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> | |
dbb5dfe6 | 27 | #include <sys/stat.h> |
3bd1e081 MD |
28 | #include <sys/types.h> |
29 | #include <unistd.h> | |
9df8df5e | 30 | #include <lttng/ust-ctl.h> |
0857097f | 31 | |
990570ed | 32 | #include <common/common.h> |
10a8a223 | 33 | #include <common/sessiond-comm/sessiond-comm.h> |
00e2e675 | 34 | #include <common/relayd/relayd.h> |
dbb5dfe6 | 35 | #include <common/compat/fcntl.h> |
10a8a223 DG |
36 | |
37 | #include "ust-consumer.h" | |
3bd1e081 MD |
38 | |
39 | extern struct lttng_consumer_global_data consumer_data; | |
40 | extern int consumer_poll_timeout; | |
41 | extern volatile int consumer_quit; | |
42 | ||
43 | /* | |
44 | * Mmap the ring buffer, read it and write the data to the tracefile. | |
45 | * | |
4078b776 | 46 | * Returns the number of bytes written, else negative value on error. |
3bd1e081 | 47 | */ |
4078b776 | 48 | ssize_t lttng_ustconsumer_on_read_subbuffer_mmap( |
3bd1e081 MD |
49 | struct lttng_consumer_local_data *ctx, |
50 | struct lttng_consumer_stream *stream, unsigned long len) | |
51 | { | |
52 | unsigned long mmap_offset; | |
47e81c02 | 53 | long ret = 0, written = 0; |
3bd1e081 MD |
54 | off_t orig_offset = stream->out_fd_offset; |
55 | int outfd = stream->out_fd; | |
00e2e675 DG |
56 | uint64_t metadata_id; |
57 | struct consumer_relayd_sock_pair *relayd = NULL; | |
58 | ||
b0b335c8 MD |
59 | /* RCU lock for the relayd pointer */ |
60 | rcu_read_lock(); | |
61 | ||
00e2e675 DG |
62 | /* Flag that the current stream if set for network streaming. */ |
63 | if (stream->net_seq_idx != -1) { | |
64 | relayd = consumer_find_relayd(stream->net_seq_idx); | |
65 | if (relayd == NULL) { | |
87c1611d DG |
66 | ERR("UST consumer mmap(), unable to find relay for index %d", |
67 | stream->net_seq_idx); | |
00e2e675 DG |
68 | goto end; |
69 | } | |
70 | } | |
3bd1e081 MD |
71 | |
72 | /* get the offset inside the fd to mmap */ | |
73 | ret = ustctl_get_mmap_read_offset(stream->chan->handle, | |
74 | stream->buf, &mmap_offset); | |
75 | if (ret != 0) { | |
87dc6a9c | 76 | errno = -ret; |
4c462e79 | 77 | PERROR("ustctl_get_mmap_read_offset"); |
47e81c02 | 78 | written = ret; |
3bd1e081 MD |
79 | goto end; |
80 | } | |
00e2e675 DG |
81 | |
82 | /* Handle stream on the relayd if the output is on the network */ | |
83 | if (relayd) { | |
84 | if (stream->metadata_flag) { | |
85 | /* Only lock if metadata since we use the control socket. */ | |
86 | pthread_mutex_lock(&relayd->ctrl_sock_mutex); | |
87 | } | |
88 | ||
89 | ret = consumer_handle_stream_before_relayd(stream, len); | |
90 | if (ret >= 0) { | |
91 | outfd = ret; | |
92 | ||
93 | /* Write metadata stream id before payload */ | |
94 | if (stream->metadata_flag) { | |
95 | metadata_id = htobe64(stream->relayd_stream_id); | |
96 | do { | |
97 | ret = write(outfd, (void *) &metadata_id, | |
98 | sizeof(stream->relayd_stream_id)); | |
6f94560a MD |
99 | } while (ret < 0 && errno == EINTR); |
100 | if (ret < 0) { | |
101 | PERROR("write metadata stream id"); | |
102 | written = ret; | |
103 | goto end; | |
104 | } | |
00e2e675 DG |
105 | DBG("Metadata stream id %zu written before data", |
106 | stream->relayd_stream_id); | |
107 | } | |
108 | } | |
109 | /* Else, use the default set before which is the filesystem. */ | |
110 | } | |
111 | ||
3bd1e081 | 112 | while (len > 0) { |
6f94560a MD |
113 | do { |
114 | ret = write(outfd, stream->mmap_base + mmap_offset, len); | |
115 | } while (ret < 0 && errno == EINTR); | |
47e81c02 | 116 | if (ret < 0) { |
6f94560a MD |
117 | PERROR("Error in file write"); |
118 | if (written == 0) { | |
119 | written = ret; | |
47e81c02 | 120 | } |
6f94560a | 121 | goto end; |
47e81c02 | 122 | } else if (ret > len) { |
00e2e675 | 123 | PERROR("ret %ld > len %lu", ret, len); |
47e81c02 | 124 | written += ret; |
3bd1e081 | 125 | goto end; |
47e81c02 MD |
126 | } else { |
127 | len -= ret; | |
128 | mmap_offset += ret; | |
3bd1e081 | 129 | } |
00e2e675 DG |
130 | DBG("UST mmap write() ret %ld (len %lu)", ret, len); |
131 | ||
132 | /* This call is useless on a socket so better save a syscall. */ | |
133 | if (!relayd) { | |
134 | /* This won't block, but will start writeout asynchronously */ | |
135 | lttng_sync_file_range(outfd, stream->out_fd_offset, ret, | |
136 | SYNC_FILE_RANGE_WRITE); | |
137 | stream->out_fd_offset += ret; | |
138 | } | |
47e81c02 | 139 | written += ret; |
3bd1e081 | 140 | } |
3bd1e081 | 141 | lttng_consumer_sync_trace_file(stream, orig_offset); |
00e2e675 | 142 | |
3bd1e081 | 143 | end: |
00e2e675 DG |
144 | if (relayd && stream->metadata_flag) { |
145 | pthread_mutex_unlock(&relayd->ctrl_sock_mutex); | |
146 | } | |
b0b335c8 | 147 | rcu_read_unlock(); |
47e81c02 | 148 | return written; |
3bd1e081 MD |
149 | } |
150 | ||
151 | /* | |
152 | * Splice the data from the ring buffer to the tracefile. | |
153 | * | |
154 | * Returns the number of bytes spliced. | |
155 | */ | |
4078b776 | 156 | ssize_t lttng_ustconsumer_on_read_subbuffer_splice( |
3bd1e081 MD |
157 | struct lttng_consumer_local_data *ctx, |
158 | struct lttng_consumer_stream *stream, unsigned long len) | |
159 | { | |
160 | return -ENOSYS; | |
161 | } | |
162 | ||
163 | /* | |
164 | * Take a snapshot for a specific fd | |
165 | * | |
166 | * Returns 0 on success, < 0 on error | |
167 | */ | |
168 | int lttng_ustconsumer_take_snapshot(struct lttng_consumer_local_data *ctx, | |
169 | struct lttng_consumer_stream *stream) | |
170 | { | |
171 | int ret = 0; | |
172 | ||
173 | ret = ustctl_snapshot(stream->chan->handle, stream->buf); | |
174 | if (ret != 0) { | |
87dc6a9c | 175 | errno = -ret; |
4c462e79 | 176 | PERROR("Getting sub-buffer snapshot."); |
3bd1e081 MD |
177 | } |
178 | ||
179 | return ret; | |
180 | } | |
181 | ||
182 | /* | |
183 | * Get the produced position | |
184 | * | |
185 | * Returns 0 on success, < 0 on error | |
186 | */ | |
187 | int lttng_ustconsumer_get_produced_snapshot( | |
188 | struct lttng_consumer_local_data *ctx, | |
189 | struct lttng_consumer_stream *stream, | |
190 | unsigned long *pos) | |
191 | { | |
192 | int ret; | |
193 | ||
194 | ret = ustctl_snapshot_get_produced(stream->chan->handle, | |
195 | stream->buf, pos); | |
196 | if (ret != 0) { | |
87dc6a9c | 197 | errno = -ret; |
4c462e79 | 198 | PERROR("kernctl_snapshot_get_produced"); |
3bd1e081 MD |
199 | } |
200 | ||
201 | return ret; | |
202 | } | |
203 | ||
204 | int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx, | |
205 | int sock, struct pollfd *consumer_sockpoll) | |
206 | { | |
207 | ssize_t ret; | |
208 | struct lttcomm_consumer_msg msg; | |
209 | ||
210 | ret = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg)); | |
211 | if (ret != sizeof(msg)) { | |
212 | lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_FD); | |
213 | return ret; | |
214 | } | |
215 | if (msg.cmd_type == LTTNG_CONSUMER_STOP) { | |
216 | return -ENOENT; | |
217 | } | |
218 | ||
b0b335c8 MD |
219 | /* relayd need RCU read-side lock */ |
220 | rcu_read_lock(); | |
221 | ||
3bd1e081 | 222 | switch (msg.cmd_type) { |
00e2e675 DG |
223 | case LTTNG_CONSUMER_ADD_RELAYD_SOCKET: |
224 | { | |
225 | int fd; | |
226 | struct consumer_relayd_sock_pair *relayd; | |
227 | ||
228 | DBG("UST Consumer adding relayd socket"); | |
229 | ||
230 | /* Get relayd reference if exists. */ | |
231 | relayd = consumer_find_relayd(msg.u.relayd_sock.net_index); | |
232 | if (relayd == NULL) { | |
233 | /* Not found. Allocate one. */ | |
234 | relayd = consumer_allocate_relayd_sock_pair( | |
235 | msg.u.relayd_sock.net_index); | |
236 | if (relayd == NULL) { | |
237 | lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR); | |
238 | goto end_nosignal; | |
239 | } | |
240 | } | |
241 | ||
242 | /* Poll on consumer socket. */ | |
243 | if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) { | |
244 | return -EINTR; | |
245 | } | |
246 | ||
247 | /* Get relayd socket from session daemon */ | |
248 | ret = lttcomm_recv_fds_unix_sock(sock, &fd, 1); | |
249 | if (ret != sizeof(fd)) { | |
250 | lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_FD); | |
251 | goto end_nosignal; | |
252 | } | |
253 | ||
254 | /* Copy socket information and received FD */ | |
255 | switch (msg.u.relayd_sock.type) { | |
256 | case LTTNG_STREAM_CONTROL: | |
257 | /* Copy received lttcomm socket */ | |
258 | lttcomm_copy_sock(&relayd->control_sock, &msg.u.relayd_sock.sock); | |
259 | ret = lttcomm_create_sock(&relayd->control_sock); | |
260 | if (ret < 0) { | |
261 | goto end_nosignal; | |
262 | } | |
263 | ||
264 | /* Close the created socket fd which is useless */ | |
265 | close(relayd->control_sock.fd); | |
266 | ||
267 | /* Assign new file descriptor */ | |
268 | relayd->control_sock.fd = fd; | |
269 | break; | |
270 | case LTTNG_STREAM_DATA: | |
271 | /* Copy received lttcomm socket */ | |
272 | lttcomm_copy_sock(&relayd->data_sock, &msg.u.relayd_sock.sock); | |
273 | ret = lttcomm_create_sock(&relayd->data_sock); | |
274 | if (ret < 0) { | |
275 | goto end_nosignal; | |
276 | } | |
277 | ||
278 | /* Close the created socket fd which is useless */ | |
279 | close(relayd->data_sock.fd); | |
280 | ||
281 | /* Assign new file descriptor */ | |
282 | relayd->data_sock.fd = fd; | |
283 | break; | |
284 | default: | |
285 | ERR("Unknown relayd socket type"); | |
286 | goto end_nosignal; | |
287 | } | |
288 | ||
289 | DBG("Consumer %s socket created successfully with net idx %d (fd: %d)", | |
290 | msg.u.relayd_sock.type == LTTNG_STREAM_CONTROL ? "control" : "data", | |
291 | relayd->net_seq_idx, fd); | |
292 | ||
293 | /* | |
294 | * Add relayd socket pair to consumer data hashtable. If object already | |
295 | * exists or on error, the function gracefully returns. | |
296 | */ | |
297 | consumer_add_relayd(relayd); | |
298 | ||
299 | goto end_nosignal; | |
300 | } | |
3bd1e081 MD |
301 | case LTTNG_CONSUMER_ADD_CHANNEL: |
302 | { | |
303 | struct lttng_consumer_channel *new_channel; | |
304 | int fds[1]; | |
305 | size_t nb_fd = 1; | |
306 | ||
307 | /* block */ | |
308 | if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) { | |
309 | return -EINTR; | |
310 | } | |
311 | ret = lttcomm_recv_fds_unix_sock(sock, fds, nb_fd); | |
312 | if (ret != sizeof(fds)) { | |
313 | lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_FD); | |
314 | return ret; | |
315 | } | |
316 | ||
317 | DBG("consumer_add_channel %d", msg.u.channel.channel_key); | |
318 | ||
319 | new_channel = consumer_allocate_channel(msg.u.channel.channel_key, | |
320 | fds[0], -1, | |
321 | msg.u.channel.mmap_len, | |
322 | msg.u.channel.max_sb_size); | |
323 | if (new_channel == NULL) { | |
324 | lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR); | |
325 | goto end_nosignal; | |
326 | } | |
327 | if (ctx->on_recv_channel != NULL) { | |
328 | ret = ctx->on_recv_channel(new_channel); | |
329 | if (ret == 0) { | |
330 | consumer_add_channel(new_channel); | |
331 | } else if (ret < 0) { | |
332 | goto end_nosignal; | |
333 | } | |
334 | } else { | |
335 | consumer_add_channel(new_channel); | |
336 | } | |
337 | goto end_nosignal; | |
338 | } | |
339 | case LTTNG_CONSUMER_ADD_STREAM: | |
340 | { | |
341 | struct lttng_consumer_stream *new_stream; | |
342 | int fds[2]; | |
343 | size_t nb_fd = 2; | |
00e2e675 | 344 | struct consumer_relayd_sock_pair *relayd = NULL; |
3bd1e081 MD |
345 | |
346 | /* block */ | |
347 | if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) { | |
348 | return -EINTR; | |
349 | } | |
350 | ret = lttcomm_recv_fds_unix_sock(sock, fds, nb_fd); | |
351 | if (ret != sizeof(fds)) { | |
352 | lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_FD); | |
353 | return ret; | |
354 | } | |
355 | ||
d41f73b7 | 356 | assert(msg.u.stream.output == LTTNG_EVENT_MMAP); |
7ad0a0cb | 357 | new_stream = consumer_allocate_stream(msg.u.channel.channel_key, |
3bd1e081 MD |
358 | msg.u.stream.stream_key, |
359 | fds[0], fds[1], | |
360 | msg.u.stream.state, | |
361 | msg.u.stream.mmap_len, | |
362 | msg.u.stream.output, | |
6df2e2c9 MD |
363 | msg.u.stream.path_name, |
364 | msg.u.stream.uid, | |
00e2e675 DG |
365 | msg.u.stream.gid, |
366 | msg.u.stream.net_index, | |
367 | msg.u.stream.metadata_flag); | |
3bd1e081 MD |
368 | if (new_stream == NULL) { |
369 | lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR); | |
370 | goto end; | |
371 | } | |
00e2e675 DG |
372 | |
373 | /* The stream is not metadata. Get relayd reference if exists. */ | |
374 | relayd = consumer_find_relayd(msg.u.stream.net_index); | |
375 | if (relayd != NULL) { | |
376 | pthread_mutex_lock(&relayd->ctrl_sock_mutex); | |
377 | /* Add stream on the relayd */ | |
378 | ret = relayd_add_stream(&relayd->control_sock, | |
379 | msg.u.stream.name, msg.u.stream.path_name, | |
380 | &new_stream->relayd_stream_id); | |
381 | pthread_mutex_unlock(&relayd->ctrl_sock_mutex); | |
382 | if (ret < 0) { | |
383 | goto end; | |
384 | } | |
385 | } else if (msg.u.stream.net_index != -1) { | |
386 | ERR("Network sequence index %d unknown. Not adding stream.", | |
387 | msg.u.stream.net_index); | |
388 | free(new_stream); | |
389 | goto end; | |
390 | } | |
391 | ||
3bd1e081 MD |
392 | if (ctx->on_recv_stream != NULL) { |
393 | ret = ctx->on_recv_stream(new_stream); | |
394 | if (ret == 0) { | |
395 | consumer_add_stream(new_stream); | |
396 | } else if (ret < 0) { | |
397 | goto end; | |
398 | } | |
399 | } else { | |
400 | consumer_add_stream(new_stream); | |
401 | } | |
00e2e675 DG |
402 | |
403 | DBG("UST consumer_add_stream %s (%d,%d) with relayd id %lu", | |
404 | msg.u.stream.path_name, fds[0], fds[1], | |
405 | new_stream->relayd_stream_id); | |
3bd1e081 MD |
406 | break; |
407 | } | |
408 | case LTTNG_CONSUMER_UPDATE_STREAM: | |
409 | { | |
7ad0a0cb MD |
410 | return -ENOSYS; |
411 | #if 0 | |
3bd1e081 MD |
412 | if (ctx->on_update_stream != NULL) { |
413 | ret = ctx->on_update_stream(msg.u.stream.stream_key, msg.u.stream.state); | |
414 | if (ret == 0) { | |
415 | consumer_change_stream_state(msg.u.stream.stream_key, msg.u.stream.state); | |
416 | } else if (ret < 0) { | |
417 | goto end; | |
418 | } | |
419 | } else { | |
420 | consumer_change_stream_state(msg.u.stream.stream_key, | |
421 | msg.u.stream.state); | |
422 | } | |
7ad0a0cb | 423 | #endif |
3bd1e081 MD |
424 | break; |
425 | } | |
426 | default: | |
427 | break; | |
428 | } | |
429 | end: | |
04fdd819 MD |
430 | /* |
431 | * Wake-up the other end by writing a null byte in the pipe | |
432 | * (non-blocking). Important note: Because writing into the | |
433 | * pipe is non-blocking (and therefore we allow dropping wakeup | |
434 | * data, as long as there is wakeup data present in the pipe | |
435 | * buffer to wake up the other end), the other end should | |
436 | * perform the following sequence for waiting: | |
437 | * 1) empty the pipe (reads). | |
438 | * 2) perform update operation. | |
439 | * 3) wait on the pipe (poll). | |
440 | */ | |
441 | do { | |
442 | ret = write(ctx->consumer_poll_pipe[1], "", 1); | |
6f94560a | 443 | } while (ret < 0 && errno == EINTR); |
3bd1e081 | 444 | end_nosignal: |
b0b335c8 | 445 | rcu_read_unlock(); |
3bd1e081 MD |
446 | return 0; |
447 | } | |
448 | ||
449 | int lttng_ustconsumer_allocate_channel(struct lttng_consumer_channel *chan) | |
450 | { | |
13161846 | 451 | struct lttng_ust_object_data obj; |
3bd1e081 MD |
452 | |
453 | obj.handle = -1; | |
454 | obj.shm_fd = chan->shm_fd; | |
455 | obj.wait_fd = chan->wait_fd; | |
456 | obj.memory_map_size = chan->mmap_len; | |
457 | chan->handle = ustctl_map_channel(&obj); | |
458 | if (!chan->handle) { | |
459 | return -ENOMEM; | |
460 | } | |
b5c5fc29 | 461 | chan->wait_fd_is_copy = 1; |
2c1dd183 | 462 | chan->shm_fd = -1; |
b5c5fc29 | 463 | |
3bd1e081 MD |
464 | return 0; |
465 | } | |
466 | ||
d056b477 MD |
467 | void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream *stream) |
468 | { | |
469 | ustctl_flush_buffer(stream->chan->handle, stream->buf, 0); | |
effcf122 | 470 | stream->hangup_flush_done = 1; |
d056b477 MD |
471 | } |
472 | ||
3bd1e081 MD |
473 | void lttng_ustconsumer_del_channel(struct lttng_consumer_channel *chan) |
474 | { | |
475 | ustctl_unmap_channel(chan->handle); | |
476 | } | |
477 | ||
478 | int lttng_ustconsumer_allocate_stream(struct lttng_consumer_stream *stream) | |
479 | { | |
13161846 | 480 | struct lttng_ust_object_data obj; |
3bd1e081 MD |
481 | int ret; |
482 | ||
483 | obj.handle = -1; | |
484 | obj.shm_fd = stream->shm_fd; | |
485 | obj.wait_fd = stream->wait_fd; | |
486 | obj.memory_map_size = stream->mmap_len; | |
487 | ret = ustctl_add_stream(stream->chan->handle, &obj); | |
488 | if (ret) | |
489 | return ret; | |
490 | stream->buf = ustctl_open_stream_read(stream->chan->handle, stream->cpu); | |
491 | if (!stream->buf) | |
492 | return -EBUSY; | |
2c1dd183 MD |
493 | /* ustctl_open_stream_read has closed the shm fd. */ |
494 | stream->wait_fd_is_copy = 1; | |
495 | stream->shm_fd = -1; | |
496 | ||
3bd1e081 MD |
497 | stream->mmap_base = ustctl_get_mmap_base(stream->chan->handle, stream->buf); |
498 | if (!stream->mmap_base) { | |
499 | return -EINVAL; | |
500 | } | |
ee77a7b0 | 501 | |
3bd1e081 MD |
502 | return 0; |
503 | } | |
504 | ||
505 | void lttng_ustconsumer_del_stream(struct lttng_consumer_stream *stream) | |
506 | { | |
507 | ustctl_close_stream_read(stream->chan->handle, stream->buf); | |
508 | } | |
d41f73b7 MD |
509 | |
510 | ||
511 | int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream *stream, | |
512 | struct lttng_consumer_local_data *ctx) | |
513 | { | |
514 | unsigned long len; | |
515 | int err; | |
516 | long ret = 0; | |
517 | struct lttng_ust_shm_handle *handle; | |
518 | struct lttng_ust_lib_ring_buffer *buf; | |
519 | char dummy; | |
520 | ssize_t readlen; | |
521 | ||
522 | DBG("In read_subbuffer (wait_fd: %d, stream key: %d)", | |
523 | stream->wait_fd, stream->key); | |
524 | ||
525 | /* We can consume the 1 byte written into the wait_fd by UST */ | |
effcf122 MD |
526 | if (!stream->hangup_flush_done) { |
527 | do { | |
528 | readlen = read(stream->wait_fd, &dummy, 1); | |
87dc6a9c | 529 | } while (readlen == -1 && errno == EINTR); |
effcf122 MD |
530 | if (readlen == -1) { |
531 | ret = readlen; | |
532 | goto end; | |
533 | } | |
d41f73b7 MD |
534 | } |
535 | ||
536 | buf = stream->buf; | |
537 | handle = stream->chan->handle; | |
538 | /* Get the next subbuffer */ | |
539 | err = ustctl_get_next_subbuf(handle, buf); | |
540 | if (err != 0) { | |
effcf122 | 541 | ret = -ret; /* ustctl_get_next_subbuf returns negative, caller expect positive. */ |
d41f73b7 MD |
542 | /* |
543 | * This is a debug message even for single-threaded consumer, | |
544 | * because poll() have more relaxed criterions than get subbuf, | |
545 | * so get_subbuf may fail for short race windows where poll() | |
546 | * would issue wakeups. | |
547 | */ | |
548 | DBG("Reserving sub buffer failed (everything is normal, " | |
549 | "it is due to concurrency)"); | |
550 | goto end; | |
551 | } | |
552 | assert(stream->output == LTTNG_EVENT_MMAP); | |
553 | /* read the used subbuffer size */ | |
554 | err = ustctl_get_padded_subbuf_size(handle, buf, &len); | |
effcf122 | 555 | assert(err == 0); |
d41f73b7 MD |
556 | /* write the subbuffer to the tracefile */ |
557 | ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, len); | |
47e81c02 | 558 | if (ret != len) { |
d41f73b7 MD |
559 | /* |
560 | * display the error but continue processing to try | |
561 | * to release the subbuffer | |
562 | */ | |
563 | ERR("Error writing to tracefile"); | |
564 | } | |
565 | err = ustctl_put_next_subbuf(handle, buf); | |
effcf122 | 566 | assert(err == 0); |
d41f73b7 MD |
567 | end: |
568 | return ret; | |
569 | } | |
570 | ||
571 | int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream *stream) | |
572 | { | |
573 | int ret; | |
574 | ||
575 | /* Opening the tracefile in write mode */ | |
00e2e675 | 576 | if (stream->path_name != NULL && stream->net_seq_idx == -1) { |
e11d277b | 577 | ret = run_as_open(stream->path_name, |
60b6c79c MD |
578 | O_WRONLY|O_CREAT|O_TRUNC, |
579 | S_IRWXU|S_IRWXG|S_IRWXO, | |
580 | stream->uid, stream->gid); | |
d41f73b7 MD |
581 | if (ret < 0) { |
582 | ERR("Opening %s", stream->path_name); | |
4c462e79 | 583 | PERROR("open"); |
d41f73b7 MD |
584 | goto error; |
585 | } | |
586 | stream->out_fd = ret; | |
587 | } | |
588 | ||
589 | /* we return 0 to let the library handle the FD internally */ | |
590 | return 0; | |
591 | ||
592 | error: | |
593 | return ret; | |
594 | } |