Consumer daemon data available command support
[lttng-tools.git] / src / common / ust-consumer / ust-consumer.c
1 /*
2 * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
3 * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 *
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.
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 *
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.
17 */
18
19 #define _GNU_SOURCE
20 #include <assert.h>
21 #include <lttng/ust-ctl.h>
22 #include <poll.h>
23 #include <pthread.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <sys/mman.h>
27 #include <sys/socket.h>
28 #include <sys/stat.h>
29 #include <sys/types.h>
30 #include <inttypes.h>
31 #include <unistd.h>
32
33 #include <common/common.h>
34 #include <common/sessiond-comm/sessiond-comm.h>
35 #include <common/relayd/relayd.h>
36 #include <common/compat/fcntl.h>
37
38 #include "ust-consumer.h"
39
40 extern struct lttng_consumer_global_data consumer_data;
41 extern int consumer_poll_timeout;
42 extern volatile int consumer_quit;
43
44 /*
45 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
46 * compiled out, we isolate it in this library.
47 */
48 int lttng_ustctl_get_mmap_read_offset(struct lttng_ust_shm_handle *handle,
49 struct lttng_ust_lib_ring_buffer *buf, unsigned long *off)
50 {
51 return ustctl_get_mmap_read_offset(handle, buf, off);
52 };
53
54 /*
55 * Take a snapshot for a specific fd
56 *
57 * Returns 0 on success, < 0 on error
58 */
59 int lttng_ustconsumer_take_snapshot(struct lttng_consumer_local_data *ctx,
60 struct lttng_consumer_stream *stream)
61 {
62 int ret = 0;
63
64 ret = ustctl_snapshot(stream->chan->handle, stream->buf);
65 if (ret != 0) {
66 errno = -ret;
67 PERROR("Getting sub-buffer snapshot.");
68 }
69
70 return ret;
71 }
72
73 /*
74 * Get the produced position
75 *
76 * Returns 0 on success, < 0 on error
77 */
78 int lttng_ustconsumer_get_produced_snapshot(
79 struct lttng_consumer_local_data *ctx,
80 struct lttng_consumer_stream *stream,
81 unsigned long *pos)
82 {
83 int ret;
84
85 ret = ustctl_snapshot_get_produced(stream->chan->handle,
86 stream->buf, pos);
87 if (ret != 0) {
88 errno = -ret;
89 PERROR("kernctl_snapshot_get_produced");
90 }
91
92 return ret;
93 }
94
95 /*
96 * Receive command from session daemon and process it.
97 *
98 * Return 1 on success else a negative value or 0.
99 */
100 int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
101 int sock, struct pollfd *consumer_sockpoll)
102 {
103 ssize_t ret;
104 struct lttcomm_consumer_msg msg;
105
106 ret = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg));
107 if (ret != sizeof(msg)) {
108 DBG("Consumer received unexpected message size %zd (expects %zu)",
109 ret, sizeof(msg));
110 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_FD);
111 return ret;
112 }
113 if (msg.cmd_type == LTTNG_CONSUMER_STOP) {
114 return -ENOENT;
115 }
116
117 /* relayd needs RCU read-side lock */
118 rcu_read_lock();
119
120 switch (msg.cmd_type) {
121 case LTTNG_CONSUMER_ADD_RELAYD_SOCKET:
122 {
123 ret = consumer_add_relayd_socket(msg.u.relayd_sock.net_index,
124 msg.u.relayd_sock.type, ctx, sock, consumer_sockpoll,
125 &msg.u.relayd_sock.sock);
126 goto end_nosignal;
127 }
128 case LTTNG_CONSUMER_ADD_CHANNEL:
129 {
130 struct lttng_consumer_channel *new_channel;
131 int fds[1];
132 size_t nb_fd = 1;
133
134 DBG("UST Consumer adding channel");
135
136 /* block */
137 if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) {
138 rcu_read_unlock();
139 return -EINTR;
140 }
141 ret = lttcomm_recv_fds_unix_sock(sock, fds, nb_fd);
142 if (ret != sizeof(fds)) {
143 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_FD);
144 rcu_read_unlock();
145 return ret;
146 }
147
148 DBG("consumer_add_channel %d", msg.u.channel.channel_key);
149
150 new_channel = consumer_allocate_channel(msg.u.channel.channel_key,
151 fds[0], -1,
152 msg.u.channel.mmap_len,
153 msg.u.channel.max_sb_size,
154 msg.u.channel.nb_init_streams);
155 if (new_channel == NULL) {
156 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
157 goto end_nosignal;
158 }
159 if (ctx->on_recv_channel != NULL) {
160 ret = ctx->on_recv_channel(new_channel);
161 if (ret == 0) {
162 consumer_add_channel(new_channel);
163 } else if (ret < 0) {
164 goto end_nosignal;
165 }
166 } else {
167 consumer_add_channel(new_channel);
168 }
169 goto end_nosignal;
170 }
171 case LTTNG_CONSUMER_ADD_STREAM:
172 {
173 struct lttng_consumer_stream *new_stream;
174 int fds[2], stream_pipe;
175 size_t nb_fd = 2;
176 struct consumer_relayd_sock_pair *relayd = NULL;
177 int alloc_ret = 0;
178
179 DBG("UST Consumer adding stream");
180
181 /* block */
182 if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) {
183 rcu_read_unlock();
184 return -EINTR;
185 }
186 ret = lttcomm_recv_fds_unix_sock(sock, fds, nb_fd);
187 if (ret != sizeof(fds)) {
188 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_FD);
189 rcu_read_unlock();
190 return ret;
191 }
192
193 DBG("Consumer command ADD_STREAM chan %d stream %d",
194 msg.u.stream.channel_key, msg.u.stream.stream_key);
195
196 assert(msg.u.stream.output == LTTNG_EVENT_MMAP);
197 new_stream = consumer_allocate_stream(msg.u.stream.channel_key,
198 msg.u.stream.stream_key,
199 fds[0], fds[1],
200 msg.u.stream.state,
201 msg.u.stream.mmap_len,
202 msg.u.stream.output,
203 msg.u.stream.path_name,
204 msg.u.stream.uid,
205 msg.u.stream.gid,
206 msg.u.stream.net_index,
207 msg.u.stream.metadata_flag,
208 msg.u.stream.session_id,
209 &alloc_ret);
210 if (new_stream == NULL) {
211 switch (alloc_ret) {
212 case -ENOMEM:
213 case -EINVAL:
214 default:
215 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
216 break;
217 case -ENOENT:
218 /*
219 * We could not find the channel. Can happen if cpu hotplug
220 * happens while tearing down.
221 */
222 DBG3("Could not find channel");
223 break;
224 }
225 goto end_nosignal;
226 }
227
228 /* The stream is not metadata. Get relayd reference if exists. */
229 relayd = consumer_find_relayd(msg.u.stream.net_index);
230 if (relayd != NULL) {
231 pthread_mutex_lock(&relayd->ctrl_sock_mutex);
232 /* Add stream on the relayd */
233 ret = relayd_add_stream(&relayd->control_sock,
234 msg.u.stream.name, msg.u.stream.path_name,
235 &new_stream->relayd_stream_id);
236 pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
237 if (ret < 0) {
238 consumer_del_stream(new_stream, NULL);
239 goto end_nosignal;
240 }
241 } else if (msg.u.stream.net_index != -1) {
242 ERR("Network sequence index %d unknown. Not adding stream.",
243 msg.u.stream.net_index);
244 consumer_del_stream(new_stream, NULL);
245 goto end_nosignal;
246 }
247
248 /* Do actions once stream has been received. */
249 if (ctx->on_recv_stream) {
250 ret = ctx->on_recv_stream(new_stream);
251 if (ret < 0) {
252 consumer_del_stream(new_stream, NULL);
253 goto end_nosignal;
254 }
255 }
256
257 /* Get the right pipe where the stream will be sent. */
258 if (new_stream->metadata_flag) {
259 stream_pipe = ctx->consumer_metadata_pipe[1];
260 } else {
261 stream_pipe = ctx->consumer_data_pipe[1];
262 }
263
264 do {
265 ret = write(stream_pipe, &new_stream, sizeof(new_stream));
266 } while (ret < 0 && errno == EINTR);
267 if (ret < 0) {
268 PERROR("Consumer write %s stream to pipe %d",
269 new_stream->metadata_flag ? "metadata" : "data",
270 stream_pipe);
271 consumer_del_stream(new_stream, NULL);
272 goto end_nosignal;
273 }
274
275 DBG("UST consumer ADD_STREAM %s (%d,%d) with relayd id %" PRIu64,
276 msg.u.stream.path_name, fds[0], fds[1],
277 new_stream->relayd_stream_id);
278 break;
279 }
280 case LTTNG_CONSUMER_DESTROY_RELAYD:
281 {
282 uint64_t index = msg.u.destroy_relayd.net_seq_idx;
283 struct consumer_relayd_sock_pair *relayd;
284
285 DBG("UST consumer destroying relayd %" PRIu64, index);
286
287 /* Get relayd reference if exists. */
288 relayd = consumer_find_relayd(index);
289 if (relayd == NULL) {
290 ERR("Unable to find relayd %" PRIu64, index);
291 goto end_nosignal;
292 }
293
294 /*
295 * Each relayd socket pair has a refcount of stream attached to it
296 * which tells if the relayd is still active or not depending on the
297 * refcount value.
298 *
299 * This will set the destroy flag of the relayd object and destroy it
300 * if the refcount reaches zero when called.
301 *
302 * The destroy can happen either here or when a stream fd hangs up.
303 */
304 consumer_flag_relayd_for_destroy(relayd);
305
306 goto end_nosignal;
307 }
308 case LTTNG_CONSUMER_UPDATE_STREAM:
309 {
310 rcu_read_unlock();
311 return -ENOSYS;
312 }
313 case LTTNG_CONSUMER_DATA_AVAILABLE:
314 {
315 int32_t ret;
316 uint64_t id = msg.u.data_available.session_id;
317
318 DBG("UST consumer data available command for id %" PRIu64, id);
319
320 ret = consumer_data_available(id);
321
322 /* Send back returned value to session daemon */
323 ret = lttcomm_send_unix_sock(sock, &ret, sizeof(ret));
324 if (ret < 0) {
325 PERROR("send data available ret code");
326 }
327 break;
328 }
329 default:
330 break;
331 }
332
333 end_nosignal:
334 rcu_read_unlock();
335
336 /*
337 * Return 1 to indicate success since the 0 value can be a socket
338 * shutdown during the recv() or send() call.
339 */
340 return 1;
341 }
342
343 int lttng_ustconsumer_allocate_channel(struct lttng_consumer_channel *chan)
344 {
345 struct lttng_ust_object_data obj;
346
347 obj.handle = -1;
348 obj.shm_fd = chan->shm_fd;
349 obj.wait_fd = chan->wait_fd;
350 obj.memory_map_size = chan->mmap_len;
351 chan->handle = ustctl_map_channel(&obj);
352 if (!chan->handle) {
353 return -ENOMEM;
354 }
355 chan->wait_fd_is_copy = 1;
356 chan->shm_fd = -1;
357
358 return 0;
359 }
360
361 void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream *stream)
362 {
363 ustctl_flush_buffer(stream->chan->handle, stream->buf, 0);
364 stream->hangup_flush_done = 1;
365 }
366
367 void lttng_ustconsumer_del_channel(struct lttng_consumer_channel *chan)
368 {
369 ustctl_unmap_channel(chan->handle);
370 }
371
372 int lttng_ustconsumer_add_stream(struct lttng_consumer_stream *stream)
373 {
374 struct lttng_ust_object_data obj;
375 int ret;
376
377 obj.handle = -1;
378 obj.shm_fd = stream->shm_fd;
379 obj.wait_fd = stream->wait_fd;
380 obj.memory_map_size = stream->mmap_len;
381 ret = ustctl_add_stream(stream->chan->handle, &obj);
382 if (ret) {
383 ERR("UST ctl add_stream failed with ret %d", ret);
384 goto error;
385 }
386
387 stream->buf = ustctl_open_stream_read(stream->chan->handle, stream->cpu);
388 if (!stream->buf) {
389 ERR("UST ctl open_stream_read failed");
390 ret = -EBUSY;
391 goto error;
392 }
393
394 /* ustctl_open_stream_read has closed the shm fd. */
395 stream->wait_fd_is_copy = 1;
396 stream->shm_fd = -1;
397
398 stream->mmap_base = ustctl_get_mmap_base(stream->chan->handle, stream->buf);
399 if (!stream->mmap_base) {
400 ERR("UST ctl get_mmap_base failed");
401 ret = -EINVAL;
402 goto mmap_error;
403 }
404
405 return 0;
406
407 mmap_error:
408 ustctl_close_stream_read(stream->chan->handle, stream->buf);
409 error:
410 return ret;
411 }
412
413 void lttng_ustconsumer_del_stream(struct lttng_consumer_stream *stream)
414 {
415 ustctl_close_stream_read(stream->chan->handle, stream->buf);
416 }
417
418
419 int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
420 struct lttng_consumer_local_data *ctx)
421 {
422 unsigned long len, subbuf_size, padding;
423 int err;
424 long ret = 0;
425 struct lttng_ust_shm_handle *handle;
426 struct lttng_ust_lib_ring_buffer *buf;
427 char dummy;
428 ssize_t readlen;
429
430 DBG("In read_subbuffer (wait_fd: %d, stream key: %d)",
431 stream->wait_fd, stream->key);
432
433 /* We can consume the 1 byte written into the wait_fd by UST */
434 if (!stream->hangup_flush_done) {
435 do {
436 readlen = read(stream->wait_fd, &dummy, 1);
437 } while (readlen == -1 && errno == EINTR);
438 if (readlen == -1) {
439 ret = readlen;
440 goto end;
441 }
442 }
443
444 buf = stream->buf;
445 handle = stream->chan->handle;
446 /* Get the next subbuffer */
447 err = ustctl_get_next_subbuf(handle, buf);
448 if (err != 0) {
449 ret = err; /* ustctl_get_next_subbuf returns negative, caller expect positive. */
450 /*
451 * This is a debug message even for single-threaded consumer,
452 * because poll() have more relaxed criterions than get subbuf,
453 * so get_subbuf may fail for short race windows where poll()
454 * would issue wakeups.
455 */
456 DBG("Reserving sub buffer failed (everything is normal, "
457 "it is due to concurrency)");
458 goto end;
459 }
460 assert(stream->output == LTTNG_EVENT_MMAP);
461 /* Get the full padded subbuffer size */
462 err = ustctl_get_padded_subbuf_size(handle, buf, &len);
463 assert(err == 0);
464
465 /* Get subbuffer data size (without padding) */
466 err = ustctl_get_subbuf_size(handle, buf, &subbuf_size);
467 assert(err == 0);
468
469 /* Make sure we don't get a subbuffer size bigger than the padded */
470 assert(len >= subbuf_size);
471
472 padding = len - subbuf_size;
473 /* write the subbuffer to the tracefile */
474 ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, subbuf_size, padding);
475 /*
476 * The mmap operation should write subbuf_size amount of data when network
477 * streaming or the full padding (len) size when we are _not_ streaming.
478 */
479 if ((ret != subbuf_size && stream->net_seq_idx != -1) ||
480 (ret != len && stream->net_seq_idx == -1)) {
481 /*
482 * Display the error but continue processing to try to release the
483 * subbuffer
484 */
485 ERR("Error writing to tracefile "
486 "(ret: %zd != len: %lu != subbuf_size: %lu)",
487 ret, len, subbuf_size);
488 }
489 err = ustctl_put_next_subbuf(handle, buf);
490 assert(err == 0);
491 end:
492 return ret;
493 }
494
495 int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream *stream)
496 {
497 int ret;
498
499 /* Opening the tracefile in write mode */
500 if (stream->path_name != NULL && stream->net_seq_idx == -1) {
501 ret = run_as_open(stream->path_name,
502 O_WRONLY|O_CREAT|O_TRUNC,
503 S_IRWXU|S_IRWXG|S_IRWXO,
504 stream->uid, stream->gid);
505 if (ret < 0) {
506 ERR("Opening %s", stream->path_name);
507 PERROR("open");
508 goto error;
509 }
510 stream->out_fd = ret;
511 }
512
513 ret = lttng_ustconsumer_add_stream(stream);
514 if (ret) {
515 consumer_del_stream(stream, NULL);
516 ret = -1;
517 goto error;
518 }
519
520 /* we return 0 to let the library handle the FD internally */
521 return 0;
522
523 error:
524 return ret;
525 }
526
527 /*
528 * Check if data is still being extracted from the buffers for a specific
529 * stream. Consumer data lock MUST be acquired before calling this function.
530 *
531 * Return 0 if the traced data are still getting read else 1 meaning that the
532 * data is available for trace viewer reading.
533 */
534 int lttng_ustconsumer_data_available(struct lttng_consumer_stream *stream)
535 {
536 int ret;
537
538 assert(stream);
539
540 /*
541 * Try to lock the stream mutex. On failure, we know that the stream is
542 * being used else where hence there is data still being extracted.
543 */
544 ret = pthread_mutex_trylock(&stream->lock);
545 if (ret == EBUSY) {
546 goto data_not_available;
547 }
548 /* The stream is now locked so we can do our ustctl calls */
549
550 ret = ustctl_get_next_subbuf(stream->chan->handle, stream->buf);
551 if (ret == 0) {
552 /* There is still data so let's put back this subbuffer. */
553 ret = ustctl_put_subbuf(stream->chan->handle, stream->buf);
554 assert(ret == 0);
555 pthread_mutex_unlock(&stream->lock);
556 goto data_not_available;
557 }
558
559 /* Data is available to be read for this stream. */
560 pthread_mutex_unlock(&stream->lock);
561 return 1;
562
563 data_not_available:
564 return 0;
565 }
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