |
| 107 | static |
| 108 | struct obj *_objd_get(int id) |
| 109 | { |
| 110 | if (id >= objd_table.len) |
| 111 | return NULL; |
| 112 | return &objd_table.array[id]; |
| 113 | } |
| 114 | |
| 115 | static |
| 116 | void *objd_private(int id) |
| 117 | { |
| 118 | struct obj *obj = _objd_get(id); |
| 119 | assert(obj); |
| 120 | return obj->u.s.private_data; |
| 121 | } |
| 122 | |
| 123 | static |
| 124 | void objd_set_private(int id, void *private_data) |
| 125 | { |
| 126 | struct obj *obj = _objd_get(id); |
| 127 | assert(obj); |
| 128 | obj->u.s.private_data = private_data; |
| 129 | } |
| 130 | |
| 131 | static |
| 132 | const struct objd_ops *objd_ops(int id) |
| 133 | { |
| 134 | struct obj *obj = _objd_get(id); |
| 135 | assert(obj); |
| 136 | return obj->u.s.ops; |
| 137 | } |
| 138 | |
| 139 | static |
| 140 | void objd_free(int id) |
| 141 | { |
| 142 | struct obj *obj = _objd_get(id); |
| 143 | |
| 144 | assert(obj); |
| 145 | obj->u.freelist_next = objd_table.freelist_head; |
| 146 | objd_table.freelist_head = obj - objd_table.array; |
| 147 | } |
| 148 | |
| 149 | static |
| 150 | void objd_ref(int id) |
| 151 | { |
| 152 | struct obj *obj = _objd_get(id); |
| 153 | obj->u.s.f_count++; |
| 154 | } |
| 155 | |
| 156 | static |
| 157 | void objd_unref(int id) |
| 158 | { |
| 159 | struct obj *obj = _objd_get(id); |
| 160 | |
| 161 | if (!(--obj->u.s.f_count)) { |
| 162 | const struct objd_ops *ops = objd_ops(id); |
| 163 | |
| 164 | if (ops->release) |
| 165 | ops->release(id); |
| 166 | objd_free(id); |
| 167 | } |
| 168 | } |
| 169 | |
| 170 | static |
| 171 | void objd_table_destroy(void) |
| 172 | { |
| 173 | free(objd_table.array); |
| 174 | } |
| 175 | |
| 176 | /* |
| 177 | * This is LTTng's own personal way to create an ABI for sessiond. |
| 178 | * We send commands over a socket. |
| 179 | */ |
| 180 | |
| 181 | static const struct objd_ops lttng_ops; |
| 182 | static const struct objd_ops lttng_session_ops; |
| 183 | static const struct objd_ops lttng_channel_ops; |
| 184 | static const struct objd_ops lttng_metadata_ops; |
| 185 | static const struct objd_ops lttng_event_ops; |
| 186 | |
| 187 | enum channel_type { |
| 188 | PER_CPU_CHANNEL, |
| 189 | METADATA_CHANNEL, |
| 190 | }; |
| 191 | |
| 192 | static |
| 193 | int lttng_abi_create_session(void) |
| 194 | { |
| 195 | struct ltt_session *session; |
| 196 | int session_objd, ret; |
| 197 | |
| 198 | session = ltt_session_create(); |
| 199 | if (!session) |
| 200 | return -ENOMEM; |
| 201 | session_objd = objd_alloc(session, <tng_session_ops); |
| 202 | if (session_objd < 0) { |
| 203 | ret = session_objd; |
| 204 | goto objd_error; |
| 205 | } |
| 206 | session->objd = session_objd; |
| 207 | return session_objd; |
| 208 | |
| 209 | objd_error: |
| 210 | ltt_session_destroy(session); |
| 211 | return ret; |
| 212 | } |
| 213 | |
| 214 | #if 0 |
| 215 | static |
| 216 | int lttng_abi_tracepoint_list(void) |
| 217 | { |
| 218 | int list_objd, ret; |
| 219 | |
| 220 | /* TODO: Create list private data */ |
| 221 | list_objd = objd_alloc(NULL, <tng_tracepoint_list_ops); |
| 222 | if (list_objd < 0) { |
| 223 | ret = list_objd; |
| 224 | goto objd_error; |
| 225 | } |
| 226 | |
| 227 | return list_objd; |
| 228 | |
| 229 | objd_error: |
| 230 | return ret; |
| 231 | } |
| 232 | #endif //0 |
| 233 | |
| 234 | static |
| 235 | long lttng_abi_tracer_version(int objd, |
| 236 | struct lttng_ust_tracer_version *v) |
| 237 | { |
| 238 | v->version = LTTNG_UST_VERSION; |
| 239 | v->patchlevel = LTTNG_UST_PATCHLEVEL; |
| 240 | v->sublevel = LTTNG_UST_SUBLEVEL; |
| 241 | return 0; |
| 242 | } |
| 243 | |
| 244 | static |
| 245 | long lttng_abi_add_context(int objd, |
| 246 | struct lttng_ust_context *context_param, |
| 247 | struct lttng_ctx **ctx, struct ltt_session *session) |
| 248 | { |
| 249 | if (session->been_active) |
| 250 | return -EPERM; |
| 251 | |
| 252 | switch (context_param->ctx) { |
| 253 | case LTTNG_UST_CONTEXT_VTID: |
| 254 | return lttng_add_vtid_to_ctx(ctx); |
| 255 | default: |
| 256 | return -EINVAL; |
| 257 | } |
| 258 | } |
| 259 | |
| 260 | /** |
| 261 | * lttng_cmd - lttng control through socket commands |
| 262 | * |
| 263 | * @objd: the object descriptor |
| 264 | * @cmd: the command |
| 265 | * @arg: command arg |
| 266 | * |
| 267 | * This descriptor implements lttng commands: |
| 268 | * LTTNG_UST_SESSION |
| 269 | * Returns a LTTng trace session object descriptor |
| 270 | * LTTNG_UST_TRACER_VERSION |
| 271 | * Returns the LTTng kernel tracer version |
| 272 | * LTTNG_UST_TRACEPOINT_LIST |
| 273 | * Returns a file descriptor listing available tracepoints |
| 274 | * LTTNG_UST_WAIT_QUIESCENT |
| 275 | * Returns after all previously running probes have completed |
| 276 | * |
| 277 | * The returned session will be deleted when its file descriptor is closed. |
| 278 | */ |
| 279 | static |
| 280 | long lttng_cmd(int objd, unsigned int cmd, unsigned long arg) |
| 281 | { |
| 282 | switch (cmd) { |
| 283 | case LTTNG_UST_SESSION: |
| 284 | return lttng_abi_create_session(); |
| 285 | case LTTNG_UST_TRACER_VERSION: |
| 286 | return lttng_abi_tracer_version(objd, |
| 287 | (struct lttng_ust_tracer_version *) arg); |
| 288 | case LTTNG_UST_TRACEPOINT_LIST: |
| 289 | return -ENOSYS; //TODO |
| 290 | //return lttng_abi_tracepoint_list(); |
| 291 | case LTTNG_UST_WAIT_QUIESCENT: |
| 292 | synchronize_trace(); |
| 293 | return 0; |
| 294 | default: |
| 295 | return -EINVAL; |
| 296 | } |
| 297 | } |
| 298 | |
| 299 | static const struct objd_ops lttng_ops = { |
| 300 | .cmd = lttng_cmd, |
| 301 | }; |
| 302 | |
| 303 | /* |
| 304 | * We tolerate no failure in this function (if one happens, we print a dmesg |
| 305 | * error, but cannot return any error, because the channel information is |
| 306 | * invariant. |
| 307 | */ |
| 308 | static |
| 309 | void lttng_metadata_create_events(int channel_objd) |
| 310 | { |
| 311 | struct ltt_channel *channel = objd_private(channel_objd); |
| 312 | static struct lttng_ust_event metadata_params = { |
| 313 | .instrumentation = LTTNG_UST_TRACEPOINT, |
| 314 | .name = "lttng_metadata", |
| 315 | }; |
| 316 | struct ltt_event *event; |
| 317 | int ret; |
| 318 | |
| 319 | /* |
| 320 | * We tolerate no failure path after event creation. It will stay |
| 321 | * invariant for the rest of the session. |
| 322 | */ |
| 323 | event = ltt_event_create(channel, &metadata_params, NULL); |
| 324 | if (!event) { |
| 325 | ret = -EINVAL; |
| 326 | goto create_error; |
| 327 | } |
| 328 | return; |
| 329 | |
| 330 | create_error: |
| 331 | WARN_ON(1); |
| 332 | return; /* not allowed to return error */ |
| 333 | } |
| 334 | |
| 335 | static |
| 336 | int lttng_abi_create_channel(int session_objd, |
| 337 | struct lttng_ust_channel *chan_param, |
| 338 | enum channel_type channel_type) |
| 339 | { |
| 340 | struct ltt_session *session = objd_private(session_objd); |
| 341 | const struct objd_ops *ops; |
| 342 | const char *transport_name; |
| 343 | struct ltt_channel *chan; |
| 344 | int chan_objd; |
| 345 | int ret = 0; |
| 346 | |
| 347 | chan_objd = objd_alloc(NULL, <tng_channel_ops); |
| 348 | if (chan_objd < 0) { |
| 349 | ret = chan_objd; |
| 350 | goto objd_error; |
| 351 | } |
| 352 | switch (channel_type) { |
| 353 | case PER_CPU_CHANNEL: |
| 354 | if (chan_param->output == LTTNG_UST_MMAP) { |
| 355 | transport_name = chan_param->overwrite ? |
| 356 | "relay-overwrite-mmap" : "relay-discard-mmap"; |
| 357 | } else { |
| 358 | return -EINVAL; |
| 359 | } |
| 360 | ops = <tng_channel_ops; |
| 361 | break; |
| 362 | case METADATA_CHANNEL: |
| 363 | if (chan_param->output == LTTNG_UST_MMAP) |
| 364 | transport_name = "relay-metadata-mmap"; |
| 365 | else |
| 366 | return -EINVAL; |
| 367 | ops = <tng_metadata_ops; |
| 368 | break; |
| 369 | default: |
| 370 | transport_name = "<unknown>"; |
| 371 | break; |
| 372 | } |
| 373 | /* |
| 374 | * We tolerate no failure path after channel creation. It will stay |
| 375 | * invariant for the rest of the session. |
| 376 | */ |
| 377 | chan = ltt_channel_create(session, transport_name, NULL, |
| 378 | chan_param->subbuf_size, |
| 379 | chan_param->num_subbuf, |
| 380 | chan_param->switch_timer_interval, |
| 381 | chan_param->read_timer_interval); |
| 382 | if (!chan) { |
| 383 | ret = -EINVAL; |
| 384 | goto chan_error; |
| 385 | } |
| 386 | objd_set_private(chan_objd, chan); |
| 387 | chan->objd = chan_objd; |
| 388 | if (channel_type == METADATA_CHANNEL) { |
| 389 | session->metadata = chan; |
| 390 | lttng_metadata_create_events(chan_objd); |
| 391 | } |
| 392 | |
| 393 | /* The channel created holds a reference on the session */ |
| 394 | objd_ref(session_objd); |
| 395 | |
| 396 | return chan_objd; |
| 397 | |
| 398 | chan_error: |
| 399 | objd_unref(chan_objd); |
| 400 | objd_error: |
| 401 | return ret; |
| 402 | } |
| 403 | |
| 404 | /** |
| 405 | * lttng_session_cmd - lttng session object command |
| 406 | * |
| 407 | * @obj: the object |
| 408 | * @cmd: the command |
| 409 | * @arg: command arg |
| 410 | * |
| 411 | * This descriptor implements lttng commands: |
| 412 | * LTTNG_UST_CHANNEL |
| 413 | * Returns a LTTng channel object descriptor |
| 414 | * LTTNG_UST_ENABLE |
| 415 | * Enables tracing for a session (weak enable) |
| 416 | * LTTNG_UST_DISABLE |
| 417 | * Disables tracing for a session (strong disable) |
| 418 | * LTTNG_UST_METADATA |
| 419 | * Returns a LTTng metadata object descriptor |
| 420 | * |
| 421 | * The returned channel will be deleted when its file descriptor is closed. |
| 422 | */ |
| 423 | static |
| 424 | long lttng_session_cmd(int objd, unsigned int cmd, unsigned long arg) |
| 425 | { |
| 426 | struct ltt_session *session = objd_private(objd); |
| 427 | |
| 428 | switch (cmd) { |
| 429 | case LTTNG_UST_CHANNEL: |
| 430 | return lttng_abi_create_channel(objd, |
| 431 | (struct lttng_ust_channel *) arg, |
| 432 | PER_CPU_CHANNEL); |
| 433 | case LTTNG_UST_SESSION_START: |
| 434 | case LTTNG_UST_ENABLE: |
| 435 | return ltt_session_enable(session); |
| 436 | case LTTNG_UST_SESSION_STOP: |
| 437 | case LTTNG_UST_DISABLE: |
| 438 | return ltt_session_disable(session); |
| 439 | case LTTNG_UST_METADATA: |
| 440 | return lttng_abi_create_channel(objd, |
| 441 | (struct lttng_ust_channel *) arg, |
| 442 | METADATA_CHANNEL); |
| 443 | default: |
| 444 | return -EINVAL; |
| 445 | } |
| 446 | } |
| 447 | |
| 448 | /* |
| 449 | * Called when the last file reference is dropped. |
| 450 | * |
| 451 | * Big fat note: channels and events are invariant for the whole session after |
| 452 | * their creation. So this session destruction also destroys all channel and |
| 453 | * event structures specific to this session (they are not destroyed when their |
| 454 | * individual file is released). |
| 455 | */ |
| 456 | static |
| 457 | int lttng_session_release(int objd) |
| 458 | { |
| 459 | struct ltt_session *session = objd_private(objd); |
| 460 | |
| 461 | if (session) |
| 462 | ltt_session_destroy(session); |
| 463 | return 0; |
| 464 | } |
| 465 | |
| 466 | static const struct objd_ops lttng_session_ops = { |
| 467 | .release = lttng_session_release, |
| 468 | .cmd = lttng_session_cmd, |
| 469 | }; |
| 470 | |
| 471 | #if 0 |
| 472 | static |
| 473 | int lttng_abi_open_stream(int channel_objd) |
| 474 | { |
| 475 | struct ltt_channel *channel = objd_private(channel_objd); |
| 476 | struct lib_ring_buffer *buf; |
| 477 | int stream_objd, ret; |
| 478 | |
| 479 | buf = channel->ops->buffer_read_open(channel->chan); |
| 480 | if (!buf) |
| 481 | return -ENOENT; |
| 482 | |
| 483 | stream_objd = objd_alloc(buf, &lib_ring_buffer_objd_ops); |
| 484 | if (stream_objd < 0) { |
| 485 | ret = stream_objd; |
| 486 | goto objd_error; |
| 487 | } |
| 488 | /* |
| 489 | * The stream holds a reference to the channel within the generic ring |
| 490 | * buffer library, so no need to hold a refcount on the channel and |
| 491 | * session files here. |
| 492 | */ |
| 493 | return stream_objd; |
| 494 | |
| 495 | objd_error: |
| 496 | channel->ops->buffer_read_close(buf); |
| 497 | return ret; |
| 498 | } |
| 499 | #endif //0 |
| 500 | |
| 501 | static |
| 502 | int lttng_abi_create_event(int channel_objd, |
| 503 | struct lttng_ust_event *event_param) |
| 504 | { |
| 505 | struct ltt_channel *channel = objd_private(channel_objd); |
| 506 | struct ltt_event *event; |
| 507 | int event_objd, ret; |
| 508 | |
| 509 | event_param->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0'; |
| 510 | event_objd = objd_alloc(NULL, <tng_event_ops); |
| 511 | if (event_objd < 0) { |
| 512 | ret = event_objd; |
| 513 | goto objd_error; |
| 514 | } |
| 515 | /* |
| 516 | * We tolerate no failure path after event creation. It will stay |
| 517 | * invariant for the rest of the session. |
| 518 | */ |
| 519 | event = ltt_event_create(channel, event_param, NULL); |
| 520 | if (!event) { |
| 521 | ret = -EINVAL; |
| 522 | goto event_error; |
| 523 | } |
| 524 | objd_set_private(event_objd, event); |
| 525 | /* The event holds a reference on the channel */ |
| 526 | objd_ref(channel_objd); |
| 527 | return event_objd; |
| 528 | |
| 529 | event_error: |
| 530 | objd_unref(event_objd); |
| 531 | objd_error: |
| 532 | return ret; |
| 533 | } |
| 534 | |
| 535 | /** |
| 536 | * lttng_channel_cmd - lttng control through object descriptors |
| 537 | * |
| 538 | * @objd: the object descriptor |
| 539 | * @cmd: the command |
| 540 | * @arg: command arg |
| 541 | * |
| 542 | * This object descriptor implements lttng commands: |
| 543 | * LTTNG_UST_STREAM |
| 544 | * Returns an event stream object descriptor or failure. |
| 545 | * (typically, one event stream records events from one CPU) |
| 546 | * LTTNG_UST_EVENT |
| 547 | * Returns an event object descriptor or failure. |
| 548 | * LTTNG_UST_CONTEXT |
| 549 | * Prepend a context field to each event in the channel |
| 550 | * LTTNG_UST_ENABLE |
| 551 | * Enable recording for events in this channel (weak enable) |
| 552 | * LTTNG_UST_DISABLE |
| 553 | * Disable recording for events in this channel (strong disable) |
| 554 | * |
| 555 | * Channel and event file descriptors also hold a reference on the session. |
| 556 | */ |
| 557 | static |
| 558 | long lttng_channel_cmd(int objd, unsigned int cmd, unsigned long arg) |
| 559 | { |
| 560 | struct ltt_channel *channel = objd_private(objd); |
| 561 | |
| 562 | switch (cmd) { |
| 563 | case LTTNG_UST_STREAM: |
| 564 | return -ENOSYS; //TODO |
| 565 | //return lttng_abi_open_stream(objd); |
| 566 | case LTTNG_UST_EVENT: |
| 567 | return lttng_abi_create_event(objd, (struct lttng_ust_event *) arg); |
| 568 | case LTTNG_UST_CONTEXT: |
| 569 | return lttng_abi_add_context(objd, |
| 570 | (struct lttng_ust_context *) arg, |
| 571 | &channel->ctx, channel->session); |
| 572 | case LTTNG_UST_ENABLE: |
| 573 | return ltt_channel_enable(channel); |
| 574 | case LTTNG_UST_DISABLE: |
| 575 | return ltt_channel_disable(channel); |
| 576 | default: |
| 577 | return -EINVAL; |
| 578 | } |
| 579 | } |
| 580 | |
| 581 | /** |
| 582 | * lttng_metadata_cmd - lttng control through object descriptors |
| 583 | * |
| 584 | * @objd: the object descriptor |
| 585 | * @cmd: the command |
| 586 | * @arg: command arg |
| 587 | * |
| 588 | * This object descriptor implements lttng commands: |
| 589 | * LTTNG_UST_STREAM |
| 590 | * Returns an event stream file descriptor or failure. |
| 591 | * |
| 592 | * Channel and event file descriptors also hold a reference on the session. |
| 593 | */ |
| 594 | static |
| 595 | long lttng_metadata_cmd(int objd, unsigned int cmd, unsigned long arg) |
| 596 | { |
| 597 | switch (cmd) { |
| 598 | case LTTNG_UST_STREAM: |
| 599 | return -ENOSYS; //TODO |
| 600 | //return lttng_abi_open_stream(objd); |
| 601 | default: |
| 602 | return -EINVAL; |
| 603 | } |
| 604 | } |
| 605 | |
| 606 | #if 0 |
| 607 | /** |
| 608 | * lttng_channel_poll - lttng stream addition/removal monitoring |
| 609 | * |
| 610 | * @file: the file |
| 611 | * @wait: poll table |
| 612 | */ |
| 613 | unsigned int lttng_channel_poll(struct file *file, poll_table *wait) |
| 614 | { |
| 615 | struct ltt_channel *channel = file->private_data; |
| 616 | unsigned int mask = 0; |
| 617 | |
| 618 | if (file->f_mode & FMODE_READ) { |
| 619 | poll_wait_set_exclusive(wait); |
| 620 | poll_wait(file, channel->ops->get_hp_wait_queue(channel->chan), |
| 621 | wait); |
| 622 | |
| 623 | if (channel->ops->is_disabled(channel->chan)) |
| 624 | return POLLERR; |
| 625 | if (channel->ops->is_finalized(channel->chan)) |
| 626 | return POLLHUP; |
| 627 | if (channel->ops->buffer_has_read_closed_stream(channel->chan)) |
| 628 | return POLLIN | POLLRDNORM; |
| 629 | return 0; |
| 630 | } |
| 631 | return mask; |
| 632 | |
| 633 | } |
| 634 | #endif //0 |
| 635 | |
| 636 | static |
| 637 | int lttng_channel_release(int objd) |
| 638 | { |
| 639 | struct ltt_channel *channel = objd_private(objd); |
| 640 | |
| 641 | if (channel) |
| 642 | objd_unref(channel->session->objd); |
| 643 | return 0; |
| 644 | } |
| 645 | |
| 646 | static const struct objd_ops lttng_channel_ops = { |
| 647 | .release = lttng_channel_release, |
| 648 | //.poll = lttng_channel_poll, |
| 649 | .cmd = lttng_channel_cmd, |
| 650 | }; |
| 651 | |
| 652 | static const struct objd_ops lttng_metadata_ops = { |
| 653 | .release = lttng_channel_release, |
| 654 | .cmd = lttng_metadata_cmd, |
| 655 | }; |
| 656 | |
| 657 | /** |
| 658 | * lttng_event_cmd - lttng control through object descriptors |
| 659 | * |
| 660 | * @objd: the object descriptor |
| 661 | * @cmd: the command |
| 662 | * @arg: command arg |
| 663 | * |
| 664 | * This object descriptor implements lttng commands: |
| 665 | * LTTNG_UST_CONTEXT |
| 666 | * Prepend a context field to each record of this event |
| 667 | * LTTNG_UST_ENABLE |
| 668 | * Enable recording for this event (weak enable) |
| 669 | * LTTNG_UST_DISABLE |
| 670 | * Disable recording for this event (strong disable) |
| 671 | */ |
| 672 | static |
| 673 | long lttng_event_cmd(int objd, unsigned int cmd, unsigned long arg) |
| 674 | { |
| 675 | struct ltt_event *event = objd_private(objd); |
| 676 | |
| 677 | switch (cmd) { |
| 678 | case LTTNG_UST_CONTEXT: |
| 679 | return lttng_abi_add_context(objd, |
| 680 | (struct lttng_ust_context *) arg, |
| 681 | &event->ctx, event->chan->session); |
| 682 | case LTTNG_UST_ENABLE: |
| 683 | return ltt_event_enable(event); |
| 684 | case LTTNG_UST_DISABLE: |
| 685 | return ltt_event_disable(event); |
| 686 | default: |
| 687 | return -EINVAL; |
| 688 | } |
| 689 | } |
| 690 | |
| 691 | static |
| 692 | int lttng_event_release(int objd) |
| 693 | { |
| 694 | struct ltt_event *event = objd_private(objd); |
| 695 | |
| 696 | if (event) |
| 697 | objd_unref(event->chan->objd); |
| 698 | return 0; |
| 699 | } |
| 700 | |
| 701 | /* TODO: filter control ioctl */ |
| 702 | static const struct objd_ops lttng_event_ops = { |
| 703 | .release = lttng_event_release, |
| 704 | .cmd = lttng_event_cmd, |
| 705 | }; |
| 706 | |
| 707 | void __attribute__((constructor)) lttng_ust_abi_init(void) |
| 708 | { |
| 709 | init_usterr(); |
| 710 | /* TODO: initialize socket */ |
| 711 | } |
| 712 | |
| 713 | static |
| 714 | void __attribute__((destructor)) lttng_ust_abi_exit(void) |
| 715 | { |
| 716 | /* TODO: teardown socket */ |
| 717 | objd_table_destroy(); |
| 718 | } |