| 1 | /* |
| 2 | * Copyright (C) 2017 - Jérémie Galarneau <jeremie.galarneau@efficios.com> |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify it |
| 5 | * under the terms of the GNU General Public License, version 2 only, as |
| 6 | * published by the Free Software Foundation. |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, but WITHOUT |
| 9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| 11 | * more details. |
| 12 | * |
| 13 | * You should have received a copy of the GNU General Public License along with |
| 14 | * this program; if not, write to the Free Software Foundation, Inc., 51 |
| 15 | * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 16 | */ |
| 17 | |
| 18 | #define _LGPL_SOURCE |
| 19 | #include <lttng/trigger/trigger.h> |
| 20 | #include <lttng/notification/channel-internal.h> |
| 21 | #include <lttng/notification/notification-internal.h> |
| 22 | #include <lttng/condition/condition-internal.h> |
| 23 | #include <lttng/condition/buffer-usage-internal.h> |
| 24 | #include <common/error.h> |
| 25 | #include <common/config/session-config.h> |
| 26 | #include <common/defaults.h> |
| 27 | #include <common/utils.h> |
| 28 | #include <common/align.h> |
| 29 | #include <common/time.h> |
| 30 | #include <sys/eventfd.h> |
| 31 | #include <sys/stat.h> |
| 32 | #include <time.h> |
| 33 | #include <signal.h> |
| 34 | |
| 35 | #include "notification-thread.h" |
| 36 | #include "notification-thread-events.h" |
| 37 | #include "notification-thread-commands.h" |
| 38 | #include "lttng-sessiond.h" |
| 39 | #include "health-sessiond.h" |
| 40 | |
| 41 | #include <urcu.h> |
| 42 | #include <urcu/list.h> |
| 43 | #include <urcu/rculfhash.h> |
| 44 | |
| 45 | /** |
| 46 | * This thread maintains an internal state associating clients and triggers. |
| 47 | * |
| 48 | * In order to speed-up and simplify queries, hash tables providing the |
| 49 | * following associations are maintained: |
| 50 | * |
| 51 | * - client_socket_ht: associate a client's socket (fd) to its "struct client" |
| 52 | * This hash table owns the "struct client" which must thus be |
| 53 | * disposed-of on removal from the hash table. |
| 54 | * |
| 55 | * - channel_triggers_ht: |
| 56 | * associates a channel key to a list of |
| 57 | * struct lttng_trigger_list_nodes. The triggers in this list are |
| 58 | * those that have conditions that apply to this channel. |
| 59 | * This hash table owns the list, but not the triggers themselves. |
| 60 | * |
| 61 | * - channel_state_ht: |
| 62 | * associates a pair (channel key, channel domain) to its last |
| 63 | * sampled state received from the consumer daemon |
| 64 | * (struct channel_state). |
| 65 | * This previous sample is kept to implement edge-triggered |
| 66 | * conditions as we need to detect the state transitions. |
| 67 | * This hash table owns the channel state. |
| 68 | * |
| 69 | * - notification_trigger_clients_ht: |
| 70 | * associates notification-emitting triggers to clients |
| 71 | * (struct notification_client_list) subscribed to those |
| 72 | * conditions. |
| 73 | * The condition's hash and match functions are used directly since |
| 74 | * all triggers in this hash table have the "notify" action. |
| 75 | * This hash table holds no ownership. |
| 76 | * |
| 77 | * - channels_ht: |
| 78 | * associates a channel_key to a struct channel_info. The hash table |
| 79 | * holds the ownership of the struct channel_info. |
| 80 | * |
| 81 | * - triggers_ht: |
| 82 | * associated a condition to a struct lttng_trigger_ht_element. |
| 83 | * The hash table holds the ownership of the |
| 84 | * lttng_trigger_ht_elements along with the triggers themselves. |
| 85 | * |
| 86 | * The thread reacts to the following internal events: |
| 87 | * 1) creation of a tracing channel, |
| 88 | * 2) destruction of a tracing channel, |
| 89 | * 3) registration of a trigger, |
| 90 | * 4) unregistration of a trigger, |
| 91 | * 5) reception of a channel monitor sample from the consumer daemon. |
| 92 | * |
| 93 | * Events specific to notification-emitting triggers: |
| 94 | * 6) connection of a notification client, |
| 95 | * 7) disconnection of a notification client, |
| 96 | * 8) subscription of a client to a conditions' notifications, |
| 97 | * 9) unsubscription of a client from a conditions' notifications, |
| 98 | * |
| 99 | * |
| 100 | * 1) Creation of a tracing channel |
| 101 | * - notification_trigger_clients_ht is traversed to identify |
| 102 | * triggers which apply to this new channel, |
| 103 | * - triggers identified are added to the channel_triggers_ht. |
| 104 | * - add channel to channels_ht |
| 105 | * |
| 106 | * 2) Destruction of a tracing channel |
| 107 | * - remove entry from channel_triggers_ht, releasing the list wrapper and |
| 108 | * elements, |
| 109 | * - remove entry from the channel_state_ht. |
| 110 | * - remove channel from channels_ht |
| 111 | * |
| 112 | * 3) Registration of a trigger |
| 113 | * - if the trigger's action is of type "notify", |
| 114 | * - traverse the list of conditions of every client to build a list of |
| 115 | * clients which have to be notified when this trigger's condition is met, |
| 116 | * - add list of clients (even if it is empty) to the |
| 117 | * notification_trigger_clients_ht, |
| 118 | * - add trigger to channel_triggers_ht (if applicable), |
| 119 | * - add trigger to triggers_ht |
| 120 | * |
| 121 | * 4) Unregistration of a trigger |
| 122 | * - if the trigger's action is of type "notify", |
| 123 | * - remove the trigger from the notification_trigger_clients_ht, |
| 124 | * - remove trigger from channel_triggers_ht (if applicable), |
| 125 | * - remove trigger from triggers_ht |
| 126 | * |
| 127 | * 5) Reception of a channel monitor sample from the consumer daemon |
| 128 | * - evaluate the conditions associated with the triggers found in |
| 129 | * the channel_triggers_ht, |
| 130 | * - if a condition evaluates to "true" and the condition is of type |
| 131 | * "notify", query the notification_trigger_clients_ht and send |
| 132 | * a notification to the clients. |
| 133 | * |
| 134 | * 6) Connection of a client |
| 135 | * - add client socket to the client_socket_ht. |
| 136 | * |
| 137 | * 7) Disconnection of a client |
| 138 | * - remove client socket from the client_socket_ht, |
| 139 | * - traverse all conditions to which the client is subscribed and remove |
| 140 | * the client from the notification_trigger_clients_ht. |
| 141 | * |
| 142 | * 8) Subscription of a client to a condition's notifications |
| 143 | * - Add the condition to the client's list of subscribed conditions, |
| 144 | * - Look-up notification_trigger_clients_ht and add the client to |
| 145 | * list of clients. |
| 146 | * |
| 147 | * 9) Unsubscription of a client to a condition's notifications |
| 148 | * - Remove the condition from the client's list of subscribed conditions, |
| 149 | * - Look-up notification_trigger_clients_ht and remove the client |
| 150 | * from the list of clients. |
| 151 | */ |
| 152 | |
| 153 | /* |
| 154 | * Destroy the thread data previously created by the init function. |
| 155 | */ |
| 156 | void notification_thread_handle_destroy( |
| 157 | struct notification_thread_handle *handle) |
| 158 | { |
| 159 | int ret; |
| 160 | |
| 161 | if (!handle) { |
| 162 | goto end; |
| 163 | } |
| 164 | |
| 165 | if (handle->cmd_queue.event_fd < 0) { |
| 166 | goto end; |
| 167 | } |
| 168 | ret = close(handle->cmd_queue.event_fd); |
| 169 | if (ret < 0) { |
| 170 | PERROR("close notification command queue event_fd"); |
| 171 | } |
| 172 | |
| 173 | assert(cds_list_empty(&handle->cmd_queue.list)); |
| 174 | pthread_mutex_destroy(&handle->cmd_queue.lock); |
| 175 | |
| 176 | if (handle->channel_monitoring_pipes.ust32_consumer >= 0) { |
| 177 | ret = close(handle->channel_monitoring_pipes.ust32_consumer); |
| 178 | if (ret) { |
| 179 | PERROR("close 32-bit consumer channel monitoring pipe"); |
| 180 | } |
| 181 | } |
| 182 | if (handle->channel_monitoring_pipes.ust64_consumer >= 0) { |
| 183 | ret = close(handle->channel_monitoring_pipes.ust64_consumer); |
| 184 | if (ret) { |
| 185 | PERROR("close 64-bit consumer channel monitoring pipe"); |
| 186 | } |
| 187 | } |
| 188 | if (handle->channel_monitoring_pipes.kernel_consumer >= 0) { |
| 189 | ret = close(handle->channel_monitoring_pipes.kernel_consumer); |
| 190 | if (ret) { |
| 191 | PERROR("close kernel consumer channel monitoring pipe"); |
| 192 | } |
| 193 | } |
| 194 | end: |
| 195 | free(handle); |
| 196 | } |
| 197 | |
| 198 | struct notification_thread_handle *notification_thread_handle_create( |
| 199 | struct lttng_pipe *ust32_channel_monitor_pipe, |
| 200 | struct lttng_pipe *ust64_channel_monitor_pipe, |
| 201 | struct lttng_pipe *kernel_channel_monitor_pipe) |
| 202 | { |
| 203 | int ret; |
| 204 | struct notification_thread_handle *handle; |
| 205 | |
| 206 | handle = zmalloc(sizeof(*handle)); |
| 207 | if (!handle) { |
| 208 | goto end; |
| 209 | } |
| 210 | |
| 211 | /* FIXME Replace eventfd by a pipe to support older kernels. */ |
| 212 | handle->cmd_queue.event_fd = eventfd(0, EFD_CLOEXEC | EFD_SEMAPHORE); |
| 213 | if (handle->cmd_queue.event_fd < 0) { |
| 214 | PERROR("eventfd notification command queue"); |
| 215 | goto error; |
| 216 | } |
| 217 | CDS_INIT_LIST_HEAD(&handle->cmd_queue.list); |
| 218 | ret = pthread_mutex_init(&handle->cmd_queue.lock, NULL); |
| 219 | if (ret) { |
| 220 | goto error; |
| 221 | } |
| 222 | |
| 223 | if (ust32_channel_monitor_pipe) { |
| 224 | handle->channel_monitoring_pipes.ust32_consumer = |
| 225 | lttng_pipe_release_readfd( |
| 226 | ust32_channel_monitor_pipe); |
| 227 | if (handle->channel_monitoring_pipes.ust32_consumer < 0) { |
| 228 | goto error; |
| 229 | } |
| 230 | } else { |
| 231 | handle->channel_monitoring_pipes.ust32_consumer = -1; |
| 232 | } |
| 233 | if (ust64_channel_monitor_pipe) { |
| 234 | handle->channel_monitoring_pipes.ust64_consumer = |
| 235 | lttng_pipe_release_readfd( |
| 236 | ust64_channel_monitor_pipe); |
| 237 | if (handle->channel_monitoring_pipes.ust64_consumer < 0) { |
| 238 | goto error; |
| 239 | } |
| 240 | } else { |
| 241 | handle->channel_monitoring_pipes.ust64_consumer = -1; |
| 242 | } |
| 243 | if (kernel_channel_monitor_pipe) { |
| 244 | handle->channel_monitoring_pipes.kernel_consumer = |
| 245 | lttng_pipe_release_readfd( |
| 246 | kernel_channel_monitor_pipe); |
| 247 | if (handle->channel_monitoring_pipes.kernel_consumer < 0) { |
| 248 | goto error; |
| 249 | } |
| 250 | } else { |
| 251 | handle->channel_monitoring_pipes.kernel_consumer = -1; |
| 252 | } |
| 253 | end: |
| 254 | return handle; |
| 255 | error: |
| 256 | notification_thread_handle_destroy(handle); |
| 257 | return NULL; |
| 258 | } |
| 259 | |
| 260 | static |
| 261 | char *get_notification_channel_sock_path(void) |
| 262 | { |
| 263 | int ret; |
| 264 | bool is_root = !getuid(); |
| 265 | char *sock_path; |
| 266 | |
| 267 | sock_path = zmalloc(LTTNG_PATH_MAX); |
| 268 | if (!sock_path) { |
| 269 | goto error; |
| 270 | } |
| 271 | |
| 272 | if (is_root) { |
| 273 | ret = snprintf(sock_path, LTTNG_PATH_MAX, |
| 274 | DEFAULT_GLOBAL_NOTIFICATION_CHANNEL_UNIX_SOCK); |
| 275 | if (ret < 0) { |
| 276 | goto error; |
| 277 | } |
| 278 | } else { |
| 279 | char *home_path = utils_get_home_dir(); |
| 280 | |
| 281 | if (!home_path) { |
| 282 | ERR("Can't get HOME directory for socket creation"); |
| 283 | goto error; |
| 284 | } |
| 285 | |
| 286 | ret = snprintf(sock_path, LTTNG_PATH_MAX, |
| 287 | DEFAULT_HOME_NOTIFICATION_CHANNEL_UNIX_SOCK, |
| 288 | home_path); |
| 289 | if (ret < 0) { |
| 290 | goto error; |
| 291 | } |
| 292 | } |
| 293 | |
| 294 | return sock_path; |
| 295 | error: |
| 296 | free(sock_path); |
| 297 | return NULL; |
| 298 | } |
| 299 | |
| 300 | static |
| 301 | void notification_channel_socket_destroy(int fd) |
| 302 | { |
| 303 | int ret; |
| 304 | char *sock_path = get_notification_channel_sock_path(); |
| 305 | |
| 306 | DBG("[notification-thread] Destroying notification channel socket"); |
| 307 | |
| 308 | if (sock_path) { |
| 309 | ret = unlink(sock_path); |
| 310 | free(sock_path); |
| 311 | if (ret < 0) { |
| 312 | PERROR("unlink notification channel socket"); |
| 313 | } |
| 314 | } |
| 315 | |
| 316 | ret = close(fd); |
| 317 | if (ret) { |
| 318 | PERROR("close notification channel socket"); |
| 319 | } |
| 320 | } |
| 321 | |
| 322 | static |
| 323 | int notification_channel_socket_create(void) |
| 324 | { |
| 325 | int fd = -1, ret; |
| 326 | char *sock_path = get_notification_channel_sock_path(); |
| 327 | |
| 328 | DBG("[notification-thread] Creating notification channel UNIX socket at %s", |
| 329 | sock_path); |
| 330 | |
| 331 | ret = lttcomm_create_unix_sock(sock_path); |
| 332 | if (ret < 0) { |
| 333 | ERR("[notification-thread] Failed to create notification socket"); |
| 334 | goto error; |
| 335 | } |
| 336 | fd = ret; |
| 337 | |
| 338 | ret = chmod(sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP); |
| 339 | if (ret < 0) { |
| 340 | ERR("Set file permissions failed: %s", sock_path); |
| 341 | PERROR("chmod notification channel socket"); |
| 342 | goto error; |
| 343 | } |
| 344 | |
| 345 | if (getuid() == 0) { |
| 346 | ret = chown(sock_path, 0, |
| 347 | utils_get_group_id(tracing_group_name)); |
| 348 | if (ret) { |
| 349 | ERR("Failed to set the notification channel socket's group"); |
| 350 | ret = -1; |
| 351 | goto error; |
| 352 | } |
| 353 | } |
| 354 | |
| 355 | DBG("[notification-thread] Notification channel UNIX socket created (fd = %i)", |
| 356 | fd); |
| 357 | free(sock_path); |
| 358 | return fd; |
| 359 | error: |
| 360 | if (fd >= 0 && close(fd) < 0) { |
| 361 | PERROR("close notification channel socket"); |
| 362 | } |
| 363 | free(sock_path); |
| 364 | return ret; |
| 365 | } |
| 366 | |
| 367 | static |
| 368 | int init_poll_set(struct lttng_poll_event *poll_set, |
| 369 | struct notification_thread_handle *handle, |
| 370 | int notification_channel_socket) |
| 371 | { |
| 372 | int ret; |
| 373 | |
| 374 | /* |
| 375 | * Create pollset with size 5: |
| 376 | * - notification channel socket (listen for new connections), |
| 377 | * - command queue event fd (internal sessiond commands), |
| 378 | * - consumerd (32-bit user space) channel monitor pipe, |
| 379 | * - consumerd (64-bit user space) channel monitor pipe, |
| 380 | * - consumerd (kernel) channel monitor pipe. |
| 381 | */ |
| 382 | ret = lttng_poll_create(poll_set, 5, LTTNG_CLOEXEC); |
| 383 | if (ret < 0) { |
| 384 | goto end; |
| 385 | } |
| 386 | |
| 387 | ret = lttng_poll_add(poll_set, notification_channel_socket, |
| 388 | LPOLLIN | LPOLLERR | LPOLLHUP | LPOLLRDHUP); |
| 389 | if (ret < 0) { |
| 390 | ERR("[notification-thread] Failed to add notification channel socket to pollset"); |
| 391 | goto error; |
| 392 | } |
| 393 | ret = lttng_poll_add(poll_set, handle->cmd_queue.event_fd, |
| 394 | LPOLLIN | LPOLLERR); |
| 395 | if (ret < 0) { |
| 396 | ERR("[notification-thread] Failed to add notification command queue event fd to pollset"); |
| 397 | goto error; |
| 398 | } |
| 399 | ret = lttng_poll_add(poll_set, |
| 400 | handle->channel_monitoring_pipes.ust32_consumer, |
| 401 | LPOLLIN | LPOLLERR); |
| 402 | if (ret < 0) { |
| 403 | ERR("[notification-thread] Failed to add ust-32 channel monitoring pipe fd to pollset"); |
| 404 | goto error; |
| 405 | } |
| 406 | ret = lttng_poll_add(poll_set, |
| 407 | handle->channel_monitoring_pipes.ust64_consumer, |
| 408 | LPOLLIN | LPOLLERR); |
| 409 | if (ret < 0) { |
| 410 | ERR("[notification-thread] Failed to add ust-64 channel monitoring pipe fd to pollset"); |
| 411 | goto error; |
| 412 | } |
| 413 | if (handle->channel_monitoring_pipes.kernel_consumer < 0) { |
| 414 | goto end; |
| 415 | } |
| 416 | ret = lttng_poll_add(poll_set, |
| 417 | handle->channel_monitoring_pipes.kernel_consumer, |
| 418 | LPOLLIN | LPOLLERR); |
| 419 | if (ret < 0) { |
| 420 | ERR("[notification-thread] Failed to add kernel channel monitoring pipe fd to pollset"); |
| 421 | goto error; |
| 422 | } |
| 423 | end: |
| 424 | return ret; |
| 425 | error: |
| 426 | lttng_poll_clean(poll_set); |
| 427 | return ret; |
| 428 | } |
| 429 | |
| 430 | static |
| 431 | void fini_thread_state(struct notification_thread_state *state) |
| 432 | { |
| 433 | int ret; |
| 434 | |
| 435 | if (state->client_socket_ht) { |
| 436 | ret = handle_notification_thread_client_disconnect_all(state); |
| 437 | assert(!ret); |
| 438 | ret = cds_lfht_destroy(state->client_socket_ht, NULL); |
| 439 | assert(!ret); |
| 440 | } |
| 441 | if (state->triggers_ht) { |
| 442 | ret = handle_notification_thread_trigger_unregister_all(state); |
| 443 | assert(!ret); |
| 444 | ret = cds_lfht_destroy(state->triggers_ht, NULL); |
| 445 | assert(!ret); |
| 446 | } |
| 447 | if (state->channel_triggers_ht) { |
| 448 | ret = cds_lfht_destroy(state->channel_triggers_ht, NULL); |
| 449 | assert(!ret); |
| 450 | } |
| 451 | if (state->channel_state_ht) { |
| 452 | ret = cds_lfht_destroy(state->channel_state_ht, NULL); |
| 453 | assert(!ret); |
| 454 | } |
| 455 | if (state->notification_trigger_clients_ht) { |
| 456 | ret = cds_lfht_destroy(state->notification_trigger_clients_ht, |
| 457 | NULL); |
| 458 | assert(!ret); |
| 459 | } |
| 460 | if (state->channels_ht) { |
| 461 | ret = cds_lfht_destroy(state->channels_ht, |
| 462 | NULL); |
| 463 | assert(!ret); |
| 464 | } |
| 465 | |
| 466 | if (state->notification_channel_socket >= 0) { |
| 467 | notification_channel_socket_destroy( |
| 468 | state->notification_channel_socket); |
| 469 | } |
| 470 | lttng_poll_clean(&state->events); |
| 471 | } |
| 472 | |
| 473 | static |
| 474 | int init_thread_state(struct notification_thread_handle *handle, |
| 475 | struct notification_thread_state *state) |
| 476 | { |
| 477 | int ret; |
| 478 | |
| 479 | memset(state, 0, sizeof(*state)); |
| 480 | state->notification_channel_socket = -1; |
| 481 | lttng_poll_init(&state->events); |
| 482 | |
| 483 | ret = notification_channel_socket_create(); |
| 484 | if (ret < 0) { |
| 485 | goto end; |
| 486 | } |
| 487 | state->notification_channel_socket = ret; |
| 488 | |
| 489 | ret = init_poll_set(&state->events, handle, |
| 490 | state->notification_channel_socket); |
| 491 | if (ret) { |
| 492 | goto end; |
| 493 | } |
| 494 | |
| 495 | DBG("[notification-thread] Listening on notification channel socket"); |
| 496 | ret = lttcomm_listen_unix_sock(state->notification_channel_socket); |
| 497 | if (ret < 0) { |
| 498 | ERR("[notification-thread] Listen failed on notification channel socket"); |
| 499 | goto error; |
| 500 | } |
| 501 | |
| 502 | state->client_socket_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0, |
| 503 | CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL); |
| 504 | if (!state->client_socket_ht) { |
| 505 | goto error; |
| 506 | } |
| 507 | |
| 508 | state->channel_triggers_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0, |
| 509 | CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL); |
| 510 | if (!state->channel_triggers_ht) { |
| 511 | goto error; |
| 512 | } |
| 513 | |
| 514 | state->channel_state_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0, |
| 515 | CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL); |
| 516 | if (!state->channel_state_ht) { |
| 517 | goto error; |
| 518 | } |
| 519 | |
| 520 | state->notification_trigger_clients_ht = cds_lfht_new(DEFAULT_HT_SIZE, |
| 521 | 1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL); |
| 522 | if (!state->notification_trigger_clients_ht) { |
| 523 | goto error; |
| 524 | } |
| 525 | |
| 526 | state->channels_ht = cds_lfht_new(DEFAULT_HT_SIZE, |
| 527 | 1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL); |
| 528 | if (!state->channels_ht) { |
| 529 | goto error; |
| 530 | } |
| 531 | |
| 532 | state->triggers_ht = cds_lfht_new(DEFAULT_HT_SIZE, |
| 533 | 1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL); |
| 534 | if (!state->triggers_ht) { |
| 535 | goto error; |
| 536 | } |
| 537 | end: |
| 538 | return 0; |
| 539 | error: |
| 540 | fini_thread_state(state); |
| 541 | return -1; |
| 542 | } |
| 543 | |
| 544 | static |
| 545 | int handle_channel_monitoring_pipe(int fd, uint32_t revents, |
| 546 | struct notification_thread_handle *handle, |
| 547 | struct notification_thread_state *state) |
| 548 | { |
| 549 | int ret = 0; |
| 550 | enum lttng_domain_type domain; |
| 551 | |
| 552 | if (fd == handle->channel_monitoring_pipes.ust32_consumer || |
| 553 | fd == handle->channel_monitoring_pipes.ust64_consumer) { |
| 554 | domain = LTTNG_DOMAIN_UST; |
| 555 | } else if (fd == handle->channel_monitoring_pipes.kernel_consumer) { |
| 556 | domain = LTTNG_DOMAIN_KERNEL; |
| 557 | } else { |
| 558 | abort(); |
| 559 | } |
| 560 | |
| 561 | if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) { |
| 562 | ret = lttng_poll_del(&state->events, fd); |
| 563 | if (ret) { |
| 564 | ERR("[notification-thread] Failed to remove consumer monitoring pipe from poll set"); |
| 565 | } |
| 566 | goto end; |
| 567 | } |
| 568 | |
| 569 | ret = handle_notification_thread_channel_sample( |
| 570 | state, fd, domain); |
| 571 | if (ret) { |
| 572 | ERR("[notification-thread] Consumer sample handling error occurred"); |
| 573 | ret = -1; |
| 574 | goto end; |
| 575 | } |
| 576 | end: |
| 577 | return ret; |
| 578 | } |
| 579 | |
| 580 | /* |
| 581 | * This thread services notification channel clients and commands received |
| 582 | * from various lttng-sessiond components over a command queue. |
| 583 | */ |
| 584 | void *thread_notification(void *data) |
| 585 | { |
| 586 | int ret; |
| 587 | struct notification_thread_handle *handle = data; |
| 588 | struct notification_thread_state state; |
| 589 | |
| 590 | DBG("[notification-thread] Started notification thread"); |
| 591 | |
| 592 | if (!handle) { |
| 593 | ERR("[notification-thread] Invalid thread context provided"); |
| 594 | goto end; |
| 595 | } |
| 596 | |
| 597 | rcu_register_thread(); |
| 598 | rcu_thread_online(); |
| 599 | |
| 600 | health_register(health_sessiond, HEALTH_SESSIOND_TYPE_NOTIFICATION); |
| 601 | health_code_update(); |
| 602 | |
| 603 | ret = init_thread_state(handle, &state); |
| 604 | if (ret) { |
| 605 | goto end; |
| 606 | } |
| 607 | |
| 608 | /* Ready to handle client connections. */ |
| 609 | sessiond_notify_ready(); |
| 610 | |
| 611 | while (true) { |
| 612 | int fd_count, i; |
| 613 | |
| 614 | health_poll_entry(); |
| 615 | DBG("[notification-thread] Entering poll wait"); |
| 616 | ret = lttng_poll_wait(&state.events, -1); |
| 617 | DBG("[notification-thread] Poll wait returned (%i)", ret); |
| 618 | health_poll_exit(); |
| 619 | if (ret < 0) { |
| 620 | /* |
| 621 | * Restart interrupted system call. |
| 622 | */ |
| 623 | if (errno == EINTR) { |
| 624 | continue; |
| 625 | } |
| 626 | ERR("[notification-thread] Error encountered during lttng_poll_wait (%i)", ret); |
| 627 | goto error; |
| 628 | } |
| 629 | |
| 630 | fd_count = ret; |
| 631 | for (i = 0; i < fd_count; i++) { |
| 632 | int fd = LTTNG_POLL_GETFD(&state.events, i); |
| 633 | uint32_t revents = LTTNG_POLL_GETEV(&state.events, i); |
| 634 | |
| 635 | if (!revents) { |
| 636 | continue; |
| 637 | } |
| 638 | DBG("[notification-thread] Handling fd (%i) activity (%u)", fd, revents); |
| 639 | |
| 640 | if (fd == state.notification_channel_socket) { |
| 641 | if (revents & LPOLLIN) { |
| 642 | ret = handle_notification_thread_client_connect( |
| 643 | &state); |
| 644 | if (ret < 0) { |
| 645 | goto error; |
| 646 | } |
| 647 | } else if (revents & |
| 648 | (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) { |
| 649 | ERR("[notification-thread] Notification socket poll error"); |
| 650 | goto error; |
| 651 | } else { |
| 652 | ERR("[notification-thread] Unexpected poll events %u for notification socket %i", revents, fd); |
| 653 | goto error; |
| 654 | } |
| 655 | } else if (fd == handle->cmd_queue.event_fd) { |
| 656 | ret = handle_notification_thread_command(handle, |
| 657 | &state); |
| 658 | if (ret < 0) { |
| 659 | DBG("[notification-thread] Error encountered while servicing command queue"); |
| 660 | goto error; |
| 661 | } else if (ret > 0) { |
| 662 | goto exit; |
| 663 | } |
| 664 | } else if (fd == handle->channel_monitoring_pipes.ust32_consumer || |
| 665 | fd == handle->channel_monitoring_pipes.ust64_consumer || |
| 666 | fd == handle->channel_monitoring_pipes.kernel_consumer) { |
| 667 | ret = handle_channel_monitoring_pipe(fd, |
| 668 | revents, handle, &state); |
| 669 | if (ret) { |
| 670 | goto error; |
| 671 | } |
| 672 | } else { |
| 673 | /* Activity on a client's socket. */ |
| 674 | if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) { |
| 675 | /* |
| 676 | * It doesn't matter if a command was |
| 677 | * pending on the client socket at this |
| 678 | * point since it now has no way to |
| 679 | * receive the notifications to which |
| 680 | * it was subscribing or unsubscribing. |
| 681 | */ |
| 682 | ret = handle_notification_thread_client_disconnect( |
| 683 | fd, &state); |
| 684 | if (ret) { |
| 685 | goto error; |
| 686 | } |
| 687 | } else { |
| 688 | if (revents & LPOLLIN) { |
| 689 | ret = handle_notification_thread_client_in( |
| 690 | &state, fd); |
| 691 | if (ret) { |
| 692 | goto error; |
| 693 | } |
| 694 | } |
| 695 | |
| 696 | if (revents & LPOLLOUT) { |
| 697 | ret = handle_notification_thread_client_out( |
| 698 | &state, fd); |
| 699 | if (ret) { |
| 700 | goto error; |
| 701 | } |
| 702 | } |
| 703 | } |
| 704 | } |
| 705 | } |
| 706 | } |
| 707 | exit: |
| 708 | error: |
| 709 | fini_thread_state(&state); |
| 710 | health_unregister(health_sessiond); |
| 711 | rcu_thread_offline(); |
| 712 | rcu_unregister_thread(); |
| 713 | end: |
| 714 | return NULL; |
| 715 | } |