src/common/consumer/consumer.h

   1 /*
   2  * Copyright (C) 2011 Julien Desfossez <julien.desfossez@polymtl.ca>
   3  * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   4  * Copyright (C) 2012 David Goulet <dgoulet@efficios.com>
   5  * Copyright (C) 2018 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   6  *
   7  * SPDX-License-Identifier: GPL-2.0-only
   8  *
   9  */
  10
  11 #ifndef LIB_CONSUMER_H
  12 #define LIB_CONSUMER_H
  13
  14 #include <limits.h>
  15 #include <poll.h>
  16 #include <unistd.h>
  17 #include <urcu/list.h>
  18
  19 #include <lttng/lttng.h>
  20
  21 #include <common/hashtable/hashtable.h>
  22 #include <common/compat/fcntl.h>
  23 #include <common/uuid.h>
  24 #include <common/sessiond-comm/sessiond-comm.h>
  25 #include <common/pipe.h>
  26 #include <common/index/ctf-index.h>
  27 #include <common/trace-chunk-registry.h>
  28 #include <common/credentials.h>
  29 #include <common/buffer-view.h>
  30
  31 /* Commands for consumer */
  32 enum lttng_consumer_command {
  33         LTTNG_CONSUMER_ADD_CHANNEL,
  34         LTTNG_CONSUMER_ADD_STREAM,
  35         /* pause, delete, active depending on fd state */
  36         LTTNG_CONSUMER_UPDATE_STREAM,
  37         /* inform the consumer to quit when all fd has hang up */
  38         LTTNG_CONSUMER_STOP,    /* deprecated */
  39         LTTNG_CONSUMER_ADD_RELAYD_SOCKET,
  40         /* Inform the consumer to kill a specific relayd connection */
  41         LTTNG_CONSUMER_DESTROY_RELAYD,
  42         /* Return to the sessiond if there is data pending for a session */
  43         LTTNG_CONSUMER_DATA_PENDING,
  44         /* Consumer creates a channel and returns it to sessiond. */
  45         LTTNG_CONSUMER_ASK_CHANNEL_CREATION,
  46         LTTNG_CONSUMER_GET_CHANNEL,
  47         LTTNG_CONSUMER_DESTROY_CHANNEL,
  48         LTTNG_CONSUMER_PUSH_METADATA,
  49         LTTNG_CONSUMER_CLOSE_METADATA,
  50         LTTNG_CONSUMER_SETUP_METADATA,
  51         LTTNG_CONSUMER_FLUSH_CHANNEL,
  52         LTTNG_CONSUMER_SNAPSHOT_CHANNEL,
  53         LTTNG_CONSUMER_SNAPSHOT_METADATA,
  54         LTTNG_CONSUMER_STREAMS_SENT,
  55         LTTNG_CONSUMER_DISCARDED_EVENTS,
  56         LTTNG_CONSUMER_LOST_PACKETS,
  57         LTTNG_CONSUMER_CLEAR_QUIESCENT_CHANNEL,
  58         LTTNG_CONSUMER_SET_CHANNEL_MONITOR_PIPE,
  59         LTTNG_CONSUMER_ROTATE_CHANNEL,
  60         LTTNG_CONSUMER_INIT,
  61         LTTNG_CONSUMER_CREATE_TRACE_CHUNK,
  62         LTTNG_CONSUMER_CLOSE_TRACE_CHUNK,
  63         LTTNG_CONSUMER_TRACE_CHUNK_EXISTS,
  64         LTTNG_CONSUMER_CLEAR_CHANNEL,
  65 };
  66
  67 enum lttng_consumer_type {
  68         LTTNG_CONSUMER_UNKNOWN = 0,
  69         LTTNG_CONSUMER_KERNEL,
  70         LTTNG_CONSUMER64_UST,
  71         LTTNG_CONSUMER32_UST,
  72 };
  73
  74 enum consumer_endpoint_status {
  75         CONSUMER_ENDPOINT_ACTIVE,
  76         CONSUMER_ENDPOINT_INACTIVE,
  77 };
  78
  79 enum consumer_channel_output {
  80         CONSUMER_CHANNEL_MMAP   = 0,
  81         CONSUMER_CHANNEL_SPLICE = 1,
  82 };
  83
  84 enum consumer_channel_type {
  85         CONSUMER_CHANNEL_TYPE_METADATA  = 0,
  86         CONSUMER_CHANNEL_TYPE_DATA      = 1,
  87 };
  88
  89 extern struct lttng_consumer_global_data consumer_data;
  90
  91 struct stream_list {
  92         struct cds_list_head head;
  93         unsigned int count;
  94 };
  95
  96 /* Stub. */
  97 struct consumer_metadata_cache;
  98
  99 struct lttng_consumer_channel {
 100         /* Is the channel published in the channel hash tables? */
 101         bool is_published;
 102         /*
 103          * Was the channel deleted (logically) and waiting to be reclaimed?
 104          * If this flag is set, no modification that is not cleaned-up by the
 105          * RCU reclamation callback should be made
 106          */
 107         bool is_deleted;
 108         /* HT node used for consumer_data.channel_ht */
 109         struct lttng_ht_node_u64 node;
 110         /* HT node used for consumer_data.channels_by_session_id_ht */
 111         struct lttng_ht_node_u64 channels_by_session_id_ht_node;
 112         /* Indexed key. Incremented value in the consumer. */
 113         uint64_t key;
 114         /* Number of streams referencing this channel */
 115         int refcount;
 116         /* Tracing session id on the session daemon side. */
 117         uint64_t session_id;
 118         /* Current trace chunk of the session in which this channel exists. */
 119         struct lttng_trace_chunk *trace_chunk;
 120         /*
 121          * Session id when requesting metadata to the session daemon for
 122          * a session with per-PID buffers.
 123          */
 124         uint64_t session_id_per_pid;
 125         /*
 126          * In the case of local streams, this field contains the channel's
 127          * output path; a path relative to the session's output path.
 128          *   e.g. ust/uid/1000/64-bit
 129          *
 130          * In the case of remote streams, the contents of this field depends
 131          * on the version of the relay daemon peer. For 2.11+ peers, the
 132          * contents are the same as in the local case. However, for legacy
 133          * peers, this contains a path of the form:
 134          *   /hostname/session_path/ust/uid/1000/64-bit
 135          */
 136         char pathname[PATH_MAX];
 137         /* Channel name. */
 138         char name[LTTNG_SYMBOL_NAME_LEN];
 139         /* Relayd id of the channel. -1ULL if it does not apply. */
 140         uint64_t relayd_id;
 141         /*
 142          * Number of streams NOT initialized yet. This is used in order to not
 143          * delete this channel if streams are getting initialized.
 144          */
 145         unsigned int nb_init_stream_left;
 146         /* Output type (mmap or splice). */
 147         enum consumer_channel_output output;
 148         /* Channel type for stream */
 149         enum consumer_channel_type type;
 150
 151         /* For UST */
 152         uid_t ust_app_uid;      /* Application UID. */
 153         struct ustctl_consumer_channel *uchan;
 154         unsigned char uuid[LTTNG_UUID_STR_LEN];
 155         /*
 156          * Temporary stream list used to store the streams once created and waiting
 157          * to be sent to the session daemon by receiving the
 158          * LTTNG_CONSUMER_GET_CHANNEL.
 159          */
 160         struct stream_list streams;
 161
 162         /*
 163          * Set if the channel is metadata. We keep a reference to the stream
 164          * because we have to flush data once pushed by the session daemon. For a
 165          * regular channel, this is always set to NULL.
 166          */
 167         struct lttng_consumer_stream *metadata_stream;
 168
 169         /* for UST */
 170         int wait_fd;
 171         /* Node within channel thread ht */
 172         struct lttng_ht_node_u64 wait_fd_node;
 173
 174         /* Metadata cache is metadata channel */
 175         struct consumer_metadata_cache *metadata_cache;
 176
 177         /* For UST metadata periodical flush */
 178         int switch_timer_enabled;
 179         timer_t switch_timer;
 180         int switch_timer_error;
 181
 182         /* For the live mode */
 183         int live_timer_enabled;
 184         timer_t live_timer;
 185         int live_timer_error;
 186         /* Channel is part of a live session ? */
 187         bool is_live;
 188
 189         /* For channel monitoring timer. */
 190         int monitor_timer_enabled;
 191         timer_t monitor_timer;
 192
 193         /* On-disk circular buffer */
 194         uint64_t tracefile_size;
 195         uint64_t tracefile_count;
 196         /*
 197          * Monitor or not the streams of this channel meaning this indicates if the
 198          * streams should be sent to the data/metadata thread or added to the no
 199          * monitor list of the channel.
 200          */
 201         unsigned int monitor;
 202
 203         /*
 204          * Channel lock.
 205          *
 206          * This lock protects against concurrent update of channel.
 207          *
 208          * This is nested INSIDE the consumer data lock.
 209          * This is nested OUTSIDE the channel timer lock.
 210          * This is nested OUTSIDE the metadata cache lock.
 211          * This is nested OUTSIDE stream lock.
 212          * This is nested OUTSIDE consumer_relayd_sock_pair lock.
 213          */
 214         pthread_mutex_t lock;
 215
 216         /*
 217          * Channel teardown lock.
 218          *
 219          * This lock protect against teardown of channel. It is _never_
 220          * taken by the timer handler.
 221          *
 222          * This is nested INSIDE the consumer data lock.
 223          * This is nested INSIDE the channel lock.
 224          * This is nested OUTSIDE the metadata cache lock.
 225          * This is nested OUTSIDE stream lock.
 226          * This is nested OUTSIDE consumer_relayd_sock_pair lock.
 227          */
 228         pthread_mutex_t timer_lock;
 229
 230         /* Timer value in usec for live streaming. */
 231         unsigned int live_timer_interval;
 232
 233         int *stream_fds;
 234         int nr_stream_fds;
 235         char root_shm_path[PATH_MAX];
 236         char shm_path[PATH_MAX];
 237         /* Only set for UST channels. */
 238         LTTNG_OPTIONAL(struct lttng_credentials) buffer_credentials;
 239         /* Total number of discarded events for that channel. */
 240         uint64_t discarded_events;
 241         /* Total number of missed packets due to overwriting (overwrite). */
 242         uint64_t lost_packets;
 243
 244         bool streams_sent_to_relayd;
 245 };
 246
 247 /*
 248  * Internal representation of the streams, sessiond_key is used to identify
 249  * uniquely a stream.
 250  */
 251 struct lttng_consumer_stream {
 252         /* HT node used by the data_ht and metadata_ht */
 253         struct lttng_ht_node_u64 node;
 254         /* stream indexed per channel key node */
 255         struct lttng_ht_node_u64 node_channel_id;
 256         /* HT node used in consumer_data.stream_list_ht */
 257         struct lttng_ht_node_u64 node_session_id;
 258         /* Pointer to associated channel. */
 259         struct lttng_consumer_channel *chan;
 260         /*
 261          * Current trace chunk. Holds a reference to the trace chunk.
 262          * `chunk` can be NULL when a stream is not associated to a chunk, e.g.
 263          * when it was created in the context of a no-output session.
 264          */
 265         struct lttng_trace_chunk *trace_chunk;
 266
 267         /* Key by which the stream is indexed for 'node'. */
 268         uint64_t key;
 269         /*
 270          * File descriptor of the data output file. This can be either a file or a
 271          * socket fd for relayd streaming.
 272          */
 273         int out_fd; /* output file to write the data */
 274         /* Write position in the output file descriptor */
 275         off_t out_fd_offset;
 276         /* Amount of bytes written to the output */
 277         uint64_t output_written;
 278         int shm_fd_is_copy;
 279         int data_read;
 280         int hangup_flush_done;
 281
 282         /*
 283          * Whether the stream is in a "complete" state (e.g. it does not have a
 284          * partially written sub-buffer.
 285          *
 286          * Initialized to "false" on stream creation (first packet is empty).
 287          *
 288          * The various transitions of the quiescent state are:
 289          *     - On "start" tracing: set to false, since the stream is not
 290          *       "complete".
 291          *     - On "stop" tracing: if !quiescent -> flush FINAL (update
 292          *       timestamp_end), and set to true; the stream has entered a
 293          *       complete/quiescent state.
 294          *     - On "destroy" or stream/application hang-up: if !quiescent ->
 295          *       flush FINAL, and set to true.
 296          *
 297          * NOTE: Update and read are protected by the stream lock.
 298          */
 299         bool quiescent;
 300
 301         /*
 302          * True if the sequence number is not available (lttng-modules < 2.8).
 303          */
 304         bool sequence_number_unavailable;
 305
 306         /*
 307          * metadata_timer_lock protects flags waiting_on_metadata and
 308          * missed_metadata_flush.
 309          */
 310         pthread_mutex_t metadata_timer_lock;
 311         /*
 312          * Flag set when awaiting metadata to be pushed. Used in the
 313          * timer thread to skip waiting on the stream (and stream lock) to
 314          * ensure we can proceed to flushing metadata in live mode.
 315          */
 316         bool waiting_on_metadata;
 317         /* Raised when a timer misses a metadata flush. */
 318         bool missed_metadata_flush;
 319
 320         enum lttng_event_output output;
 321         /* Maximum subbuffer size (in bytes). */
 322         unsigned long max_sb_size;
 323
 324         /*
 325          * Still used by the kernel for MMAP output. For UST, the ustctl getter is
 326          * used for the mmap base and offset.
 327          */
 328         void *mmap_base;
 329         unsigned long mmap_len;
 330
 331         /* For UST */
 332
 333         int wait_fd;
 334         /* Network sequence number. Indicating on which relayd socket it goes. */
 335         uint64_t net_seq_idx;
 336         /*
 337          * Indicate if this stream was successfully sent to a relayd. This is set
 338          * after the refcount of the relayd is incremented and is checked when the
 339          * stream is closed before decrementing the refcount in order to avoid an
 340          * unbalanced state.
 341          */
 342         unsigned int sent_to_relayd;
 343
 344         /* Identify if the stream is the metadata */
 345         unsigned int metadata_flag;
 346         /*
 347          * Last known metadata version, reset the metadata file in case
 348          * of change.
 349          */
 350         uint64_t metadata_version;
 351         /* Used when the stream is set for network streaming */
 352         uint64_t relayd_stream_id;
 353         /*
 354          * When sending a stream packet to a relayd, this number is used to track
 355          * the packet sent by the consumer and seen by the relayd. When sending the
 356          * data header to the relayd, this number is sent and if the transmission
 357          * was successful, it is incremented.
 358          *
 359          * Even if the full data is not fully transmitted it won't matter since
 360          * only two possible error can happen after that where either the relayd
 361          * died or a read error is detected on the stream making this value useless
 362          * after that.
 363          *
 364          * This value SHOULD be read/updated atomically or with the lock acquired.
 365          */
 366         uint64_t next_net_seq_num;
 367         /*
 368          * Lock to use the stream FDs since they are used between threads.
 369          *
 370          * This is nested INSIDE the consumer_data lock.
 371          * This is nested INSIDE the channel lock.
 372          * This is nested INSIDE the channel timer lock.
 373          * This is nested OUTSIDE the metadata cache lock.
 374          * This is nested OUTSIDE consumer_relayd_sock_pair lock.
 375          */
 376         pthread_mutex_t lock;
 377         /* Tracing session id */
 378         uint64_t session_id;
 379         /*
 380          * Indicates if the stream end point is still active or not (network
 381          * streaming or local file system). The thread "owning" the stream is
 382          * handling this status and can be notified of a state change through the
 383          * consumer data appropriate pipe.
 384          */
 385         enum consumer_endpoint_status endpoint_status;
 386         /* Stream name. Format is: <channel_name>_<cpu_number> */
 387         char name[LTTNG_SYMBOL_NAME_LEN];
 388         /* Internal state of libustctl. */
 389         struct ustctl_consumer_stream *ustream;
 390         struct cds_list_head send_node;
 391         /* On-disk circular buffer */
 392         uint64_t tracefile_size_current;
 393         uint64_t tracefile_count_current;
 394         /*
 395          * Monitor or not the streams of this channel meaning this indicates if the
 396          * streams should be sent to the data/metadata thread or added to the no
 397          * monitor list of the channel.
 398          */
 399         unsigned int monitor;
 400         /*
 401          * Indicate if the stream is globally visible meaning that it has been
 402          * added to the multiple hash tables. If *not* set, NO lock should be
 403          * acquired in the destroy path.
 404          */
 405         unsigned int globally_visible;
 406         /*
 407          * Pipe to wake up the metadata poll thread when the UST metadata
 408          * cache is updated.
 409          */
 410         int ust_metadata_poll_pipe[2];
 411         /*
 412          * How much metadata was read from the metadata cache and sent
 413          * to the channel.
 414          */
 415         uint64_t ust_metadata_pushed;
 416         /*
 417          * Copy of the last discarded event value to detect the overflow of
 418          * the counter.
 419          */
 420         uint64_t last_discarded_events;
 421         /* Copy of the sequence number of the last packet extracted. */
 422         uint64_t last_sequence_number;
 423         /*
 424          * Index file object of the index file for this stream.
 425          */
 426         struct lttng_index_file *index_file;
 427
 428         /*
 429          * Local pipe to extract data when using splice.
 430          */
 431         int splice_pipe[2];
 432
 433         /*
 434          * Rendez-vous point between data and metadata stream in live mode.
 435          */
 436         pthread_cond_t metadata_rdv;
 437         pthread_mutex_t metadata_rdv_lock;
 438
 439         /*
 440          * rotate_position represents the packet sequence number of the last
 441          * packet which belongs to the current trace chunk prior to the rotation.
 442          * When that position is reached, this tracefile can be closed and a
 443          * new one is created in channel_read_only_attributes.path.
 444          */
 445         uint64_t rotate_position;
 446
 447         /*
 448          * Read-only copies of channel values. We cannot safely access the
 449          * channel from a stream, so we need to have a local copy of these
 450          * fields in the stream object. These fields should be removed from
 451          * the stream objects when we introduce refcounting.
 452          */
 453         struct {
 454                 uint64_t tracefile_size;
 455         } channel_read_only_attributes;
 456
 457         /*
 458          * Flag to inform the data or metadata thread that a stream is
 459          * ready to be rotated.
 460          */
 461         bool rotate_ready;
 462
 463         /* Indicate if the stream still has some data to be read. */
 464         unsigned int has_data:1;
 465         /*
 466          * Inform the consumer or relay to reset the metadata
 467          * file before writing in it (regeneration).
 468          */
 469         unsigned int reset_metadata_flag:1;
 470 };
 471
 472 /*
 473  * Internal representation of a relayd socket pair.
 474  */
 475 struct consumer_relayd_sock_pair {
 476         /* Network sequence number. */
 477         uint64_t net_seq_idx;
 478         /* Number of stream associated with this relayd */
 479         int refcount;
 480
 481         /*
 482          * This flag indicates whether or not we should destroy this object. The
 483          * destruction should ONLY occurs when this flag is set and the refcount is
 484          * set to zero.
 485          */
 486         unsigned int destroy_flag;
 487
 488         /*
 489          * Mutex protecting the control socket to avoid out of order packets
 490          * between threads sending data to the relayd. Since metadata data is sent
 491          * over that socket, at least two sendmsg() are needed (header + data)
 492          * creating a race for packets to overlap between threads using it.
 493          *
 494          * This is nested INSIDE the consumer_data lock.
 495          * This is nested INSIDE the stream lock.
 496          */
 497         pthread_mutex_t ctrl_sock_mutex;
 498
 499         /* Control socket. Command and metadata are passed over it */
 500         struct lttcomm_relayd_sock control_sock;
 501
 502         /*
 503          * We don't need a mutex at this point since we only splice or write single
 504          * large chunk of data with a header appended at the begining. Moreover,
 505          * this socket is for now only used in a single thread.
 506          */
 507         struct lttcomm_relayd_sock data_sock;
 508         struct lttng_ht_node_u64 node;
 509
 510         /* Session id on both sides for the sockets. */
 511         uint64_t relayd_session_id;
 512         uint64_t sessiond_session_id;
 513         struct lttng_consumer_local_data *ctx;
 514 };
 515
 516 /*
 517  * UST consumer local data to the program. One or more instance per
 518  * process.
 519  */
 520 struct lttng_consumer_local_data {
 521         /*
 522          * Function to call when data is available on a buffer.
 523          * Returns the number of bytes read, or negative error value.
 524          */
 525         ssize_t (*on_buffer_ready)(struct lttng_consumer_stream *stream,
 526                         struct lttng_consumer_local_data *ctx);
 527         /*
 528          * function to call when we receive a new channel, it receives a
 529          * newly allocated channel, depending on the return code of this
 530          * function, the new channel will be handled by the application
 531          * or the library.
 532          *
 533          * Returns:
 534          *    > 0 (success, FD is kept by application)
 535          *   == 0 (success, FD is left to library)
 536          *    < 0 (error)
 537          */
 538         int (*on_recv_channel)(struct lttng_consumer_channel *channel);
 539         /*
 540          * function to call when we receive a new stream, it receives a
 541          * newly allocated stream, depending on the return code of this
 542          * function, the new stream will be handled by the application
 543          * or the library.
 544          *
 545          * Returns:
 546          *    > 0 (success, FD is kept by application)
 547          *   == 0 (success, FD is left to library)
 548          *    < 0 (error)
 549          */
 550         int (*on_recv_stream)(struct lttng_consumer_stream *stream);
 551         /*
 552          * function to call when a stream is getting updated by the session
 553          * daemon, this function receives the sessiond key and the new
 554          * state, depending on the return code of this function the
 555          * update of state for the stream is handled by the application
 556          * or the library.
 557          *
 558          * Returns:
 559          *    > 0 (success, FD is kept by application)
 560          *   == 0 (success, FD is left to library)
 561          *    < 0 (error)
 562          */
 563         int (*on_update_stream)(uint64_t sessiond_key, uint32_t state);
 564         enum lttng_consumer_type type;
 565         /* socket to communicate errors with sessiond */
 566         int consumer_error_socket;
 567         /* socket to ask metadata to sessiond. */
 568         int consumer_metadata_socket;
 569         /*
 570          * Protect consumer_metadata_socket.
 571          *
 572          * This is nested OUTSIDE the metadata cache lock.
 573          */
 574         pthread_mutex_t metadata_socket_lock;
 575         /* socket to exchange commands with sessiond */
 576         char *consumer_command_sock_path;
 577         /* communication with splice */
 578         int consumer_channel_pipe[2];
 579         /* Data stream poll thread pipe. To transfer data stream to the thread */
 580         struct lttng_pipe *consumer_data_pipe;
 581
 582         /*
 583          * Data thread use that pipe to catch wakeup from read subbuffer that
 584          * detects that there is still data to be read for the stream encountered.
 585          * Before doing so, the stream is flagged to indicate that there is still
 586          * data to be read.
 587          *
 588          * Both pipes (read/write) are owned and used inside the data thread.
 589          */
 590         struct lttng_pipe *consumer_wakeup_pipe;
 591         /* Indicate if the wakeup thread has been notified. */
 592         unsigned int has_wakeup:1;
 593
 594         /* to let the signal handler wake up the fd receiver thread */
 595         int consumer_should_quit[2];
 596         /* Metadata poll thread pipe. Transfer metadata stream to it */
 597         struct lttng_pipe *consumer_metadata_pipe;
 598         /*
 599          * Pipe used by the channel monitoring timers to provide state samples
 600          * to the session daemon (write-only).
 601          */
 602         int channel_monitor_pipe;
 603         LTTNG_OPTIONAL(lttng_uuid) sessiond_uuid;
 604 };
 605
 606 /*
 607  * Library-level data. One instance per process.
 608  */
 609 struct lttng_consumer_global_data {
 610         /*
 611          * At this time, this lock is used to ensure coherence between the count
 612          * and number of element in the hash table. It's also a protection for
 613          * concurrent read/write between threads.
 614          *
 615          * This is nested OUTSIDE the stream lock.
 616          * This is nested OUTSIDE the consumer_relayd_sock_pair lock.
 617          */
 618         pthread_mutex_t lock;
 619
 620         /*
 621          * Number of streams in the data stream hash table declared outside.
 622          * Protected by consumer_data.lock.
 623          */
 624         int stream_count;
 625
 626         /* Channel hash table protected by consumer_data.lock. */
 627         struct lttng_ht *channel_ht;
 628         /* Channel hash table indexed by session id. */
 629         struct lttng_ht *channels_by_session_id_ht;
 630         /*
 631          * Flag specifying if the local array of FDs needs update in the
 632          * poll function. Protected by consumer_data.lock.
 633          */
 634         unsigned int need_update;
 635         enum lttng_consumer_type type;
 636
 637         /*
 638          * Relayd socket(s) hashtable indexed by network sequence number. Each
 639          * stream has an index which associate the right relayd socket to use.
 640          */
 641         struct lttng_ht *relayd_ht;
 642
 643         /*
 644          * This hash table contains all streams (metadata and data) indexed by
 645          * session id. In other words, the ht is indexed by session id and each
 646          * bucket contains the list of associated streams.
 647          *
 648          * This HT uses the "node_session_id" of the consumer stream.
 649          */
 650         struct lttng_ht *stream_list_ht;
 651
 652         /*
 653          * This HT uses the "node_channel_id" of the consumer stream.
 654          */
 655         struct lttng_ht *stream_per_chan_id_ht;
 656
 657         /*
 658          * Trace chunk registry indexed by (session_id, chunk_id).
 659          */
 660         struct lttng_trace_chunk_registry *chunk_registry;
 661 };
 662
 663 /*
 664  * Set to nonzero when the consumer is exiting. Updated by signal
 665  * handler and thread exit, read by threads.
 666  */
 667 extern int consumer_quit;
 668
 669 /*
 670  * Set to nonzero when the consumer is exiting. Updated by signal
 671  * handler and thread exit, read by threads.
 672  */
 673 extern int consumer_quit;
 674
 675 /* Flag used to temporarily pause data consumption from testpoints. */
 676 extern int data_consumption_paused;
 677
 678 /* Return a human-readable consumer type string that is suitable for logging. */
 679 static inline
 680 const char *lttng_consumer_type_str(enum lttng_consumer_type type)
 681 {
 682         switch (type) {
 683         case LTTNG_CONSUMER_UNKNOWN:
 684                 return "unknown";
 685         case LTTNG_CONSUMER_KERNEL:
 686                 return "kernel";
 687         case LTTNG_CONSUMER32_UST:
 688                 return "32-bit user space";
 689         case LTTNG_CONSUMER64_UST:
 690                 return "64-bit user space";
 691         default:
 692                 abort();
 693         }
 694 }
 695
 696 /*
 697  * Init consumer data structures.
 698  */
 699 int lttng_consumer_init(void);
 700
 701 /*
 702  * Set the error socket for communication with a session daemon.
 703  */
 704 void lttng_consumer_set_error_sock(struct lttng_consumer_local_data *ctx,
 705                 int sock);
 706
 707 /*
 708  * Set the command socket path for communication with a session daemon.
 709  */
 710 void lttng_consumer_set_command_sock_path(
 711                 struct lttng_consumer_local_data *ctx, char *sock);
 712
 713 /*
 714  * Send return code to session daemon.
 715  *
 716  * Returns the return code of sendmsg : the number of bytes transmitted or -1
 717  * on error.
 718  */
 719 int lttng_consumer_send_error(struct lttng_consumer_local_data *ctx, int cmd);
 720
 721 /*
 722  * Called from signal handler to ensure a clean exit.
 723  */
 724 void lttng_consumer_should_exit(struct lttng_consumer_local_data *ctx);
 725
 726 /*
 727  * Cleanup the daemon's socket on exit.
 728  */
 729 void lttng_consumer_cleanup(void);
 730
 731 /*
 732  * Poll on the should_quit pipe and the command socket return -1 on error and
 733  * should exit, 0 if data is available on the command socket
 734  */
 735 int lttng_consumer_poll_socket(struct pollfd *kconsumer_sockpoll);
 736
 737 /*
 738  * Copy the fields from the channel that need to be accessed (read-only)
 739  * directly from the stream.
 740  */
 741 void consumer_stream_update_channel_attributes(
 742                 struct lttng_consumer_stream *stream,
 743                 struct lttng_consumer_channel *channel);
 744
 745 struct lttng_consumer_stream *consumer_allocate_stream(
 746                 struct lttng_consumer_channel *channel,
 747                 uint64_t channel_key,
 748                 uint64_t stream_key,
 749                 const char *channel_name,
 750                 uint64_t relayd_id,
 751                 uint64_t session_id,
 752                 struct lttng_trace_chunk *trace_chunk,
 753                 int cpu,
 754                 int *alloc_ret,
 755                 enum consumer_channel_type type,
 756                 unsigned int monitor);
 757 struct lttng_consumer_channel *consumer_allocate_channel(uint64_t key,
 758                 uint64_t session_id,
 759                 const uint64_t *chunk_id,
 760                 const char *pathname,
 761                 const char *name,
 762                 uint64_t relayd_id,
 763                 enum lttng_event_output output,
 764                 uint64_t tracefile_size,
 765                 uint64_t tracefile_count,
 766                 uint64_t session_id_per_pid,
 767                 unsigned int monitor,
 768                 unsigned int live_timer_interval,
 769                 bool is_in_live_session,
 770                 const char *root_shm_path,
 771                 const char *shm_path);
 772 void consumer_del_stream(struct lttng_consumer_stream *stream,
 773                 struct lttng_ht *ht);
 774 void consumer_del_metadata_stream(struct lttng_consumer_stream *stream,
 775                 struct lttng_ht *ht);
 776 int consumer_add_channel(struct lttng_consumer_channel *channel,
 777                 struct lttng_consumer_local_data *ctx);
 778 void consumer_del_channel(struct lttng_consumer_channel *channel);
 779
 780 /* lttng-relayd consumer command */
 781 struct consumer_relayd_sock_pair *consumer_find_relayd(uint64_t key);
 782 int consumer_send_relayd_stream(struct lttng_consumer_stream *stream, char *path);
 783 int consumer_send_relayd_streams_sent(uint64_t net_seq_idx);
 784 void close_relayd_stream(struct lttng_consumer_stream *stream);
 785 struct lttng_consumer_channel *consumer_find_channel(uint64_t key);
 786 int consumer_handle_stream_before_relayd(struct lttng_consumer_stream *stream,
 787                 size_t data_size);
 788 void consumer_steal_stream_key(int key, struct lttng_ht *ht);
 789
 790 struct lttng_consumer_local_data *lttng_consumer_create(
 791                 enum lttng_consumer_type type,
 792                 ssize_t (*buffer_ready)(struct lttng_consumer_stream *stream,
 793                         struct lttng_consumer_local_data *ctx),
 794                 int (*recv_channel)(struct lttng_consumer_channel *channel),
 795                 int (*recv_stream)(struct lttng_consumer_stream *stream),
 796                 int (*update_stream)(uint64_t sessiond_key, uint32_t state));
 797 void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx);
 798 ssize_t lttng_consumer_on_read_subbuffer_mmap(
 799                 struct lttng_consumer_local_data *ctx,
 800                 struct lttng_consumer_stream *stream,
 801                 const struct lttng_buffer_view *buffer,
 802                 unsigned long padding,
 803                 struct ctf_packet_index *index);
 804 ssize_t lttng_consumer_on_read_subbuffer_splice(
 805                 struct lttng_consumer_local_data *ctx,
 806                 struct lttng_consumer_stream *stream, unsigned long len,
 807                 unsigned long padding,
 808                 struct ctf_packet_index *index);
 809 int lttng_consumer_sample_snapshot_positions(struct lttng_consumer_stream *stream);
 810 int lttng_consumer_take_snapshot(struct lttng_consumer_stream *stream);
 811 int lttng_consumer_get_produced_snapshot(struct lttng_consumer_stream *stream,
 812                 unsigned long *pos);
 813 int lttng_consumer_get_consumed_snapshot(struct lttng_consumer_stream *stream,
 814                 unsigned long *pos);
 815 int lttng_ustconsumer_get_wakeup_fd(struct lttng_consumer_stream *stream);
 816 int lttng_ustconsumer_close_wakeup_fd(struct lttng_consumer_stream *stream);
 817 void *consumer_thread_metadata_poll(void *data);
 818 void *consumer_thread_data_poll(void *data);
 819 void *consumer_thread_sessiond_poll(void *data);
 820 void *consumer_thread_channel_poll(void *data);
 821 int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 822                 int sock, struct pollfd *consumer_sockpoll);
 823
 824 ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream,
 825                 struct lttng_consumer_local_data *ctx);
 826 int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream);
 827 void consumer_add_relayd_socket(uint64_t net_seq_idx, int sock_type,
 828                 struct lttng_consumer_local_data *ctx, int sock,
 829                 struct pollfd *consumer_sockpoll, struct lttcomm_relayd_sock *relayd_sock,
 830                 uint64_t sessiond_id, uint64_t relayd_session_id);
 831 void consumer_flag_relayd_for_destroy(
 832                 struct consumer_relayd_sock_pair *relayd);
 833 int consumer_data_pending(uint64_t id);
 834 int consumer_send_status_msg(int sock, int ret_code);
 835 int consumer_send_status_channel(int sock,
 836                 struct lttng_consumer_channel *channel);
 837 void notify_thread_del_channel(struct lttng_consumer_local_data *ctx,
 838                 uint64_t key);
 839 void consumer_destroy_relayd(struct consumer_relayd_sock_pair *relayd);
 840 unsigned long consumer_get_consume_start_pos(unsigned long consumed_pos,
 841                 unsigned long produced_pos, uint64_t nb_packets_per_stream,
 842                 uint64_t max_sb_size);
 843 void consumer_add_data_stream(struct lttng_consumer_stream *stream);
 844 void consumer_del_stream_for_data(struct lttng_consumer_stream *stream);
 845 void consumer_add_metadata_stream(struct lttng_consumer_stream *stream);
 846 void consumer_del_stream_for_metadata(struct lttng_consumer_stream *stream);
 847 int consumer_create_index_file(struct lttng_consumer_stream *stream);
 848 int lttng_consumer_rotate_channel(struct lttng_consumer_channel *channel,
 849                 uint64_t key, uint64_t relayd_id, uint32_t metadata,
 850                 struct lttng_consumer_local_data *ctx);
 851 int lttng_consumer_stream_is_rotate_ready(struct lttng_consumer_stream *stream);
 852 int lttng_consumer_rotate_stream(struct lttng_consumer_local_data *ctx,
 853                 struct lttng_consumer_stream *stream);
 854 int lttng_consumer_rotate_ready_streams(struct lttng_consumer_channel *channel,
 855                 uint64_t key, struct lttng_consumer_local_data *ctx);
 856 void lttng_consumer_reset_stream_rotate_state(struct lttng_consumer_stream *stream);
 857 enum lttcomm_return_code lttng_consumer_create_trace_chunk(
 858                 const uint64_t *relayd_id, uint64_t session_id,
 859                 uint64_t chunk_id,
 860                 time_t chunk_creation_timestamp,
 861                 const char *chunk_override_name,
 862                 const struct lttng_credentials *credentials,
 863                 struct lttng_directory_handle *chunk_directory_handle);
 864 enum lttcomm_return_code lttng_consumer_close_trace_chunk(
 865                 const uint64_t *relayd_id, uint64_t session_id,
 866                 uint64_t chunk_id, time_t chunk_close_timestamp,
 867                 const enum lttng_trace_chunk_command_type *close_command,
 868                 char *path);
 869 enum lttcomm_return_code lttng_consumer_trace_chunk_exists(
 870                 const uint64_t *relayd_id, uint64_t session_id,
 871                 uint64_t chunk_id);
 872 void lttng_consumer_cleanup_relayd(struct consumer_relayd_sock_pair *relayd);
 873 enum lttcomm_return_code lttng_consumer_init_command(
 874                 struct lttng_consumer_local_data *ctx,
 875                 const lttng_uuid sessiond_uuid);
 876 int lttng_consumer_clear_channel(struct lttng_consumer_channel *channel);
 877
 878 #endif /* LIB_CONSUMER_H */