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 | ||
19 | #define _GNU_SOURCE | |
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 | |
990570ed | 32 | #include <common/common.h> |
10a8a223 | 33 | #include <common/kernel-ctl/kernel-ctl.h> |
10a8a223 | 34 | #include <common/sessiond-comm/sessiond-comm.h> |
00e2e675 | 35 | #include <common/sessiond-comm/relayd.h> |
dbb5dfe6 | 36 | #include <common/compat/fcntl.h> |
00e2e675 | 37 | #include <common/relayd/relayd.h> |
0857097f | 38 | |
10a8a223 | 39 | #include "kernel-consumer.h" |
3bd1e081 MD |
40 | |
41 | extern struct lttng_consumer_global_data consumer_data; | |
42 | extern int consumer_poll_timeout; | |
43 | extern volatile int consumer_quit; | |
44 | ||
3bd1e081 MD |
45 | /* |
46 | * Take a snapshot for a specific fd | |
47 | * | |
48 | * Returns 0 on success, < 0 on error | |
49 | */ | |
50 | int lttng_kconsumer_take_snapshot(struct lttng_consumer_local_data *ctx, | |
51 | struct lttng_consumer_stream *stream) | |
52 | { | |
53 | int ret = 0; | |
54 | int infd = stream->wait_fd; | |
55 | ||
56 | ret = kernctl_snapshot(infd); | |
57 | if (ret != 0) { | |
87dc6a9c | 58 | errno = -ret; |
3bd1e081 MD |
59 | perror("Getting sub-buffer snapshot."); |
60 | } | |
61 | ||
62 | return ret; | |
63 | } | |
64 | ||
65 | /* | |
66 | * Get the produced position | |
67 | * | |
68 | * Returns 0 on success, < 0 on error | |
69 | */ | |
70 | int lttng_kconsumer_get_produced_snapshot( | |
71 | struct lttng_consumer_local_data *ctx, | |
72 | struct lttng_consumer_stream *stream, | |
73 | unsigned long *pos) | |
74 | { | |
75 | int ret; | |
76 | int infd = stream->wait_fd; | |
77 | ||
78 | ret = kernctl_snapshot_get_produced(infd, pos); | |
79 | if (ret != 0) { | |
87dc6a9c | 80 | errno = -ret; |
3bd1e081 MD |
81 | perror("kernctl_snapshot_get_produced"); |
82 | } | |
83 | ||
84 | return ret; | |
85 | } | |
86 | ||
87 | int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx, | |
88 | int sock, struct pollfd *consumer_sockpoll) | |
89 | { | |
90 | ssize_t ret; | |
f50f23d9 | 91 | enum lttng_error_code ret_code = LTTNG_OK; |
3bd1e081 MD |
92 | struct lttcomm_consumer_msg msg; |
93 | ||
94 | ret = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg)); | |
95 | if (ret != sizeof(msg)) { | |
f73fabfd | 96 | lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_CMD); |
3bd1e081 MD |
97 | return ret; |
98 | } | |
99 | if (msg.cmd_type == LTTNG_CONSUMER_STOP) { | |
f50f23d9 DG |
100 | /* |
101 | * Notify the session daemon that the command is completed. | |
102 | * | |
103 | * On transport layer error, the function call will print an error | |
104 | * message so handling the returned code is a bit useless since we | |
105 | * return an error code anyway. | |
106 | */ | |
107 | (void) consumer_send_status_msg(sock, ret_code); | |
3bd1e081 MD |
108 | return -ENOENT; |
109 | } | |
110 | ||
b0b335c8 MD |
111 | /* relayd needs RCU read-side protection */ |
112 | rcu_read_lock(); | |
113 | ||
3bd1e081 | 114 | switch (msg.cmd_type) { |
00e2e675 DG |
115 | case LTTNG_CONSUMER_ADD_RELAYD_SOCKET: |
116 | { | |
f50f23d9 | 117 | /* Session daemon status message are handled in the following call. */ |
7735ef9e DG |
118 | ret = consumer_add_relayd_socket(msg.u.relayd_sock.net_index, |
119 | msg.u.relayd_sock.type, ctx, sock, consumer_sockpoll, | |
46e6455f | 120 | &msg.u.relayd_sock.sock, msg.u.relayd_sock.session_id); |
00e2e675 DG |
121 | goto end_nosignal; |
122 | } | |
3bd1e081 MD |
123 | case LTTNG_CONSUMER_ADD_CHANNEL: |
124 | { | |
125 | struct lttng_consumer_channel *new_channel; | |
126 | ||
f50f23d9 DG |
127 | /* First send a status message before receiving the fds. */ |
128 | ret = consumer_send_status_msg(sock, ret_code); | |
129 | if (ret < 0) { | |
130 | /* Somehow, the session daemon is not responding anymore. */ | |
131 | goto end_nosignal; | |
132 | } | |
133 | ||
3bd1e081 MD |
134 | DBG("consumer_add_channel %d", msg.u.channel.channel_key); |
135 | new_channel = consumer_allocate_channel(msg.u.channel.channel_key, | |
136 | -1, -1, | |
137 | msg.u.channel.mmap_len, | |
c30aaa51 MD |
138 | msg.u.channel.max_sb_size, |
139 | msg.u.channel.nb_init_streams); | |
3bd1e081 | 140 | if (new_channel == NULL) { |
f73fabfd | 141 | lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR); |
3bd1e081 MD |
142 | goto end_nosignal; |
143 | } | |
144 | if (ctx->on_recv_channel != NULL) { | |
145 | ret = ctx->on_recv_channel(new_channel); | |
146 | if (ret == 0) { | |
147 | consumer_add_channel(new_channel); | |
148 | } else if (ret < 0) { | |
149 | goto end_nosignal; | |
150 | } | |
151 | } else { | |
152 | consumer_add_channel(new_channel); | |
153 | } | |
154 | goto end_nosignal; | |
155 | } | |
156 | case LTTNG_CONSUMER_ADD_STREAM: | |
157 | { | |
50f8ae69 | 158 | int fd, stream_pipe; |
00e2e675 DG |
159 | struct consumer_relayd_sock_pair *relayd = NULL; |
160 | struct lttng_consumer_stream *new_stream; | |
c80048c6 | 161 | int alloc_ret = 0; |
3bd1e081 | 162 | |
f50f23d9 DG |
163 | /* First send a status message before receiving the fds. */ |
164 | ret = consumer_send_status_msg(sock, ret_code); | |
165 | if (ret < 0) { | |
166 | /* Somehow, the session daemon is not responding anymore. */ | |
167 | goto end_nosignal; | |
168 | } | |
169 | ||
3bd1e081 MD |
170 | /* block */ |
171 | if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) { | |
3f8e211f | 172 | rcu_read_unlock(); |
3bd1e081 MD |
173 | return -EINTR; |
174 | } | |
00e2e675 DG |
175 | |
176 | /* Get stream file descriptor from socket */ | |
f2fc6720 MD |
177 | ret = lttcomm_recv_fds_unix_sock(sock, &fd, 1); |
178 | if (ret != sizeof(fd)) { | |
f73fabfd | 179 | lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_FD); |
3f8e211f | 180 | rcu_read_unlock(); |
3bd1e081 MD |
181 | return ret; |
182 | } | |
3bd1e081 | 183 | |
f50f23d9 DG |
184 | /* |
185 | * Send status code to session daemon only if the recv works. If the | |
186 | * above recv() failed, the session daemon is notified through the | |
187 | * error socket and the teardown is eventually done. | |
188 | */ | |
189 | ret = consumer_send_status_msg(sock, ret_code); | |
190 | if (ret < 0) { | |
191 | /* Somehow, the session daemon is not responding anymore. */ | |
192 | goto end_nosignal; | |
193 | } | |
194 | ||
3bd1e081 MD |
195 | new_stream = consumer_allocate_stream(msg.u.stream.channel_key, |
196 | msg.u.stream.stream_key, | |
f2fc6720 | 197 | fd, fd, |
3bd1e081 MD |
198 | msg.u.stream.state, |
199 | msg.u.stream.mmap_len, | |
200 | msg.u.stream.output, | |
6df2e2c9 MD |
201 | msg.u.stream.path_name, |
202 | msg.u.stream.uid, | |
00e2e675 DG |
203 | msg.u.stream.gid, |
204 | msg.u.stream.net_index, | |
c80048c6 | 205 | msg.u.stream.metadata_flag, |
53632229 | 206 | msg.u.stream.session_id, |
c80048c6 | 207 | &alloc_ret); |
3bd1e081 | 208 | if (new_stream == NULL) { |
c80048c6 MD |
209 | switch (alloc_ret) { |
210 | case -ENOMEM: | |
211 | case -EINVAL: | |
212 | default: | |
213 | lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR); | |
214 | break; | |
215 | case -ENOENT: | |
216 | /* | |
217 | * We could not find the channel. Can happen if cpu hotplug | |
218 | * happens while tearing down. | |
219 | */ | |
220 | DBG3("Could not find channel"); | |
221 | break; | |
222 | } | |
3f8e211f | 223 | goto end_nosignal; |
3bd1e081 | 224 | } |
00e2e675 | 225 | |
fb3a43a9 DG |
226 | /* |
227 | * The buffer flush is done on the session daemon side for the kernel | |
228 | * so no need for the stream "hangup_flush_done" variable to be | |
229 | * tracked. This is important for a kernel stream since we don't rely | |
230 | * on the flush state of the stream to read data. It's not the case for | |
231 | * user space tracing. | |
232 | */ | |
233 | new_stream->hangup_flush_done = 0; | |
234 | ||
00e2e675 DG |
235 | /* The stream is not metadata. Get relayd reference if exists. */ |
236 | relayd = consumer_find_relayd(msg.u.stream.net_index); | |
237 | if (relayd != NULL) { | |
238 | /* Add stream on the relayd */ | |
239 | pthread_mutex_lock(&relayd->ctrl_sock_mutex); | |
240 | ret = relayd_add_stream(&relayd->control_sock, | |
241 | msg.u.stream.name, msg.u.stream.path_name, | |
242 | &new_stream->relayd_stream_id); | |
243 | pthread_mutex_unlock(&relayd->ctrl_sock_mutex); | |
244 | if (ret < 0) { | |
e316aad5 | 245 | consumer_del_stream(new_stream, NULL); |
3f8e211f | 246 | goto end_nosignal; |
00e2e675 DG |
247 | } |
248 | } else if (msg.u.stream.net_index != -1) { | |
249 | ERR("Network sequence index %d unknown. Not adding stream.", | |
250 | msg.u.stream.net_index); | |
e316aad5 | 251 | consumer_del_stream(new_stream, NULL); |
3f8e211f | 252 | goto end_nosignal; |
00e2e675 DG |
253 | } |
254 | ||
633d0084 DG |
255 | if (ctx->on_recv_stream) { |
256 | ret = ctx->on_recv_stream(new_stream); | |
257 | if (ret < 0) { | |
e316aad5 | 258 | consumer_del_stream(new_stream, NULL); |
633d0084 | 259 | goto end_nosignal; |
fb3a43a9 | 260 | } |
633d0084 | 261 | } |
fb3a43a9 | 262 | |
50f8ae69 | 263 | /* Get the right pipe where the stream will be sent. */ |
633d0084 | 264 | if (new_stream->metadata_flag) { |
50f8ae69 | 265 | stream_pipe = ctx->consumer_metadata_pipe[1]; |
3bd1e081 | 266 | } else { |
50f8ae69 DG |
267 | stream_pipe = ctx->consumer_data_pipe[1]; |
268 | } | |
269 | ||
270 | do { | |
271 | ret = write(stream_pipe, &new_stream, sizeof(new_stream)); | |
272 | } while (ret < 0 && errno == EINTR); | |
273 | if (ret < 0) { | |
274 | PERROR("Consumer write %s stream to pipe %d", | |
275 | new_stream->metadata_flag ? "metadata" : "data", | |
276 | stream_pipe); | |
277 | consumer_del_stream(new_stream, NULL); | |
278 | goto end_nosignal; | |
3bd1e081 | 279 | } |
00e2e675 | 280 | |
50f8ae69 DG |
281 | DBG("Kernel consumer ADD_STREAM %s (fd: %d) with relayd id %" PRIu64, |
282 | msg.u.stream.path_name, fd, new_stream->relayd_stream_id); | |
3bd1e081 MD |
283 | break; |
284 | } | |
285 | case LTTNG_CONSUMER_UPDATE_STREAM: | |
286 | { | |
3f8e211f DG |
287 | rcu_read_unlock(); |
288 | return -ENOSYS; | |
289 | } | |
290 | case LTTNG_CONSUMER_DESTROY_RELAYD: | |
291 | { | |
a6ba4fe1 | 292 | uint64_t index = msg.u.destroy_relayd.net_seq_idx; |
3f8e211f DG |
293 | struct consumer_relayd_sock_pair *relayd; |
294 | ||
a6ba4fe1 | 295 | DBG("Kernel consumer destroying relayd %" PRIu64, index); |
3f8e211f DG |
296 | |
297 | /* Get relayd reference if exists. */ | |
a6ba4fe1 | 298 | relayd = consumer_find_relayd(index); |
3f8e211f | 299 | if (relayd == NULL) { |
a6ba4fe1 | 300 | ERR("Unable to find relayd %" PRIu64, index); |
f50f23d9 | 301 | ret_code = LTTNG_ERR_NO_CONSUMER; |
3bd1e081 | 302 | } |
3f8e211f | 303 | |
a6ba4fe1 DG |
304 | /* |
305 | * Each relayd socket pair has a refcount of stream attached to it | |
306 | * which tells if the relayd is still active or not depending on the | |
307 | * refcount value. | |
308 | * | |
309 | * This will set the destroy flag of the relayd object and destroy it | |
310 | * if the refcount reaches zero when called. | |
311 | * | |
312 | * The destroy can happen either here or when a stream fd hangs up. | |
313 | */ | |
f50f23d9 DG |
314 | if (relayd) { |
315 | consumer_flag_relayd_for_destroy(relayd); | |
316 | } | |
317 | ||
318 | ret = consumer_send_status_msg(sock, ret_code); | |
319 | if (ret < 0) { | |
320 | /* Somehow, the session daemon is not responding anymore. */ | |
321 | goto end_nosignal; | |
322 | } | |
3f8e211f | 323 | |
3f8e211f | 324 | goto end_nosignal; |
3bd1e081 | 325 | } |
6d805429 | 326 | case LTTNG_CONSUMER_DATA_PENDING: |
53632229 | 327 | { |
c8f59ee5 | 328 | int32_t ret; |
6d805429 | 329 | uint64_t id = msg.u.data_pending.session_id; |
c8f59ee5 | 330 | |
6d805429 | 331 | DBG("Kernel consumer data pending command for id %" PRIu64, id); |
c8f59ee5 | 332 | |
6d805429 | 333 | ret = consumer_data_pending(id); |
c8f59ee5 DG |
334 | |
335 | /* Send back returned value to session daemon */ | |
336 | ret = lttcomm_send_unix_sock(sock, &ret, sizeof(ret)); | |
337 | if (ret < 0) { | |
6d805429 | 338 | PERROR("send data pending ret code"); |
c8f59ee5 | 339 | } |
f50f23d9 DG |
340 | |
341 | /* | |
342 | * No need to send back a status message since the data pending | |
343 | * returned value is the response. | |
344 | */ | |
c8f59ee5 | 345 | break; |
53632229 | 346 | } |
3bd1e081 | 347 | default: |
3f8e211f | 348 | goto end_nosignal; |
3bd1e081 | 349 | } |
3f8e211f | 350 | |
3bd1e081 | 351 | end_nosignal: |
b0b335c8 | 352 | rcu_read_unlock(); |
4cbc1a04 DG |
353 | |
354 | /* | |
355 | * Return 1 to indicate success since the 0 value can be a socket | |
356 | * shutdown during the recv() or send() call. | |
357 | */ | |
358 | return 1; | |
3bd1e081 | 359 | } |
d41f73b7 MD |
360 | |
361 | /* | |
362 | * Consume data on a file descriptor and write it on a trace file. | |
363 | */ | |
4078b776 | 364 | ssize_t lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream *stream, |
d41f73b7 MD |
365 | struct lttng_consumer_local_data *ctx) |
366 | { | |
1d4dfdef | 367 | unsigned long len, subbuf_size, padding; |
d41f73b7 | 368 | int err; |
4078b776 | 369 | ssize_t ret = 0; |
d41f73b7 MD |
370 | int infd = stream->wait_fd; |
371 | ||
372 | DBG("In read_subbuffer (infd : %d)", infd); | |
373 | /* Get the next subbuffer */ | |
374 | err = kernctl_get_next_subbuf(infd); | |
375 | if (err != 0) { | |
1d4dfdef | 376 | ret = err; |
d41f73b7 MD |
377 | /* |
378 | * This is a debug message even for single-threaded consumer, | |
379 | * because poll() have more relaxed criterions than get subbuf, | |
380 | * so get_subbuf may fail for short race windows where poll() | |
381 | * would issue wakeups. | |
382 | */ | |
383 | DBG("Reserving sub buffer failed (everything is normal, " | |
384 | "it is due to concurrency)"); | |
385 | goto end; | |
386 | } | |
387 | ||
1d4dfdef DG |
388 | /* Get the full subbuffer size including padding */ |
389 | err = kernctl_get_padded_subbuf_size(infd, &len); | |
390 | if (err != 0) { | |
391 | errno = -err; | |
392 | perror("Getting sub-buffer len failed."); | |
393 | ret = err; | |
394 | goto end; | |
395 | } | |
396 | ||
d41f73b7 | 397 | switch (stream->output) { |
1d4dfdef | 398 | case LTTNG_EVENT_SPLICE: |
d41f73b7 | 399 | |
1d4dfdef DG |
400 | /* |
401 | * XXX: The lttng-modules splice "actor" does not handle copying | |
402 | * partial pages hence only using the subbuffer size without the | |
403 | * padding makes the splice fail. | |
404 | */ | |
405 | subbuf_size = len; | |
406 | padding = 0; | |
407 | ||
408 | /* splice the subbuffer to the tracefile */ | |
91dfef6e DG |
409 | ret = lttng_consumer_on_read_subbuffer_splice(ctx, stream, subbuf_size, |
410 | padding); | |
411 | /* | |
412 | * XXX: Splice does not support network streaming so the return value | |
413 | * is simply checked against subbuf_size and not like the mmap() op. | |
414 | */ | |
1d4dfdef DG |
415 | if (ret != subbuf_size) { |
416 | /* | |
417 | * display the error but continue processing to try | |
418 | * to release the subbuffer | |
419 | */ | |
420 | ERR("Error splicing to tracefile (ret: %zd != len: %lu)", | |
421 | ret, subbuf_size); | |
422 | } | |
423 | break; | |
424 | case LTTNG_EVENT_MMAP: | |
425 | /* Get subbuffer size without padding */ | |
426 | err = kernctl_get_subbuf_size(infd, &subbuf_size); | |
427 | if (err != 0) { | |
428 | errno = -err; | |
429 | perror("Getting sub-buffer len failed."); | |
430 | ret = err; | |
431 | goto end; | |
432 | } | |
47e81c02 | 433 | |
1d4dfdef DG |
434 | /* Make sure the tracer is not gone mad on us! */ |
435 | assert(len >= subbuf_size); | |
436 | ||
437 | padding = len - subbuf_size; | |
438 | ||
439 | /* write the subbuffer to the tracefile */ | |
91dfef6e DG |
440 | ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, subbuf_size, |
441 | padding); | |
442 | /* | |
443 | * The mmap operation should write subbuf_size amount of data when | |
444 | * network streaming or the full padding (len) size when we are _not_ | |
445 | * streaming. | |
446 | */ | |
447 | if ((ret != subbuf_size && stream->net_seq_idx != -1) || | |
448 | (ret != len && stream->net_seq_idx == -1)) { | |
1d4dfdef | 449 | /* |
91dfef6e DG |
450 | * Display the error but continue processing to try to release the |
451 | * subbuffer | |
1d4dfdef | 452 | */ |
91dfef6e DG |
453 | ERR("Error writing to tracefile " |
454 | "(ret: %zd != len: %lu != subbuf_size: %lu)", | |
455 | ret, len, subbuf_size); | |
1d4dfdef DG |
456 | } |
457 | break; | |
458 | default: | |
459 | ERR("Unknown output method"); | |
460 | ret = -1; | |
d41f73b7 MD |
461 | } |
462 | ||
463 | err = kernctl_put_next_subbuf(infd); | |
464 | if (err != 0) { | |
21073eaa | 465 | errno = -err; |
d41f73b7 MD |
466 | if (errno == EFAULT) { |
467 | perror("Error in unreserving sub buffer\n"); | |
468 | } else if (errno == EIO) { | |
469 | /* Should never happen with newer LTTng versions */ | |
470 | perror("Reader has been pushed by the writer, last sub-buffer corrupted."); | |
471 | } | |
21073eaa DG |
472 | |
473 | ret = -err; | |
d41f73b7 MD |
474 | goto end; |
475 | } | |
476 | ||
477 | end: | |
478 | return ret; | |
479 | } | |
480 | ||
481 | int lttng_kconsumer_on_recv_stream(struct lttng_consumer_stream *stream) | |
482 | { | |
483 | int ret; | |
484 | ||
485 | /* Opening the tracefile in write mode */ | |
00e2e675 | 486 | if (strlen(stream->path_name) > 0 && stream->net_seq_idx == -1) { |
e11d277b | 487 | ret = run_as_open(stream->path_name, |
60b6c79c MD |
488 | O_WRONLY|O_CREAT|O_TRUNC, |
489 | S_IRWXU|S_IRWXG|S_IRWXO, | |
490 | stream->uid, stream->gid); | |
d41f73b7 MD |
491 | if (ret < 0) { |
492 | ERR("Opening %s", stream->path_name); | |
493 | perror("open"); | |
494 | goto error; | |
495 | } | |
496 | stream->out_fd = ret; | |
497 | } | |
498 | ||
499 | if (stream->output == LTTNG_EVENT_MMAP) { | |
500 | /* get the len of the mmap region */ | |
501 | unsigned long mmap_len; | |
502 | ||
503 | ret = kernctl_get_mmap_len(stream->wait_fd, &mmap_len); | |
504 | if (ret != 0) { | |
87dc6a9c | 505 | errno = -ret; |
d41f73b7 MD |
506 | perror("kernctl_get_mmap_len"); |
507 | goto error_close_fd; | |
508 | } | |
509 | stream->mmap_len = (size_t) mmap_len; | |
510 | ||
511 | stream->mmap_base = mmap(NULL, stream->mmap_len, | |
512 | PROT_READ, MAP_PRIVATE, stream->wait_fd, 0); | |
513 | if (stream->mmap_base == MAP_FAILED) { | |
514 | perror("Error mmaping"); | |
515 | ret = -1; | |
516 | goto error_close_fd; | |
517 | } | |
518 | } | |
519 | ||
520 | /* we return 0 to let the library handle the FD internally */ | |
521 | return 0; | |
522 | ||
523 | error_close_fd: | |
524 | { | |
525 | int err; | |
526 | ||
527 | err = close(stream->out_fd); | |
528 | assert(!err); | |
529 | } | |
530 | error: | |
531 | return ret; | |
532 | } | |
533 | ||
ca22feea DG |
534 | /* |
535 | * Check if data is still being extracted from the buffers for a specific | |
4e9a4686 DG |
536 | * stream. Consumer data lock MUST be acquired before calling this function |
537 | * and the stream lock. | |
ca22feea | 538 | * |
6d805429 | 539 | * Return 1 if the traced data are still getting read else 0 meaning that the |
ca22feea DG |
540 | * data is available for trace viewer reading. |
541 | */ | |
6d805429 | 542 | int lttng_kconsumer_data_pending(struct lttng_consumer_stream *stream) |
ca22feea DG |
543 | { |
544 | int ret; | |
545 | ||
546 | assert(stream); | |
547 | ||
ca22feea DG |
548 | ret = kernctl_get_next_subbuf(stream->wait_fd); |
549 | if (ret == 0) { | |
550 | /* There is still data so let's put back this subbuffer. */ | |
551 | ret = kernctl_put_subbuf(stream->wait_fd); | |
552 | assert(ret == 0); | |
6d805429 | 553 | ret = 1; /* Data is pending */ |
4e9a4686 | 554 | goto end; |
ca22feea DG |
555 | } |
556 | ||
6d805429 DG |
557 | /* Data is NOT pending and ready to be read. */ |
558 | ret = 0; | |
ca22feea | 559 | |
6efae65e DG |
560 | end: |
561 | return ret; | |
ca22feea | 562 | } |