| 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, but WITHOUT |
| 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| 12 | * 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 <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> |
| 28 | #include <unistd.h> |
| 29 | |
| 30 | #include <common/common.h> |
| 31 | #include <common/kernel-ctl/kernel-ctl.h> |
| 32 | #include <common/sessiond-comm/sessiond-comm.h> |
| 33 | #include <common/kernel-consumer/kernel-consumer.h> |
| 34 | #include <common/ust-consumer/ust-consumer.h> |
| 35 | |
| 36 | #include "consumer.h" |
| 37 | |
| 38 | struct lttng_consumer_global_data consumer_data = { |
| 39 | .stream_count = 0, |
| 40 | .need_update = 1, |
| 41 | .type = LTTNG_CONSUMER_UNKNOWN, |
| 42 | }; |
| 43 | |
| 44 | /* timeout parameter, to control the polling thread grace period. */ |
| 45 | int consumer_poll_timeout = -1; |
| 46 | |
| 47 | /* |
| 48 | * Flag to inform the polling thread to quit when all fd hung up. Updated by |
| 49 | * the consumer_thread_receive_fds when it notices that all fds has hung up. |
| 50 | * Also updated by the signal handler (consumer_should_exit()). Read by the |
| 51 | * polling threads. |
| 52 | */ |
| 53 | volatile int consumer_quit = 0; |
| 54 | |
| 55 | /* |
| 56 | * Find a stream. The consumer_data.lock must be locked during this |
| 57 | * call. |
| 58 | */ |
| 59 | static struct lttng_consumer_stream *consumer_find_stream(int key) |
| 60 | { |
| 61 | struct lttng_ht_iter iter; |
| 62 | struct lttng_ht_node_ulong *node; |
| 63 | struct lttng_consumer_stream *stream = NULL; |
| 64 | |
| 65 | /* Negative keys are lookup failures */ |
| 66 | if (key < 0) |
| 67 | return NULL; |
| 68 | |
| 69 | rcu_read_lock(); |
| 70 | |
| 71 | lttng_ht_lookup(consumer_data.stream_ht, (void *)((unsigned long) key), |
| 72 | &iter); |
| 73 | node = lttng_ht_iter_get_node_ulong(&iter); |
| 74 | if (node != NULL) { |
| 75 | stream = caa_container_of(node, struct lttng_consumer_stream, node); |
| 76 | } |
| 77 | |
| 78 | rcu_read_unlock(); |
| 79 | |
| 80 | return stream; |
| 81 | } |
| 82 | |
| 83 | static void consumer_steal_stream_key(int key) |
| 84 | { |
| 85 | struct lttng_consumer_stream *stream; |
| 86 | |
| 87 | rcu_read_lock(); |
| 88 | stream = consumer_find_stream(key); |
| 89 | if (stream) { |
| 90 | stream->key = -1; |
| 91 | /* |
| 92 | * We don't want the lookup to match, but we still need |
| 93 | * to iterate on this stream when iterating over the hash table. Just |
| 94 | * change the node key. |
| 95 | */ |
| 96 | stream->node.key = -1; |
| 97 | } |
| 98 | rcu_read_unlock(); |
| 99 | } |
| 100 | |
| 101 | static struct lttng_consumer_channel *consumer_find_channel(int key) |
| 102 | { |
| 103 | struct lttng_ht_iter iter; |
| 104 | struct lttng_ht_node_ulong *node; |
| 105 | struct lttng_consumer_channel *channel = NULL; |
| 106 | |
| 107 | /* Negative keys are lookup failures */ |
| 108 | if (key < 0) |
| 109 | return NULL; |
| 110 | |
| 111 | rcu_read_lock(); |
| 112 | |
| 113 | lttng_ht_lookup(consumer_data.channel_ht, (void *)((unsigned long) key), |
| 114 | &iter); |
| 115 | node = lttng_ht_iter_get_node_ulong(&iter); |
| 116 | if (node != NULL) { |
| 117 | channel = caa_container_of(node, struct lttng_consumer_channel, node); |
| 118 | } |
| 119 | |
| 120 | rcu_read_unlock(); |
| 121 | |
| 122 | return channel; |
| 123 | } |
| 124 | |
| 125 | static void consumer_steal_channel_key(int key) |
| 126 | { |
| 127 | struct lttng_consumer_channel *channel; |
| 128 | |
| 129 | rcu_read_lock(); |
| 130 | channel = consumer_find_channel(key); |
| 131 | if (channel) { |
| 132 | channel->key = -1; |
| 133 | /* |
| 134 | * We don't want the lookup to match, but we still need |
| 135 | * to iterate on this channel when iterating over the hash table. Just |
| 136 | * change the node key. |
| 137 | */ |
| 138 | channel->node.key = -1; |
| 139 | } |
| 140 | rcu_read_unlock(); |
| 141 | } |
| 142 | |
| 143 | static |
| 144 | void consumer_free_stream(struct rcu_head *head) |
| 145 | { |
| 146 | struct lttng_ht_node_ulong *node = |
| 147 | caa_container_of(head, struct lttng_ht_node_ulong, head); |
| 148 | struct lttng_consumer_stream *stream = |
| 149 | caa_container_of(node, struct lttng_consumer_stream, node); |
| 150 | |
| 151 | free(stream); |
| 152 | } |
| 153 | |
| 154 | /* |
| 155 | * Remove a stream from the global list protected by a mutex. This |
| 156 | * function is also responsible for freeing its data structures. |
| 157 | */ |
| 158 | void consumer_del_stream(struct lttng_consumer_stream *stream) |
| 159 | { |
| 160 | int ret; |
| 161 | struct lttng_ht_iter iter; |
| 162 | struct lttng_consumer_channel *free_chan = NULL; |
| 163 | |
| 164 | pthread_mutex_lock(&consumer_data.lock); |
| 165 | |
| 166 | switch (consumer_data.type) { |
| 167 | case LTTNG_CONSUMER_KERNEL: |
| 168 | if (stream->mmap_base != NULL) { |
| 169 | ret = munmap(stream->mmap_base, stream->mmap_len); |
| 170 | if (ret != 0) { |
| 171 | perror("munmap"); |
| 172 | } |
| 173 | } |
| 174 | break; |
| 175 | case LTTNG_CONSUMER32_UST: |
| 176 | case LTTNG_CONSUMER64_UST: |
| 177 | lttng_ustconsumer_del_stream(stream); |
| 178 | break; |
| 179 | default: |
| 180 | ERR("Unknown consumer_data type"); |
| 181 | assert(0); |
| 182 | goto end; |
| 183 | } |
| 184 | |
| 185 | rcu_read_lock(); |
| 186 | iter.iter.node = &stream->node.node; |
| 187 | ret = lttng_ht_del(consumer_data.stream_ht, &iter); |
| 188 | assert(!ret); |
| 189 | |
| 190 | rcu_read_unlock(); |
| 191 | |
| 192 | if (consumer_data.stream_count <= 0) { |
| 193 | goto end; |
| 194 | } |
| 195 | consumer_data.stream_count--; |
| 196 | if (!stream) { |
| 197 | goto end; |
| 198 | } |
| 199 | if (stream->out_fd >= 0) { |
| 200 | ret = close(stream->out_fd); |
| 201 | if (ret) { |
| 202 | PERROR("close"); |
| 203 | } |
| 204 | } |
| 205 | if (stream->wait_fd >= 0 && !stream->wait_fd_is_copy) { |
| 206 | ret = close(stream->wait_fd); |
| 207 | if (ret) { |
| 208 | PERROR("close"); |
| 209 | } |
| 210 | } |
| 211 | if (stream->shm_fd >= 0 && stream->wait_fd != stream->shm_fd) { |
| 212 | ret = close(stream->shm_fd); |
| 213 | if (ret) { |
| 214 | PERROR("close"); |
| 215 | } |
| 216 | } |
| 217 | if (!--stream->chan->refcount) |
| 218 | free_chan = stream->chan; |
| 219 | |
| 220 | call_rcu(&stream->node.head, consumer_free_stream); |
| 221 | end: |
| 222 | consumer_data.need_update = 1; |
| 223 | pthread_mutex_unlock(&consumer_data.lock); |
| 224 | |
| 225 | if (free_chan) |
| 226 | consumer_del_channel(free_chan); |
| 227 | } |
| 228 | |
| 229 | struct lttng_consumer_stream *consumer_allocate_stream( |
| 230 | int channel_key, int stream_key, |
| 231 | int shm_fd, int wait_fd, |
| 232 | enum lttng_consumer_stream_state state, |
| 233 | uint64_t mmap_len, |
| 234 | enum lttng_event_output output, |
| 235 | const char *path_name, |
| 236 | uid_t uid, |
| 237 | gid_t gid) |
| 238 | { |
| 239 | struct lttng_consumer_stream *stream; |
| 240 | int ret; |
| 241 | |
| 242 | stream = zmalloc(sizeof(*stream)); |
| 243 | if (stream == NULL) { |
| 244 | perror("malloc struct lttng_consumer_stream"); |
| 245 | goto end; |
| 246 | } |
| 247 | stream->chan = consumer_find_channel(channel_key); |
| 248 | if (!stream->chan) { |
| 249 | perror("Unable to find channel key"); |
| 250 | goto end; |
| 251 | } |
| 252 | stream->chan->refcount++; |
| 253 | stream->key = stream_key; |
| 254 | stream->shm_fd = shm_fd; |
| 255 | stream->wait_fd = wait_fd; |
| 256 | stream->out_fd = -1; |
| 257 | stream->out_fd_offset = 0; |
| 258 | stream->state = state; |
| 259 | stream->mmap_len = mmap_len; |
| 260 | stream->mmap_base = NULL; |
| 261 | stream->output = output; |
| 262 | stream->uid = uid; |
| 263 | stream->gid = gid; |
| 264 | strncpy(stream->path_name, path_name, PATH_MAX - 1); |
| 265 | stream->path_name[PATH_MAX - 1] = '\0'; |
| 266 | lttng_ht_node_init_ulong(&stream->node, stream->key); |
| 267 | |
| 268 | switch (consumer_data.type) { |
| 269 | case LTTNG_CONSUMER_KERNEL: |
| 270 | break; |
| 271 | case LTTNG_CONSUMER32_UST: |
| 272 | case LTTNG_CONSUMER64_UST: |
| 273 | stream->cpu = stream->chan->cpucount++; |
| 274 | ret = lttng_ustconsumer_allocate_stream(stream); |
| 275 | if (ret) { |
| 276 | free(stream); |
| 277 | return NULL; |
| 278 | } |
| 279 | break; |
| 280 | default: |
| 281 | ERR("Unknown consumer_data type"); |
| 282 | assert(0); |
| 283 | goto end; |
| 284 | } |
| 285 | DBG("Allocated stream %s (key %d, shm_fd %d, wait_fd %d, mmap_len %llu, out_fd %d)", |
| 286 | stream->path_name, stream->key, |
| 287 | stream->shm_fd, |
| 288 | stream->wait_fd, |
| 289 | (unsigned long long) stream->mmap_len, |
| 290 | stream->out_fd); |
| 291 | end: |
| 292 | return stream; |
| 293 | } |
| 294 | |
| 295 | /* |
| 296 | * Add a stream to the global list protected by a mutex. |
| 297 | */ |
| 298 | int consumer_add_stream(struct lttng_consumer_stream *stream) |
| 299 | { |
| 300 | int ret = 0; |
| 301 | struct lttng_ht_node_ulong *node; |
| 302 | struct lttng_ht_iter iter; |
| 303 | |
| 304 | pthread_mutex_lock(&consumer_data.lock); |
| 305 | /* Steal stream identifier, for UST */ |
| 306 | consumer_steal_stream_key(stream->key); |
| 307 | rcu_read_lock(); |
| 308 | |
| 309 | lttng_ht_lookup(consumer_data.stream_ht, |
| 310 | (void *)((unsigned long) stream->key), &iter); |
| 311 | node = lttng_ht_iter_get_node_ulong(&iter); |
| 312 | if (node != NULL) { |
| 313 | rcu_read_unlock(); |
| 314 | /* Stream already exist. Ignore the insertion */ |
| 315 | goto end; |
| 316 | } |
| 317 | |
| 318 | lttng_ht_add_unique_ulong(consumer_data.stream_ht, &stream->node); |
| 319 | rcu_read_unlock(); |
| 320 | consumer_data.stream_count++; |
| 321 | consumer_data.need_update = 1; |
| 322 | |
| 323 | switch (consumer_data.type) { |
| 324 | case LTTNG_CONSUMER_KERNEL: |
| 325 | break; |
| 326 | case LTTNG_CONSUMER32_UST: |
| 327 | case LTTNG_CONSUMER64_UST: |
| 328 | /* Streams are in CPU number order (we rely on this) */ |
| 329 | stream->cpu = stream->chan->nr_streams++; |
| 330 | break; |
| 331 | default: |
| 332 | ERR("Unknown consumer_data type"); |
| 333 | assert(0); |
| 334 | goto end; |
| 335 | } |
| 336 | |
| 337 | end: |
| 338 | pthread_mutex_unlock(&consumer_data.lock); |
| 339 | |
| 340 | return ret; |
| 341 | } |
| 342 | |
| 343 | /* |
| 344 | * Update a stream according to what we just received. |
| 345 | */ |
| 346 | void consumer_change_stream_state(int stream_key, |
| 347 | enum lttng_consumer_stream_state state) |
| 348 | { |
| 349 | struct lttng_consumer_stream *stream; |
| 350 | |
| 351 | pthread_mutex_lock(&consumer_data.lock); |
| 352 | stream = consumer_find_stream(stream_key); |
| 353 | if (stream) { |
| 354 | stream->state = state; |
| 355 | } |
| 356 | consumer_data.need_update = 1; |
| 357 | pthread_mutex_unlock(&consumer_data.lock); |
| 358 | } |
| 359 | |
| 360 | static |
| 361 | void consumer_free_channel(struct rcu_head *head) |
| 362 | { |
| 363 | struct lttng_ht_node_ulong *node = |
| 364 | caa_container_of(head, struct lttng_ht_node_ulong, head); |
| 365 | struct lttng_consumer_channel *channel = |
| 366 | caa_container_of(node, struct lttng_consumer_channel, node); |
| 367 | |
| 368 | free(channel); |
| 369 | } |
| 370 | |
| 371 | /* |
| 372 | * Remove a channel from the global list protected by a mutex. This |
| 373 | * function is also responsible for freeing its data structures. |
| 374 | */ |
| 375 | void consumer_del_channel(struct lttng_consumer_channel *channel) |
| 376 | { |
| 377 | int ret; |
| 378 | struct lttng_ht_iter iter; |
| 379 | |
| 380 | pthread_mutex_lock(&consumer_data.lock); |
| 381 | |
| 382 | switch (consumer_data.type) { |
| 383 | case LTTNG_CONSUMER_KERNEL: |
| 384 | break; |
| 385 | case LTTNG_CONSUMER32_UST: |
| 386 | case LTTNG_CONSUMER64_UST: |
| 387 | lttng_ustconsumer_del_channel(channel); |
| 388 | break; |
| 389 | default: |
| 390 | ERR("Unknown consumer_data type"); |
| 391 | assert(0); |
| 392 | goto end; |
| 393 | } |
| 394 | |
| 395 | rcu_read_lock(); |
| 396 | iter.iter.node = &channel->node.node; |
| 397 | ret = lttng_ht_del(consumer_data.channel_ht, &iter); |
| 398 | assert(!ret); |
| 399 | rcu_read_unlock(); |
| 400 | |
| 401 | if (channel->mmap_base != NULL) { |
| 402 | ret = munmap(channel->mmap_base, channel->mmap_len); |
| 403 | if (ret != 0) { |
| 404 | perror("munmap"); |
| 405 | } |
| 406 | } |
| 407 | if (channel->wait_fd >= 0 && !channel->wait_fd_is_copy) { |
| 408 | ret = close(channel->wait_fd); |
| 409 | if (ret) { |
| 410 | PERROR("close"); |
| 411 | } |
| 412 | } |
| 413 | if (channel->shm_fd >= 0 && channel->wait_fd != channel->shm_fd) { |
| 414 | ret = close(channel->shm_fd); |
| 415 | if (ret) { |
| 416 | PERROR("close"); |
| 417 | } |
| 418 | } |
| 419 | |
| 420 | call_rcu(&channel->node.head, consumer_free_channel); |
| 421 | end: |
| 422 | pthread_mutex_unlock(&consumer_data.lock); |
| 423 | } |
| 424 | |
| 425 | struct lttng_consumer_channel *consumer_allocate_channel( |
| 426 | int channel_key, |
| 427 | int shm_fd, int wait_fd, |
| 428 | uint64_t mmap_len, |
| 429 | uint64_t max_sb_size) |
| 430 | { |
| 431 | struct lttng_consumer_channel *channel; |
| 432 | int ret; |
| 433 | |
| 434 | channel = zmalloc(sizeof(*channel)); |
| 435 | if (channel == NULL) { |
| 436 | perror("malloc struct lttng_consumer_channel"); |
| 437 | goto end; |
| 438 | } |
| 439 | channel->key = channel_key; |
| 440 | channel->shm_fd = shm_fd; |
| 441 | channel->wait_fd = wait_fd; |
| 442 | channel->mmap_len = mmap_len; |
| 443 | channel->max_sb_size = max_sb_size; |
| 444 | channel->refcount = 0; |
| 445 | channel->nr_streams = 0; |
| 446 | lttng_ht_node_init_ulong(&channel->node, channel->key); |
| 447 | |
| 448 | switch (consumer_data.type) { |
| 449 | case LTTNG_CONSUMER_KERNEL: |
| 450 | channel->mmap_base = NULL; |
| 451 | channel->mmap_len = 0; |
| 452 | break; |
| 453 | case LTTNG_CONSUMER32_UST: |
| 454 | case LTTNG_CONSUMER64_UST: |
| 455 | ret = lttng_ustconsumer_allocate_channel(channel); |
| 456 | if (ret) { |
| 457 | free(channel); |
| 458 | return NULL; |
| 459 | } |
| 460 | break; |
| 461 | default: |
| 462 | ERR("Unknown consumer_data type"); |
| 463 | assert(0); |
| 464 | goto end; |
| 465 | } |
| 466 | DBG("Allocated channel (key %d, shm_fd %d, wait_fd %d, mmap_len %llu, max_sb_size %llu)", |
| 467 | channel->key, |
| 468 | channel->shm_fd, |
| 469 | channel->wait_fd, |
| 470 | (unsigned long long) channel->mmap_len, |
| 471 | (unsigned long long) channel->max_sb_size); |
| 472 | end: |
| 473 | return channel; |
| 474 | } |
| 475 | |
| 476 | /* |
| 477 | * Add a channel to the global list protected by a mutex. |
| 478 | */ |
| 479 | int consumer_add_channel(struct lttng_consumer_channel *channel) |
| 480 | { |
| 481 | struct lttng_ht_node_ulong *node; |
| 482 | struct lttng_ht_iter iter; |
| 483 | |
| 484 | pthread_mutex_lock(&consumer_data.lock); |
| 485 | /* Steal channel identifier, for UST */ |
| 486 | consumer_steal_channel_key(channel->key); |
| 487 | rcu_read_lock(); |
| 488 | |
| 489 | lttng_ht_lookup(consumer_data.channel_ht, |
| 490 | (void *)((unsigned long) channel->key), &iter); |
| 491 | node = lttng_ht_iter_get_node_ulong(&iter); |
| 492 | if (node != NULL) { |
| 493 | /* Channel already exist. Ignore the insertion */ |
| 494 | goto end; |
| 495 | } |
| 496 | |
| 497 | lttng_ht_add_unique_ulong(consumer_data.channel_ht, &channel->node); |
| 498 | |
| 499 | end: |
| 500 | rcu_read_unlock(); |
| 501 | pthread_mutex_unlock(&consumer_data.lock); |
| 502 | |
| 503 | return 0; |
| 504 | } |
| 505 | |
| 506 | /* |
| 507 | * Allocate the pollfd structure and the local view of the out fds to avoid |
| 508 | * doing a lookup in the linked list and concurrency issues when writing is |
| 509 | * needed. Called with consumer_data.lock held. |
| 510 | * |
| 511 | * Returns the number of fds in the structures. |
| 512 | */ |
| 513 | int consumer_update_poll_array( |
| 514 | struct lttng_consumer_local_data *ctx, struct pollfd **pollfd, |
| 515 | struct lttng_consumer_stream **local_stream) |
| 516 | { |
| 517 | int i = 0; |
| 518 | struct lttng_ht_iter iter; |
| 519 | struct lttng_consumer_stream *stream; |
| 520 | |
| 521 | DBG("Updating poll fd array"); |
| 522 | rcu_read_lock(); |
| 523 | cds_lfht_for_each_entry(consumer_data.stream_ht->ht, &iter.iter, stream, |
| 524 | node.node) { |
| 525 | if (stream->state != LTTNG_CONSUMER_ACTIVE_STREAM) { |
| 526 | continue; |
| 527 | } |
| 528 | DBG("Active FD %d", stream->wait_fd); |
| 529 | (*pollfd)[i].fd = stream->wait_fd; |
| 530 | (*pollfd)[i].events = POLLIN | POLLPRI; |
| 531 | local_stream[i] = stream; |
| 532 | i++; |
| 533 | } |
| 534 | rcu_read_unlock(); |
| 535 | |
| 536 | /* |
| 537 | * Insert the consumer_poll_pipe at the end of the array and don't |
| 538 | * increment i so nb_fd is the number of real FD. |
| 539 | */ |
| 540 | (*pollfd)[i].fd = ctx->consumer_poll_pipe[0]; |
| 541 | (*pollfd)[i].events = POLLIN | POLLPRI; |
| 542 | return i; |
| 543 | } |
| 544 | |
| 545 | /* |
| 546 | * Poll on the should_quit pipe and the command socket return -1 on error and |
| 547 | * should exit, 0 if data is available on the command socket |
| 548 | */ |
| 549 | int lttng_consumer_poll_socket(struct pollfd *consumer_sockpoll) |
| 550 | { |
| 551 | int num_rdy; |
| 552 | |
| 553 | restart: |
| 554 | num_rdy = poll(consumer_sockpoll, 2, -1); |
| 555 | if (num_rdy == -1) { |
| 556 | /* |
| 557 | * Restart interrupted system call. |
| 558 | */ |
| 559 | if (errno == EINTR) { |
| 560 | goto restart; |
| 561 | } |
| 562 | perror("Poll error"); |
| 563 | goto exit; |
| 564 | } |
| 565 | if (consumer_sockpoll[0].revents & (POLLIN | POLLPRI)) { |
| 566 | DBG("consumer_should_quit wake up"); |
| 567 | goto exit; |
| 568 | } |
| 569 | return 0; |
| 570 | |
| 571 | exit: |
| 572 | return -1; |
| 573 | } |
| 574 | |
| 575 | /* |
| 576 | * Set the error socket. |
| 577 | */ |
| 578 | void lttng_consumer_set_error_sock( |
| 579 | struct lttng_consumer_local_data *ctx, int sock) |
| 580 | { |
| 581 | ctx->consumer_error_socket = sock; |
| 582 | } |
| 583 | |
| 584 | /* |
| 585 | * Set the command socket path. |
| 586 | */ |
| 587 | |
| 588 | void lttng_consumer_set_command_sock_path( |
| 589 | struct lttng_consumer_local_data *ctx, char *sock) |
| 590 | { |
| 591 | ctx->consumer_command_sock_path = sock; |
| 592 | } |
| 593 | |
| 594 | /* |
| 595 | * Send return code to the session daemon. |
| 596 | * If the socket is not defined, we return 0, it is not a fatal error |
| 597 | */ |
| 598 | int lttng_consumer_send_error( |
| 599 | struct lttng_consumer_local_data *ctx, int cmd) |
| 600 | { |
| 601 | if (ctx->consumer_error_socket > 0) { |
| 602 | return lttcomm_send_unix_sock(ctx->consumer_error_socket, &cmd, |
| 603 | sizeof(enum lttcomm_sessiond_command)); |
| 604 | } |
| 605 | |
| 606 | return 0; |
| 607 | } |
| 608 | |
| 609 | /* |
| 610 | * Close all the tracefiles and stream fds, should be called when all instances |
| 611 | * are destroyed. |
| 612 | */ |
| 613 | void lttng_consumer_cleanup(void) |
| 614 | { |
| 615 | struct lttng_ht_iter iter; |
| 616 | struct lttng_ht_node_ulong *node; |
| 617 | |
| 618 | rcu_read_lock(); |
| 619 | |
| 620 | /* |
| 621 | * close all outfd. Called when there are no more threads running (after |
| 622 | * joining on the threads), no need to protect list iteration with mutex. |
| 623 | */ |
| 624 | cds_lfht_for_each_entry(consumer_data.stream_ht->ht, &iter.iter, node, |
| 625 | node) { |
| 626 | struct lttng_consumer_stream *stream = |
| 627 | caa_container_of(node, struct lttng_consumer_stream, node); |
| 628 | consumer_del_stream(stream); |
| 629 | } |
| 630 | |
| 631 | cds_lfht_for_each_entry(consumer_data.channel_ht->ht, &iter.iter, node, |
| 632 | node) { |
| 633 | struct lttng_consumer_channel *channel = |
| 634 | caa_container_of(node, struct lttng_consumer_channel, node); |
| 635 | consumer_del_channel(channel); |
| 636 | } |
| 637 | |
| 638 | rcu_read_unlock(); |
| 639 | |
| 640 | lttng_ht_destroy(consumer_data.stream_ht); |
| 641 | lttng_ht_destroy(consumer_data.channel_ht); |
| 642 | } |
| 643 | |
| 644 | /* |
| 645 | * Called from signal handler. |
| 646 | */ |
| 647 | void lttng_consumer_should_exit(struct lttng_consumer_local_data *ctx) |
| 648 | { |
| 649 | int ret; |
| 650 | consumer_quit = 1; |
| 651 | ret = write(ctx->consumer_should_quit[1], "4", 1); |
| 652 | if (ret < 0) { |
| 653 | perror("write consumer quit"); |
| 654 | } |
| 655 | } |
| 656 | |
| 657 | void lttng_consumer_sync_trace_file( |
| 658 | struct lttng_consumer_stream *stream, off_t orig_offset) |
| 659 | { |
| 660 | int outfd = stream->out_fd; |
| 661 | |
| 662 | /* |
| 663 | * This does a blocking write-and-wait on any page that belongs to the |
| 664 | * subbuffer prior to the one we just wrote. |
| 665 | * Don't care about error values, as these are just hints and ways to |
| 666 | * limit the amount of page cache used. |
| 667 | */ |
| 668 | if (orig_offset < stream->chan->max_sb_size) { |
| 669 | return; |
| 670 | } |
| 671 | lttng_sync_file_range(outfd, orig_offset - stream->chan->max_sb_size, |
| 672 | stream->chan->max_sb_size, |
| 673 | SYNC_FILE_RANGE_WAIT_BEFORE |
| 674 | | SYNC_FILE_RANGE_WRITE |
| 675 | | SYNC_FILE_RANGE_WAIT_AFTER); |
| 676 | /* |
| 677 | * Give hints to the kernel about how we access the file: |
| 678 | * POSIX_FADV_DONTNEED : we won't re-access data in a near future after |
| 679 | * we write it. |
| 680 | * |
| 681 | * We need to call fadvise again after the file grows because the |
| 682 | * kernel does not seem to apply fadvise to non-existing parts of the |
| 683 | * file. |
| 684 | * |
| 685 | * Call fadvise _after_ having waited for the page writeback to |
| 686 | * complete because the dirty page writeback semantic is not well |
| 687 | * defined. So it can be expected to lead to lower throughput in |
| 688 | * streaming. |
| 689 | */ |
| 690 | posix_fadvise(outfd, orig_offset - stream->chan->max_sb_size, |
| 691 | stream->chan->max_sb_size, POSIX_FADV_DONTNEED); |
| 692 | } |
| 693 | |
| 694 | /* |
| 695 | * Initialise the necessary environnement : |
| 696 | * - create a new context |
| 697 | * - create the poll_pipe |
| 698 | * - create the should_quit pipe (for signal handler) |
| 699 | * - create the thread pipe (for splice) |
| 700 | * |
| 701 | * Takes a function pointer as argument, this function is called when data is |
| 702 | * available on a buffer. This function is responsible to do the |
| 703 | * kernctl_get_next_subbuf, read the data with mmap or splice depending on the |
| 704 | * buffer configuration and then kernctl_put_next_subbuf at the end. |
| 705 | * |
| 706 | * Returns a pointer to the new context or NULL on error. |
| 707 | */ |
| 708 | struct lttng_consumer_local_data *lttng_consumer_create( |
| 709 | enum lttng_consumer_type type, |
| 710 | ssize_t (*buffer_ready)(struct lttng_consumer_stream *stream, |
| 711 | struct lttng_consumer_local_data *ctx), |
| 712 | int (*recv_channel)(struct lttng_consumer_channel *channel), |
| 713 | int (*recv_stream)(struct lttng_consumer_stream *stream), |
| 714 | int (*update_stream)(int stream_key, uint32_t state)) |
| 715 | { |
| 716 | int ret, i; |
| 717 | struct lttng_consumer_local_data *ctx; |
| 718 | |
| 719 | assert(consumer_data.type == LTTNG_CONSUMER_UNKNOWN || |
| 720 | consumer_data.type == type); |
| 721 | consumer_data.type = type; |
| 722 | |
| 723 | ctx = zmalloc(sizeof(struct lttng_consumer_local_data)); |
| 724 | if (ctx == NULL) { |
| 725 | perror("allocating context"); |
| 726 | goto error; |
| 727 | } |
| 728 | |
| 729 | ctx->consumer_error_socket = -1; |
| 730 | /* assign the callbacks */ |
| 731 | ctx->on_buffer_ready = buffer_ready; |
| 732 | ctx->on_recv_channel = recv_channel; |
| 733 | ctx->on_recv_stream = recv_stream; |
| 734 | ctx->on_update_stream = update_stream; |
| 735 | |
| 736 | ret = pipe(ctx->consumer_poll_pipe); |
| 737 | if (ret < 0) { |
| 738 | perror("Error creating poll pipe"); |
| 739 | goto error_poll_pipe; |
| 740 | } |
| 741 | |
| 742 | /* set read end of the pipe to non-blocking */ |
| 743 | ret = fcntl(ctx->consumer_poll_pipe[0], F_SETFL, O_NONBLOCK); |
| 744 | if (ret < 0) { |
| 745 | perror("fcntl O_NONBLOCK"); |
| 746 | goto error_poll_fcntl; |
| 747 | } |
| 748 | |
| 749 | /* set write end of the pipe to non-blocking */ |
| 750 | ret = fcntl(ctx->consumer_poll_pipe[1], F_SETFL, O_NONBLOCK); |
| 751 | if (ret < 0) { |
| 752 | perror("fcntl O_NONBLOCK"); |
| 753 | goto error_poll_fcntl; |
| 754 | } |
| 755 | |
| 756 | ret = pipe(ctx->consumer_should_quit); |
| 757 | if (ret < 0) { |
| 758 | perror("Error creating recv pipe"); |
| 759 | goto error_quit_pipe; |
| 760 | } |
| 761 | |
| 762 | ret = pipe(ctx->consumer_thread_pipe); |
| 763 | if (ret < 0) { |
| 764 | perror("Error creating thread pipe"); |
| 765 | goto error_thread_pipe; |
| 766 | } |
| 767 | |
| 768 | return ctx; |
| 769 | |
| 770 | |
| 771 | error_thread_pipe: |
| 772 | for (i = 0; i < 2; i++) { |
| 773 | int err; |
| 774 | |
| 775 | err = close(ctx->consumer_should_quit[i]); |
| 776 | if (err) { |
| 777 | PERROR("close"); |
| 778 | } |
| 779 | } |
| 780 | error_poll_fcntl: |
| 781 | error_quit_pipe: |
| 782 | for (i = 0; i < 2; i++) { |
| 783 | int err; |
| 784 | |
| 785 | err = close(ctx->consumer_poll_pipe[i]); |
| 786 | if (err) { |
| 787 | PERROR("close"); |
| 788 | } |
| 789 | } |
| 790 | error_poll_pipe: |
| 791 | free(ctx); |
| 792 | error: |
| 793 | return NULL; |
| 794 | } |
| 795 | |
| 796 | /* |
| 797 | * Close all fds associated with the instance and free the context. |
| 798 | */ |
| 799 | void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx) |
| 800 | { |
| 801 | int ret; |
| 802 | |
| 803 | ret = close(ctx->consumer_error_socket); |
| 804 | if (ret) { |
| 805 | PERROR("close"); |
| 806 | } |
| 807 | ret = close(ctx->consumer_thread_pipe[0]); |
| 808 | if (ret) { |
| 809 | PERROR("close"); |
| 810 | } |
| 811 | ret = close(ctx->consumer_thread_pipe[1]); |
| 812 | if (ret) { |
| 813 | PERROR("close"); |
| 814 | } |
| 815 | ret = close(ctx->consumer_poll_pipe[0]); |
| 816 | if (ret) { |
| 817 | PERROR("close"); |
| 818 | } |
| 819 | ret = close(ctx->consumer_poll_pipe[1]); |
| 820 | if (ret) { |
| 821 | PERROR("close"); |
| 822 | } |
| 823 | ret = close(ctx->consumer_should_quit[0]); |
| 824 | if (ret) { |
| 825 | PERROR("close"); |
| 826 | } |
| 827 | ret = close(ctx->consumer_should_quit[1]); |
| 828 | if (ret) { |
| 829 | PERROR("close"); |
| 830 | } |
| 831 | unlink(ctx->consumer_command_sock_path); |
| 832 | free(ctx); |
| 833 | } |
| 834 | |
| 835 | /* |
| 836 | * Mmap the ring buffer, read it and write the data to the tracefile. |
| 837 | * |
| 838 | * Returns the number of bytes written |
| 839 | */ |
| 840 | ssize_t lttng_consumer_on_read_subbuffer_mmap( |
| 841 | struct lttng_consumer_local_data *ctx, |
| 842 | struct lttng_consumer_stream *stream, unsigned long len) |
| 843 | { |
| 844 | switch (consumer_data.type) { |
| 845 | case LTTNG_CONSUMER_KERNEL: |
| 846 | return lttng_kconsumer_on_read_subbuffer_mmap(ctx, stream, len); |
| 847 | case LTTNG_CONSUMER32_UST: |
| 848 | case LTTNG_CONSUMER64_UST: |
| 849 | return lttng_ustconsumer_on_read_subbuffer_mmap(ctx, stream, len); |
| 850 | default: |
| 851 | ERR("Unknown consumer_data type"); |
| 852 | assert(0); |
| 853 | } |
| 854 | |
| 855 | return 0; |
| 856 | } |
| 857 | |
| 858 | /* |
| 859 | * Splice the data from the ring buffer to the tracefile. |
| 860 | * |
| 861 | * Returns the number of bytes spliced. |
| 862 | */ |
| 863 | ssize_t lttng_consumer_on_read_subbuffer_splice( |
| 864 | struct lttng_consumer_local_data *ctx, |
| 865 | struct lttng_consumer_stream *stream, unsigned long len) |
| 866 | { |
| 867 | switch (consumer_data.type) { |
| 868 | case LTTNG_CONSUMER_KERNEL: |
| 869 | return lttng_kconsumer_on_read_subbuffer_splice(ctx, stream, len); |
| 870 | case LTTNG_CONSUMER32_UST: |
| 871 | case LTTNG_CONSUMER64_UST: |
| 872 | return -ENOSYS; |
| 873 | default: |
| 874 | ERR("Unknown consumer_data type"); |
| 875 | assert(0); |
| 876 | return -ENOSYS; |
| 877 | } |
| 878 | |
| 879 | } |
| 880 | |
| 881 | /* |
| 882 | * Take a snapshot for a specific fd |
| 883 | * |
| 884 | * Returns 0 on success, < 0 on error |
| 885 | */ |
| 886 | int lttng_consumer_take_snapshot(struct lttng_consumer_local_data *ctx, |
| 887 | struct lttng_consumer_stream *stream) |
| 888 | { |
| 889 | switch (consumer_data.type) { |
| 890 | case LTTNG_CONSUMER_KERNEL: |
| 891 | return lttng_kconsumer_take_snapshot(ctx, stream); |
| 892 | case LTTNG_CONSUMER32_UST: |
| 893 | case LTTNG_CONSUMER64_UST: |
| 894 | return lttng_ustconsumer_take_snapshot(ctx, stream); |
| 895 | default: |
| 896 | ERR("Unknown consumer_data type"); |
| 897 | assert(0); |
| 898 | return -ENOSYS; |
| 899 | } |
| 900 | |
| 901 | } |
| 902 | |
| 903 | /* |
| 904 | * Get the produced position |
| 905 | * |
| 906 | * Returns 0 on success, < 0 on error |
| 907 | */ |
| 908 | int lttng_consumer_get_produced_snapshot( |
| 909 | struct lttng_consumer_local_data *ctx, |
| 910 | struct lttng_consumer_stream *stream, |
| 911 | unsigned long *pos) |
| 912 | { |
| 913 | switch (consumer_data.type) { |
| 914 | case LTTNG_CONSUMER_KERNEL: |
| 915 | return lttng_kconsumer_get_produced_snapshot(ctx, stream, pos); |
| 916 | case LTTNG_CONSUMER32_UST: |
| 917 | case LTTNG_CONSUMER64_UST: |
| 918 | return lttng_ustconsumer_get_produced_snapshot(ctx, stream, pos); |
| 919 | default: |
| 920 | ERR("Unknown consumer_data type"); |
| 921 | assert(0); |
| 922 | return -ENOSYS; |
| 923 | } |
| 924 | } |
| 925 | |
| 926 | int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx, |
| 927 | int sock, struct pollfd *consumer_sockpoll) |
| 928 | { |
| 929 | switch (consumer_data.type) { |
| 930 | case LTTNG_CONSUMER_KERNEL: |
| 931 | return lttng_kconsumer_recv_cmd(ctx, sock, consumer_sockpoll); |
| 932 | case LTTNG_CONSUMER32_UST: |
| 933 | case LTTNG_CONSUMER64_UST: |
| 934 | return lttng_ustconsumer_recv_cmd(ctx, sock, consumer_sockpoll); |
| 935 | default: |
| 936 | ERR("Unknown consumer_data type"); |
| 937 | assert(0); |
| 938 | return -ENOSYS; |
| 939 | } |
| 940 | } |
| 941 | |
| 942 | /* |
| 943 | * This thread polls the fds in the set to consume the data and write |
| 944 | * it to tracefile if necessary. |
| 945 | */ |
| 946 | void *lttng_consumer_thread_poll_fds(void *data) |
| 947 | { |
| 948 | int num_rdy, num_hup, high_prio, ret, i; |
| 949 | struct pollfd *pollfd = NULL; |
| 950 | /* local view of the streams */ |
| 951 | struct lttng_consumer_stream **local_stream = NULL; |
| 952 | /* local view of consumer_data.fds_count */ |
| 953 | int nb_fd = 0; |
| 954 | struct lttng_consumer_local_data *ctx = data; |
| 955 | |
| 956 | rcu_register_thread(); |
| 957 | |
| 958 | local_stream = zmalloc(sizeof(struct lttng_consumer_stream)); |
| 959 | |
| 960 | while (1) { |
| 961 | high_prio = 0; |
| 962 | num_hup = 0; |
| 963 | |
| 964 | /* |
| 965 | * the fds set has been updated, we need to update our |
| 966 | * local array as well |
| 967 | */ |
| 968 | pthread_mutex_lock(&consumer_data.lock); |
| 969 | if (consumer_data.need_update) { |
| 970 | if (pollfd != NULL) { |
| 971 | free(pollfd); |
| 972 | pollfd = NULL; |
| 973 | } |
| 974 | if (local_stream != NULL) { |
| 975 | free(local_stream); |
| 976 | local_stream = NULL; |
| 977 | } |
| 978 | |
| 979 | /* allocate for all fds + 1 for the consumer_poll_pipe */ |
| 980 | pollfd = zmalloc((consumer_data.stream_count + 1) * sizeof(struct pollfd)); |
| 981 | if (pollfd == NULL) { |
| 982 | perror("pollfd malloc"); |
| 983 | pthread_mutex_unlock(&consumer_data.lock); |
| 984 | goto end; |
| 985 | } |
| 986 | |
| 987 | /* allocate for all fds + 1 for the consumer_poll_pipe */ |
| 988 | local_stream = zmalloc((consumer_data.stream_count + 1) * |
| 989 | sizeof(struct lttng_consumer_stream)); |
| 990 | if (local_stream == NULL) { |
| 991 | perror("local_stream malloc"); |
| 992 | pthread_mutex_unlock(&consumer_data.lock); |
| 993 | goto end; |
| 994 | } |
| 995 | ret = consumer_update_poll_array(ctx, &pollfd, local_stream); |
| 996 | if (ret < 0) { |
| 997 | ERR("Error in allocating pollfd or local_outfds"); |
| 998 | lttng_consumer_send_error(ctx, CONSUMERD_POLL_ERROR); |
| 999 | pthread_mutex_unlock(&consumer_data.lock); |
| 1000 | goto end; |
| 1001 | } |
| 1002 | nb_fd = ret; |
| 1003 | consumer_data.need_update = 0; |
| 1004 | } |
| 1005 | pthread_mutex_unlock(&consumer_data.lock); |
| 1006 | |
| 1007 | /* No FDs and consumer_quit, consumer_cleanup the thread */ |
| 1008 | if (nb_fd == 0 && consumer_quit == 1) { |
| 1009 | goto end; |
| 1010 | } |
| 1011 | /* poll on the array of fds */ |
| 1012 | restart: |
| 1013 | DBG("polling on %d fd", nb_fd + 1); |
| 1014 | num_rdy = poll(pollfd, nb_fd + 1, consumer_poll_timeout); |
| 1015 | DBG("poll num_rdy : %d", num_rdy); |
| 1016 | if (num_rdy == -1) { |
| 1017 | /* |
| 1018 | * Restart interrupted system call. |
| 1019 | */ |
| 1020 | if (errno == EINTR) { |
| 1021 | goto restart; |
| 1022 | } |
| 1023 | perror("Poll error"); |
| 1024 | lttng_consumer_send_error(ctx, CONSUMERD_POLL_ERROR); |
| 1025 | goto end; |
| 1026 | } else if (num_rdy == 0) { |
| 1027 | DBG("Polling thread timed out"); |
| 1028 | goto end; |
| 1029 | } |
| 1030 | |
| 1031 | /* |
| 1032 | * If the consumer_poll_pipe triggered poll go |
| 1033 | * directly to the beginning of the loop to update the |
| 1034 | * array. We want to prioritize array update over |
| 1035 | * low-priority reads. |
| 1036 | */ |
| 1037 | if (pollfd[nb_fd].revents & (POLLIN | POLLPRI)) { |
| 1038 | size_t pipe_readlen; |
| 1039 | char tmp; |
| 1040 | |
| 1041 | DBG("consumer_poll_pipe wake up"); |
| 1042 | /* Consume 1 byte of pipe data */ |
| 1043 | do { |
| 1044 | pipe_readlen = read(ctx->consumer_poll_pipe[0], &tmp, 1); |
| 1045 | } while (pipe_readlen == -1 && errno == EINTR); |
| 1046 | continue; |
| 1047 | } |
| 1048 | |
| 1049 | /* Take care of high priority channels first. */ |
| 1050 | for (i = 0; i < nb_fd; i++) { |
| 1051 | if (pollfd[i].revents & POLLPRI) { |
| 1052 | ssize_t len; |
| 1053 | |
| 1054 | DBG("Urgent read on fd %d", pollfd[i].fd); |
| 1055 | high_prio = 1; |
| 1056 | len = ctx->on_buffer_ready(local_stream[i], ctx); |
| 1057 | /* it's ok to have an unavailable sub-buffer */ |
| 1058 | if (len < 0 && len != -EAGAIN) { |
| 1059 | goto end; |
| 1060 | } else if (len > 0) { |
| 1061 | local_stream[i]->data_read = 1; |
| 1062 | } |
| 1063 | } |
| 1064 | } |
| 1065 | |
| 1066 | /* |
| 1067 | * If we read high prio channel in this loop, try again |
| 1068 | * for more high prio data. |
| 1069 | */ |
| 1070 | if (high_prio) { |
| 1071 | continue; |
| 1072 | } |
| 1073 | |
| 1074 | /* Take care of low priority channels. */ |
| 1075 | for (i = 0; i < nb_fd; i++) { |
| 1076 | if ((pollfd[i].revents & POLLIN) || |
| 1077 | local_stream[i]->hangup_flush_done) { |
| 1078 | ssize_t len; |
| 1079 | |
| 1080 | DBG("Normal read on fd %d", pollfd[i].fd); |
| 1081 | len = ctx->on_buffer_ready(local_stream[i], ctx); |
| 1082 | /* it's ok to have an unavailable sub-buffer */ |
| 1083 | if (len < 0 && len != -EAGAIN) { |
| 1084 | goto end; |
| 1085 | } else if (len > 0) { |
| 1086 | local_stream[i]->data_read = 1; |
| 1087 | } |
| 1088 | } |
| 1089 | } |
| 1090 | |
| 1091 | /* Handle hangup and errors */ |
| 1092 | for (i = 0; i < nb_fd; i++) { |
| 1093 | if (!local_stream[i]->hangup_flush_done |
| 1094 | && (pollfd[i].revents & (POLLHUP | POLLERR | POLLNVAL)) |
| 1095 | && (consumer_data.type == LTTNG_CONSUMER32_UST |
| 1096 | || consumer_data.type == LTTNG_CONSUMER64_UST)) { |
| 1097 | DBG("fd %d is hup|err|nval. Attempting flush and read.", |
| 1098 | pollfd[i].fd); |
| 1099 | lttng_ustconsumer_on_stream_hangup(local_stream[i]); |
| 1100 | /* Attempt read again, for the data we just flushed. */ |
| 1101 | local_stream[i]->data_read = 1; |
| 1102 | } |
| 1103 | /* |
| 1104 | * If the poll flag is HUP/ERR/NVAL and we have |
| 1105 | * read no data in this pass, we can remove the |
| 1106 | * stream from its hash table. |
| 1107 | */ |
| 1108 | if ((pollfd[i].revents & POLLHUP)) { |
| 1109 | DBG("Polling fd %d tells it has hung up.", pollfd[i].fd); |
| 1110 | if (!local_stream[i]->data_read) { |
| 1111 | consumer_del_stream(local_stream[i]); |
| 1112 | num_hup++; |
| 1113 | } |
| 1114 | } else if (pollfd[i].revents & POLLERR) { |
| 1115 | ERR("Error returned in polling fd %d.", pollfd[i].fd); |
| 1116 | if (!local_stream[i]->data_read) { |
| 1117 | consumer_del_stream(local_stream[i]); |
| 1118 | num_hup++; |
| 1119 | } |
| 1120 | } else if (pollfd[i].revents & POLLNVAL) { |
| 1121 | ERR("Polling fd %d tells fd is not open.", pollfd[i].fd); |
| 1122 | if (!local_stream[i]->data_read) { |
| 1123 | consumer_del_stream(local_stream[i]); |
| 1124 | num_hup++; |
| 1125 | } |
| 1126 | } |
| 1127 | local_stream[i]->data_read = 0; |
| 1128 | } |
| 1129 | } |
| 1130 | end: |
| 1131 | DBG("polling thread exiting"); |
| 1132 | if (pollfd != NULL) { |
| 1133 | free(pollfd); |
| 1134 | pollfd = NULL; |
| 1135 | } |
| 1136 | if (local_stream != NULL) { |
| 1137 | free(local_stream); |
| 1138 | local_stream = NULL; |
| 1139 | } |
| 1140 | rcu_unregister_thread(); |
| 1141 | return NULL; |
| 1142 | } |
| 1143 | |
| 1144 | /* |
| 1145 | * This thread listens on the consumerd socket and receives the file |
| 1146 | * descriptors from the session daemon. |
| 1147 | */ |
| 1148 | void *lttng_consumer_thread_receive_fds(void *data) |
| 1149 | { |
| 1150 | int sock, client_socket, ret; |
| 1151 | /* |
| 1152 | * structure to poll for incoming data on communication socket avoids |
| 1153 | * making blocking sockets. |
| 1154 | */ |
| 1155 | struct pollfd consumer_sockpoll[2]; |
| 1156 | struct lttng_consumer_local_data *ctx = data; |
| 1157 | |
| 1158 | rcu_register_thread(); |
| 1159 | |
| 1160 | DBG("Creating command socket %s", ctx->consumer_command_sock_path); |
| 1161 | unlink(ctx->consumer_command_sock_path); |
| 1162 | client_socket = lttcomm_create_unix_sock(ctx->consumer_command_sock_path); |
| 1163 | if (client_socket < 0) { |
| 1164 | ERR("Cannot create command socket"); |
| 1165 | goto end; |
| 1166 | } |
| 1167 | |
| 1168 | ret = lttcomm_listen_unix_sock(client_socket); |
| 1169 | if (ret < 0) { |
| 1170 | goto end; |
| 1171 | } |
| 1172 | |
| 1173 | DBG("Sending ready command to lttng-sessiond"); |
| 1174 | ret = lttng_consumer_send_error(ctx, CONSUMERD_COMMAND_SOCK_READY); |
| 1175 | /* return < 0 on error, but == 0 is not fatal */ |
| 1176 | if (ret < 0) { |
| 1177 | ERR("Error sending ready command to lttng-sessiond"); |
| 1178 | goto end; |
| 1179 | } |
| 1180 | |
| 1181 | ret = fcntl(client_socket, F_SETFL, O_NONBLOCK); |
| 1182 | if (ret < 0) { |
| 1183 | perror("fcntl O_NONBLOCK"); |
| 1184 | goto end; |
| 1185 | } |
| 1186 | |
| 1187 | /* prepare the FDs to poll : to client socket and the should_quit pipe */ |
| 1188 | consumer_sockpoll[0].fd = ctx->consumer_should_quit[0]; |
| 1189 | consumer_sockpoll[0].events = POLLIN | POLLPRI; |
| 1190 | consumer_sockpoll[1].fd = client_socket; |
| 1191 | consumer_sockpoll[1].events = POLLIN | POLLPRI; |
| 1192 | |
| 1193 | if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) { |
| 1194 | goto end; |
| 1195 | } |
| 1196 | DBG("Connection on client_socket"); |
| 1197 | |
| 1198 | /* Blocking call, waiting for transmission */ |
| 1199 | sock = lttcomm_accept_unix_sock(client_socket); |
| 1200 | if (sock <= 0) { |
| 1201 | WARN("On accept"); |
| 1202 | goto end; |
| 1203 | } |
| 1204 | ret = fcntl(sock, F_SETFL, O_NONBLOCK); |
| 1205 | if (ret < 0) { |
| 1206 | perror("fcntl O_NONBLOCK"); |
| 1207 | goto end; |
| 1208 | } |
| 1209 | |
| 1210 | /* update the polling structure to poll on the established socket */ |
| 1211 | consumer_sockpoll[1].fd = sock; |
| 1212 | consumer_sockpoll[1].events = POLLIN | POLLPRI; |
| 1213 | |
| 1214 | while (1) { |
| 1215 | if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) { |
| 1216 | goto end; |
| 1217 | } |
| 1218 | DBG("Incoming command on sock"); |
| 1219 | ret = lttng_consumer_recv_cmd(ctx, sock, consumer_sockpoll); |
| 1220 | if (ret == -ENOENT) { |
| 1221 | DBG("Received STOP command"); |
| 1222 | goto end; |
| 1223 | } |
| 1224 | if (ret < 0) { |
| 1225 | ERR("Communication interrupted on command socket"); |
| 1226 | goto end; |
| 1227 | } |
| 1228 | if (consumer_quit) { |
| 1229 | DBG("consumer_thread_receive_fds received quit from signal"); |
| 1230 | goto end; |
| 1231 | } |
| 1232 | DBG("received fds on sock"); |
| 1233 | } |
| 1234 | end: |
| 1235 | DBG("consumer_thread_receive_fds exiting"); |
| 1236 | |
| 1237 | /* |
| 1238 | * when all fds have hung up, the polling thread |
| 1239 | * can exit cleanly |
| 1240 | */ |
| 1241 | consumer_quit = 1; |
| 1242 | |
| 1243 | /* |
| 1244 | * 2s of grace period, if no polling events occur during |
| 1245 | * this period, the polling thread will exit even if there |
| 1246 | * are still open FDs (should not happen, but safety mechanism). |
| 1247 | */ |
| 1248 | consumer_poll_timeout = LTTNG_CONSUMER_POLL_TIMEOUT; |
| 1249 | |
| 1250 | /* |
| 1251 | * Wake-up the other end by writing a null byte in the pipe |
| 1252 | * (non-blocking). Important note: Because writing into the |
| 1253 | * pipe is non-blocking (and therefore we allow dropping wakeup |
| 1254 | * data, as long as there is wakeup data present in the pipe |
| 1255 | * buffer to wake up the other end), the other end should |
| 1256 | * perform the following sequence for waiting: |
| 1257 | * 1) empty the pipe (reads). |
| 1258 | * 2) perform update operation. |
| 1259 | * 3) wait on the pipe (poll). |
| 1260 | */ |
| 1261 | do { |
| 1262 | ret = write(ctx->consumer_poll_pipe[1], "", 1); |
| 1263 | } while (ret == -1UL && errno == EINTR); |
| 1264 | rcu_unregister_thread(); |
| 1265 | return NULL; |
| 1266 | } |
| 1267 | |
| 1268 | ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream, |
| 1269 | struct lttng_consumer_local_data *ctx) |
| 1270 | { |
| 1271 | switch (consumer_data.type) { |
| 1272 | case LTTNG_CONSUMER_KERNEL: |
| 1273 | return lttng_kconsumer_read_subbuffer(stream, ctx); |
| 1274 | case LTTNG_CONSUMER32_UST: |
| 1275 | case LTTNG_CONSUMER64_UST: |
| 1276 | return lttng_ustconsumer_read_subbuffer(stream, ctx); |
| 1277 | default: |
| 1278 | ERR("Unknown consumer_data type"); |
| 1279 | assert(0); |
| 1280 | return -ENOSYS; |
| 1281 | } |
| 1282 | } |
| 1283 | |
| 1284 | int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream) |
| 1285 | { |
| 1286 | switch (consumer_data.type) { |
| 1287 | case LTTNG_CONSUMER_KERNEL: |
| 1288 | return lttng_kconsumer_on_recv_stream(stream); |
| 1289 | case LTTNG_CONSUMER32_UST: |
| 1290 | case LTTNG_CONSUMER64_UST: |
| 1291 | return lttng_ustconsumer_on_recv_stream(stream); |
| 1292 | default: |
| 1293 | ERR("Unknown consumer_data type"); |
| 1294 | assert(0); |
| 1295 | return -ENOSYS; |
| 1296 | } |
| 1297 | } |
| 1298 | |
| 1299 | /* |
| 1300 | * Allocate and set consumer data hash tables. |
| 1301 | */ |
| 1302 | void lttng_consumer_init(void) |
| 1303 | { |
| 1304 | consumer_data.stream_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG); |
| 1305 | consumer_data.channel_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG); |
| 1306 | } |
| 1307 | |