Commit | Line | Data |
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3bd1e081 MD |
1 | /* |
2 | * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca> | |
3 | * Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
4 | * | |
d14d33bf AM |
5 | * This program is free software; you can redistribute it and/or modify |
6 | * it under the terms of the GNU General Public License, version 2 only, | |
7 | * as published by the Free Software Foundation. | |
3bd1e081 MD |
8 | * |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
d14d33bf AM |
14 | * You should have received a copy of the GNU General Public License along |
15 | * with this program; if not, write to the Free Software Foundation, Inc., | |
16 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. | |
3bd1e081 MD |
17 | */ |
18 | ||
6c1c0768 | 19 | #define _LGPL_SOURCE |
3bd1e081 | 20 | #include <assert.h> |
3bd1e081 MD |
21 | #include <poll.h> |
22 | #include <pthread.h> | |
23 | #include <stdlib.h> | |
24 | #include <string.h> | |
25 | #include <sys/mman.h> | |
26 | #include <sys/socket.h> | |
27 | #include <sys/types.h> | |
77c7c900 | 28 | #include <inttypes.h> |
3bd1e081 | 29 | #include <unistd.h> |
dbb5dfe6 | 30 | #include <sys/stat.h> |
3bd1e081 | 31 | |
51a9e1c7 | 32 | #include <bin/lttng-consumerd/health-consumerd.h> |
990570ed | 33 | #include <common/common.h> |
10a8a223 | 34 | #include <common/kernel-ctl/kernel-ctl.h> |
10a8a223 | 35 | #include <common/sessiond-comm/sessiond-comm.h> |
00e2e675 | 36 | #include <common/sessiond-comm/relayd.h> |
dbb5dfe6 | 37 | #include <common/compat/fcntl.h> |
f263b7fd | 38 | #include <common/compat/endian.h> |
acdb9057 | 39 | #include <common/pipe.h> |
00e2e675 | 40 | #include <common/relayd/relayd.h> |
fe4477ee | 41 | #include <common/utils.h> |
c8fea79c | 42 | #include <common/consumer/consumer-stream.h> |
309167d2 | 43 | #include <common/index/index.h> |
c8fea79c | 44 | #include <common/consumer/consumer-timer.h> |
0857097f | 45 | |
10a8a223 | 46 | #include "kernel-consumer.h" |
3bd1e081 MD |
47 | |
48 | extern struct lttng_consumer_global_data consumer_data; | |
49 | extern int consumer_poll_timeout; | |
50 | extern volatile int consumer_quit; | |
51 | ||
3bd1e081 MD |
52 | /* |
53 | * Take a snapshot for a specific fd | |
54 | * | |
55 | * Returns 0 on success, < 0 on error | |
56 | */ | |
ffe60014 | 57 | int lttng_kconsumer_take_snapshot(struct lttng_consumer_stream *stream) |
3bd1e081 MD |
58 | { |
59 | int ret = 0; | |
60 | int infd = stream->wait_fd; | |
61 | ||
62 | ret = kernctl_snapshot(infd); | |
ee6bb36a JD |
63 | /* |
64 | * -EAGAIN is not an error, it just means that there is no data to | |
65 | * be read. | |
66 | */ | |
67 | if (ret != 0 && ret != -EAGAIN) { | |
5a510c9f | 68 | PERROR("Getting sub-buffer snapshot."); |
3bd1e081 MD |
69 | } |
70 | ||
71 | return ret; | |
72 | } | |
73 | ||
74 | /* | |
75 | * Get the produced position | |
76 | * | |
77 | * Returns 0 on success, < 0 on error | |
78 | */ | |
ffe60014 | 79 | int lttng_kconsumer_get_produced_snapshot(struct lttng_consumer_stream *stream, |
3bd1e081 MD |
80 | unsigned long *pos) |
81 | { | |
82 | int ret; | |
83 | int infd = stream->wait_fd; | |
84 | ||
85 | ret = kernctl_snapshot_get_produced(infd, pos); | |
86 | if (ret != 0) { | |
5a510c9f | 87 | PERROR("kernctl_snapshot_get_produced"); |
3bd1e081 MD |
88 | } |
89 | ||
90 | return ret; | |
91 | } | |
92 | ||
07b86b52 JD |
93 | /* |
94 | * Get the consumerd position | |
95 | * | |
96 | * Returns 0 on success, < 0 on error | |
97 | */ | |
98 | int lttng_kconsumer_get_consumed_snapshot(struct lttng_consumer_stream *stream, | |
99 | unsigned long *pos) | |
100 | { | |
101 | int ret; | |
102 | int infd = stream->wait_fd; | |
103 | ||
104 | ret = kernctl_snapshot_get_consumed(infd, pos); | |
105 | if (ret != 0) { | |
5a510c9f | 106 | PERROR("kernctl_snapshot_get_consumed"); |
07b86b52 JD |
107 | } |
108 | ||
109 | return ret; | |
110 | } | |
111 | ||
07b86b52 JD |
112 | /* |
113 | * Take a snapshot of all the stream of a channel | |
114 | * | |
115 | * Returns 0 on success, < 0 on error | |
116 | */ | |
117 | int lttng_kconsumer_snapshot_channel(uint64_t key, char *path, | |
d07ceecd | 118 | uint64_t relayd_id, uint64_t nb_packets_per_stream, |
5c786ded | 119 | struct lttng_consumer_local_data *ctx) |
07b86b52 JD |
120 | { |
121 | int ret; | |
07b86b52 JD |
122 | struct lttng_consumer_channel *channel; |
123 | struct lttng_consumer_stream *stream; | |
124 | ||
6a00837f | 125 | DBG("Kernel consumer snapshot channel %" PRIu64, key); |
07b86b52 JD |
126 | |
127 | rcu_read_lock(); | |
128 | ||
129 | channel = consumer_find_channel(key); | |
130 | if (!channel) { | |
6a00837f | 131 | ERR("No channel found for key %" PRIu64, key); |
07b86b52 JD |
132 | ret = -1; |
133 | goto end; | |
134 | } | |
135 | ||
136 | /* Splice is not supported yet for channel snapshot. */ | |
137 | if (channel->output != CONSUMER_CHANNEL_MMAP) { | |
138 | ERR("Unsupported output %d", channel->output); | |
139 | ret = -1; | |
140 | goto end; | |
141 | } | |
142 | ||
10a50311 | 143 | cds_list_for_each_entry(stream, &channel->streams.head, send_node) { |
923333cd | 144 | unsigned long consumed_pos, produced_pos; |
9ce5646a MD |
145 | |
146 | health_code_update(); | |
147 | ||
07b86b52 JD |
148 | /* |
149 | * Lock stream because we are about to change its state. | |
150 | */ | |
151 | pthread_mutex_lock(&stream->lock); | |
152 | ||
29decac3 DG |
153 | /* |
154 | * Assign the received relayd ID so we can use it for streaming. The streams | |
155 | * are not visible to anyone so this is OK to change it. | |
156 | */ | |
07b86b52 JD |
157 | stream->net_seq_idx = relayd_id; |
158 | channel->relayd_id = relayd_id; | |
159 | if (relayd_id != (uint64_t) -1ULL) { | |
10a50311 | 160 | ret = consumer_send_relayd_stream(stream, path); |
07b86b52 JD |
161 | if (ret < 0) { |
162 | ERR("sending stream to relayd"); | |
163 | goto end_unlock; | |
164 | } | |
07b86b52 JD |
165 | } else { |
166 | ret = utils_create_stream_file(path, stream->name, | |
10a50311 JD |
167 | stream->chan->tracefile_size, |
168 | stream->tracefile_count_current, | |
309167d2 | 169 | stream->uid, stream->gid, NULL); |
07b86b52 JD |
170 | if (ret < 0) { |
171 | ERR("utils_create_stream_file"); | |
172 | goto end_unlock; | |
173 | } | |
174 | ||
175 | stream->out_fd = ret; | |
176 | stream->tracefile_size_current = 0; | |
177 | ||
81ea21bf MD |
178 | DBG("Kernel consumer snapshot stream %s/%s (%" PRIu64 ")", |
179 | path, stream->name, stream->key); | |
07b86b52 | 180 | } |
601262d6 JD |
181 | if (relayd_id != -1ULL) { |
182 | ret = consumer_send_relayd_streams_sent(relayd_id); | |
183 | if (ret < 0) { | |
184 | ERR("sending streams sent to relayd"); | |
185 | goto end_unlock; | |
186 | } | |
b7fa98e6 | 187 | channel->streams_sent_to_relayd = true; |
a4baae1b | 188 | } |
07b86b52 | 189 | |
612b8ed8 | 190 | ret = kernctl_buffer_flush_empty(stream->wait_fd); |
07b86b52 | 191 | if (ret < 0) { |
612b8ed8 MD |
192 | /* |
193 | * Doing a buffer flush which does not take into | |
194 | * account empty packets. This is not perfect | |
195 | * for stream intersection, but required as a | |
196 | * fall-back when "flush_empty" is not | |
197 | * implemented by lttng-modules. | |
198 | */ | |
199 | ret = kernctl_buffer_flush(stream->wait_fd); | |
200 | if (ret < 0) { | |
201 | ERR("Failed to flush kernel stream"); | |
202 | goto end_unlock; | |
203 | } | |
07b86b52 JD |
204 | goto end_unlock; |
205 | } | |
206 | ||
207 | ret = lttng_kconsumer_take_snapshot(stream); | |
208 | if (ret < 0) { | |
209 | ERR("Taking kernel snapshot"); | |
210 | goto end_unlock; | |
211 | } | |
212 | ||
213 | ret = lttng_kconsumer_get_produced_snapshot(stream, &produced_pos); | |
214 | if (ret < 0) { | |
215 | ERR("Produced kernel snapshot position"); | |
216 | goto end_unlock; | |
217 | } | |
218 | ||
219 | ret = lttng_kconsumer_get_consumed_snapshot(stream, &consumed_pos); | |
220 | if (ret < 0) { | |
221 | ERR("Consumerd kernel snapshot position"); | |
222 | goto end_unlock; | |
223 | } | |
224 | ||
225 | if (stream->max_sb_size == 0) { | |
226 | ret = kernctl_get_max_subbuf_size(stream->wait_fd, | |
227 | &stream->max_sb_size); | |
228 | if (ret < 0) { | |
229 | ERR("Getting kernel max_sb_size"); | |
230 | goto end_unlock; | |
231 | } | |
232 | } | |
233 | ||
d07ceecd MD |
234 | consumed_pos = consumer_get_consume_start_pos(consumed_pos, |
235 | produced_pos, nb_packets_per_stream, | |
236 | stream->max_sb_size); | |
5c786ded | 237 | |
07b86b52 JD |
238 | while (consumed_pos < produced_pos) { |
239 | ssize_t read_len; | |
240 | unsigned long len, padded_len; | |
241 | ||
9ce5646a MD |
242 | health_code_update(); |
243 | ||
07b86b52 JD |
244 | DBG("Kernel consumer taking snapshot at pos %lu", consumed_pos); |
245 | ||
246 | ret = kernctl_get_subbuf(stream->wait_fd, &consumed_pos); | |
247 | if (ret < 0) { | |
32af2c95 | 248 | if (ret != -EAGAIN) { |
07b86b52 JD |
249 | PERROR("kernctl_get_subbuf snapshot"); |
250 | goto end_unlock; | |
251 | } | |
252 | DBG("Kernel consumer get subbuf failed. Skipping it."); | |
253 | consumed_pos += stream->max_sb_size; | |
6e1f2e92 | 254 | stream->chan->lost_packets++; |
07b86b52 JD |
255 | continue; |
256 | } | |
257 | ||
258 | ret = kernctl_get_subbuf_size(stream->wait_fd, &len); | |
259 | if (ret < 0) { | |
260 | ERR("Snapshot kernctl_get_subbuf_size"); | |
29decac3 | 261 | goto error_put_subbuf; |
07b86b52 JD |
262 | } |
263 | ||
264 | ret = kernctl_get_padded_subbuf_size(stream->wait_fd, &padded_len); | |
265 | if (ret < 0) { | |
266 | ERR("Snapshot kernctl_get_padded_subbuf_size"); | |
29decac3 | 267 | goto error_put_subbuf; |
07b86b52 JD |
268 | } |
269 | ||
270 | read_len = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, len, | |
309167d2 | 271 | padded_len - len, NULL); |
07b86b52 | 272 | /* |
29decac3 DG |
273 | * We write the padded len in local tracefiles but the data len |
274 | * when using a relay. Display the error but continue processing | |
275 | * to try to release the subbuffer. | |
07b86b52 JD |
276 | */ |
277 | if (relayd_id != (uint64_t) -1ULL) { | |
278 | if (read_len != len) { | |
279 | ERR("Error sending to the relay (ret: %zd != len: %lu)", | |
280 | read_len, len); | |
281 | } | |
282 | } else { | |
283 | if (read_len != padded_len) { | |
284 | ERR("Error writing to tracefile (ret: %zd != len: %lu)", | |
285 | read_len, padded_len); | |
286 | } | |
287 | } | |
288 | ||
289 | ret = kernctl_put_subbuf(stream->wait_fd); | |
290 | if (ret < 0) { | |
291 | ERR("Snapshot kernctl_put_subbuf"); | |
292 | goto end_unlock; | |
293 | } | |
294 | consumed_pos += stream->max_sb_size; | |
295 | } | |
296 | ||
297 | if (relayd_id == (uint64_t) -1ULL) { | |
fdf9986c MD |
298 | if (stream->out_fd >= 0) { |
299 | ret = close(stream->out_fd); | |
300 | if (ret < 0) { | |
301 | PERROR("Kernel consumer snapshot close out_fd"); | |
302 | goto end_unlock; | |
303 | } | |
304 | stream->out_fd = -1; | |
07b86b52 | 305 | } |
07b86b52 JD |
306 | } else { |
307 | close_relayd_stream(stream); | |
308 | stream->net_seq_idx = (uint64_t) -1ULL; | |
309 | } | |
310 | pthread_mutex_unlock(&stream->lock); | |
311 | } | |
312 | ||
313 | /* All good! */ | |
314 | ret = 0; | |
315 | goto end; | |
316 | ||
29decac3 DG |
317 | error_put_subbuf: |
318 | ret = kernctl_put_subbuf(stream->wait_fd); | |
319 | if (ret < 0) { | |
320 | ERR("Snapshot kernctl_put_subbuf error path"); | |
321 | } | |
07b86b52 JD |
322 | end_unlock: |
323 | pthread_mutex_unlock(&stream->lock); | |
324 | end: | |
325 | rcu_read_unlock(); | |
326 | return ret; | |
327 | } | |
328 | ||
329 | /* | |
330 | * Read the whole metadata available for a snapshot. | |
331 | * | |
332 | * Returns 0 on success, < 0 on error | |
333 | */ | |
334 | int lttng_kconsumer_snapshot_metadata(uint64_t key, char *path, | |
e2039c7a | 335 | uint64_t relayd_id, struct lttng_consumer_local_data *ctx) |
07b86b52 | 336 | { |
d771f832 DG |
337 | int ret, use_relayd = 0; |
338 | ssize_t ret_read; | |
07b86b52 JD |
339 | struct lttng_consumer_channel *metadata_channel; |
340 | struct lttng_consumer_stream *metadata_stream; | |
d771f832 DG |
341 | |
342 | assert(ctx); | |
07b86b52 JD |
343 | |
344 | DBG("Kernel consumer snapshot metadata with key %" PRIu64 " at path %s", | |
345 | key, path); | |
346 | ||
347 | rcu_read_lock(); | |
348 | ||
349 | metadata_channel = consumer_find_channel(key); | |
350 | if (!metadata_channel) { | |
d771f832 | 351 | ERR("Kernel snapshot metadata not found for key %" PRIu64, key); |
07b86b52 | 352 | ret = -1; |
d771f832 | 353 | goto error; |
07b86b52 JD |
354 | } |
355 | ||
356 | metadata_stream = metadata_channel->metadata_stream; | |
357 | assert(metadata_stream); | |
358 | ||
d771f832 | 359 | /* Flag once that we have a valid relayd for the stream. */ |
e2039c7a | 360 | if (relayd_id != (uint64_t) -1ULL) { |
d771f832 DG |
361 | use_relayd = 1; |
362 | } | |
363 | ||
364 | if (use_relayd) { | |
10a50311 | 365 | ret = consumer_send_relayd_stream(metadata_stream, path); |
e2039c7a | 366 | if (ret < 0) { |
d771f832 | 367 | goto error; |
e2039c7a | 368 | } |
e2039c7a JD |
369 | } else { |
370 | ret = utils_create_stream_file(path, metadata_stream->name, | |
371 | metadata_stream->chan->tracefile_size, | |
372 | metadata_stream->tracefile_count_current, | |
309167d2 | 373 | metadata_stream->uid, metadata_stream->gid, NULL); |
e2039c7a | 374 | if (ret < 0) { |
d771f832 | 375 | goto error; |
e2039c7a JD |
376 | } |
377 | metadata_stream->out_fd = ret; | |
07b86b52 | 378 | } |
07b86b52 | 379 | |
d771f832 | 380 | do { |
9ce5646a MD |
381 | health_code_update(); |
382 | ||
d771f832 DG |
383 | ret_read = lttng_kconsumer_read_subbuffer(metadata_stream, ctx); |
384 | if (ret_read < 0) { | |
56591bac | 385 | if (ret_read != -EAGAIN) { |
6a00837f | 386 | ERR("Kernel snapshot reading metadata subbuffer (ret: %zd)", |
d771f832 DG |
387 | ret_read); |
388 | goto error; | |
07b86b52 | 389 | } |
d771f832 | 390 | /* ret_read is negative at this point so we will exit the loop. */ |
07b86b52 JD |
391 | continue; |
392 | } | |
d771f832 | 393 | } while (ret_read >= 0); |
07b86b52 | 394 | |
d771f832 DG |
395 | if (use_relayd) { |
396 | close_relayd_stream(metadata_stream); | |
397 | metadata_stream->net_seq_idx = (uint64_t) -1ULL; | |
398 | } else { | |
fdf9986c MD |
399 | if (metadata_stream->out_fd >= 0) { |
400 | ret = close(metadata_stream->out_fd); | |
401 | if (ret < 0) { | |
402 | PERROR("Kernel consumer snapshot metadata close out_fd"); | |
403 | /* | |
404 | * Don't go on error here since the snapshot was successful at this | |
405 | * point but somehow the close failed. | |
406 | */ | |
407 | } | |
408 | metadata_stream->out_fd = -1; | |
e2039c7a | 409 | } |
e2039c7a JD |
410 | } |
411 | ||
07b86b52 | 412 | ret = 0; |
d771f832 | 413 | |
cf53a8a6 JD |
414 | cds_list_del(&metadata_stream->send_node); |
415 | consumer_stream_destroy(metadata_stream, NULL); | |
416 | metadata_channel->metadata_stream = NULL; | |
d771f832 | 417 | error: |
07b86b52 JD |
418 | rcu_read_unlock(); |
419 | return ret; | |
420 | } | |
421 | ||
1803a064 MD |
422 | /* |
423 | * Receive command from session daemon and process it. | |
424 | * | |
425 | * Return 1 on success else a negative value or 0. | |
426 | */ | |
3bd1e081 MD |
427 | int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx, |
428 | int sock, struct pollfd *consumer_sockpoll) | |
429 | { | |
430 | ssize_t ret; | |
0c759fc9 | 431 | enum lttcomm_return_code ret_code = LTTCOMM_CONSUMERD_SUCCESS; |
3bd1e081 MD |
432 | struct lttcomm_consumer_msg msg; |
433 | ||
9ce5646a MD |
434 | health_code_update(); |
435 | ||
3bd1e081 MD |
436 | ret = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg)); |
437 | if (ret != sizeof(msg)) { | |
1803a064 | 438 | if (ret > 0) { |
c6857fcf | 439 | lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_CMD); |
1803a064 MD |
440 | ret = -1; |
441 | } | |
3bd1e081 MD |
442 | return ret; |
443 | } | |
9ce5646a MD |
444 | |
445 | health_code_update(); | |
446 | ||
84382d49 MD |
447 | /* Deprecated command */ |
448 | assert(msg.cmd_type != LTTNG_CONSUMER_STOP); | |
3bd1e081 | 449 | |
9ce5646a MD |
450 | health_code_update(); |
451 | ||
b0b335c8 MD |
452 | /* relayd needs RCU read-side protection */ |
453 | rcu_read_lock(); | |
454 | ||
3bd1e081 | 455 | switch (msg.cmd_type) { |
00e2e675 DG |
456 | case LTTNG_CONSUMER_ADD_RELAYD_SOCKET: |
457 | { | |
f50f23d9 | 458 | /* Session daemon status message are handled in the following call. */ |
7735ef9e DG |
459 | ret = consumer_add_relayd_socket(msg.u.relayd_sock.net_index, |
460 | msg.u.relayd_sock.type, ctx, sock, consumer_sockpoll, | |
d3e2ba59 JD |
461 | &msg.u.relayd_sock.sock, msg.u.relayd_sock.session_id, |
462 | msg.u.relayd_sock.relayd_session_id); | |
00e2e675 DG |
463 | goto end_nosignal; |
464 | } | |
3bd1e081 MD |
465 | case LTTNG_CONSUMER_ADD_CHANNEL: |
466 | { | |
467 | struct lttng_consumer_channel *new_channel; | |
e43c41c5 | 468 | int ret_recv; |
3bd1e081 | 469 | |
9ce5646a MD |
470 | health_code_update(); |
471 | ||
f50f23d9 DG |
472 | /* First send a status message before receiving the fds. */ |
473 | ret = consumer_send_status_msg(sock, ret_code); | |
474 | if (ret < 0) { | |
475 | /* Somehow, the session daemon is not responding anymore. */ | |
1803a064 | 476 | goto error_fatal; |
f50f23d9 | 477 | } |
9ce5646a MD |
478 | |
479 | health_code_update(); | |
480 | ||
d88aee68 | 481 | DBG("consumer_add_channel %" PRIu64, msg.u.channel.channel_key); |
3bd1e081 | 482 | new_channel = consumer_allocate_channel(msg.u.channel.channel_key, |
ffe60014 DG |
483 | msg.u.channel.session_id, msg.u.channel.pathname, |
484 | msg.u.channel.name, msg.u.channel.uid, msg.u.channel.gid, | |
1624d5b7 JD |
485 | msg.u.channel.relayd_id, msg.u.channel.output, |
486 | msg.u.channel.tracefile_size, | |
1950109e | 487 | msg.u.channel.tracefile_count, 0, |
ecc48a90 | 488 | msg.u.channel.monitor, |
d7ba1388 | 489 | msg.u.channel.live_timer_interval, |
3d071855 | 490 | NULL, NULL); |
3bd1e081 | 491 | if (new_channel == NULL) { |
f73fabfd | 492 | lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR); |
3bd1e081 MD |
493 | goto end_nosignal; |
494 | } | |
ffe60014 | 495 | new_channel->nb_init_stream_left = msg.u.channel.nb_init_streams; |
95a1109b JD |
496 | switch (msg.u.channel.output) { |
497 | case LTTNG_EVENT_SPLICE: | |
498 | new_channel->output = CONSUMER_CHANNEL_SPLICE; | |
499 | break; | |
500 | case LTTNG_EVENT_MMAP: | |
501 | new_channel->output = CONSUMER_CHANNEL_MMAP; | |
502 | break; | |
503 | default: | |
504 | ERR("Channel output unknown %d", msg.u.channel.output); | |
505 | goto end_nosignal; | |
506 | } | |
ffe60014 DG |
507 | |
508 | /* Translate and save channel type. */ | |
509 | switch (msg.u.channel.type) { | |
510 | case CONSUMER_CHANNEL_TYPE_DATA: | |
511 | case CONSUMER_CHANNEL_TYPE_METADATA: | |
512 | new_channel->type = msg.u.channel.type; | |
513 | break; | |
514 | default: | |
515 | assert(0); | |
516 | goto end_nosignal; | |
517 | }; | |
518 | ||
9ce5646a MD |
519 | health_code_update(); |
520 | ||
3bd1e081 | 521 | if (ctx->on_recv_channel != NULL) { |
e43c41c5 JD |
522 | ret_recv = ctx->on_recv_channel(new_channel); |
523 | if (ret_recv == 0) { | |
524 | ret = consumer_add_channel(new_channel, ctx); | |
525 | } else if (ret_recv < 0) { | |
3bd1e081 MD |
526 | goto end_nosignal; |
527 | } | |
528 | } else { | |
e43c41c5 | 529 | ret = consumer_add_channel(new_channel, ctx); |
3bd1e081 | 530 | } |
94d49140 JD |
531 | if (CONSUMER_CHANNEL_TYPE_DATA) { |
532 | consumer_timer_live_start(new_channel, | |
533 | msg.u.channel.live_timer_interval); | |
534 | } | |
e43c41c5 | 535 | |
9ce5646a MD |
536 | health_code_update(); |
537 | ||
e43c41c5 | 538 | /* If we received an error in add_channel, we need to report it. */ |
821fffb2 | 539 | if (ret < 0) { |
1803a064 MD |
540 | ret = consumer_send_status_msg(sock, ret); |
541 | if (ret < 0) { | |
542 | goto error_fatal; | |
543 | } | |
e43c41c5 JD |
544 | goto end_nosignal; |
545 | } | |
546 | ||
3bd1e081 MD |
547 | goto end_nosignal; |
548 | } | |
549 | case LTTNG_CONSUMER_ADD_STREAM: | |
550 | { | |
dae10966 DG |
551 | int fd; |
552 | struct lttng_pipe *stream_pipe; | |
00e2e675 | 553 | struct lttng_consumer_stream *new_stream; |
ffe60014 | 554 | struct lttng_consumer_channel *channel; |
c80048c6 | 555 | int alloc_ret = 0; |
3bd1e081 | 556 | |
ffe60014 DG |
557 | /* |
558 | * Get stream's channel reference. Needed when adding the stream to the | |
559 | * global hash table. | |
560 | */ | |
561 | channel = consumer_find_channel(msg.u.stream.channel_key); | |
562 | if (!channel) { | |
563 | /* | |
564 | * We could not find the channel. Can happen if cpu hotplug | |
565 | * happens while tearing down. | |
566 | */ | |
d88aee68 | 567 | ERR("Unable to find channel key %" PRIu64, msg.u.stream.channel_key); |
e462382a | 568 | ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND; |
ffe60014 DG |
569 | } |
570 | ||
9ce5646a MD |
571 | health_code_update(); |
572 | ||
f50f23d9 DG |
573 | /* First send a status message before receiving the fds. */ |
574 | ret = consumer_send_status_msg(sock, ret_code); | |
1803a064 | 575 | if (ret < 0) { |
d771f832 | 576 | /* Somehow, the session daemon is not responding anymore. */ |
1803a064 MD |
577 | goto error_fatal; |
578 | } | |
9ce5646a MD |
579 | |
580 | health_code_update(); | |
581 | ||
0c759fc9 | 582 | if (ret_code != LTTCOMM_CONSUMERD_SUCCESS) { |
d771f832 | 583 | /* Channel was not found. */ |
f50f23d9 DG |
584 | goto end_nosignal; |
585 | } | |
586 | ||
d771f832 | 587 | /* Blocking call */ |
9ce5646a MD |
588 | health_poll_entry(); |
589 | ret = lttng_consumer_poll_socket(consumer_sockpoll); | |
590 | health_poll_exit(); | |
84382d49 MD |
591 | if (ret) { |
592 | goto error_fatal; | |
3bd1e081 | 593 | } |
00e2e675 | 594 | |
9ce5646a MD |
595 | health_code_update(); |
596 | ||
00e2e675 | 597 | /* Get stream file descriptor from socket */ |
f2fc6720 MD |
598 | ret = lttcomm_recv_fds_unix_sock(sock, &fd, 1); |
599 | if (ret != sizeof(fd)) { | |
f73fabfd | 600 | lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_FD); |
3f8e211f | 601 | rcu_read_unlock(); |
3bd1e081 MD |
602 | return ret; |
603 | } | |
3bd1e081 | 604 | |
9ce5646a MD |
605 | health_code_update(); |
606 | ||
f50f23d9 DG |
607 | /* |
608 | * Send status code to session daemon only if the recv works. If the | |
609 | * above recv() failed, the session daemon is notified through the | |
610 | * error socket and the teardown is eventually done. | |
611 | */ | |
612 | ret = consumer_send_status_msg(sock, ret_code); | |
613 | if (ret < 0) { | |
614 | /* Somehow, the session daemon is not responding anymore. */ | |
615 | goto end_nosignal; | |
616 | } | |
617 | ||
9ce5646a MD |
618 | health_code_update(); |
619 | ||
ffe60014 DG |
620 | new_stream = consumer_allocate_stream(channel->key, |
621 | fd, | |
622 | LTTNG_CONSUMER_ACTIVE_STREAM, | |
623 | channel->name, | |
624 | channel->uid, | |
625 | channel->gid, | |
626 | channel->relayd_id, | |
627 | channel->session_id, | |
628 | msg.u.stream.cpu, | |
629 | &alloc_ret, | |
4891ece8 DG |
630 | channel->type, |
631 | channel->monitor); | |
3bd1e081 | 632 | if (new_stream == NULL) { |
c80048c6 MD |
633 | switch (alloc_ret) { |
634 | case -ENOMEM: | |
635 | case -EINVAL: | |
636 | default: | |
637 | lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR); | |
638 | break; | |
c80048c6 | 639 | } |
3f8e211f | 640 | goto end_nosignal; |
3bd1e081 | 641 | } |
d771f832 | 642 | |
ffe60014 DG |
643 | new_stream->chan = channel; |
644 | new_stream->wait_fd = fd; | |
07b86b52 JD |
645 | switch (channel->output) { |
646 | case CONSUMER_CHANNEL_SPLICE: | |
647 | new_stream->output = LTTNG_EVENT_SPLICE; | |
a2361a61 JD |
648 | ret = utils_create_pipe(new_stream->splice_pipe); |
649 | if (ret < 0) { | |
650 | goto end_nosignal; | |
651 | } | |
07b86b52 JD |
652 | break; |
653 | case CONSUMER_CHANNEL_MMAP: | |
654 | new_stream->output = LTTNG_EVENT_MMAP; | |
655 | break; | |
656 | default: | |
657 | ERR("Stream output unknown %d", channel->output); | |
658 | goto end_nosignal; | |
659 | } | |
00e2e675 | 660 | |
a0c83db9 DG |
661 | /* |
662 | * We've just assigned the channel to the stream so increment the | |
07b86b52 JD |
663 | * refcount right now. We don't need to increment the refcount for |
664 | * streams in no monitor because we handle manually the cleanup of | |
665 | * those. It is very important to make sure there is NO prior | |
666 | * consumer_del_stream() calls or else the refcount will be unbalanced. | |
a0c83db9 | 667 | */ |
07b86b52 JD |
668 | if (channel->monitor) { |
669 | uatomic_inc(&new_stream->chan->refcount); | |
670 | } | |
9d9353f9 | 671 | |
fb3a43a9 DG |
672 | /* |
673 | * The buffer flush is done on the session daemon side for the kernel | |
674 | * so no need for the stream "hangup_flush_done" variable to be | |
675 | * tracked. This is important for a kernel stream since we don't rely | |
676 | * on the flush state of the stream to read data. It's not the case for | |
677 | * user space tracing. | |
678 | */ | |
679 | new_stream->hangup_flush_done = 0; | |
680 | ||
9ce5646a MD |
681 | health_code_update(); |
682 | ||
633d0084 DG |
683 | if (ctx->on_recv_stream) { |
684 | ret = ctx->on_recv_stream(new_stream); | |
685 | if (ret < 0) { | |
d771f832 | 686 | consumer_stream_free(new_stream); |
633d0084 | 687 | goto end_nosignal; |
fb3a43a9 | 688 | } |
633d0084 | 689 | } |
fb3a43a9 | 690 | |
9ce5646a MD |
691 | health_code_update(); |
692 | ||
07b86b52 JD |
693 | if (new_stream->metadata_flag) { |
694 | channel->metadata_stream = new_stream; | |
695 | } | |
696 | ||
2bba9e53 DG |
697 | /* Do not monitor this stream. */ |
698 | if (!channel->monitor) { | |
5eecee74 | 699 | DBG("Kernel consumer add stream %s in no monitor mode with " |
6dc3064a | 700 | "relayd id %" PRIu64, new_stream->name, |
5eecee74 | 701 | new_stream->net_seq_idx); |
10a50311 | 702 | cds_list_add(&new_stream->send_node, &channel->streams.head); |
6dc3064a DG |
703 | break; |
704 | } | |
705 | ||
e1b71bdc DG |
706 | /* Send stream to relayd if the stream has an ID. */ |
707 | if (new_stream->net_seq_idx != (uint64_t) -1ULL) { | |
194ee077 DG |
708 | ret = consumer_send_relayd_stream(new_stream, |
709 | new_stream->chan->pathname); | |
e1b71bdc DG |
710 | if (ret < 0) { |
711 | consumer_stream_free(new_stream); | |
712 | goto end_nosignal; | |
713 | } | |
b7fa98e6 MD |
714 | |
715 | /* | |
716 | * If adding an extra stream to an already | |
717 | * existing channel (e.g. cpu hotplug), we need | |
718 | * to send the "streams_sent" command to relayd. | |
719 | */ | |
720 | if (channel->streams_sent_to_relayd) { | |
721 | ret = consumer_send_relayd_streams_sent( | |
722 | new_stream->net_seq_idx); | |
723 | if (ret < 0) { | |
724 | goto end_nosignal; | |
725 | } | |
726 | } | |
e2039c7a JD |
727 | } |
728 | ||
50f8ae69 | 729 | /* Get the right pipe where the stream will be sent. */ |
633d0084 | 730 | if (new_stream->metadata_flag) { |
5ab66908 MD |
731 | ret = consumer_add_metadata_stream(new_stream); |
732 | if (ret) { | |
733 | ERR("Consumer add metadata stream %" PRIu64 " failed. Continuing", | |
734 | new_stream->key); | |
735 | consumer_stream_free(new_stream); | |
736 | goto end_nosignal; | |
737 | } | |
dae10966 | 738 | stream_pipe = ctx->consumer_metadata_pipe; |
3bd1e081 | 739 | } else { |
5ab66908 MD |
740 | ret = consumer_add_data_stream(new_stream); |
741 | if (ret) { | |
742 | ERR("Consumer add stream %" PRIu64 " failed. Continuing", | |
743 | new_stream->key); | |
744 | consumer_stream_free(new_stream); | |
745 | goto end_nosignal; | |
746 | } | |
dae10966 | 747 | stream_pipe = ctx->consumer_data_pipe; |
50f8ae69 DG |
748 | } |
749 | ||
5ab66908 MD |
750 | /* Vitible to other threads */ |
751 | new_stream->globally_visible = 1; | |
752 | ||
9ce5646a MD |
753 | health_code_update(); |
754 | ||
dae10966 | 755 | ret = lttng_pipe_write(stream_pipe, &new_stream, sizeof(new_stream)); |
50f8ae69 | 756 | if (ret < 0) { |
dae10966 | 757 | ERR("Consumer write %s stream to pipe %d", |
50f8ae69 | 758 | new_stream->metadata_flag ? "metadata" : "data", |
dae10966 | 759 | lttng_pipe_get_writefd(stream_pipe)); |
5ab66908 MD |
760 | if (new_stream->metadata_flag) { |
761 | consumer_del_stream_for_metadata(new_stream); | |
762 | } else { | |
763 | consumer_del_stream_for_data(new_stream); | |
764 | } | |
50f8ae69 | 765 | goto end_nosignal; |
3bd1e081 | 766 | } |
00e2e675 | 767 | |
50f8ae69 | 768 | DBG("Kernel consumer ADD_STREAM %s (fd: %d) with relayd id %" PRIu64, |
ffe60014 | 769 | new_stream->name, fd, new_stream->relayd_stream_id); |
3bd1e081 MD |
770 | break; |
771 | } | |
a4baae1b JD |
772 | case LTTNG_CONSUMER_STREAMS_SENT: |
773 | { | |
774 | struct lttng_consumer_channel *channel; | |
775 | ||
776 | /* | |
777 | * Get stream's channel reference. Needed when adding the stream to the | |
778 | * global hash table. | |
779 | */ | |
780 | channel = consumer_find_channel(msg.u.sent_streams.channel_key); | |
781 | if (!channel) { | |
782 | /* | |
783 | * We could not find the channel. Can happen if cpu hotplug | |
784 | * happens while tearing down. | |
785 | */ | |
786 | ERR("Unable to find channel key %" PRIu64, | |
787 | msg.u.sent_streams.channel_key); | |
e462382a | 788 | ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND; |
a4baae1b JD |
789 | } |
790 | ||
791 | health_code_update(); | |
792 | ||
793 | /* | |
794 | * Send status code to session daemon. | |
795 | */ | |
796 | ret = consumer_send_status_msg(sock, ret_code); | |
f261ad0a | 797 | if (ret < 0 || ret_code != LTTCOMM_CONSUMERD_SUCCESS) { |
a4baae1b JD |
798 | /* Somehow, the session daemon is not responding anymore. */ |
799 | goto end_nosignal; | |
800 | } | |
801 | ||
802 | health_code_update(); | |
803 | ||
804 | /* | |
805 | * We should not send this message if we don't monitor the | |
806 | * streams in this channel. | |
807 | */ | |
808 | if (!channel->monitor) { | |
809 | break; | |
810 | } | |
811 | ||
812 | health_code_update(); | |
813 | /* Send stream to relayd if the stream has an ID. */ | |
814 | if (msg.u.sent_streams.net_seq_idx != (uint64_t) -1ULL) { | |
815 | ret = consumer_send_relayd_streams_sent( | |
816 | msg.u.sent_streams.net_seq_idx); | |
817 | if (ret < 0) { | |
818 | goto end_nosignal; | |
819 | } | |
b7fa98e6 | 820 | channel->streams_sent_to_relayd = true; |
a4baae1b JD |
821 | } |
822 | break; | |
823 | } | |
3bd1e081 MD |
824 | case LTTNG_CONSUMER_UPDATE_STREAM: |
825 | { | |
3f8e211f DG |
826 | rcu_read_unlock(); |
827 | return -ENOSYS; | |
828 | } | |
829 | case LTTNG_CONSUMER_DESTROY_RELAYD: | |
830 | { | |
a6ba4fe1 | 831 | uint64_t index = msg.u.destroy_relayd.net_seq_idx; |
3f8e211f DG |
832 | struct consumer_relayd_sock_pair *relayd; |
833 | ||
a6ba4fe1 | 834 | DBG("Kernel consumer destroying relayd %" PRIu64, index); |
3f8e211f DG |
835 | |
836 | /* Get relayd reference if exists. */ | |
a6ba4fe1 | 837 | relayd = consumer_find_relayd(index); |
3f8e211f | 838 | if (relayd == NULL) { |
3448e266 | 839 | DBG("Unable to find relayd %" PRIu64, index); |
e462382a | 840 | ret_code = LTTCOMM_CONSUMERD_RELAYD_FAIL; |
3bd1e081 | 841 | } |
3f8e211f | 842 | |
a6ba4fe1 DG |
843 | /* |
844 | * Each relayd socket pair has a refcount of stream attached to it | |
845 | * which tells if the relayd is still active or not depending on the | |
846 | * refcount value. | |
847 | * | |
848 | * This will set the destroy flag of the relayd object and destroy it | |
849 | * if the refcount reaches zero when called. | |
850 | * | |
851 | * The destroy can happen either here or when a stream fd hangs up. | |
852 | */ | |
f50f23d9 DG |
853 | if (relayd) { |
854 | consumer_flag_relayd_for_destroy(relayd); | |
855 | } | |
856 | ||
9ce5646a MD |
857 | health_code_update(); |
858 | ||
f50f23d9 DG |
859 | ret = consumer_send_status_msg(sock, ret_code); |
860 | if (ret < 0) { | |
861 | /* Somehow, the session daemon is not responding anymore. */ | |
1803a064 | 862 | goto error_fatal; |
f50f23d9 | 863 | } |
3f8e211f | 864 | |
3f8e211f | 865 | goto end_nosignal; |
3bd1e081 | 866 | } |
6d805429 | 867 | case LTTNG_CONSUMER_DATA_PENDING: |
53632229 | 868 | { |
c8f59ee5 | 869 | int32_t ret; |
6d805429 | 870 | uint64_t id = msg.u.data_pending.session_id; |
c8f59ee5 | 871 | |
6d805429 | 872 | DBG("Kernel consumer data pending command for id %" PRIu64, id); |
c8f59ee5 | 873 | |
6d805429 | 874 | ret = consumer_data_pending(id); |
c8f59ee5 | 875 | |
9ce5646a MD |
876 | health_code_update(); |
877 | ||
c8f59ee5 DG |
878 | /* Send back returned value to session daemon */ |
879 | ret = lttcomm_send_unix_sock(sock, &ret, sizeof(ret)); | |
880 | if (ret < 0) { | |
6d805429 | 881 | PERROR("send data pending ret code"); |
1803a064 | 882 | goto error_fatal; |
c8f59ee5 | 883 | } |
f50f23d9 DG |
884 | |
885 | /* | |
886 | * No need to send back a status message since the data pending | |
887 | * returned value is the response. | |
888 | */ | |
c8f59ee5 | 889 | break; |
53632229 | 890 | } |
6dc3064a DG |
891 | case LTTNG_CONSUMER_SNAPSHOT_CHANNEL: |
892 | { | |
07b86b52 JD |
893 | if (msg.u.snapshot_channel.metadata == 1) { |
894 | ret = lttng_kconsumer_snapshot_metadata(msg.u.snapshot_channel.key, | |
e2039c7a JD |
895 | msg.u.snapshot_channel.pathname, |
896 | msg.u.snapshot_channel.relayd_id, ctx); | |
07b86b52 JD |
897 | if (ret < 0) { |
898 | ERR("Snapshot metadata failed"); | |
e462382a | 899 | ret_code = LTTCOMM_CONSUMERD_ERROR_METADATA; |
07b86b52 JD |
900 | } |
901 | } else { | |
902 | ret = lttng_kconsumer_snapshot_channel(msg.u.snapshot_channel.key, | |
903 | msg.u.snapshot_channel.pathname, | |
5c786ded | 904 | msg.u.snapshot_channel.relayd_id, |
d07ceecd | 905 | msg.u.snapshot_channel.nb_packets_per_stream, |
5c786ded | 906 | ctx); |
07b86b52 JD |
907 | if (ret < 0) { |
908 | ERR("Snapshot channel failed"); | |
e462382a | 909 | ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND; |
07b86b52 JD |
910 | } |
911 | } | |
912 | ||
9ce5646a MD |
913 | health_code_update(); |
914 | ||
6dc3064a DG |
915 | ret = consumer_send_status_msg(sock, ret_code); |
916 | if (ret < 0) { | |
917 | /* Somehow, the session daemon is not responding anymore. */ | |
918 | goto end_nosignal; | |
919 | } | |
920 | break; | |
921 | } | |
07b86b52 JD |
922 | case LTTNG_CONSUMER_DESTROY_CHANNEL: |
923 | { | |
924 | uint64_t key = msg.u.destroy_channel.key; | |
925 | struct lttng_consumer_channel *channel; | |
926 | ||
927 | channel = consumer_find_channel(key); | |
928 | if (!channel) { | |
929 | ERR("Kernel consumer destroy channel %" PRIu64 " not found", key); | |
e462382a | 930 | ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND; |
07b86b52 JD |
931 | } |
932 | ||
9ce5646a MD |
933 | health_code_update(); |
934 | ||
07b86b52 JD |
935 | ret = consumer_send_status_msg(sock, ret_code); |
936 | if (ret < 0) { | |
937 | /* Somehow, the session daemon is not responding anymore. */ | |
938 | goto end_nosignal; | |
939 | } | |
940 | ||
9ce5646a MD |
941 | health_code_update(); |
942 | ||
15dc512a DG |
943 | /* Stop right now if no channel was found. */ |
944 | if (!channel) { | |
945 | goto end_nosignal; | |
946 | } | |
947 | ||
07b86b52 JD |
948 | /* |
949 | * This command should ONLY be issued for channel with streams set in | |
950 | * no monitor mode. | |
951 | */ | |
952 | assert(!channel->monitor); | |
953 | ||
954 | /* | |
955 | * The refcount should ALWAYS be 0 in the case of a channel in no | |
956 | * monitor mode. | |
957 | */ | |
958 | assert(!uatomic_sub_return(&channel->refcount, 1)); | |
959 | ||
960 | consumer_del_channel(channel); | |
961 | ||
962 | goto end_nosignal; | |
963 | } | |
fb83fe64 JD |
964 | case LTTNG_CONSUMER_DISCARDED_EVENTS: |
965 | { | |
966 | uint64_t ret; | |
967 | struct lttng_consumer_channel *channel; | |
968 | uint64_t id = msg.u.discarded_events.session_id; | |
969 | uint64_t key = msg.u.discarded_events.channel_key; | |
970 | ||
e5742757 MD |
971 | DBG("Kernel consumer discarded events command for session id %" |
972 | PRIu64 ", channel key %" PRIu64, id, key); | |
973 | ||
fb83fe64 JD |
974 | channel = consumer_find_channel(key); |
975 | if (!channel) { | |
976 | ERR("Kernel consumer discarded events channel %" | |
977 | PRIu64 " not found", key); | |
e5742757 MD |
978 | ret = 0; |
979 | } else { | |
980 | ret = channel->discarded_events; | |
fb83fe64 JD |
981 | } |
982 | ||
fb83fe64 JD |
983 | health_code_update(); |
984 | ||
985 | /* Send back returned value to session daemon */ | |
986 | ret = lttcomm_send_unix_sock(sock, &ret, sizeof(ret)); | |
987 | if (ret < 0) { | |
988 | PERROR("send discarded events"); | |
989 | goto error_fatal; | |
990 | } | |
991 | ||
992 | break; | |
993 | } | |
994 | case LTTNG_CONSUMER_LOST_PACKETS: | |
995 | { | |
996 | uint64_t ret; | |
997 | struct lttng_consumer_channel *channel; | |
998 | uint64_t id = msg.u.lost_packets.session_id; | |
999 | uint64_t key = msg.u.lost_packets.channel_key; | |
1000 | ||
e5742757 MD |
1001 | DBG("Kernel consumer lost packets command for session id %" |
1002 | PRIu64 ", channel key %" PRIu64, id, key); | |
1003 | ||
fb83fe64 JD |
1004 | channel = consumer_find_channel(key); |
1005 | if (!channel) { | |
1006 | ERR("Kernel consumer lost packets channel %" | |
1007 | PRIu64 " not found", key); | |
e5742757 MD |
1008 | ret = 0; |
1009 | } else { | |
1010 | ret = channel->lost_packets; | |
fb83fe64 JD |
1011 | } |
1012 | ||
fb83fe64 JD |
1013 | health_code_update(); |
1014 | ||
1015 | /* Send back returned value to session daemon */ | |
1016 | ret = lttcomm_send_unix_sock(sock, &ret, sizeof(ret)); | |
1017 | if (ret < 0) { | |
1018 | PERROR("send lost packets"); | |
1019 | goto error_fatal; | |
1020 | } | |
1021 | ||
1022 | break; | |
1023 | } | |
3bd1e081 | 1024 | default: |
3f8e211f | 1025 | goto end_nosignal; |
3bd1e081 | 1026 | } |
3f8e211f | 1027 | |
3bd1e081 | 1028 | end_nosignal: |
b0b335c8 | 1029 | rcu_read_unlock(); |
4cbc1a04 DG |
1030 | |
1031 | /* | |
1032 | * Return 1 to indicate success since the 0 value can be a socket | |
1033 | * shutdown during the recv() or send() call. | |
1034 | */ | |
9ce5646a | 1035 | health_code_update(); |
4cbc1a04 | 1036 | return 1; |
1803a064 MD |
1037 | |
1038 | error_fatal: | |
1039 | rcu_read_unlock(); | |
1040 | /* This will issue a consumer stop. */ | |
1041 | return -1; | |
3bd1e081 | 1042 | } |
d41f73b7 | 1043 | |
309167d2 JD |
1044 | /* |
1045 | * Populate index values of a kernel stream. Values are set in big endian order. | |
1046 | * | |
1047 | * Return 0 on success or else a negative value. | |
1048 | */ | |
50adc264 | 1049 | static int get_index_values(struct ctf_packet_index *index, int infd) |
309167d2 JD |
1050 | { |
1051 | int ret; | |
1052 | ||
1053 | ret = kernctl_get_timestamp_begin(infd, &index->timestamp_begin); | |
1054 | if (ret < 0) { | |
1055 | PERROR("kernctl_get_timestamp_begin"); | |
1056 | goto error; | |
1057 | } | |
1058 | index->timestamp_begin = htobe64(index->timestamp_begin); | |
1059 | ||
1060 | ret = kernctl_get_timestamp_end(infd, &index->timestamp_end); | |
1061 | if (ret < 0) { | |
1062 | PERROR("kernctl_get_timestamp_end"); | |
1063 | goto error; | |
1064 | } | |
1065 | index->timestamp_end = htobe64(index->timestamp_end); | |
1066 | ||
1067 | ret = kernctl_get_events_discarded(infd, &index->events_discarded); | |
1068 | if (ret < 0) { | |
1069 | PERROR("kernctl_get_events_discarded"); | |
1070 | goto error; | |
1071 | } | |
1072 | index->events_discarded = htobe64(index->events_discarded); | |
1073 | ||
1074 | ret = kernctl_get_content_size(infd, &index->content_size); | |
1075 | if (ret < 0) { | |
1076 | PERROR("kernctl_get_content_size"); | |
1077 | goto error; | |
1078 | } | |
1079 | index->content_size = htobe64(index->content_size); | |
1080 | ||
1081 | ret = kernctl_get_packet_size(infd, &index->packet_size); | |
1082 | if (ret < 0) { | |
1083 | PERROR("kernctl_get_packet_size"); | |
1084 | goto error; | |
1085 | } | |
1086 | index->packet_size = htobe64(index->packet_size); | |
1087 | ||
1088 | ret = kernctl_get_stream_id(infd, &index->stream_id); | |
1089 | if (ret < 0) { | |
1090 | PERROR("kernctl_get_stream_id"); | |
1091 | goto error; | |
1092 | } | |
1093 | index->stream_id = htobe64(index->stream_id); | |
1094 | ||
234cd636 JD |
1095 | ret = kernctl_get_instance_id(infd, &index->stream_instance_id); |
1096 | if (ret < 0) { | |
f0b03c22 MD |
1097 | if (ret == -ENOTTY) { |
1098 | /* Command not implemented by lttng-modules. */ | |
1099 | index->stream_instance_id = -1ULL; | |
1100 | ret = 0; | |
1101 | } else { | |
1102 | PERROR("kernctl_get_instance_id"); | |
1103 | goto error; | |
1104 | } | |
234cd636 JD |
1105 | } |
1106 | index->stream_instance_id = htobe64(index->stream_instance_id); | |
1107 | ||
1108 | ret = kernctl_get_sequence_number(infd, &index->packet_seq_num); | |
1109 | if (ret < 0) { | |
f0b03c22 MD |
1110 | if (ret == -ENOTTY) { |
1111 | /* Command not implemented by lttng-modules. */ | |
1112 | index->packet_seq_num = -1ULL; | |
1113 | ret = 0; | |
1114 | } else { | |
1115 | PERROR("kernctl_get_sequence_number"); | |
1116 | goto error; | |
1117 | } | |
234cd636 JD |
1118 | } |
1119 | index->packet_seq_num = htobe64(index->packet_seq_num); | |
1120 | ||
309167d2 JD |
1121 | error: |
1122 | return ret; | |
1123 | } | |
94d49140 JD |
1124 | /* |
1125 | * Sync metadata meaning request them to the session daemon and snapshot to the | |
1126 | * metadata thread can consumer them. | |
1127 | * | |
1128 | * Metadata stream lock MUST be acquired. | |
1129 | * | |
1130 | * Return 0 if new metadatda is available, EAGAIN if the metadata stream | |
1131 | * is empty or a negative value on error. | |
1132 | */ | |
1133 | int lttng_kconsumer_sync_metadata(struct lttng_consumer_stream *metadata) | |
1134 | { | |
1135 | int ret; | |
1136 | ||
1137 | assert(metadata); | |
1138 | ||
1139 | ret = kernctl_buffer_flush(metadata->wait_fd); | |
1140 | if (ret < 0) { | |
1141 | ERR("Failed to flush kernel stream"); | |
1142 | goto end; | |
1143 | } | |
1144 | ||
1145 | ret = kernctl_snapshot(metadata->wait_fd); | |
1146 | if (ret < 0) { | |
32af2c95 | 1147 | if (ret != -EAGAIN) { |
94d49140 JD |
1148 | ERR("Sync metadata, taking kernel snapshot failed."); |
1149 | goto end; | |
1150 | } | |
1151 | DBG("Sync metadata, no new kernel metadata"); | |
1152 | /* No new metadata, exit. */ | |
1153 | ret = ENODATA; | |
1154 | goto end; | |
1155 | } | |
1156 | ||
1157 | end: | |
1158 | return ret; | |
1159 | } | |
309167d2 | 1160 | |
fb83fe64 JD |
1161 | static |
1162 | int update_stream_stats(struct lttng_consumer_stream *stream) | |
1163 | { | |
1164 | int ret; | |
1165 | uint64_t seq, discarded; | |
1166 | ||
1167 | ret = kernctl_get_sequence_number(stream->wait_fd, &seq); | |
1168 | if (ret < 0) { | |
f0b03c22 MD |
1169 | if (ret == -ENOTTY) { |
1170 | /* Command not implemented by lttng-modules. */ | |
1171 | seq = -1ULL; | |
1172 | ret = 0; | |
1173 | } else { | |
1174 | PERROR("kernctl_get_sequence_number"); | |
1175 | goto end; | |
1176 | } | |
fb83fe64 JD |
1177 | } |
1178 | ||
1179 | /* | |
1180 | * Start the sequence when we extract the first packet in case we don't | |
1181 | * start at 0 (for example if a consumer is not connected to the | |
1182 | * session immediately after the beginning). | |
1183 | */ | |
1184 | if (stream->last_sequence_number == -1ULL) { | |
1185 | stream->last_sequence_number = seq; | |
1186 | } else if (seq > stream->last_sequence_number) { | |
1187 | stream->chan->lost_packets += seq - | |
1188 | stream->last_sequence_number - 1; | |
1189 | } else { | |
1190 | /* seq <= last_sequence_number */ | |
1191 | ERR("Sequence number inconsistent : prev = %" PRIu64 | |
1192 | ", current = %" PRIu64, | |
1193 | stream->last_sequence_number, seq); | |
1194 | ret = -1; | |
1195 | goto end; | |
1196 | } | |
1197 | stream->last_sequence_number = seq; | |
1198 | ||
1199 | ret = kernctl_get_events_discarded(stream->wait_fd, &discarded); | |
1200 | if (ret < 0) { | |
1201 | PERROR("kernctl_get_events_discarded"); | |
1202 | goto end; | |
1203 | } | |
1204 | if (discarded < stream->last_discarded_events) { | |
1205 | /* | |
83f4233d MJ |
1206 | * Overflow has occurred. We assume only one wrap-around |
1207 | * has occurred. | |
fb83fe64 JD |
1208 | */ |
1209 | stream->chan->discarded_events += (1ULL << (CAA_BITS_PER_LONG - 1)) - | |
1210 | stream->last_discarded_events + discarded; | |
1211 | } else { | |
1212 | stream->chan->discarded_events += discarded - | |
1213 | stream->last_discarded_events; | |
1214 | } | |
1215 | stream->last_discarded_events = discarded; | |
1216 | ret = 0; | |
1217 | ||
1218 | end: | |
1219 | return ret; | |
1220 | } | |
1221 | ||
93ec662e JD |
1222 | /* |
1223 | * Check if the local version of the metadata stream matches with the version | |
1224 | * of the metadata stream in the kernel. If it was updated, set the reset flag | |
1225 | * on the stream. | |
1226 | */ | |
1227 | static | |
1228 | int metadata_stream_check_version(int infd, struct lttng_consumer_stream *stream) | |
1229 | { | |
1230 | int ret; | |
1231 | uint64_t cur_version; | |
1232 | ||
1233 | ret = kernctl_get_metadata_version(infd, &cur_version); | |
1234 | if (ret < 0) { | |
f0b03c22 MD |
1235 | if (ret == -ENOTTY) { |
1236 | /* | |
1237 | * LTTng-modules does not implement this | |
1238 | * command. | |
1239 | */ | |
1240 | ret = 0; | |
1241 | goto end; | |
1242 | } | |
93ec662e JD |
1243 | ERR("Failed to get the metadata version"); |
1244 | goto end; | |
1245 | } | |
1246 | ||
1247 | if (stream->metadata_version == cur_version) { | |
1248 | ret = 0; | |
1249 | goto end; | |
1250 | } | |
1251 | ||
1252 | DBG("New metadata version detected"); | |
1253 | stream->metadata_version = cur_version; | |
1254 | stream->reset_metadata_flag = 1; | |
1255 | ret = 0; | |
1256 | ||
1257 | end: | |
1258 | return ret; | |
1259 | } | |
1260 | ||
d41f73b7 MD |
1261 | /* |
1262 | * Consume data on a file descriptor and write it on a trace file. | |
1263 | */ | |
4078b776 | 1264 | ssize_t lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream *stream, |
d41f73b7 MD |
1265 | struct lttng_consumer_local_data *ctx) |
1266 | { | |
1d4dfdef | 1267 | unsigned long len, subbuf_size, padding; |
1c20f0e2 | 1268 | int err, write_index = 1; |
4078b776 | 1269 | ssize_t ret = 0; |
d41f73b7 | 1270 | int infd = stream->wait_fd; |
50adc264 | 1271 | struct ctf_packet_index index; |
d41f73b7 MD |
1272 | |
1273 | DBG("In read_subbuffer (infd : %d)", infd); | |
309167d2 | 1274 | |
d41f73b7 MD |
1275 | /* Get the next subbuffer */ |
1276 | err = kernctl_get_next_subbuf(infd); | |
1277 | if (err != 0) { | |
d41f73b7 MD |
1278 | /* |
1279 | * This is a debug message even for single-threaded consumer, | |
1280 | * because poll() have more relaxed criterions than get subbuf, | |
1281 | * so get_subbuf may fail for short race windows where poll() | |
1282 | * would issue wakeups. | |
1283 | */ | |
1284 | DBG("Reserving sub buffer failed (everything is normal, " | |
1285 | "it is due to concurrency)"); | |
32af2c95 | 1286 | ret = err; |
d41f73b7 MD |
1287 | goto end; |
1288 | } | |
1289 | ||
1d4dfdef DG |
1290 | /* Get the full subbuffer size including padding */ |
1291 | err = kernctl_get_padded_subbuf_size(infd, &len); | |
1292 | if (err != 0) { | |
5a510c9f | 1293 | PERROR("Getting sub-buffer len failed."); |
8265f19e MD |
1294 | err = kernctl_put_subbuf(infd); |
1295 | if (err != 0) { | |
32af2c95 | 1296 | if (err == -EFAULT) { |
5a510c9f | 1297 | PERROR("Error in unreserving sub buffer\n"); |
32af2c95 | 1298 | } else if (err == -EIO) { |
8265f19e | 1299 | /* Should never happen with newer LTTng versions */ |
5a510c9f | 1300 | PERROR("Reader has been pushed by the writer, last sub-buffer corrupted."); |
8265f19e | 1301 | } |
32af2c95 | 1302 | ret = err; |
8265f19e MD |
1303 | goto end; |
1304 | } | |
32af2c95 | 1305 | ret = err; |
1d4dfdef DG |
1306 | goto end; |
1307 | } | |
1308 | ||
1c20f0e2 | 1309 | if (!stream->metadata_flag) { |
309167d2 JD |
1310 | ret = get_index_values(&index, infd); |
1311 | if (ret < 0) { | |
8265f19e MD |
1312 | err = kernctl_put_subbuf(infd); |
1313 | if (err != 0) { | |
32af2c95 | 1314 | if (err == -EFAULT) { |
5a510c9f | 1315 | PERROR("Error in unreserving sub buffer\n"); |
32af2c95 | 1316 | } else if (err == -EIO) { |
8265f19e | 1317 | /* Should never happen with newer LTTng versions */ |
5a510c9f | 1318 | PERROR("Reader has been pushed by the writer, last sub-buffer corrupted."); |
8265f19e | 1319 | } |
32af2c95 | 1320 | ret = err; |
8265f19e MD |
1321 | goto end; |
1322 | } | |
309167d2 JD |
1323 | goto end; |
1324 | } | |
fb83fe64 JD |
1325 | ret = update_stream_stats(stream); |
1326 | if (ret < 0) { | |
becac7c4 MD |
1327 | err = kernctl_put_subbuf(infd); |
1328 | if (err != 0) { | |
1329 | if (err == -EFAULT) { | |
1330 | PERROR("Error in unreserving sub buffer\n"); | |
1331 | } else if (err == -EIO) { | |
1332 | /* Should never happen with newer LTTng versions */ | |
1333 | PERROR("Reader has been pushed by the writer, last sub-buffer corrupted."); | |
1334 | } | |
1335 | ret = err; | |
1336 | goto end; | |
1337 | } | |
fb83fe64 JD |
1338 | goto end; |
1339 | } | |
1c20f0e2 JD |
1340 | } else { |
1341 | write_index = 0; | |
93ec662e JD |
1342 | ret = metadata_stream_check_version(infd, stream); |
1343 | if (ret < 0) { | |
becac7c4 MD |
1344 | err = kernctl_put_subbuf(infd); |
1345 | if (err != 0) { | |
1346 | if (err == -EFAULT) { | |
1347 | PERROR("Error in unreserving sub buffer\n"); | |
1348 | } else if (err == -EIO) { | |
1349 | /* Should never happen with newer LTTng versions */ | |
1350 | PERROR("Reader has been pushed by the writer, last sub-buffer corrupted."); | |
1351 | } | |
1352 | ret = err; | |
1353 | goto end; | |
1354 | } | |
93ec662e JD |
1355 | goto end; |
1356 | } | |
309167d2 JD |
1357 | } |
1358 | ||
ffe60014 | 1359 | switch (stream->chan->output) { |
07b86b52 | 1360 | case CONSUMER_CHANNEL_SPLICE: |
1d4dfdef DG |
1361 | /* |
1362 | * XXX: The lttng-modules splice "actor" does not handle copying | |
1363 | * partial pages hence only using the subbuffer size without the | |
1364 | * padding makes the splice fail. | |
1365 | */ | |
1366 | subbuf_size = len; | |
1367 | padding = 0; | |
1368 | ||
1369 | /* splice the subbuffer to the tracefile */ | |
91dfef6e | 1370 | ret = lttng_consumer_on_read_subbuffer_splice(ctx, stream, subbuf_size, |
309167d2 | 1371 | padding, &index); |
91dfef6e DG |
1372 | /* |
1373 | * XXX: Splice does not support network streaming so the return value | |
1374 | * is simply checked against subbuf_size and not like the mmap() op. | |
1375 | */ | |
1d4dfdef DG |
1376 | if (ret != subbuf_size) { |
1377 | /* | |
1378 | * display the error but continue processing to try | |
1379 | * to release the subbuffer | |
1380 | */ | |
1381 | ERR("Error splicing to tracefile (ret: %zd != len: %lu)", | |
1382 | ret, subbuf_size); | |
309167d2 | 1383 | write_index = 0; |
1d4dfdef DG |
1384 | } |
1385 | break; | |
07b86b52 | 1386 | case CONSUMER_CHANNEL_MMAP: |
1d4dfdef DG |
1387 | /* Get subbuffer size without padding */ |
1388 | err = kernctl_get_subbuf_size(infd, &subbuf_size); | |
1389 | if (err != 0) { | |
5a510c9f | 1390 | PERROR("Getting sub-buffer len failed."); |
8265f19e MD |
1391 | err = kernctl_put_subbuf(infd); |
1392 | if (err != 0) { | |
32af2c95 | 1393 | if (err == -EFAULT) { |
5a510c9f | 1394 | PERROR("Error in unreserving sub buffer\n"); |
32af2c95 | 1395 | } else if (err == -EIO) { |
8265f19e | 1396 | /* Should never happen with newer LTTng versions */ |
5a510c9f | 1397 | PERROR("Reader has been pushed by the writer, last sub-buffer corrupted."); |
8265f19e | 1398 | } |
32af2c95 | 1399 | ret = err; |
8265f19e MD |
1400 | goto end; |
1401 | } | |
32af2c95 | 1402 | ret = err; |
1d4dfdef DG |
1403 | goto end; |
1404 | } | |
47e81c02 | 1405 | |
1d4dfdef DG |
1406 | /* Make sure the tracer is not gone mad on us! */ |
1407 | assert(len >= subbuf_size); | |
1408 | ||
1409 | padding = len - subbuf_size; | |
1410 | ||
1411 | /* write the subbuffer to the tracefile */ | |
91dfef6e | 1412 | ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, subbuf_size, |
309167d2 | 1413 | padding, &index); |
91dfef6e DG |
1414 | /* |
1415 | * The mmap operation should write subbuf_size amount of data when | |
1416 | * network streaming or the full padding (len) size when we are _not_ | |
1417 | * streaming. | |
1418 | */ | |
d88aee68 DG |
1419 | if ((ret != subbuf_size && stream->net_seq_idx != (uint64_t) -1ULL) || |
1420 | (ret != len && stream->net_seq_idx == (uint64_t) -1ULL)) { | |
1d4dfdef | 1421 | /* |
91dfef6e | 1422 | * Display the error but continue processing to try to release the |
2336629e DG |
1423 | * subbuffer. This is a DBG statement since this is possible to |
1424 | * happen without being a critical error. | |
1d4dfdef | 1425 | */ |
2336629e | 1426 | DBG("Error writing to tracefile " |
91dfef6e DG |
1427 | "(ret: %zd != len: %lu != subbuf_size: %lu)", |
1428 | ret, len, subbuf_size); | |
309167d2 | 1429 | write_index = 0; |
1d4dfdef DG |
1430 | } |
1431 | break; | |
1432 | default: | |
1433 | ERR("Unknown output method"); | |
56591bac | 1434 | ret = -EPERM; |
d41f73b7 MD |
1435 | } |
1436 | ||
1437 | err = kernctl_put_next_subbuf(infd); | |
1438 | if (err != 0) { | |
32af2c95 | 1439 | if (err == -EFAULT) { |
5a510c9f | 1440 | PERROR("Error in unreserving sub buffer\n"); |
32af2c95 | 1441 | } else if (err == -EIO) { |
d41f73b7 | 1442 | /* Should never happen with newer LTTng versions */ |
5a510c9f | 1443 | PERROR("Reader has been pushed by the writer, last sub-buffer corrupted."); |
d41f73b7 | 1444 | } |
32af2c95 | 1445 | ret = err; |
d41f73b7 MD |
1446 | goto end; |
1447 | } | |
1448 | ||
309167d2 | 1449 | /* Write index if needed. */ |
1c20f0e2 JD |
1450 | if (!write_index) { |
1451 | goto end; | |
1452 | } | |
1453 | ||
94d49140 JD |
1454 | if (stream->chan->live_timer_interval && !stream->metadata_flag) { |
1455 | /* | |
1456 | * In live, block until all the metadata is sent. | |
1457 | */ | |
c585821b MD |
1458 | pthread_mutex_lock(&stream->metadata_timer_lock); |
1459 | assert(!stream->missed_metadata_flush); | |
1460 | stream->waiting_on_metadata = true; | |
1461 | pthread_mutex_unlock(&stream->metadata_timer_lock); | |
1462 | ||
94d49140 | 1463 | err = consumer_stream_sync_metadata(ctx, stream->session_id); |
c585821b MD |
1464 | |
1465 | pthread_mutex_lock(&stream->metadata_timer_lock); | |
1466 | stream->waiting_on_metadata = false; | |
1467 | if (stream->missed_metadata_flush) { | |
1468 | stream->missed_metadata_flush = false; | |
1469 | pthread_mutex_unlock(&stream->metadata_timer_lock); | |
1470 | (void) consumer_flush_kernel_index(stream); | |
1471 | } else { | |
1472 | pthread_mutex_unlock(&stream->metadata_timer_lock); | |
1473 | } | |
94d49140 JD |
1474 | if (err < 0) { |
1475 | goto end; | |
1476 | } | |
1477 | } | |
1478 | ||
1c20f0e2 JD |
1479 | err = consumer_stream_write_index(stream, &index); |
1480 | if (err < 0) { | |
1481 | goto end; | |
309167d2 JD |
1482 | } |
1483 | ||
d41f73b7 MD |
1484 | end: |
1485 | return ret; | |
1486 | } | |
1487 | ||
1488 | int lttng_kconsumer_on_recv_stream(struct lttng_consumer_stream *stream) | |
1489 | { | |
1490 | int ret; | |
ffe60014 DG |
1491 | |
1492 | assert(stream); | |
1493 | ||
2bba9e53 DG |
1494 | /* |
1495 | * Don't create anything if this is set for streaming or should not be | |
1496 | * monitored. | |
1497 | */ | |
1498 | if (stream->net_seq_idx == (uint64_t) -1ULL && stream->chan->monitor) { | |
fe4477ee JD |
1499 | ret = utils_create_stream_file(stream->chan->pathname, stream->name, |
1500 | stream->chan->tracefile_size, stream->tracefile_count_current, | |
309167d2 | 1501 | stream->uid, stream->gid, NULL); |
fe4477ee JD |
1502 | if (ret < 0) { |
1503 | goto error; | |
1504 | } | |
1505 | stream->out_fd = ret; | |
1506 | stream->tracefile_size_current = 0; | |
309167d2 JD |
1507 | |
1508 | if (!stream->metadata_flag) { | |
e0547b83 MD |
1509 | struct lttng_index_file *index_file; |
1510 | ||
1511 | index_file = lttng_index_file_create(stream->chan->pathname, | |
309167d2 JD |
1512 | stream->name, stream->uid, stream->gid, |
1513 | stream->chan->tracefile_size, | |
e0547b83 MD |
1514 | stream->tracefile_count_current, |
1515 | CTF_INDEX_MAJOR, CTF_INDEX_MINOR); | |
1516 | if (!index_file) { | |
309167d2 JD |
1517 | goto error; |
1518 | } | |
e0547b83 | 1519 | stream->index_file = index_file; |
309167d2 | 1520 | } |
ffe60014 | 1521 | } |
d41f73b7 | 1522 | |
d41f73b7 MD |
1523 | if (stream->output == LTTNG_EVENT_MMAP) { |
1524 | /* get the len of the mmap region */ | |
1525 | unsigned long mmap_len; | |
1526 | ||
1527 | ret = kernctl_get_mmap_len(stream->wait_fd, &mmap_len); | |
1528 | if (ret != 0) { | |
ffe60014 | 1529 | PERROR("kernctl_get_mmap_len"); |
d41f73b7 MD |
1530 | goto error_close_fd; |
1531 | } | |
1532 | stream->mmap_len = (size_t) mmap_len; | |
1533 | ||
ffe60014 DG |
1534 | stream->mmap_base = mmap(NULL, stream->mmap_len, PROT_READ, |
1535 | MAP_PRIVATE, stream->wait_fd, 0); | |
d41f73b7 | 1536 | if (stream->mmap_base == MAP_FAILED) { |
ffe60014 | 1537 | PERROR("Error mmaping"); |
d41f73b7 MD |
1538 | ret = -1; |
1539 | goto error_close_fd; | |
1540 | } | |
1541 | } | |
1542 | ||
1543 | /* we return 0 to let the library handle the FD internally */ | |
1544 | return 0; | |
1545 | ||
1546 | error_close_fd: | |
2f225ce2 | 1547 | if (stream->out_fd >= 0) { |
d41f73b7 MD |
1548 | int err; |
1549 | ||
1550 | err = close(stream->out_fd); | |
1551 | assert(!err); | |
2f225ce2 | 1552 | stream->out_fd = -1; |
d41f73b7 MD |
1553 | } |
1554 | error: | |
1555 | return ret; | |
1556 | } | |
1557 | ||
ca22feea DG |
1558 | /* |
1559 | * Check if data is still being extracted from the buffers for a specific | |
4e9a4686 DG |
1560 | * stream. Consumer data lock MUST be acquired before calling this function |
1561 | * and the stream lock. | |
ca22feea | 1562 | * |
6d805429 | 1563 | * Return 1 if the traced data are still getting read else 0 meaning that the |
ca22feea DG |
1564 | * data is available for trace viewer reading. |
1565 | */ | |
6d805429 | 1566 | int lttng_kconsumer_data_pending(struct lttng_consumer_stream *stream) |
ca22feea DG |
1567 | { |
1568 | int ret; | |
1569 | ||
1570 | assert(stream); | |
1571 | ||
873b9e9a MD |
1572 | if (stream->endpoint_status != CONSUMER_ENDPOINT_ACTIVE) { |
1573 | ret = 0; | |
1574 | goto end; | |
1575 | } | |
1576 | ||
ca22feea DG |
1577 | ret = kernctl_get_next_subbuf(stream->wait_fd); |
1578 | if (ret == 0) { | |
1579 | /* There is still data so let's put back this subbuffer. */ | |
1580 | ret = kernctl_put_subbuf(stream->wait_fd); | |
1581 | assert(ret == 0); | |
6d805429 | 1582 | ret = 1; /* Data is pending */ |
4e9a4686 | 1583 | goto end; |
ca22feea DG |
1584 | } |
1585 | ||
6d805429 DG |
1586 | /* Data is NOT pending and ready to be read. */ |
1587 | ret = 0; | |
ca22feea | 1588 | |
6efae65e DG |
1589 | end: |
1590 | return ret; | |
ca22feea | 1591 | } |