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ab0ee2ca JG |
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> | |
ab0ee2ca JG |
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 | |
d0119529 | 71 | * (struct notification_client_list) subscribed to those |
ab0ee2ca JG |
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; | |
ab0ee2ca JG |
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 | ||
8ada111f | 173 | assert(cds_list_empty(&handle->cmd_queue.list)); |
ab0ee2ca JG |
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. */ | |
d72c8834 | 212 | handle->cmd_queue.event_fd = eventfd(0, EFD_CLOEXEC | EFD_SEMAPHORE); |
ab0ee2ca JG |
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 occured"); | |
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 | ||
2d01d977 JG |
635 | if (!revents) { |
636 | continue; | |
637 | } | |
ab0ee2ca JG |
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 | } |