| 1 | /* |
| 2 | * Copyright (C) 2020 Jérémie Galarneau <jeremie.galarneau@efficios.com> |
| 3 | * |
| 4 | * SPDX-License-Identifier: GPL-2.0-only |
| 5 | * |
| 6 | */ |
| 7 | |
| 8 | #include "action-executor.h" |
| 9 | #include "cmd.h" |
| 10 | #include "health-sessiond.h" |
| 11 | #include "lttng-sessiond.h" |
| 12 | #include "notification-thread-internal.h" |
| 13 | #include "session.h" |
| 14 | #include "thread.h" |
| 15 | #include <common/macros.h> |
| 16 | #include <common/optional.h> |
| 17 | #include <lttng/action/action-internal.h> |
| 18 | #include <lttng/action/group.h> |
| 19 | #include <lttng/action/notify-internal.h> |
| 20 | #include <lttng/action/notify.h> |
| 21 | #include <lttng/action/rotate-session.h> |
| 22 | #include <lttng/action/snapshot-session.h> |
| 23 | #include <lttng/action/start-session.h> |
| 24 | #include <lttng/action/stop-session.h> |
| 25 | #include <lttng/condition/evaluation.h> |
| 26 | #include <lttng/condition/on-event-internal.h> |
| 27 | #include <lttng/lttng-error.h> |
| 28 | #include <lttng/trigger/trigger-internal.h> |
| 29 | #include <pthread.h> |
| 30 | #include <stdbool.h> |
| 31 | #include <stddef.h> |
| 32 | #include <urcu/list.h> |
| 33 | |
| 34 | #define THREAD_NAME "Action Executor" |
| 35 | #define MAX_QUEUED_WORK_COUNT 8192 |
| 36 | |
| 37 | struct action_work_item { |
| 38 | uint64_t id; |
| 39 | struct lttng_trigger *trigger; |
| 40 | struct lttng_evaluation *evaluation; |
| 41 | struct notification_client_list *client_list; |
| 42 | LTTNG_OPTIONAL(struct lttng_credentials) object_creds; |
| 43 | struct cds_list_head list_node; |
| 44 | }; |
| 45 | |
| 46 | struct action_executor { |
| 47 | struct lttng_thread *thread; |
| 48 | struct notification_thread_handle *notification_thread_handle; |
| 49 | struct { |
| 50 | uint64_t pending_count; |
| 51 | struct cds_list_head list; |
| 52 | pthread_cond_t cond; |
| 53 | pthread_mutex_t lock; |
| 54 | } work; |
| 55 | bool should_quit; |
| 56 | uint64_t next_work_item_id; |
| 57 | }; |
| 58 | |
| 59 | /* |
| 60 | * Only return non-zero on a fatal error that should shut down the action |
| 61 | * executor. |
| 62 | */ |
| 63 | typedef int (*action_executor_handler)(struct action_executor *executor, |
| 64 | const struct action_work_item *, |
| 65 | const struct lttng_action *action); |
| 66 | |
| 67 | static int action_executor_notify_handler(struct action_executor *executor, |
| 68 | const struct action_work_item *, |
| 69 | const struct lttng_action *); |
| 70 | static int action_executor_start_session_handler(struct action_executor *executor, |
| 71 | const struct action_work_item *, |
| 72 | const struct lttng_action *); |
| 73 | static int action_executor_stop_session_handler(struct action_executor *executor, |
| 74 | const struct action_work_item *, |
| 75 | const struct lttng_action *); |
| 76 | static int action_executor_rotate_session_handler(struct action_executor *executor, |
| 77 | const struct action_work_item *, |
| 78 | const struct lttng_action *); |
| 79 | static int action_executor_snapshot_session_handler(struct action_executor *executor, |
| 80 | const struct action_work_item *, |
| 81 | const struct lttng_action *); |
| 82 | static int action_executor_group_handler(struct action_executor *executor, |
| 83 | const struct action_work_item *, |
| 84 | const struct lttng_action *); |
| 85 | static int action_executor_generic_handler(struct action_executor *executor, |
| 86 | const struct action_work_item *, |
| 87 | const struct lttng_action *); |
| 88 | |
| 89 | static const action_executor_handler action_executors[] = { |
| 90 | [LTTNG_ACTION_TYPE_NOTIFY] = action_executor_notify_handler, |
| 91 | [LTTNG_ACTION_TYPE_START_SESSION] = action_executor_start_session_handler, |
| 92 | [LTTNG_ACTION_TYPE_STOP_SESSION] = action_executor_stop_session_handler, |
| 93 | [LTTNG_ACTION_TYPE_ROTATE_SESSION] = action_executor_rotate_session_handler, |
| 94 | [LTTNG_ACTION_TYPE_SNAPSHOT_SESSION] = action_executor_snapshot_session_handler, |
| 95 | [LTTNG_ACTION_TYPE_GROUP] = action_executor_group_handler, |
| 96 | }; |
| 97 | |
| 98 | static const char *action_type_names[] = { |
| 99 | [LTTNG_ACTION_TYPE_NOTIFY] = "Notify", |
| 100 | [LTTNG_ACTION_TYPE_START_SESSION] = "Start session", |
| 101 | [LTTNG_ACTION_TYPE_STOP_SESSION] = "Stop session", |
| 102 | [LTTNG_ACTION_TYPE_ROTATE_SESSION] = "Rotate session", |
| 103 | [LTTNG_ACTION_TYPE_SNAPSHOT_SESSION] = "Snapshot session", |
| 104 | [LTTNG_ACTION_TYPE_GROUP] = "Group", |
| 105 | }; |
| 106 | |
| 107 | static const char *get_action_name(const struct lttng_action *action) |
| 108 | { |
| 109 | const enum lttng_action_type action_type = lttng_action_get_type(action); |
| 110 | |
| 111 | assert(action_type != LTTNG_ACTION_TYPE_UNKNOWN); |
| 112 | |
| 113 | return action_type_names[action_type]; |
| 114 | } |
| 115 | |
| 116 | /* Check if this trigger allowed to interect with a given session. */ |
| 117 | static bool is_trigger_allowed_for_session(const struct lttng_trigger *trigger, |
| 118 | struct ltt_session *session) |
| 119 | { |
| 120 | bool is_allowed = false; |
| 121 | const struct lttng_credentials session_creds = { |
| 122 | .uid = LTTNG_OPTIONAL_INIT_VALUE(session->uid), |
| 123 | .gid = LTTNG_OPTIONAL_INIT_VALUE(session->gid), |
| 124 | }; |
| 125 | /* Can never be NULL. */ |
| 126 | const struct lttng_credentials *trigger_creds = |
| 127 | lttng_trigger_get_credentials(trigger); |
| 128 | |
| 129 | is_allowed = (lttng_credentials_is_equal_uid(trigger_creds, &session_creds)) || |
| 130 | (lttng_credentials_get_uid(trigger_creds) == 0); |
| 131 | if (!is_allowed) { |
| 132 | WARN("Trigger is not allowed to interact with session `%s`: session uid = %ld, session gid = %ld, trigger uid = %ld", |
| 133 | session->name, |
| 134 | (long int) session->uid, |
| 135 | (long int) session->gid, |
| 136 | (long int) lttng_credentials_get_uid(trigger_creds)); |
| 137 | } |
| 138 | |
| 139 | return is_allowed; |
| 140 | } |
| 141 | |
| 142 | static const char *get_trigger_name(const struct lttng_trigger *trigger) |
| 143 | { |
| 144 | const char *trigger_name; |
| 145 | enum lttng_trigger_status trigger_status; |
| 146 | |
| 147 | trigger_status = lttng_trigger_get_name(trigger, &trigger_name); |
| 148 | assert(trigger_status == LTTNG_TRIGGER_STATUS_OK); |
| 149 | |
| 150 | return trigger_name; |
| 151 | } |
| 152 | |
| 153 | static int client_handle_transmission_status( |
| 154 | struct notification_client *client, |
| 155 | enum client_transmission_status status, |
| 156 | void *user_data) |
| 157 | { |
| 158 | int ret = 0; |
| 159 | struct action_executor *executor = user_data; |
| 160 | bool update_communication = true; |
| 161 | |
| 162 | switch (status) { |
| 163 | case CLIENT_TRANSMISSION_STATUS_COMPLETE: |
| 164 | DBG("Successfully sent full notification to client, client_id = %" PRIu64, |
| 165 | client->id); |
| 166 | update_communication = false; |
| 167 | break; |
| 168 | case CLIENT_TRANSMISSION_STATUS_QUEUED: |
| 169 | DBG("Queued notification in client outgoing buffer, client_id = %" PRIu64, |
| 170 | client->id); |
| 171 | break; |
| 172 | case CLIENT_TRANSMISSION_STATUS_FAIL: |
| 173 | DBG("Communication error occurred while sending notification to client, client_id = %" PRIu64, |
| 174 | client->id); |
| 175 | break; |
| 176 | default: |
| 177 | ERR("Fatal error encoutered while sending notification to client, client_id = %" PRIu64, |
| 178 | client->id); |
| 179 | ret = -1; |
| 180 | goto end; |
| 181 | } |
| 182 | |
| 183 | if (!update_communication) { |
| 184 | goto end; |
| 185 | } |
| 186 | |
| 187 | /* Safe to read client's id without locking as it is immutable. */ |
| 188 | ret = notification_thread_client_communication_update( |
| 189 | executor->notification_thread_handle, client->id, |
| 190 | status); |
| 191 | end: |
| 192 | return ret; |
| 193 | } |
| 194 | |
| 195 | static int action_executor_notify_handler(struct action_executor *executor, |
| 196 | const struct action_work_item *work_item, |
| 197 | const struct lttng_action *action) |
| 198 | { |
| 199 | return notification_client_list_send_evaluation(work_item->client_list, |
| 200 | work_item->trigger, |
| 201 | work_item->evaluation, |
| 202 | work_item->object_creds.is_set ? |
| 203 | &(work_item->object_creds.value) : |
| 204 | NULL, |
| 205 | client_handle_transmission_status, executor); |
| 206 | } |
| 207 | |
| 208 | static int action_executor_start_session_handler(struct action_executor *executor, |
| 209 | const struct action_work_item *work_item, |
| 210 | const struct lttng_action *action) |
| 211 | { |
| 212 | int ret = 0; |
| 213 | const char *session_name; |
| 214 | enum lttng_action_status action_status; |
| 215 | struct ltt_session *session; |
| 216 | enum lttng_error_code cmd_ret; |
| 217 | |
| 218 | action_status = lttng_action_start_session_get_session_name( |
| 219 | action, &session_name); |
| 220 | if (action_status != LTTNG_ACTION_STATUS_OK) { |
| 221 | ERR("Failed to get session name from `%s` action", |
| 222 | get_action_name(action)); |
| 223 | ret = -1; |
| 224 | goto end; |
| 225 | } |
| 226 | |
| 227 | session_lock_list(); |
| 228 | session = session_find_by_name(session_name); |
| 229 | if (!session) { |
| 230 | DBG("Failed to find session `%s` by name while executing `%s` action of trigger `%s`", |
| 231 | session_name, get_action_name(action), |
| 232 | get_trigger_name(work_item->trigger)); |
| 233 | goto error_unlock_list; |
| 234 | } |
| 235 | |
| 236 | session_lock(session); |
| 237 | if (!is_trigger_allowed_for_session(work_item->trigger, session)) { |
| 238 | goto error_dispose_session; |
| 239 | } |
| 240 | |
| 241 | cmd_ret = cmd_start_trace(session); |
| 242 | switch (cmd_ret) { |
| 243 | case LTTNG_OK: |
| 244 | DBG("Successfully started session `%s` on behalf of trigger `%s`", |
| 245 | session_name, get_trigger_name(work_item->trigger)); |
| 246 | break; |
| 247 | case LTTNG_ERR_TRACE_ALREADY_STARTED: |
| 248 | DBG("Attempted to start session `%s` on behalf of trigger `%s` but it was already started", |
| 249 | session_name, get_trigger_name(work_item->trigger)); |
| 250 | break; |
| 251 | default: |
| 252 | WARN("Failed to start session `%s` on behalf of trigger `%s`: %s", |
| 253 | session_name, get_trigger_name(work_item->trigger), |
| 254 | lttng_strerror(-cmd_ret)); |
| 255 | break; |
| 256 | } |
| 257 | |
| 258 | error_dispose_session: |
| 259 | session_unlock(session); |
| 260 | session_put(session); |
| 261 | error_unlock_list: |
| 262 | session_unlock_list(); |
| 263 | end: |
| 264 | return ret; |
| 265 | } |
| 266 | |
| 267 | static int action_executor_stop_session_handler(struct action_executor *executor, |
| 268 | const struct action_work_item *work_item, |
| 269 | const struct lttng_action *action) |
| 270 | { |
| 271 | int ret = 0; |
| 272 | const char *session_name; |
| 273 | enum lttng_action_status action_status; |
| 274 | struct ltt_session *session; |
| 275 | enum lttng_error_code cmd_ret; |
| 276 | |
| 277 | action_status = lttng_action_stop_session_get_session_name( |
| 278 | action, &session_name); |
| 279 | if (action_status != LTTNG_ACTION_STATUS_OK) { |
| 280 | ERR("Failed to get session name from `%s` action", |
| 281 | get_action_name(action)); |
| 282 | ret = -1; |
| 283 | goto end; |
| 284 | } |
| 285 | |
| 286 | session_lock_list(); |
| 287 | session = session_find_by_name(session_name); |
| 288 | if (!session) { |
| 289 | DBG("Failed to find session `%s` by name while executing `%s` action of trigger `%s`", |
| 290 | session_name, get_action_name(action), |
| 291 | get_trigger_name(work_item->trigger)); |
| 292 | goto error_unlock_list; |
| 293 | } |
| 294 | |
| 295 | session_lock(session); |
| 296 | if (!is_trigger_allowed_for_session(work_item->trigger, session)) { |
| 297 | goto error_dispose_session; |
| 298 | } |
| 299 | |
| 300 | cmd_ret = cmd_stop_trace(session); |
| 301 | switch (cmd_ret) { |
| 302 | case LTTNG_OK: |
| 303 | DBG("Successfully stopped session `%s` on behalf of trigger `%s`", |
| 304 | session_name, get_trigger_name(work_item->trigger)); |
| 305 | break; |
| 306 | case LTTNG_ERR_TRACE_ALREADY_STOPPED: |
| 307 | DBG("Attempted to stop session `%s` on behalf of trigger `%s` but it was already stopped", |
| 308 | session_name, get_trigger_name(work_item->trigger)); |
| 309 | break; |
| 310 | default: |
| 311 | WARN("Failed to stop session `%s` on behalf of trigger `%s`: %s", |
| 312 | session_name, get_trigger_name(work_item->trigger), |
| 313 | lttng_strerror(-cmd_ret)); |
| 314 | break; |
| 315 | } |
| 316 | |
| 317 | error_dispose_session: |
| 318 | session_unlock(session); |
| 319 | session_put(session); |
| 320 | error_unlock_list: |
| 321 | session_unlock_list(); |
| 322 | end: |
| 323 | return ret; |
| 324 | } |
| 325 | |
| 326 | static int action_executor_rotate_session_handler(struct action_executor *executor, |
| 327 | const struct action_work_item *work_item, |
| 328 | const struct lttng_action *action) |
| 329 | { |
| 330 | int ret = 0; |
| 331 | const char *session_name; |
| 332 | enum lttng_action_status action_status; |
| 333 | struct ltt_session *session; |
| 334 | enum lttng_error_code cmd_ret; |
| 335 | |
| 336 | action_status = lttng_action_rotate_session_get_session_name( |
| 337 | action, &session_name); |
| 338 | if (action_status != LTTNG_ACTION_STATUS_OK) { |
| 339 | ERR("Failed to get session name from `%s` action", |
| 340 | get_action_name(action)); |
| 341 | ret = -1; |
| 342 | goto end; |
| 343 | } |
| 344 | |
| 345 | session_lock_list(); |
| 346 | session = session_find_by_name(session_name); |
| 347 | if (!session) { |
| 348 | DBG("Failed to find session `%s` by name while executing `%s` action of trigger `%s`", |
| 349 | session_name, get_action_name(action), |
| 350 | get_trigger_name(work_item->trigger)); |
| 351 | goto error_unlock_list; |
| 352 | } |
| 353 | |
| 354 | session_lock(session); |
| 355 | if (!is_trigger_allowed_for_session(work_item->trigger, session)) { |
| 356 | goto error_dispose_session; |
| 357 | } |
| 358 | |
| 359 | cmd_ret = cmd_rotate_session(session, NULL, false, |
| 360 | LTTNG_TRACE_CHUNK_COMMAND_TYPE_MOVE_TO_COMPLETED); |
| 361 | switch (cmd_ret) { |
| 362 | case LTTNG_OK: |
| 363 | DBG("Successfully started rotation of session `%s` on behalf of trigger `%s`", |
| 364 | session_name, get_trigger_name(work_item->trigger)); |
| 365 | break; |
| 366 | case LTTNG_ERR_ROTATION_PENDING: |
| 367 | DBG("Attempted to start a rotation of session `%s` on behalf of trigger `%s` but a rotation is already ongoing", |
| 368 | session_name, get_trigger_name(work_item->trigger)); |
| 369 | break; |
| 370 | case LTTNG_ERR_ROTATION_MULTIPLE_AFTER_STOP: |
| 371 | case LTTNG_ERR_ROTATION_AFTER_STOP_CLEAR: |
| 372 | DBG("Attempted to start a rotation of session `%s` on behalf of trigger `%s` but a rotation has already been completed since the last stop or clear", |
| 373 | session_name, get_trigger_name(work_item->trigger)); |
| 374 | break; |
| 375 | default: |
| 376 | WARN("Failed to start a rotation of session `%s` on behalf of trigger `%s`: %s", |
| 377 | session_name, get_trigger_name(work_item->trigger), |
| 378 | lttng_strerror(-cmd_ret)); |
| 379 | break; |
| 380 | } |
| 381 | |
| 382 | error_dispose_session: |
| 383 | session_unlock(session); |
| 384 | session_put(session); |
| 385 | error_unlock_list: |
| 386 | session_unlock_list(); |
| 387 | end: |
| 388 | return ret; |
| 389 | } |
| 390 | |
| 391 | static int action_executor_snapshot_session_handler(struct action_executor *executor, |
| 392 | const struct action_work_item *work_item, |
| 393 | const struct lttng_action *action) |
| 394 | { |
| 395 | int ret = 0; |
| 396 | const char *session_name; |
| 397 | enum lttng_action_status action_status; |
| 398 | struct ltt_session *session; |
| 399 | const struct lttng_snapshot_output default_snapshot_output = { |
| 400 | .max_size = UINT64_MAX, |
| 401 | }; |
| 402 | const struct lttng_snapshot_output *snapshot_output = |
| 403 | &default_snapshot_output; |
| 404 | enum lttng_error_code cmd_ret; |
| 405 | |
| 406 | action_status = lttng_action_snapshot_session_get_session_name( |
| 407 | action, &session_name); |
| 408 | if (action_status != LTTNG_ACTION_STATUS_OK) { |
| 409 | ERR("Failed to get session name from `%s` action", |
| 410 | get_action_name(action)); |
| 411 | ret = -1; |
| 412 | goto end; |
| 413 | } |
| 414 | |
| 415 | action_status = lttng_action_snapshot_session_get_output( |
| 416 | action, &snapshot_output); |
| 417 | if (action_status != LTTNG_ACTION_STATUS_OK && |
| 418 | action_status != LTTNG_ACTION_STATUS_UNSET) { |
| 419 | ERR("Failed to get output from `%s` action", |
| 420 | get_action_name(action)); |
| 421 | ret = -1; |
| 422 | goto end; |
| 423 | } |
| 424 | |
| 425 | session_lock_list(); |
| 426 | session = session_find_by_name(session_name); |
| 427 | if (!session) { |
| 428 | DBG("Failed to find session `%s` by name while executing `%s` action of trigger `%s`", |
| 429 | session_name, get_action_name(action), |
| 430 | get_trigger_name(work_item->trigger)); |
| 431 | goto error_unlock_list; |
| 432 | } |
| 433 | |
| 434 | |
| 435 | session_lock(session); |
| 436 | if (!is_trigger_allowed_for_session(work_item->trigger, session)) { |
| 437 | goto error_dispose_session; |
| 438 | } |
| 439 | |
| 440 | cmd_ret = cmd_snapshot_record(session, snapshot_output, 0); |
| 441 | switch (cmd_ret) { |
| 442 | case LTTNG_OK: |
| 443 | DBG("Successfully recorded snapshot of session `%s` on behalf of trigger `%s`", |
| 444 | session_name, get_trigger_name(work_item->trigger)); |
| 445 | break; |
| 446 | default: |
| 447 | WARN("Failed to record snapshot of session `%s` on behalf of trigger `%s`: %s", |
| 448 | session_name, get_trigger_name(work_item->trigger), |
| 449 | lttng_strerror(-cmd_ret)); |
| 450 | break; |
| 451 | } |
| 452 | |
| 453 | error_dispose_session: |
| 454 | session_unlock(session); |
| 455 | session_put(session); |
| 456 | error_unlock_list: |
| 457 | session_unlock_list(); |
| 458 | end: |
| 459 | return ret; |
| 460 | } |
| 461 | |
| 462 | static int action_executor_group_handler(struct action_executor *executor, |
| 463 | const struct action_work_item *work_item, |
| 464 | const struct lttng_action *action_group) |
| 465 | { |
| 466 | int ret = 0; |
| 467 | unsigned int i, count; |
| 468 | enum lttng_action_status action_status; |
| 469 | |
| 470 | action_status = lttng_action_group_get_count(action_group, &count); |
| 471 | if (action_status != LTTNG_ACTION_STATUS_OK) { |
| 472 | /* Fatal error. */ |
| 473 | ERR("Failed to get count of action in action group"); |
| 474 | ret = -1; |
| 475 | goto end; |
| 476 | } |
| 477 | |
| 478 | DBG("Action group has %u action%s", count, count != 1 ? "s" : ""); |
| 479 | for (i = 0; i < count; i++) { |
| 480 | const struct lttng_action *action = |
| 481 | lttng_action_group_get_at_index( |
| 482 | action_group, i); |
| 483 | |
| 484 | ret = action_executor_generic_handler( |
| 485 | executor, work_item, action); |
| 486 | if (ret) { |
| 487 | ERR("Stopping the execution of the action group of trigger `%s` following a fatal error", |
| 488 | get_trigger_name(work_item->trigger)); |
| 489 | goto end; |
| 490 | } |
| 491 | } |
| 492 | end: |
| 493 | return ret; |
| 494 | } |
| 495 | |
| 496 | static int action_executor_generic_handler(struct action_executor *executor, |
| 497 | const struct action_work_item *work_item, |
| 498 | const struct lttng_action *action) |
| 499 | { |
| 500 | const enum lttng_action_type action_type = lttng_action_get_type(action); |
| 501 | |
| 502 | assert(action_type != LTTNG_ACTION_TYPE_UNKNOWN); |
| 503 | |
| 504 | DBG("Executing action `%s` of trigger `%s` action work item %" PRIu64, |
| 505 | get_action_name(action), |
| 506 | get_trigger_name(work_item->trigger), |
| 507 | work_item->id); |
| 508 | |
| 509 | return action_executors[action_type]( |
| 510 | executor, work_item, action); |
| 511 | } |
| 512 | |
| 513 | static int action_work_item_execute(struct action_executor *executor, |
| 514 | struct action_work_item *work_item) |
| 515 | { |
| 516 | int ret; |
| 517 | const struct lttng_action *action = |
| 518 | lttng_trigger_get_const_action(work_item->trigger); |
| 519 | |
| 520 | DBG("Starting execution of action work item %" PRIu64 " of trigger `%s`", |
| 521 | work_item->id, get_trigger_name(work_item->trigger)); |
| 522 | ret = action_executor_generic_handler(executor, work_item, action); |
| 523 | DBG("Completed execution of action work item %" PRIu64 " of trigger `%s`", |
| 524 | work_item->id, get_trigger_name(work_item->trigger)); |
| 525 | return ret; |
| 526 | } |
| 527 | |
| 528 | static void action_work_item_destroy(struct action_work_item *work_item) |
| 529 | { |
| 530 | lttng_trigger_put(work_item->trigger); |
| 531 | lttng_evaluation_destroy(work_item->evaluation); |
| 532 | notification_client_list_put(work_item->client_list); |
| 533 | free(work_item); |
| 534 | } |
| 535 | |
| 536 | static void *action_executor_thread(void *_data) |
| 537 | { |
| 538 | struct action_executor *executor = _data; |
| 539 | |
| 540 | assert(executor); |
| 541 | |
| 542 | health_register(the_health_sessiond, |
| 543 | HEALTH_SESSIOND_TYPE_ACTION_EXECUTOR); |
| 544 | |
| 545 | rcu_register_thread(); |
| 546 | rcu_thread_online(); |
| 547 | |
| 548 | DBG("Entering work execution loop"); |
| 549 | pthread_mutex_lock(&executor->work.lock); |
| 550 | while (!executor->should_quit) { |
| 551 | int ret; |
| 552 | struct action_work_item *work_item; |
| 553 | |
| 554 | health_code_update(); |
| 555 | if (executor->work.pending_count == 0) { |
| 556 | health_poll_entry(); |
| 557 | DBG("No work items enqueued, entering wait"); |
| 558 | pthread_cond_wait(&executor->work.cond, |
| 559 | &executor->work.lock); |
| 560 | DBG("Woke-up from wait"); |
| 561 | health_poll_exit(); |
| 562 | continue; |
| 563 | } |
| 564 | |
| 565 | /* Pop item from front of the list with work lock held. */ |
| 566 | work_item = cds_list_first_entry(&executor->work.list, |
| 567 | struct action_work_item, list_node); |
| 568 | cds_list_del(&work_item->list_node); |
| 569 | executor->work.pending_count--; |
| 570 | |
| 571 | /* |
| 572 | * Work can be performed without holding the work lock, |
| 573 | * allowing new items to be queued. |
| 574 | */ |
| 575 | pthread_mutex_unlock(&executor->work.lock); |
| 576 | ret = action_work_item_execute(executor, work_item); |
| 577 | action_work_item_destroy(work_item); |
| 578 | if (ret) { |
| 579 | /* Fatal error. */ |
| 580 | break; |
| 581 | } |
| 582 | |
| 583 | health_code_update(); |
| 584 | pthread_mutex_lock(&executor->work.lock); |
| 585 | } |
| 586 | |
| 587 | if (executor->should_quit) { |
| 588 | pthread_mutex_unlock(&executor->work.lock); |
| 589 | } |
| 590 | DBG("Left work execution loop"); |
| 591 | |
| 592 | health_code_update(); |
| 593 | |
| 594 | rcu_thread_offline(); |
| 595 | rcu_unregister_thread(); |
| 596 | health_unregister(the_health_sessiond); |
| 597 | |
| 598 | return NULL; |
| 599 | } |
| 600 | |
| 601 | static bool shutdown_action_executor_thread(void *_data) |
| 602 | { |
| 603 | struct action_executor *executor = _data; |
| 604 | |
| 605 | pthread_mutex_lock(&executor->work.lock); |
| 606 | executor->should_quit = true; |
| 607 | pthread_cond_signal(&executor->work.cond); |
| 608 | pthread_mutex_unlock(&executor->work.lock); |
| 609 | return true; |
| 610 | } |
| 611 | |
| 612 | static void clean_up_action_executor_thread(void *_data) |
| 613 | { |
| 614 | struct action_executor *executor = _data; |
| 615 | |
| 616 | assert(cds_list_empty(&executor->work.list)); |
| 617 | |
| 618 | pthread_mutex_destroy(&executor->work.lock); |
| 619 | pthread_cond_destroy(&executor->work.cond); |
| 620 | free(executor); |
| 621 | } |
| 622 | |
| 623 | struct action_executor *action_executor_create( |
| 624 | struct notification_thread_handle *handle) |
| 625 | { |
| 626 | struct action_executor *executor = zmalloc(sizeof(*executor)); |
| 627 | |
| 628 | if (!executor) { |
| 629 | goto end; |
| 630 | } |
| 631 | |
| 632 | CDS_INIT_LIST_HEAD(&executor->work.list); |
| 633 | pthread_cond_init(&executor->work.cond, NULL); |
| 634 | pthread_mutex_init(&executor->work.lock, NULL); |
| 635 | executor->notification_thread_handle = handle; |
| 636 | |
| 637 | executor->thread = lttng_thread_create(THREAD_NAME, |
| 638 | action_executor_thread, shutdown_action_executor_thread, |
| 639 | clean_up_action_executor_thread, executor); |
| 640 | end: |
| 641 | return executor; |
| 642 | } |
| 643 | |
| 644 | void action_executor_destroy(struct action_executor *executor) |
| 645 | { |
| 646 | struct action_work_item *work_item, *tmp; |
| 647 | |
| 648 | /* TODO Wait for work list to drain? */ |
| 649 | lttng_thread_shutdown(executor->thread); |
| 650 | pthread_mutex_lock(&executor->work.lock); |
| 651 | if (executor->work.pending_count != 0) { |
| 652 | WARN("%" PRIu64 |
| 653 | " trigger action%s still queued for execution and will be discarded", |
| 654 | executor->work.pending_count, |
| 655 | executor->work.pending_count == 1 ? " is" : |
| 656 | "s are"); |
| 657 | } |
| 658 | |
| 659 | cds_list_for_each_entry_safe ( |
| 660 | work_item, tmp, &executor->work.list, list_node) { |
| 661 | WARN("Discarding action work item %" PRIu64 |
| 662 | " associated to trigger `%s`", |
| 663 | work_item->id, get_trigger_name(work_item->trigger)); |
| 664 | cds_list_del(&work_item->list_node); |
| 665 | action_work_item_destroy(work_item); |
| 666 | } |
| 667 | pthread_mutex_unlock(&executor->work.lock); |
| 668 | lttng_thread_put(executor->thread); |
| 669 | } |
| 670 | |
| 671 | /* RCU read-lock must be held by the caller. */ |
| 672 | enum action_executor_status action_executor_enqueue( |
| 673 | struct action_executor *executor, |
| 674 | struct lttng_trigger *trigger, |
| 675 | struct lttng_evaluation *evaluation, |
| 676 | const struct lttng_credentials *object_creds, |
| 677 | struct notification_client_list *client_list) |
| 678 | { |
| 679 | enum action_executor_status executor_status = ACTION_EXECUTOR_STATUS_OK; |
| 680 | const uint64_t work_item_id = executor->next_work_item_id++; |
| 681 | struct action_work_item *work_item; |
| 682 | bool signal = false; |
| 683 | |
| 684 | pthread_mutex_lock(&executor->work.lock); |
| 685 | /* Check for queue overflow. */ |
| 686 | if (executor->work.pending_count >= MAX_QUEUED_WORK_COUNT) { |
| 687 | /* Most likely spammy, remove if it is the case. */ |
| 688 | DBG("Refusing to enqueue action for trigger `%s` as work item %" PRIu64 |
| 689 | " (overflow)", get_trigger_name(trigger), work_item_id); |
| 690 | executor_status = ACTION_EXECUTOR_STATUS_OVERFLOW; |
| 691 | goto error_unlock; |
| 692 | } |
| 693 | |
| 694 | work_item = zmalloc(sizeof(*work_item)); |
| 695 | if (!work_item) { |
| 696 | PERROR("Failed to allocate action executor work item on behalf of trigger `%s`", |
| 697 | get_trigger_name(trigger)); |
| 698 | executor_status = ACTION_EXECUTOR_STATUS_ERROR; |
| 699 | goto error_unlock; |
| 700 | } |
| 701 | |
| 702 | lttng_trigger_get(trigger); |
| 703 | if (client_list) { |
| 704 | const bool reference_acquired = |
| 705 | notification_client_list_get(client_list); |
| 706 | |
| 707 | assert(reference_acquired); |
| 708 | } |
| 709 | |
| 710 | *work_item = (typeof(*work_item)){ |
| 711 | .id = work_item_id, |
| 712 | .trigger = trigger, |
| 713 | /* Ownership transferred to the work item. */ |
| 714 | .evaluation = evaluation, |
| 715 | .object_creds = { |
| 716 | .is_set = !!object_creds, |
| 717 | .value = object_creds ? *object_creds : |
| 718 | (typeof(work_item->object_creds.value)) {}, |
| 719 | }, |
| 720 | .client_list = client_list, |
| 721 | .list_node = CDS_LIST_HEAD_INIT(work_item->list_node), |
| 722 | }; |
| 723 | |
| 724 | evaluation = NULL; |
| 725 | cds_list_add_tail(&work_item->list_node, &executor->work.list); |
| 726 | executor->work.pending_count++; |
| 727 | DBG("Enqueued action for trigger `%s` as work item #%" PRIu64, |
| 728 | get_trigger_name(trigger), work_item_id); |
| 729 | signal = true; |
| 730 | |
| 731 | error_unlock: |
| 732 | if (signal) { |
| 733 | pthread_cond_signal(&executor->work.cond); |
| 734 | } |
| 735 | pthread_mutex_unlock(&executor->work.lock); |
| 736 | |
| 737 | lttng_evaluation_destroy(evaluation); |
| 738 | return executor_status; |
| 739 | } |