| 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 | enum lttng_error_code ret_code = LTTNG_OK; |
| 105 | struct lttcomm_consumer_msg msg; |
| 106 | |
| 107 | ret = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg)); |
| 108 | if (ret != sizeof(msg)) { |
| 109 | DBG("Consumer received unexpected message size %zd (expects %zu)", |
| 110 | ret, sizeof(msg)); |
| 111 | lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_FD); |
| 112 | return ret; |
| 113 | } |
| 114 | if (msg.cmd_type == LTTNG_CONSUMER_STOP) { |
| 115 | /* |
| 116 | * Notify the session daemon that the command is completed. |
| 117 | * |
| 118 | * On transport layer error, the function call will print an error |
| 119 | * message so handling the returned code is a bit useless since we |
| 120 | * return an error code anyway. |
| 121 | */ |
| 122 | (void) consumer_send_status_msg(sock, ret_code); |
| 123 | return -ENOENT; |
| 124 | } |
| 125 | |
| 126 | /* relayd needs RCU read-side lock */ |
| 127 | rcu_read_lock(); |
| 128 | |
| 129 | switch (msg.cmd_type) { |
| 130 | case LTTNG_CONSUMER_ADD_RELAYD_SOCKET: |
| 131 | { |
| 132 | /* Session daemon status message are handled in the following call. */ |
| 133 | ret = consumer_add_relayd_socket(msg.u.relayd_sock.net_index, |
| 134 | msg.u.relayd_sock.type, ctx, sock, consumer_sockpoll, |
| 135 | &msg.u.relayd_sock.sock, msg.u.relayd_sock.session_id); |
| 136 | goto end_nosignal; |
| 137 | } |
| 138 | case LTTNG_CONSUMER_ADD_CHANNEL: |
| 139 | { |
| 140 | struct lttng_consumer_channel *new_channel; |
| 141 | int fds[1]; |
| 142 | size_t nb_fd = 1; |
| 143 | |
| 144 | DBG("UST Consumer adding channel"); |
| 145 | |
| 146 | /* First send a status message before receiving the fds. */ |
| 147 | ret = consumer_send_status_msg(sock, ret_code); |
| 148 | if (ret < 0) { |
| 149 | /* Somehow, the session daemon is not responding anymore. */ |
| 150 | goto end_nosignal; |
| 151 | } |
| 152 | |
| 153 | /* block */ |
| 154 | if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) { |
| 155 | rcu_read_unlock(); |
| 156 | return -EINTR; |
| 157 | } |
| 158 | ret = lttcomm_recv_fds_unix_sock(sock, fds, nb_fd); |
| 159 | if (ret != sizeof(fds)) { |
| 160 | lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_FD); |
| 161 | rcu_read_unlock(); |
| 162 | return ret; |
| 163 | } |
| 164 | |
| 165 | /* |
| 166 | * Send status code to session daemon only if the recv works. If the |
| 167 | * above recv() failed, the session daemon is notified through the |
| 168 | * error socket and the teardown is eventually done. |
| 169 | */ |
| 170 | ret = consumer_send_status_msg(sock, ret_code); |
| 171 | if (ret < 0) { |
| 172 | /* Somehow, the session daemon is not responding anymore. */ |
| 173 | goto end_nosignal; |
| 174 | } |
| 175 | |
| 176 | DBG("consumer_add_channel %d", msg.u.channel.channel_key); |
| 177 | |
| 178 | new_channel = consumer_allocate_channel(msg.u.channel.channel_key, |
| 179 | fds[0], -1, |
| 180 | msg.u.channel.mmap_len, |
| 181 | msg.u.channel.max_sb_size, |
| 182 | msg.u.channel.nb_init_streams); |
| 183 | if (new_channel == NULL) { |
| 184 | lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR); |
| 185 | goto end_nosignal; |
| 186 | } |
| 187 | if (ctx->on_recv_channel != NULL) { |
| 188 | ret = ctx->on_recv_channel(new_channel); |
| 189 | if (ret == 0) { |
| 190 | consumer_add_channel(new_channel); |
| 191 | } else if (ret < 0) { |
| 192 | goto end_nosignal; |
| 193 | } |
| 194 | } else { |
| 195 | consumer_add_channel(new_channel); |
| 196 | } |
| 197 | goto end_nosignal; |
| 198 | } |
| 199 | case LTTNG_CONSUMER_ADD_STREAM: |
| 200 | { |
| 201 | struct lttng_consumer_stream *new_stream; |
| 202 | int fds[2], stream_pipe; |
| 203 | size_t nb_fd = 2; |
| 204 | struct consumer_relayd_sock_pair *relayd = NULL; |
| 205 | int alloc_ret = 0; |
| 206 | |
| 207 | DBG("UST Consumer adding stream"); |
| 208 | |
| 209 | /* First send a status message before receiving the fds. */ |
| 210 | ret = consumer_send_status_msg(sock, ret_code); |
| 211 | if (ret < 0) { |
| 212 | /* Somehow, the session daemon is not responding anymore. */ |
| 213 | goto end_nosignal; |
| 214 | } |
| 215 | |
| 216 | /* block */ |
| 217 | if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) { |
| 218 | rcu_read_unlock(); |
| 219 | return -EINTR; |
| 220 | } |
| 221 | ret = lttcomm_recv_fds_unix_sock(sock, fds, nb_fd); |
| 222 | if (ret != sizeof(fds)) { |
| 223 | lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_FD); |
| 224 | rcu_read_unlock(); |
| 225 | return ret; |
| 226 | } |
| 227 | |
| 228 | /* |
| 229 | * Send status code to session daemon only if the recv works. If the |
| 230 | * above recv() failed, the session daemon is notified through the |
| 231 | * error socket and the teardown is eventually done. |
| 232 | */ |
| 233 | ret = consumer_send_status_msg(sock, ret_code); |
| 234 | if (ret < 0) { |
| 235 | /* Somehow, the session daemon is not responding anymore. */ |
| 236 | goto end_nosignal; |
| 237 | } |
| 238 | |
| 239 | DBG("Consumer command ADD_STREAM chan %d stream %d", |
| 240 | msg.u.stream.channel_key, msg.u.stream.stream_key); |
| 241 | |
| 242 | assert(msg.u.stream.output == LTTNG_EVENT_MMAP); |
| 243 | new_stream = consumer_allocate_stream(msg.u.stream.channel_key, |
| 244 | msg.u.stream.stream_key, |
| 245 | fds[0], fds[1], |
| 246 | msg.u.stream.state, |
| 247 | msg.u.stream.mmap_len, |
| 248 | msg.u.stream.output, |
| 249 | msg.u.stream.path_name, |
| 250 | msg.u.stream.uid, |
| 251 | msg.u.stream.gid, |
| 252 | msg.u.stream.net_index, |
| 253 | msg.u.stream.metadata_flag, |
| 254 | msg.u.stream.session_id, |
| 255 | &alloc_ret); |
| 256 | if (new_stream == NULL) { |
| 257 | switch (alloc_ret) { |
| 258 | case -ENOMEM: |
| 259 | case -EINVAL: |
| 260 | default: |
| 261 | lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR); |
| 262 | break; |
| 263 | case -ENOENT: |
| 264 | /* |
| 265 | * We could not find the channel. Can happen if cpu hotplug |
| 266 | * happens while tearing down. |
| 267 | */ |
| 268 | DBG3("Could not find channel"); |
| 269 | break; |
| 270 | } |
| 271 | goto end_nosignal; |
| 272 | } |
| 273 | |
| 274 | /* The stream is not metadata. Get relayd reference if exists. */ |
| 275 | relayd = consumer_find_relayd(msg.u.stream.net_index); |
| 276 | if (relayd != NULL) { |
| 277 | pthread_mutex_lock(&relayd->ctrl_sock_mutex); |
| 278 | /* Add stream on the relayd */ |
| 279 | ret = relayd_add_stream(&relayd->control_sock, |
| 280 | msg.u.stream.name, msg.u.stream.path_name, |
| 281 | &new_stream->relayd_stream_id); |
| 282 | pthread_mutex_unlock(&relayd->ctrl_sock_mutex); |
| 283 | if (ret < 0) { |
| 284 | consumer_del_stream(new_stream, NULL); |
| 285 | goto end_nosignal; |
| 286 | } |
| 287 | } else if (msg.u.stream.net_index != -1) { |
| 288 | ERR("Network sequence index %d unknown. Not adding stream.", |
| 289 | msg.u.stream.net_index); |
| 290 | consumer_del_stream(new_stream, NULL); |
| 291 | goto end_nosignal; |
| 292 | } |
| 293 | |
| 294 | /* Do actions once stream has been received. */ |
| 295 | if (ctx->on_recv_stream) { |
| 296 | ret = ctx->on_recv_stream(new_stream); |
| 297 | if (ret < 0) { |
| 298 | consumer_del_stream(new_stream, NULL); |
| 299 | goto end_nosignal; |
| 300 | } |
| 301 | } |
| 302 | |
| 303 | /* Get the right pipe where the stream will be sent. */ |
| 304 | if (new_stream->metadata_flag) { |
| 305 | stream_pipe = ctx->consumer_metadata_pipe[1]; |
| 306 | } else { |
| 307 | stream_pipe = ctx->consumer_data_pipe[1]; |
| 308 | } |
| 309 | |
| 310 | do { |
| 311 | ret = write(stream_pipe, &new_stream, sizeof(new_stream)); |
| 312 | } while (ret < 0 && errno == EINTR); |
| 313 | if (ret < 0) { |
| 314 | PERROR("Consumer write %s stream to pipe %d", |
| 315 | new_stream->metadata_flag ? "metadata" : "data", |
| 316 | stream_pipe); |
| 317 | consumer_del_stream(new_stream, NULL); |
| 318 | goto end_nosignal; |
| 319 | } |
| 320 | |
| 321 | DBG("UST consumer ADD_STREAM %s (%d,%d) with relayd id %" PRIu64, |
| 322 | msg.u.stream.path_name, fds[0], fds[1], |
| 323 | new_stream->relayd_stream_id); |
| 324 | break; |
| 325 | } |
| 326 | case LTTNG_CONSUMER_DESTROY_RELAYD: |
| 327 | { |
| 328 | uint64_t index = msg.u.destroy_relayd.net_seq_idx; |
| 329 | struct consumer_relayd_sock_pair *relayd; |
| 330 | |
| 331 | DBG("UST consumer destroying relayd %" PRIu64, index); |
| 332 | |
| 333 | /* Get relayd reference if exists. */ |
| 334 | relayd = consumer_find_relayd(index); |
| 335 | if (relayd == NULL) { |
| 336 | ERR("Unable to find relayd %" PRIu64, index); |
| 337 | ret_code = LTTNG_ERR_NO_CONSUMER; |
| 338 | } |
| 339 | |
| 340 | /* |
| 341 | * Each relayd socket pair has a refcount of stream attached to it |
| 342 | * which tells if the relayd is still active or not depending on the |
| 343 | * refcount value. |
| 344 | * |
| 345 | * This will set the destroy flag of the relayd object and destroy it |
| 346 | * if the refcount reaches zero when called. |
| 347 | * |
| 348 | * The destroy can happen either here or when a stream fd hangs up. |
| 349 | */ |
| 350 | if (relayd) { |
| 351 | consumer_flag_relayd_for_destroy(relayd); |
| 352 | } |
| 353 | |
| 354 | ret = consumer_send_status_msg(sock, ret_code); |
| 355 | if (ret < 0) { |
| 356 | /* Somehow, the session daemon is not responding anymore. */ |
| 357 | goto end_nosignal; |
| 358 | } |
| 359 | |
| 360 | goto end_nosignal; |
| 361 | } |
| 362 | case LTTNG_CONSUMER_UPDATE_STREAM: |
| 363 | { |
| 364 | rcu_read_unlock(); |
| 365 | return -ENOSYS; |
| 366 | } |
| 367 | case LTTNG_CONSUMER_DATA_PENDING: |
| 368 | { |
| 369 | int32_t ret; |
| 370 | uint64_t id = msg.u.data_pending.session_id; |
| 371 | |
| 372 | DBG("UST consumer data pending command for id %" PRIu64, id); |
| 373 | |
| 374 | ret = consumer_data_pending(id); |
| 375 | |
| 376 | /* Send back returned value to session daemon */ |
| 377 | ret = lttcomm_send_unix_sock(sock, &ret, sizeof(ret)); |
| 378 | if (ret < 0) { |
| 379 | PERROR("send data pending ret code"); |
| 380 | } |
| 381 | |
| 382 | /* |
| 383 | * No need to send back a status message since the data pending |
| 384 | * returned value is the response. |
| 385 | */ |
| 386 | break; |
| 387 | } |
| 388 | default: |
| 389 | break; |
| 390 | } |
| 391 | |
| 392 | end_nosignal: |
| 393 | rcu_read_unlock(); |
| 394 | |
| 395 | /* |
| 396 | * Return 1 to indicate success since the 0 value can be a socket |
| 397 | * shutdown during the recv() or send() call. |
| 398 | */ |
| 399 | return 1; |
| 400 | } |
| 401 | |
| 402 | int lttng_ustconsumer_allocate_channel(struct lttng_consumer_channel *chan) |
| 403 | { |
| 404 | struct lttng_ust_object_data obj; |
| 405 | |
| 406 | obj.handle = -1; |
| 407 | obj.shm_fd = chan->shm_fd; |
| 408 | obj.wait_fd = chan->wait_fd; |
| 409 | obj.memory_map_size = chan->mmap_len; |
| 410 | chan->handle = ustctl_map_channel(&obj); |
| 411 | if (!chan->handle) { |
| 412 | return -ENOMEM; |
| 413 | } |
| 414 | chan->wait_fd_is_copy = 1; |
| 415 | chan->shm_fd = -1; |
| 416 | |
| 417 | return 0; |
| 418 | } |
| 419 | |
| 420 | void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream *stream) |
| 421 | { |
| 422 | ustctl_flush_buffer(stream->chan->handle, stream->buf, 0); |
| 423 | stream->hangup_flush_done = 1; |
| 424 | } |
| 425 | |
| 426 | void lttng_ustconsumer_del_channel(struct lttng_consumer_channel *chan) |
| 427 | { |
| 428 | ustctl_unmap_channel(chan->handle); |
| 429 | } |
| 430 | |
| 431 | int lttng_ustconsumer_add_stream(struct lttng_consumer_stream *stream) |
| 432 | { |
| 433 | struct lttng_ust_object_data obj; |
| 434 | int ret; |
| 435 | |
| 436 | obj.handle = -1; |
| 437 | obj.shm_fd = stream->shm_fd; |
| 438 | obj.wait_fd = stream->wait_fd; |
| 439 | obj.memory_map_size = stream->mmap_len; |
| 440 | ret = ustctl_add_stream(stream->chan->handle, &obj); |
| 441 | if (ret) { |
| 442 | ERR("UST ctl add_stream failed with ret %d", ret); |
| 443 | goto error; |
| 444 | } |
| 445 | |
| 446 | stream->buf = ustctl_open_stream_read(stream->chan->handle, stream->cpu); |
| 447 | if (!stream->buf) { |
| 448 | ERR("UST ctl open_stream_read failed"); |
| 449 | ret = -EBUSY; |
| 450 | goto error; |
| 451 | } |
| 452 | |
| 453 | /* ustctl_open_stream_read has closed the shm fd. */ |
| 454 | stream->wait_fd_is_copy = 1; |
| 455 | stream->shm_fd = -1; |
| 456 | |
| 457 | stream->mmap_base = ustctl_get_mmap_base(stream->chan->handle, stream->buf); |
| 458 | if (!stream->mmap_base) { |
| 459 | ERR("UST ctl get_mmap_base failed"); |
| 460 | ret = -EINVAL; |
| 461 | goto mmap_error; |
| 462 | } |
| 463 | |
| 464 | return 0; |
| 465 | |
| 466 | mmap_error: |
| 467 | ustctl_close_stream_read(stream->chan->handle, stream->buf); |
| 468 | error: |
| 469 | return ret; |
| 470 | } |
| 471 | |
| 472 | void lttng_ustconsumer_del_stream(struct lttng_consumer_stream *stream) |
| 473 | { |
| 474 | ustctl_close_stream_read(stream->chan->handle, stream->buf); |
| 475 | } |
| 476 | |
| 477 | |
| 478 | int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream *stream, |
| 479 | struct lttng_consumer_local_data *ctx) |
| 480 | { |
| 481 | unsigned long len, subbuf_size, padding; |
| 482 | int err; |
| 483 | long ret = 0; |
| 484 | struct lttng_ust_shm_handle *handle; |
| 485 | struct lttng_ust_lib_ring_buffer *buf; |
| 486 | char dummy; |
| 487 | |
| 488 | DBG("In read_subbuffer (wait_fd: %d, stream key: %d)", |
| 489 | stream->wait_fd, stream->key); |
| 490 | |
| 491 | /* We can consume the 1 byte written into the wait_fd by UST */ |
| 492 | if (!stream->hangup_flush_done) { |
| 493 | ssize_t readlen; |
| 494 | |
| 495 | do { |
| 496 | readlen = read(stream->wait_fd, &dummy, 1); |
| 497 | } while (readlen == -1 && errno == EINTR); |
| 498 | if (readlen == -1) { |
| 499 | ret = readlen; |
| 500 | goto end; |
| 501 | } |
| 502 | } |
| 503 | |
| 504 | buf = stream->buf; |
| 505 | handle = stream->chan->handle; |
| 506 | /* Get the next subbuffer */ |
| 507 | err = ustctl_get_next_subbuf(handle, buf); |
| 508 | if (err != 0) { |
| 509 | ret = err; /* ustctl_get_next_subbuf returns negative, caller expect positive. */ |
| 510 | /* |
| 511 | * This is a debug message even for single-threaded consumer, |
| 512 | * because poll() have more relaxed criterions than get subbuf, |
| 513 | * so get_subbuf may fail for short race windows where poll() |
| 514 | * would issue wakeups. |
| 515 | */ |
| 516 | DBG("Reserving sub buffer failed (everything is normal, " |
| 517 | "it is due to concurrency)"); |
| 518 | goto end; |
| 519 | } |
| 520 | assert(stream->output == LTTNG_EVENT_MMAP); |
| 521 | /* Get the full padded subbuffer size */ |
| 522 | err = ustctl_get_padded_subbuf_size(handle, buf, &len); |
| 523 | assert(err == 0); |
| 524 | |
| 525 | /* Get subbuffer data size (without padding) */ |
| 526 | err = ustctl_get_subbuf_size(handle, buf, &subbuf_size); |
| 527 | assert(err == 0); |
| 528 | |
| 529 | /* Make sure we don't get a subbuffer size bigger than the padded */ |
| 530 | assert(len >= subbuf_size); |
| 531 | |
| 532 | padding = len - subbuf_size; |
| 533 | /* write the subbuffer to the tracefile */ |
| 534 | ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, subbuf_size, padding); |
| 535 | /* |
| 536 | * The mmap operation should write subbuf_size amount of data when network |
| 537 | * streaming or the full padding (len) size when we are _not_ streaming. |
| 538 | */ |
| 539 | if ((ret != subbuf_size && stream->net_seq_idx != -1) || |
| 540 | (ret != len && stream->net_seq_idx == -1)) { |
| 541 | /* |
| 542 | * Display the error but continue processing to try to release the |
| 543 | * subbuffer |
| 544 | */ |
| 545 | ERR("Error writing to tracefile " |
| 546 | "(ret: %zd != len: %lu != subbuf_size: %lu)", |
| 547 | ret, len, subbuf_size); |
| 548 | } |
| 549 | err = ustctl_put_next_subbuf(handle, buf); |
| 550 | assert(err == 0); |
| 551 | end: |
| 552 | return ret; |
| 553 | } |
| 554 | |
| 555 | int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream *stream) |
| 556 | { |
| 557 | int ret; |
| 558 | |
| 559 | /* Opening the tracefile in write mode */ |
| 560 | if (stream->path_name != NULL && stream->net_seq_idx == -1) { |
| 561 | ret = run_as_open(stream->path_name, |
| 562 | O_WRONLY|O_CREAT|O_TRUNC, |
| 563 | S_IRWXU|S_IRWXG|S_IRWXO, |
| 564 | stream->uid, stream->gid); |
| 565 | if (ret < 0) { |
| 566 | ERR("Opening %s", stream->path_name); |
| 567 | PERROR("open"); |
| 568 | goto error; |
| 569 | } |
| 570 | stream->out_fd = ret; |
| 571 | } |
| 572 | |
| 573 | ret = lttng_ustconsumer_add_stream(stream); |
| 574 | if (ret) { |
| 575 | consumer_del_stream(stream, NULL); |
| 576 | ret = -1; |
| 577 | goto error; |
| 578 | } |
| 579 | |
| 580 | /* we return 0 to let the library handle the FD internally */ |
| 581 | return 0; |
| 582 | |
| 583 | error: |
| 584 | return ret; |
| 585 | } |
| 586 | |
| 587 | /* |
| 588 | * Check if data is still being extracted from the buffers for a specific |
| 589 | * stream. Consumer data lock MUST be acquired before calling this function |
| 590 | * and the stream lock. |
| 591 | * |
| 592 | * Return 1 if the traced data are still getting read else 0 meaning that the |
| 593 | * data is available for trace viewer reading. |
| 594 | */ |
| 595 | int lttng_ustconsumer_data_pending(struct lttng_consumer_stream *stream) |
| 596 | { |
| 597 | int ret; |
| 598 | |
| 599 | assert(stream); |
| 600 | |
| 601 | DBG("UST consumer checking data pending"); |
| 602 | |
| 603 | ret = ustctl_get_next_subbuf(stream->chan->handle, stream->buf); |
| 604 | if (ret == 0) { |
| 605 | /* There is still data so let's put back this subbuffer. */ |
| 606 | ret = ustctl_put_subbuf(stream->chan->handle, stream->buf); |
| 607 | assert(ret == 0); |
| 608 | ret = 1; /* Data is pending */ |
| 609 | goto end; |
| 610 | } |
| 611 | |
| 612 | /* Data is NOT pending so ready to be read. */ |
| 613 | ret = 0; |
| 614 | |
| 615 | end: |
| 616 | return ret; |
| 617 | } |