src/common/consumer.h

   1 /*
   2  * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
   3  *                      Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   4  *               2012 - David Goulet <dgoulet@efficios.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License, version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  13  * more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18  */
  19
  20 #ifndef LIB_CONSUMER_H
  21 #define LIB_CONSUMER_H
  22
  23 #include <limits.h>
  24 #include <poll.h>
  25 #include <unistd.h>
  26 #include <urcu/list.h>
  27
  28 #include <lttng/lttng.h>
  29
  30 #include <common/hashtable/hashtable.h>
  31 #include <common/compat/fcntl.h>
  32 #include <common/compat/uuid.h>
  33 #include <common/sessiond-comm/sessiond-comm.h>
  34 #include <common/pipe.h>
  35
  36 /* Commands for consumer */
  37 enum lttng_consumer_command {
  38         LTTNG_CONSUMER_ADD_CHANNEL,
  39         LTTNG_CONSUMER_ADD_STREAM,
  40         /* pause, delete, active depending on fd state */
  41         LTTNG_CONSUMER_UPDATE_STREAM,
  42         /* inform the consumer to quit when all fd has hang up */
  43         LTTNG_CONSUMER_STOP,
  44         LTTNG_CONSUMER_ADD_RELAYD_SOCKET,
  45         /* Inform the consumer to kill a specific relayd connection */
  46         LTTNG_CONSUMER_DESTROY_RELAYD,
  47         /* Return to the sessiond if there is data pending for a session */
  48         LTTNG_CONSUMER_DATA_PENDING,
  49         /* Consumer creates a channel and returns it to sessiond. */
  50         LTTNG_CONSUMER_ASK_CHANNEL_CREATION,
  51         LTTNG_CONSUMER_GET_CHANNEL,
  52         LTTNG_CONSUMER_DESTROY_CHANNEL,
  53         LTTNG_CONSUMER_PUSH_METADATA,
  54         LTTNG_CONSUMER_CLOSE_METADATA,
  55         LTTNG_CONSUMER_SETUP_METADATA,
  56         LTTNG_CONSUMER_FLUSH_CHANNEL,
  57         LTTNG_CONSUMER_SNAPSHOT_CHANNEL,
  58         LTTNG_CONSUMER_SNAPSHOT_METADATA,
  59 };
  60
  61 /* State of each fd in consumer */
  62 enum lttng_consumer_stream_state {
  63         LTTNG_CONSUMER_ACTIVE_STREAM,
  64         LTTNG_CONSUMER_PAUSE_STREAM,
  65         LTTNG_CONSUMER_DELETE_STREAM,
  66 };
  67
  68 enum lttng_consumer_type {
  69         LTTNG_CONSUMER_UNKNOWN = 0,
  70         LTTNG_CONSUMER_KERNEL,
  71         LTTNG_CONSUMER64_UST,
  72         LTTNG_CONSUMER32_UST,
  73 };
  74
  75 enum consumer_endpoint_status {
  76         CONSUMER_ENDPOINT_ACTIVE,
  77         CONSUMER_ENDPOINT_INACTIVE,
  78 };
  79
  80 enum consumer_channel_output {
  81         CONSUMER_CHANNEL_MMAP   = 0,
  82         CONSUMER_CHANNEL_SPLICE = 1,
  83 };
  84
  85 enum consumer_channel_type {
  86         CONSUMER_CHANNEL_TYPE_METADATA  = 0,
  87         CONSUMER_CHANNEL_TYPE_DATA      = 1,
  88 };
  89
  90 extern struct lttng_consumer_global_data consumer_data;
  91
  92 struct stream_list {
  93         struct cds_list_head head;
  94         unsigned int count;
  95 };
  96
  97 /* Stub. */
  98 struct consumer_metadata_cache;
  99
 100 struct lttng_consumer_channel {
 101         /* HT node used for consumer_data.channel_ht */
 102         struct lttng_ht_node_u64 node;
 103         /* Indexed key. Incremented value in the consumer. */
 104         uint64_t key;
 105         /* Number of streams referencing this channel */
 106         int refcount;
 107         /* Tracing session id on the session daemon side. */
 108         uint64_t session_id;
 109         /*
 110          * Session id when requesting metadata to the session daemon for
 111          * a session with per-PID buffers.
 112          */
 113         uint64_t session_id_per_pid;
 114         /* Channel trace file path name. */
 115         char pathname[PATH_MAX];
 116         /* Channel name. */
 117         char name[LTTNG_SYMBOL_NAME_LEN];
 118         /* UID and GID of the channel. */
 119         uid_t uid;
 120         gid_t gid;
 121         /* Relayd id of the channel. -1ULL if it does not apply. */
 122         uint64_t relayd_id;
 123         /*
 124          * Number of streams NOT initialized yet. This is used in order to not
 125          * delete this channel if streams are getting initialized.
 126          */
 127         unsigned int nb_init_stream_left;
 128         /* Output type (mmap or splice). */
 129         enum consumer_channel_output output;
 130         /* Channel type for stream */
 131         enum consumer_channel_type type;
 132
 133         /* For UST */
 134         struct ustctl_consumer_channel *uchan;
 135         unsigned char uuid[UUID_STR_LEN];
 136         /*
 137          * Temporary stream list used to store the streams once created and waiting
 138          * to be sent to the session daemon by receiving the
 139          * LTTNG_CONSUMER_GET_CHANNEL.
 140          */
 141         struct stream_list streams;
 142
 143         /*
 144          * Set if the channel is metadata. We keep a reference to the stream
 145          * because we have to flush data once pushed by the session daemon. For a
 146          * regular channel, this is always set to NULL.
 147          */
 148         struct lttng_consumer_stream *metadata_stream;
 149
 150         /* for UST */
 151         int wait_fd;
 152         /* Node within channel thread ht */
 153         struct lttng_ht_node_u64 wait_fd_node;
 154
 155         /* Metadata cache is metadata channel */
 156         struct consumer_metadata_cache *metadata_cache;
 157         /* For metadata periodical flush */
 158         int switch_timer_enabled;
 159         timer_t switch_timer;
 160         int switch_timer_error;
 161
 162         /* On-disk circular buffer */
 163         uint64_t tracefile_size;
 164         uint64_t tracefile_count;
 165         /*
 166          * Monitor or not the streams of this channel meaning this indicates if the
 167          * streams should be sent to the data/metadata thread or added to the no
 168          * monitor list of the channel.
 169          */
 170         unsigned int monitor;
 171
 172         /*
 173          * Channel lock.
 174          *
 175          * This is nested INSIDE the consumer data lock.
 176          * This is nested OUTSIDE the metadata cache lock.
 177          * This is nested OUTSIDE stream lock.
 178          * This is nested OUTSIDE consumer_relayd_sock_pair lock.
 179          */
 180         pthread_mutex_t lock;
 181 };
 182
 183 /*
 184  * Internal representation of the streams, sessiond_key is used to identify
 185  * uniquely a stream.
 186  */
 187 struct lttng_consumer_stream {
 188         /* HT node used by the data_ht and metadata_ht */
 189         struct lttng_ht_node_u64 node;
 190         /* stream indexed per channel key node */
 191         struct lttng_ht_node_u64 node_channel_id;
 192         /* HT node used in consumer_data.stream_list_ht */
 193         struct lttng_ht_node_u64 node_session_id;
 194         /* Pointer to associated channel. */
 195         struct lttng_consumer_channel *chan;
 196
 197         /* Key by which the stream is indexed for 'node'. */
 198         uint64_t key;
 199         /*
 200          * File descriptor of the data output file. This can be either a file or a
 201          * socket fd for relayd streaming.
 202          */
 203         int out_fd; /* output file to write the data */
 204         /* Write position in the output file descriptor */
 205         off_t out_fd_offset;
 206         enum lttng_consumer_stream_state state;
 207         int shm_fd_is_copy;
 208         int data_read;
 209         int hangup_flush_done;
 210         enum lttng_event_output output;
 211         /* Maximum subbuffer size. */
 212         unsigned long max_sb_size;
 213
 214         /*
 215          * Still used by the kernel for MMAP output. For UST, the ustctl getter is
 216          * used for the mmap base and offset.
 217          */
 218         void *mmap_base;
 219         unsigned long mmap_len;
 220
 221         /* For UST */
 222
 223         int wait_fd;
 224         /* UID/GID of the user owning the session to which stream belongs */
 225         uid_t uid;
 226         gid_t gid;
 227         /* Network sequence number. Indicating on which relayd socket it goes. */
 228         uint64_t net_seq_idx;
 229         /*
 230          * Indicate if this stream was successfully sent to a relayd. This is set
 231          * after the refcount of the relayd is incremented and is checked when the
 232          * stream is closed before decrementing the refcount in order to avoid an
 233          * unbalanced state.
 234          */
 235         unsigned int sent_to_relayd;
 236
 237         /* Identify if the stream is the metadata */
 238         unsigned int metadata_flag;
 239         /* Used when the stream is set for network streaming */
 240         uint64_t relayd_stream_id;
 241         /*
 242          * When sending a stream packet to a relayd, this number is used to track
 243          * the packet sent by the consumer and seen by the relayd. When sending the
 244          * data header to the relayd, this number is sent and if the transmission
 245          * was successful, it is incremented.
 246          *
 247          * Even if the full data is not fully transmitted it won't matter since
 248          * only two possible error can happen after that where either the relayd
 249          * died or a read error is detected on the stream making this value useless
 250          * after that.
 251          *
 252          * This value SHOULD be read/updated atomically or with the lock acquired.
 253          */
 254         uint64_t next_net_seq_num;
 255         /*
 256          * Lock to use the stream FDs since they are used between threads.
 257          *
 258          * This is nested INSIDE the consumer_data lock.
 259          * This is nested INSIDE the metadata cache lock.
 260          * This is nested INSIDE the channel lock.
 261          * This is nested OUTSIDE consumer_relayd_sock_pair lock.
 262          */
 263         pthread_mutex_t lock;
 264         /* Tracing session id */
 265         uint64_t session_id;
 266         /*
 267          * Indicates if the stream end point is still active or not (network
 268          * streaming or local file system). The thread "owning" the stream is
 269          * handling this status and can be notified of a state change through the
 270          * consumer data appropriate pipe.
 271          */
 272         enum consumer_endpoint_status endpoint_status;
 273         /* Stream name. Format is: <channel_name>_<cpu_number> */
 274         char name[LTTNG_SYMBOL_NAME_LEN];
 275         /* Internal state of libustctl. */
 276         struct ustctl_consumer_stream *ustream;
 277         struct cds_list_head send_node;
 278         /* On-disk circular buffer */
 279         uint64_t tracefile_size_current;
 280         uint64_t tracefile_count_current;
 281         /*
 282          * Monitor or not the streams of this channel meaning this indicates if the
 283          * streams should be sent to the data/metadata thread or added to the no
 284          * monitor list of the channel.
 285          */
 286         unsigned int monitor;
 287         /*
 288          * Indicate if the stream is globally visible meaning that it has been
 289          * added to the multiple hash tables. If *not* set, NO lock should be
 290          * acquired in the destroy path.
 291          */
 292         unsigned int globally_visible;
 293         /*
 294          * Pipe to wake up the metadata poll thread when the UST metadata
 295          * cache is updated.
 296          */
 297         int ust_metadata_poll_pipe[2];
 298         /*
 299          * How much metadata was read from the metadata cache and sent
 300          * to the channel.
 301          */
 302         uint64_t ust_metadata_pushed;
 303 };
 304
 305 /*
 306  * Internal representation of a relayd socket pair.
 307  */
 308 struct consumer_relayd_sock_pair {
 309         /* Network sequence number. */
 310         uint64_t net_seq_idx;
 311         /* Number of stream associated with this relayd */
 312         unsigned int refcount;
 313
 314         /*
 315          * This flag indicates whether or not we should destroy this object. The
 316          * destruction should ONLY occurs when this flag is set and the refcount is
 317          * set to zero.
 318          */
 319         unsigned int destroy_flag;
 320
 321         /*
 322          * Mutex protecting the control socket to avoid out of order packets
 323          * between threads sending data to the relayd. Since metadata data is sent
 324          * over that socket, at least two sendmsg() are needed (header + data)
 325          * creating a race for packets to overlap between threads using it.
 326          *
 327          * This is nested INSIDE the consumer_data lock.
 328          * This is nested INSIDE the stream lock.
 329          */
 330         pthread_mutex_t ctrl_sock_mutex;
 331
 332         /* Control socket. Command and metadata are passed over it */
 333         struct lttcomm_relayd_sock control_sock;
 334
 335         /*
 336          * We don't need a mutex at this point since we only splice or write single
 337          * large chunk of data with a header appended at the begining. Moreover,
 338          * this socket is for now only used in a single thread.
 339          */
 340         struct lttcomm_relayd_sock data_sock;
 341         struct lttng_ht_node_u64 node;
 342
 343         /* Session id on both sides for the sockets. */
 344         uint64_t relayd_session_id;
 345         uint64_t sessiond_session_id;
 346 };
 347
 348 /*
 349  * UST consumer local data to the program. One or more instance per
 350  * process.
 351  */
 352 struct lttng_consumer_local_data {
 353         /*
 354          * Function to call when data is available on a buffer.
 355          * Returns the number of bytes read, or negative error value.
 356          */
 357         ssize_t (*on_buffer_ready)(struct lttng_consumer_stream *stream,
 358                         struct lttng_consumer_local_data *ctx);
 359         /*
 360          * function to call when we receive a new channel, it receives a
 361          * newly allocated channel, depending on the return code of this
 362          * function, the new channel will be handled by the application
 363          * or the library.
 364          *
 365          * Returns:
 366          *    > 0 (success, FD is kept by application)
 367          *   == 0 (success, FD is left to library)
 368          *    < 0 (error)
 369          */
 370         int (*on_recv_channel)(struct lttng_consumer_channel *channel);
 371         /*
 372          * function to call when we receive a new stream, it receives a
 373          * newly allocated stream, depending on the return code of this
 374          * function, the new stream will be handled by the application
 375          * or the library.
 376          *
 377          * Returns:
 378          *    > 0 (success, FD is kept by application)
 379          *   == 0 (success, FD is left to library)
 380          *    < 0 (error)
 381          */
 382         int (*on_recv_stream)(struct lttng_consumer_stream *stream);
 383         /*
 384          * function to call when a stream is getting updated by the session
 385          * daemon, this function receives the sessiond key and the new
 386          * state, depending on the return code of this function the
 387          * update of state for the stream is handled by the application
 388          * or the library.
 389          *
 390          * Returns:
 391          *    > 0 (success, FD is kept by application)
 392          *   == 0 (success, FD is left to library)
 393          *    < 0 (error)
 394          */
 395         int (*on_update_stream)(uint64_t sessiond_key, uint32_t state);
 396         enum lttng_consumer_type type;
 397         /* socket to communicate errors with sessiond */
 398         int consumer_error_socket;
 399         /* socket to ask metadata to sessiond. */
 400         int consumer_metadata_socket;
 401         /* Protect consumer_metadata_socket. */
 402         pthread_mutex_t metadata_socket_lock;
 403         /* socket to exchange commands with sessiond */
 404         char *consumer_command_sock_path;
 405         /* communication with splice */
 406         int consumer_thread_pipe[2];
 407         int consumer_channel_pipe[2];
 408         int consumer_splice_metadata_pipe[2];
 409         /* Data stream poll thread pipe. To transfer data stream to the thread */
 410         struct lttng_pipe *consumer_data_pipe;
 411         /* to let the signal handler wake up the fd receiver thread */
 412         int consumer_should_quit[2];
 413         /* Metadata poll thread pipe. Transfer metadata stream to it */
 414         struct lttng_pipe *consumer_metadata_pipe;
 415 };
 416
 417 /*
 418  * Library-level data. One instance per process.
 419  */
 420 struct lttng_consumer_global_data {
 421         /*
 422          * At this time, this lock is used to ensure coherence between the count
 423          * and number of element in the hash table. It's also a protection for
 424          * concurrent read/write between threads.
 425          *
 426          * This is nested OUTSIDE the stream lock.
 427          * This is nested OUTSIDE the consumer_relayd_sock_pair lock.
 428          */
 429         pthread_mutex_t lock;
 430
 431         /*
 432          * Number of streams in the data stream hash table declared outside.
 433          * Protected by consumer_data.lock.
 434          */
 435         int stream_count;
 436
 437         /* Channel hash table protected by consumer_data.lock. */
 438         struct lttng_ht *channel_ht;
 439         /*
 440          * Flag specifying if the local array of FDs needs update in the
 441          * poll function. Protected by consumer_data.lock.
 442          */
 443         unsigned int need_update;
 444         enum lttng_consumer_type type;
 445
 446         /*
 447          * Relayd socket(s) hashtable indexed by network sequence number. Each
 448          * stream has an index which associate the right relayd socket to use.
 449          */
 450         struct lttng_ht *relayd_ht;
 451
 452         /*
 453          * This hash table contains all streams (metadata and data) indexed by
 454          * session id. In other words, the ht is indexed by session id and each
 455          * bucket contains the list of associated streams.
 456          *
 457          * This HT uses the "node_session_id" of the consumer stream.
 458          */
 459         struct lttng_ht *stream_list_ht;
 460
 461         /*
 462          * This HT uses the "node_channel_id" of the consumer stream.
 463          */
 464         struct lttng_ht *stream_per_chan_id_ht;
 465 };
 466
 467 /*
 468  * Init consumer data structures.
 469  */
 470 void lttng_consumer_init(void);
 471
 472 /*
 473  * Set the error socket for communication with a session daemon.
 474  */
 475 void lttng_consumer_set_error_sock(struct lttng_consumer_local_data *ctx,
 476                 int sock);
 477
 478 /*
 479  * Set the command socket path for communication with a session daemon.
 480  */
 481 void lttng_consumer_set_command_sock_path(
 482                 struct lttng_consumer_local_data *ctx, char *sock);
 483
 484 /*
 485  * Send return code to session daemon.
 486  *
 487  * Returns the return code of sendmsg : the number of bytes transmitted or -1
 488  * on error.
 489  */
 490 int lttng_consumer_send_error(struct lttng_consumer_local_data *ctx, int cmd);
 491
 492 /*
 493  * Called from signal handler to ensure a clean exit.
 494  */
 495 void lttng_consumer_should_exit(struct lttng_consumer_local_data *ctx);
 496
 497 /*
 498  * Cleanup the daemon's socket on exit.
 499  */
 500 void lttng_consumer_cleanup(void);
 501
 502 /*
 503  * Flush pending writes to trace output disk file.
 504  */
 505 void lttng_consumer_sync_trace_file(struct lttng_consumer_stream *stream,
 506                 off_t orig_offset);
 507
 508 /*
 509  * Poll on the should_quit pipe and the command socket return -1 on error and
 510  * should exit, 0 if data is available on the command socket
 511  */
 512 int lttng_consumer_poll_socket(struct pollfd *kconsumer_sockpoll);
 513
 514 struct lttng_consumer_stream *consumer_allocate_stream(uint64_t channel_key,
 515                 uint64_t stream_key,
 516                 enum lttng_consumer_stream_state state,
 517                 const char *channel_name,
 518                 uid_t uid,
 519                 gid_t gid,
 520                 uint64_t relayd_id,
 521                 uint64_t session_id,
 522                 int cpu,
 523                 int *alloc_ret,
 524                 enum consumer_channel_type type,
 525                 unsigned int monitor);
 526 struct lttng_consumer_channel *consumer_allocate_channel(uint64_t key,
 527                 uint64_t session_id,
 528                 const char *pathname,
 529                 const char *name,
 530                 uid_t uid,
 531                 gid_t gid,
 532                 uint64_t relayd_id,
 533                 enum lttng_event_output output,
 534                 uint64_t tracefile_size,
 535                 uint64_t tracefile_count,
 536                 uint64_t session_id_per_pid,
 537                 unsigned int monitor);
 538 void consumer_del_stream(struct lttng_consumer_stream *stream,
 539                 struct lttng_ht *ht);
 540 void consumer_del_metadata_stream(struct lttng_consumer_stream *stream,
 541                 struct lttng_ht *ht);
 542 int consumer_add_channel(struct lttng_consumer_channel *channel,
 543                 struct lttng_consumer_local_data *ctx);
 544 void consumer_del_channel(struct lttng_consumer_channel *channel);
 545
 546 /* lttng-relayd consumer command */
 547 struct consumer_relayd_sock_pair *consumer_allocate_relayd_sock_pair(
 548                 uint64_t net_seq_idx);
 549 struct consumer_relayd_sock_pair *consumer_find_relayd(uint64_t key);
 550 int consumer_send_relayd_stream(struct lttng_consumer_stream *stream, char *path);
 551 void close_relayd_stream(struct lttng_consumer_stream *stream);
 552 struct lttng_consumer_channel *consumer_find_channel(uint64_t key);
 553 int consumer_handle_stream_before_relayd(struct lttng_consumer_stream *stream,
 554                 size_t data_size);
 555 void consumer_steal_stream_key(int key, struct lttng_ht *ht);
 556
 557 struct lttng_consumer_local_data *lttng_consumer_create(
 558                 enum lttng_consumer_type type,
 559                 ssize_t (*buffer_ready)(struct lttng_consumer_stream *stream,
 560                         struct lttng_consumer_local_data *ctx),
 561                 int (*recv_channel)(struct lttng_consumer_channel *channel),
 562                 int (*recv_stream)(struct lttng_consumer_stream *stream),
 563                 int (*update_stream)(uint64_t sessiond_key, uint32_t state));
 564 void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx);
 565 ssize_t lttng_consumer_on_read_subbuffer_mmap(
 566                 struct lttng_consumer_local_data *ctx,
 567                 struct lttng_consumer_stream *stream, unsigned long len,
 568                 unsigned long padding);
 569 ssize_t lttng_consumer_on_read_subbuffer_splice(
 570                 struct lttng_consumer_local_data *ctx,
 571                 struct lttng_consumer_stream *stream, unsigned long len,
 572                 unsigned long padding);
 573 int lttng_consumer_take_snapshot(struct lttng_consumer_stream *stream);
 574 int lttng_consumer_get_produced_snapshot(struct lttng_consumer_stream *stream,
 575                 unsigned long *pos);
 576 void *consumer_thread_metadata_poll(void *data);
 577 void *consumer_thread_data_poll(void *data);
 578 void *consumer_thread_sessiond_poll(void *data);
 579 void *consumer_thread_channel_poll(void *data);
 580 int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 581                 int sock, struct pollfd *consumer_sockpoll);
 582
 583 ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream,
 584                 struct lttng_consumer_local_data *ctx);
 585 int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream);
 586 int consumer_add_relayd_socket(uint64_t net_seq_idx, int sock_type,
 587                 struct lttng_consumer_local_data *ctx, int sock,
 588                 struct pollfd *consumer_sockpoll, struct lttcomm_relayd_sock *relayd_sock,
 589                 uint64_t sessiond_id);
 590 void consumer_flag_relayd_for_destroy(
 591                 struct consumer_relayd_sock_pair *relayd);
 592 int consumer_data_pending(uint64_t id);
 593 int consumer_send_status_msg(int sock, int ret_code);
 594 int consumer_send_status_channel(int sock,
 595                 struct lttng_consumer_channel *channel);
 596 void notify_thread_del_channel(struct lttng_consumer_local_data *ctx,
 597                 uint64_t key);
 598 void consumer_destroy_relayd(struct consumer_relayd_sock_pair *relayd);
 599 unsigned long consumer_get_consumed_maxsize(unsigned long consumed_pos,
 600                 unsigned long produced_pos, uint64_t max_stream_size);
 601
 602 #endif /* LIB_CONSUMER_H */