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