src/common/consumer/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 #include <common/index/ctf-index.h>
  36 #include <common/buffer-view.h>
  37 #include <common/optional.h>
  38
  39 struct lttng_consumer_local_data;
  40
  41 /* Commands for consumer */
  42 enum lttng_consumer_command {
  43         LTTNG_CONSUMER_ADD_CHANNEL,
  44         LTTNG_CONSUMER_ADD_STREAM,
  45         /* pause, delete, active depending on fd state */
  46         LTTNG_CONSUMER_UPDATE_STREAM,
  47         /* inform the consumer to quit when all fd has hang up */
  48         LTTNG_CONSUMER_STOP,    /* deprecated */
  49         LTTNG_CONSUMER_ADD_RELAYD_SOCKET,
  50         /* Inform the consumer to kill a specific relayd connection */
  51         LTTNG_CONSUMER_DESTROY_RELAYD,
  52         /* Return to the sessiond if there is data pending for a session */
  53         LTTNG_CONSUMER_DATA_PENDING,
  54         /* Consumer creates a channel and returns it to sessiond. */
  55         LTTNG_CONSUMER_ASK_CHANNEL_CREATION,
  56         LTTNG_CONSUMER_GET_CHANNEL,
  57         LTTNG_CONSUMER_DESTROY_CHANNEL,
  58         LTTNG_CONSUMER_PUSH_METADATA,
  59         LTTNG_CONSUMER_CLOSE_METADATA,
  60         LTTNG_CONSUMER_SETUP_METADATA,
  61         LTTNG_CONSUMER_FLUSH_CHANNEL,
  62         LTTNG_CONSUMER_SNAPSHOT_CHANNEL,
  63         LTTNG_CONSUMER_SNAPSHOT_METADATA,
  64         LTTNG_CONSUMER_STREAMS_SENT,
  65         LTTNG_CONSUMER_DISCARDED_EVENTS,
  66         LTTNG_CONSUMER_LOST_PACKETS,
  67         LTTNG_CONSUMER_CLEAR_QUIESCENT_CHANNEL,
  68 };
  69
  70 /* State of each fd in consumer */
  71 enum lttng_consumer_stream_state {
  72         LTTNG_CONSUMER_ACTIVE_STREAM,
  73         LTTNG_CONSUMER_PAUSE_STREAM,
  74         LTTNG_CONSUMER_DELETE_STREAM,
  75 };
  76
  77 enum lttng_consumer_type {
  78         LTTNG_CONSUMER_UNKNOWN = 0,
  79         LTTNG_CONSUMER_KERNEL,
  80         LTTNG_CONSUMER64_UST,
  81         LTTNG_CONSUMER32_UST,
  82 };
  83
  84 enum consumer_endpoint_status {
  85         CONSUMER_ENDPOINT_ACTIVE,
  86         CONSUMER_ENDPOINT_INACTIVE,
  87 };
  88
  89 enum consumer_channel_output {
  90         CONSUMER_CHANNEL_MMAP   = 0,
  91         CONSUMER_CHANNEL_SPLICE = 1,
  92 };
  93
  94 enum consumer_channel_type {
  95         CONSUMER_CHANNEL_TYPE_METADATA  = 0,
  96         CONSUMER_CHANNEL_TYPE_DATA      = 1,
  97 };
  98
  99 extern struct lttng_consumer_global_data consumer_data;
 100
 101 struct stream_list {
 102         struct cds_list_head head;
 103         unsigned int count;
 104 };
 105
 106 /* Stub. */
 107 struct consumer_metadata_cache;
 108
 109 struct lttng_consumer_channel {
 110         /* HT node used for consumer_data.channel_ht */
 111         struct lttng_ht_node_u64 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         /*
 119          * Session id when requesting metadata to the session daemon for
 120          * a session with per-PID buffers.
 121          */
 122         uint64_t session_id_per_pid;
 123         /* Channel trace file path name. */
 124         char pathname[PATH_MAX];
 125         /* Channel name. */
 126         char name[LTTNG_SYMBOL_NAME_LEN];
 127         /* UID and GID of the session owning this channel. */
 128         uid_t uid;
 129         gid_t gid;
 130         /* Relayd id of the channel. -1ULL if it does not apply. */
 131         uint64_t relayd_id;
 132         /*
 133          * Number of streams NOT initialized yet. This is used in order to not
 134          * delete this channel if streams are getting initialized.
 135          */
 136         unsigned int nb_init_stream_left;
 137         /* Output type (mmap or splice). */
 138         enum consumer_channel_output output;
 139         /* Channel type for stream */
 140         enum consumer_channel_type type;
 141
 142         /* For UST */
 143         uid_t ust_app_uid;      /* Application UID. */
 144         struct ustctl_consumer_channel *uchan;
 145         unsigned char uuid[UUID_STR_LEN];
 146         /*
 147          * Temporary stream list used to store the streams once created and waiting
 148          * to be sent to the session daemon by receiving the
 149          * LTTNG_CONSUMER_GET_CHANNEL.
 150          */
 151         struct stream_list streams;
 152
 153         /*
 154          * Set if the channel is metadata. We keep a reference to the stream
 155          * because we have to flush data once pushed by the session daemon. For a
 156          * regular channel, this is always set to NULL.
 157          */
 158         struct lttng_consumer_stream *metadata_stream;
 159
 160         /* for UST */
 161         int wait_fd;
 162         /* Node within channel thread ht */
 163         struct lttng_ht_node_u64 wait_fd_node;
 164
 165         /* Metadata cache is metadata channel */
 166         struct consumer_metadata_cache *metadata_cache;
 167         /* For UST metadata periodical flush */
 168         int switch_timer_enabled;
 169         timer_t switch_timer;
 170         int switch_timer_error;
 171
 172         /* For the live mode */
 173         int live_timer_enabled;
 174         timer_t live_timer;
 175         int live_timer_error;
 176         /* Channel is part of a live session ? */
 177         bool is_live;
 178
 179         /* On-disk circular buffer */
 180         uint64_t tracefile_size;
 181         uint64_t tracefile_count;
 182         /*
 183          * Monitor or not the streams of this channel meaning this indicates if the
 184          * streams should be sent to the data/metadata thread or added to the no
 185          * monitor list of the channel.
 186          */
 187         unsigned int monitor;
 188
 189         /*
 190          * Channel lock.
 191          *
 192          * This lock protects against concurrent update of channel.
 193          *
 194          * This is nested INSIDE the consumer data lock.
 195          * This is nested OUTSIDE the channel timer lock.
 196          * This is nested OUTSIDE the metadata cache lock.
 197          * This is nested OUTSIDE stream lock.
 198          * This is nested OUTSIDE consumer_relayd_sock_pair lock.
 199          */
 200         pthread_mutex_t lock;
 201
 202         /*
 203          * Channel teardown lock.
 204          *
 205          * This lock protect against teardown of channel. It is _never_
 206          * taken by the timer handler.
 207          *
 208          * This is nested INSIDE the consumer data lock.
 209          * This is nested INSIDE the channel 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 timer_lock;
 215
 216         /* Timer value in usec for live streaming. */
 217         unsigned int live_timer_interval;
 218
 219         int *stream_fds;
 220         int nr_stream_fds;
 221         char root_shm_path[PATH_MAX];
 222         char shm_path[PATH_MAX];
 223         /* Total number of discarded events for that channel. */
 224         uint64_t discarded_events;
 225         /* Total number of missed packets due to overwriting (overwrite). */
 226         uint64_t lost_packets;
 227
 228         bool streams_sent_to_relayd;
 229 };
 230
 231 struct stream_subbuffer {
 232         union {
 233                 /*
 234                  * CONSUMER_CHANNEL_SPLICE
 235                  * No ownership assumed.
 236                  */
 237                 int fd;
 238                 /* CONSUMER_CHANNEL_MMAP */
 239                 struct lttng_buffer_view buffer;
 240         } buffer;
 241         union {
 242                 /*
 243                  * Common members are fine to access through either
 244                  * union entries (as per C11, Common Initial Sequence).
 245                  */
 246                 struct {
 247                         unsigned long subbuf_size;
 248                         unsigned long padded_subbuf_size;
 249                         uint64_t version;
 250                 } metadata;
 251                 struct {
 252                         unsigned long subbuf_size;
 253                         unsigned long padded_subbuf_size;
 254                         uint64_t packet_size;
 255                         uint64_t content_size;
 256                         uint64_t timestamp_begin;
 257                         uint64_t timestamp_end;
 258                         uint64_t events_discarded;
 259                         /* Left unset when unsupported. */
 260                         LTTNG_OPTIONAL(uint64_t) sequence_number;
 261                         uint64_t stream_id;
 262                         /* Left unset when unsupported. */
 263                         LTTNG_OPTIONAL(uint64_t) stream_instance_id;
 264                 } data;
 265         } info;
 266 };
 267
 268 /*
 269  * Perform any operation required to acknowledge
 270  * the wake-up of a consumer stream (e.g. consume a byte on a wake-up pipe).
 271  *
 272  * Stream and channel locks are acquired during this call.
 273  */
 274 typedef int (*on_wake_up_cb)(struct lttng_consumer_stream *);
 275
 276 /*
 277  * Perform any operation required before a consumer stream is put
 278  * to sleep before awaiting a data availability notification.
 279  *
 280  * Stream and channel locks are acquired during this call.
 281  */
 282 typedef int (*on_sleep_cb)(struct lttng_consumer_stream *,
 283                 struct lttng_consumer_local_data *);
 284
 285 /*
 286  * Acquire the subbuffer at the current 'consumed' position.
 287  *
 288  * Stream and channel locks are acquired during this call.
 289  */
 290 typedef int (*get_next_subbuffer_cb)(struct lttng_consumer_stream *,
 291                 struct stream_subbuffer *);
 292
 293 /*
 294  * Populate the stream_subbuffer's info member. The info to populate
 295  * depends on the type (metadata/data) of the stream.
 296  *
 297  * Stream and channel locks are acquired during this call.
 298  */
 299 typedef int (*extract_subbuffer_info_cb)(
 300                 struct lttng_consumer_stream *, struct stream_subbuffer *);
 301
 302 /*
 303  * Invoked after a subbuffer's info has been filled.
 304  *
 305  * Stream and channel locks are acquired during this call.
 306  */
 307 typedef int (*pre_consume_subbuffer_cb)(struct lttng_consumer_stream *,
 308                 const struct stream_subbuffer *);
 309
 310 /*
 311  * Consume subbuffer contents.
 312  *
 313  * Stream and channel locks are acquired during this call.
 314  */
 315 typedef ssize_t (*consume_subbuffer_cb)(struct lttng_consumer_local_data *,
 316                 struct lttng_consumer_stream *,
 317                 const struct stream_subbuffer *);
 318
 319 /*
 320  * Release the current subbuffer and advance the 'consumed' position by
 321  * one subbuffer.
 322  *
 323  * Stream and channel locks are acquired during this call.
 324  */
 325 typedef int (*put_next_subbuffer_cb)(struct lttng_consumer_stream *,
 326                 struct stream_subbuffer *);
 327
 328 /*
 329  * Invoked after consuming a subbuffer.
 330  *
 331  * Stream and channel locks are acquired during this call.
 332  */
 333 typedef int (*post_consume_cb)(struct lttng_consumer_stream *,
 334                 const struct stream_subbuffer *,
 335                 struct lttng_consumer_local_data *);
 336
 337 /*
 338  * Send a live beacon if no data is available.
 339  *
 340  * Stream and channel locks are acquired during this call.
 341  */
 342 typedef int (*send_live_beacon_cb)(struct lttng_consumer_stream *);
 343
 344 /*
 345  * Lock the stream and channel locks and any other stream-type specific
 346  * lock that need to be acquired during the processing of an
 347  * availability notification.
 348  */
 349 typedef void (*lock_cb)(struct lttng_consumer_stream *);
 350
 351 /*
 352  * Unlock the stream and channel locks and any other stream-type specific
 353  * lock before sleeping until the next availability notification.
 354  *
 355  * Stream and channel locks are acquired during this call.
 356  */
 357 typedef void (*unlock_cb)(struct lttng_consumer_stream *);
 358
 359 /*
 360  * Invoked when a subbuffer's metadata version does not match the last
 361  * known metadata version.
 362  *
 363  * Stream and channel locks are acquired during this call.
 364  */
 365 typedef void (*reset_metadata_cb)(struct lttng_consumer_stream *);
 366
 367 /*
 368  * Internal representation of the streams, sessiond_key is used to identify
 369  * uniquely a stream.
 370  */
 371 struct lttng_consumer_stream {
 372         /* HT node used by the data_ht and metadata_ht */
 373         struct lttng_ht_node_u64 node;
 374         /* stream indexed per channel key node */
 375         struct lttng_ht_node_u64 node_channel_id;
 376         /* HT node used in consumer_data.stream_list_ht */
 377         struct lttng_ht_node_u64 node_session_id;
 378         /* Pointer to associated channel. */
 379         struct lttng_consumer_channel *chan;
 380
 381         /* Key by which the stream is indexed for 'node'. */
 382         uint64_t key;
 383         /*
 384          * File descriptor of the data output file. This can be either a file or a
 385          * socket fd for relayd streaming.
 386          */
 387         int out_fd; /* output file to write the data */
 388         /* Write position in the output file descriptor */
 389         off_t out_fd_offset;
 390         /* Amount of bytes written to the output */
 391         uint64_t output_written;
 392         enum lttng_consumer_stream_state state;
 393         int shm_fd_is_copy;
 394         int data_read;
 395         int hangup_flush_done;
 396
 397         /*
 398          * Whether the stream is in a "complete" state (e.g. it does not have a
 399          * partially written sub-buffer.
 400          *
 401          * Initialized to "false" on stream creation (first packet is empty).
 402          *
 403          * The various transitions of the quiescent state are:
 404          *     - On "start" tracing: set to false, since the stream is not
 405          *       "complete".
 406          *     - On "stop" tracing: if !quiescent -> flush FINAL (update
 407          *       timestamp_end), and set to true; the stream has entered a
 408          *       complete/quiescent state.
 409          *     - On "destroy" or stream/application hang-up: if !quiescent ->
 410          *       flush FINAL, and set to true.
 411          *
 412          * NOTE: Update and read are protected by the stream lock.
 413          */
 414         bool quiescent;
 415
 416         /*
 417          * metadata_timer_lock protects flags waiting_on_metadata and
 418          * missed_metadata_flush.
 419          */
 420         pthread_mutex_t metadata_timer_lock;
 421         /*
 422          * Flag set when awaiting metadata to be pushed. Used in the
 423          * timer thread to skip waiting on the stream (and stream lock) to
 424          * ensure we can proceed to flushing metadata in live mode.
 425          */
 426         bool waiting_on_metadata;
 427         /* Raised when a timer misses a metadata flush. */
 428         bool missed_metadata_flush;
 429
 430         enum lttng_event_output output;
 431         /* Maximum subbuffer size. */
 432         unsigned long max_sb_size;
 433
 434         /*
 435          * Still used by the kernel for MMAP output. For UST, the ustctl getter is
 436          * used for the mmap base and offset.
 437          */
 438         void *mmap_base;
 439         unsigned long mmap_len;
 440
 441         /* For UST */
 442
 443         int wait_fd;
 444         /* UID/GID of the user owning the session to which stream belongs */
 445         uid_t uid;
 446         gid_t gid;
 447         /*
 448          * Relayd id, indicating on which relayd socket it goes. Set to -1ULL if
 449          * not the stream is not associated to a relay daemon.
 450          */
 451         uint64_t relayd_id;
 452         /*
 453          * Indicate if this stream was successfully sent to a relayd. This is set
 454          * after the refcount of the relayd is incremented and is checked when the
 455          * stream is closed before decrementing the refcount in order to avoid an
 456          * unbalanced state.
 457          */
 458         unsigned int sent_to_relayd;
 459
 460         /* Identify if the stream is the metadata */
 461         unsigned int metadata_flag;
 462         /*
 463          * Last known metadata version, reset the metadata file in case
 464          * of change.
 465          */
 466         uint64_t metadata_version;
 467         /* Used when the stream is set for network streaming */
 468         uint64_t relayd_stream_id;
 469         /*
 470          * When sending a stream packet to a relayd, this number is used to track
 471          * the packet sent by the consumer and seen by the relayd. When sending the
 472          * data header to the relayd, this number is sent and if the transmission
 473          * was successful, it is incremented.
 474          *
 475          * Even if the full data is not fully transmitted it won't matter since
 476          * only two possible error can happen after that where either the relayd
 477          * died or a read error is detected on the stream making this value useless
 478          * after that.
 479          *
 480          * This value SHOULD be read/updated atomically or with the lock acquired.
 481          */
 482         uint64_t next_net_seq_num;
 483         /*
 484          * Lock to use the stream FDs since they are used between threads.
 485          *
 486          * This is nested INSIDE the consumer_data lock.
 487          * This is nested INSIDE the channel lock.
 488          * This is nested INSIDE the channel timer lock.
 489          * This is nested OUTSIDE the metadata cache lock.
 490          * This is nested OUTSIDE consumer_relayd_sock_pair lock.
 491          */
 492         pthread_mutex_t lock;
 493         /* Tracing session id */
 494         uint64_t session_id;
 495         /*
 496          * Indicates if the stream end point is still active or not (network
 497          * streaming or local file system). The thread "owning" the stream is
 498          * handling this status and can be notified of a state change through the
 499          * consumer data appropriate pipe.
 500          */
 501         enum consumer_endpoint_status endpoint_status;
 502         /* Stream name. Format is: <channel_name>_<cpu_number> */
 503         char name[LTTNG_SYMBOL_NAME_LEN];
 504         /* Internal state of libustctl. */
 505         struct ustctl_consumer_stream *ustream;
 506         struct cds_list_head send_node;
 507         /* On-disk circular buffer */
 508         uint64_t tracefile_size_current;
 509         uint64_t tracefile_count_current;
 510         /*
 511          * Monitor or not the streams of this channel meaning this indicates if the
 512          * streams should be sent to the data/metadata thread or added to the no
 513          * monitor list of the channel.
 514          */
 515         unsigned int monitor;
 516         /*
 517          * Indicate if the stream is globally visible meaning that it has been
 518          * added to the multiple hash tables. If *not* set, NO lock should be
 519          * acquired in the destroy path.
 520          */
 521         unsigned int globally_visible;
 522         /*
 523          * Pipe to wake up the metadata poll thread when the UST metadata
 524          * cache is updated.
 525          */
 526         int ust_metadata_poll_pipe[2];
 527         /*
 528          * How much metadata was read from the metadata cache and sent
 529          * to the channel.
 530          */
 531         uint64_t ust_metadata_pushed;
 532         /*
 533          * Copy of the last discarded event value to detect the overflow of
 534          * the counter.
 535          */
 536         uint64_t last_discarded_events;
 537         /* Copy of the sequence number of the last packet extracted. */
 538         uint64_t last_sequence_number;
 539         /*
 540          * Index file object of the index file for this stream.
 541          */
 542         struct lttng_index_file *index_file;
 543
 544         /*
 545          * Local pipe to extract data when using splice.
 546          */
 547         int splice_pipe[2];
 548
 549         /*
 550          * Rendez-vous point between data and metadata stream in live mode.
 551          */
 552         pthread_cond_t metadata_rdv;
 553         pthread_mutex_t metadata_rdv_lock;
 554
 555         /* Indicate if the stream still has some data to be read. */
 556         unsigned int has_data:1;
 557         /*
 558          * Inform the consumer or relay to reset the metadata
 559          * file before writing in it (regeneration).
 560          */
 561         unsigned int reset_metadata_flag:1;
 562         struct {
 563                 /*
 564                  * Invoked in the order of declaration.
 565                  * See callback type definitions.
 566                  */
 567                 lock_cb lock;
 568                 on_wake_up_cb on_wake_up;
 569                 get_next_subbuffer_cb get_next_subbuffer;
 570                 extract_subbuffer_info_cb extract_subbuffer_info;
 571                 pre_consume_subbuffer_cb pre_consume_subbuffer;
 572                 reset_metadata_cb reset_metadata;
 573                 consume_subbuffer_cb consume_subbuffer;
 574                 put_next_subbuffer_cb put_next_subbuffer;
 575                 post_consume_cb post_consume;
 576                 send_live_beacon_cb send_live_beacon;
 577                 on_sleep_cb on_sleep;
 578                 unlock_cb unlock;
 579         } read_subbuffer_ops;
 580 };
 581
 582 /*
 583  * Internal representation of a relayd socket pair.
 584  */
 585 struct consumer_relayd_sock_pair {
 586         /* Network sequence number. */
 587         uint64_t id;
 588         /* Number of stream associated with this relayd */
 589         int refcount;
 590
 591         /*
 592          * This flag indicates whether or not we should destroy this object. The
 593          * destruction should ONLY occurs when this flag is set and the refcount is
 594          * set to zero.
 595          */
 596         unsigned int destroy_flag;
 597
 598         /*
 599          * Mutex protecting the control socket to avoid out of order packets
 600          * between threads sending data to the relayd. Since metadata data is sent
 601          * over that socket, at least two sendmsg() are needed (header + data)
 602          * creating a race for packets to overlap between threads using it.
 603          *
 604          * This is nested INSIDE the consumer_data lock.
 605          * This is nested INSIDE the stream lock.
 606          */
 607         pthread_mutex_t ctrl_sock_mutex;
 608
 609         /* Control socket. Command and metadata are passed over it */
 610         struct lttcomm_relayd_sock control_sock;
 611
 612         /*
 613          * We don't need a mutex at this point since we only splice or write single
 614          * large chunk of data with a header appended at the begining. Moreover,
 615          * this socket is for now only used in a single thread.
 616          */
 617         struct lttcomm_relayd_sock data_sock;
 618         struct lttng_ht_node_u64 node;
 619
 620         /* Session id on both sides for the sockets. */
 621         uint64_t relayd_session_id;
 622         uint64_t sessiond_session_id;
 623         struct lttng_consumer_local_data *ctx;
 624 };
 625
 626 /*
 627  * UST consumer local data to the program. One or more instance per
 628  * process.
 629  */
 630 struct lttng_consumer_local_data {
 631         /*
 632          * Function to call when data is available on a buffer.
 633          * Returns the number of bytes read, or negative error value.
 634          */
 635         ssize_t (*on_buffer_ready)(struct lttng_consumer_stream *stream,
 636                         struct lttng_consumer_local_data *ctx,
 637                         bool locked_by_caller);
 638         /*
 639          * function to call when we receive a new channel, it receives a
 640          * newly allocated channel, depending on the return code of this
 641          * function, the new channel will be handled by the application
 642          * or the library.
 643          *
 644          * Returns:
 645          *    > 0 (success, FD is kept by application)
 646          *   == 0 (success, FD is left to library)
 647          *    < 0 (error)
 648          */
 649         int (*on_recv_channel)(struct lttng_consumer_channel *channel);
 650         /*
 651          * function to call when we receive a new stream, it receives a
 652          * newly allocated stream, depending on the return code of this
 653          * function, the new stream will be handled by the application
 654          * or the library.
 655          *
 656          * Returns:
 657          *    > 0 (success, FD is kept by application)
 658          *   == 0 (success, FD is left to library)
 659          *    < 0 (error)
 660          */
 661         int (*on_recv_stream)(struct lttng_consumer_stream *stream);
 662         /*
 663          * function to call when a stream is getting updated by the session
 664          * daemon, this function receives the sessiond key and the new
 665          * state, depending on the return code of this function the
 666          * update of state for the stream is handled by the application
 667          * or the library.
 668          *
 669          * Returns:
 670          *    > 0 (success, FD is kept by application)
 671          *   == 0 (success, FD is left to library)
 672          *    < 0 (error)
 673          */
 674         int (*on_update_stream)(uint64_t sessiond_key, uint32_t state);
 675         enum lttng_consumer_type type;
 676         /* socket to communicate errors with sessiond */
 677         int consumer_error_socket;
 678         /* socket to ask metadata to sessiond. */
 679         int consumer_metadata_socket;
 680         /*
 681          * Protect consumer_metadata_socket.
 682          *
 683          * This is nested OUTSIDE the metadata cache lock.
 684          */
 685         pthread_mutex_t metadata_socket_lock;
 686         /* socket to exchange commands with sessiond */
 687         char *consumer_command_sock_path;
 688         /* communication with splice */
 689         int consumer_channel_pipe[2];
 690         /* Data stream poll thread pipe. To transfer data stream to the thread */
 691         struct lttng_pipe *consumer_data_pipe;
 692
 693         /*
 694          * Data thread use that pipe to catch wakeup from read subbuffer that
 695          * detects that there is still data to be read for the stream encountered.
 696          * Before doing so, the stream is flagged to indicate that there is still
 697          * data to be read.
 698          *
 699          * Both pipes (read/write) are owned and used inside the data thread.
 700          */
 701         struct lttng_pipe *consumer_wakeup_pipe;
 702         /* Indicate if the wakeup thread has been notified. */
 703         unsigned int has_wakeup:1;
 704
 705         /* to let the signal handler wake up the fd receiver thread */
 706         int consumer_should_quit[2];
 707         /* Metadata poll thread pipe. Transfer metadata stream to it */
 708         struct lttng_pipe *consumer_metadata_pipe;
 709 };
 710
 711 /*
 712  * Library-level data. One instance per process.
 713  */
 714 struct lttng_consumer_global_data {
 715         /*
 716          * At this time, this lock is used to ensure coherence between the count
 717          * and number of element in the hash table. It's also a protection for
 718          * concurrent read/write between threads.
 719          *
 720          * This is nested OUTSIDE the stream lock.
 721          * This is nested OUTSIDE the consumer_relayd_sock_pair lock.
 722          */
 723         pthread_mutex_t lock;
 724
 725         /*
 726          * Number of streams in the data stream hash table declared outside.
 727          * Protected by consumer_data.lock.
 728          */
 729         int stream_count;
 730
 731         /* Channel hash table protected by consumer_data.lock. */
 732         struct lttng_ht *channel_ht;
 733         /*
 734          * Flag specifying if the local array of FDs needs update in the
 735          * poll function. Protected by consumer_data.lock.
 736          */
 737         unsigned int need_update;
 738         enum lttng_consumer_type type;
 739
 740         /*
 741          * Relayd socket(s) hashtable indexed by network sequence number. Each
 742          * stream has an index which associate the right relayd socket to use.
 743          */
 744         struct lttng_ht *relayd_ht;
 745
 746         /*
 747          * This hash table contains all streams (metadata and data) indexed by
 748          * session id. In other words, the ht is indexed by session id and each
 749          * bucket contains the list of associated streams.
 750          *
 751          * This HT uses the "node_session_id" of the consumer stream.
 752          */
 753         struct lttng_ht *stream_list_ht;
 754
 755         /*
 756          * This HT uses the "node_channel_id" of the consumer stream.
 757          */
 758         struct lttng_ht *stream_per_chan_id_ht;
 759 };
 760
 761 /*
 762  * Set to nonzero when the consumer is exiting. Updated by signal
 763  * handler and thread exit, read by threads.
 764  */
 765 extern volatile int consumer_quit;
 766
 767 /*
 768  * Init consumer data structures.
 769  */
 770 int lttng_consumer_init(void);
 771
 772 /*
 773  * Set the error socket for communication with a session daemon.
 774  */
 775 void lttng_consumer_set_error_sock(struct lttng_consumer_local_data *ctx,
 776                 int sock);
 777
 778 /*
 779  * Set the command socket path for communication with a session daemon.
 780  */
 781 void lttng_consumer_set_command_sock_path(
 782                 struct lttng_consumer_local_data *ctx, char *sock);
 783
 784 /*
 785  * Send return code to session daemon.
 786  *
 787  * Returns the return code of sendmsg : the number of bytes transmitted or -1
 788  * on error.
 789  */
 790 int lttng_consumer_send_error(struct lttng_consumer_local_data *ctx, int cmd);
 791
 792 /*
 793  * Called from signal handler to ensure a clean exit.
 794  */
 795 void lttng_consumer_should_exit(struct lttng_consumer_local_data *ctx);
 796
 797 /*
 798  * Cleanup the daemon's socket on exit.
 799  */
 800 void lttng_consumer_cleanup(void);
 801
 802 /*
 803  * Poll on the should_quit pipe and the command socket return -1 on error and
 804  * should exit, 0 if data is available on the command socket
 805  */
 806 int lttng_consumer_poll_socket(struct pollfd *kconsumer_sockpoll);
 807
 808 struct lttng_consumer_stream *consumer_allocate_stream(
 809                 struct lttng_consumer_channel *channel,
 810                 uint64_t channel_key,
 811                 uint64_t stream_key,
 812                 enum lttng_consumer_stream_state state,
 813                 const char *channel_name,
 814                 uid_t uid,
 815                 gid_t gid,
 816                 uint64_t relayd_id,
 817                 uint64_t session_id,
 818                 int cpu,
 819                 int *alloc_ret,
 820                 enum consumer_channel_type type,
 821                 unsigned int monitor);
 822 struct lttng_consumer_channel *consumer_allocate_channel(uint64_t key,
 823                 uint64_t session_id,
 824                 const char *pathname,
 825                 const char *name,
 826                 uid_t uid,
 827                 gid_t gid,
 828                 uint64_t relayd_id,
 829                 enum lttng_event_output output,
 830                 uint64_t tracefile_size,
 831                 uint64_t tracefile_count,
 832                 uint64_t session_id_per_pid,
 833                 unsigned int monitor,
 834                 unsigned int live_timer_interval,
 835                 bool is_in_live_session,
 836                 const char *root_shm_path,
 837                 const char *shm_path);
 838 void consumer_del_stream(struct lttng_consumer_stream *stream,
 839                 struct lttng_ht *ht);
 840 void consumer_del_metadata_stream(struct lttng_consumer_stream *stream,
 841                 struct lttng_ht *ht);
 842 int consumer_add_channel(struct lttng_consumer_channel *channel,
 843                 struct lttng_consumer_local_data *ctx);
 844 void consumer_del_channel(struct lttng_consumer_channel *channel);
 845
 846 /* lttng-relayd consumer command */
 847 struct consumer_relayd_sock_pair *consumer_find_relayd(uint64_t key);
 848 int consumer_send_relayd_stream(struct lttng_consumer_stream *stream, char *path);
 849 int consumer_send_relayd_streams_sent(uint64_t relayd_id);
 850 void close_relayd_stream(struct lttng_consumer_stream *stream);
 851 struct lttng_consumer_channel *consumer_find_channel(uint64_t key);
 852 int consumer_handle_stream_before_relayd(struct lttng_consumer_stream *stream,
 853                 size_t data_size);
 854 void consumer_steal_stream_key(int key, struct lttng_ht *ht);
 855
 856 struct lttng_consumer_local_data *lttng_consumer_create(
 857                 enum lttng_consumer_type type,
 858                 ssize_t (*buffer_ready)(struct lttng_consumer_stream *stream,
 859                         struct lttng_consumer_local_data *ctx,
 860                         bool locked_by_caller),
 861                 int (*recv_channel)(struct lttng_consumer_channel *channel),
 862                 int (*recv_stream)(struct lttng_consumer_stream *stream),
 863                 int (*update_stream)(uint64_t sessiond_key, uint32_t state));
 864 void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx);
 865 ssize_t lttng_consumer_on_read_subbuffer_mmap(
 866                 struct lttng_consumer_local_data *ctx,
 867                 struct lttng_consumer_stream *stream,
 868                 const struct lttng_buffer_view *buffer,
 869                 unsigned long padding);
 870 ssize_t lttng_consumer_on_read_subbuffer_splice(
 871                 struct lttng_consumer_local_data *ctx,
 872                 struct lttng_consumer_stream *stream, unsigned long len,
 873                 unsigned long padding);
 874 int lttng_consumer_take_snapshot(struct lttng_consumer_stream *stream);
 875 int lttng_consumer_get_produced_snapshot(struct lttng_consumer_stream *stream,
 876                 unsigned long *pos);
 877 int lttng_ustconsumer_get_wakeup_fd(struct lttng_consumer_stream *stream);
 878 int lttng_ustconsumer_close_wakeup_fd(struct lttng_consumer_stream *stream);
 879 void *consumer_thread_metadata_poll(void *data);
 880 void *consumer_thread_data_poll(void *data);
 881 void *consumer_thread_sessiond_poll(void *data);
 882 void *consumer_thread_channel_poll(void *data);
 883 int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 884                 int sock, struct pollfd *consumer_sockpoll);
 885
 886 ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream,
 887                 struct lttng_consumer_local_data *ctx,
 888                 bool locked_by_caller);
 889 int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream);
 890 void consumer_add_relayd_socket(uint64_t relayd_id, int sock_type,
 891                 struct lttng_consumer_local_data *ctx, int sock,
 892                 struct pollfd *consumer_sockpoll, struct lttcomm_relayd_sock *relayd_sock,
 893                 uint64_t sessiond_id, uint64_t relayd_session_id);
 894 void consumer_flag_relayd_for_destroy(
 895                 struct consumer_relayd_sock_pair *relayd);
 896 int consumer_data_pending(uint64_t id);
 897 int consumer_send_status_msg(int sock, int ret_code);
 898 int consumer_send_status_channel(int sock,
 899                 struct lttng_consumer_channel *channel);
 900 void notify_thread_del_channel(struct lttng_consumer_local_data *ctx,
 901                 uint64_t key);
 902 void consumer_destroy_relayd(struct consumer_relayd_sock_pair *relayd);
 903 unsigned long consumer_get_consume_start_pos(unsigned long consumed_pos,
 904                 unsigned long produced_pos, uint64_t nb_packets_per_stream,
 905                 uint64_t max_sb_size);
 906 int consumer_add_data_stream(struct lttng_consumer_stream *stream);
 907 void consumer_del_stream_for_data(struct lttng_consumer_stream *stream);
 908 int consumer_add_metadata_stream(struct lttng_consumer_stream *stream);
 909 void consumer_del_stream_for_metadata(struct lttng_consumer_stream *stream);
 910 int consumer_create_index_file(struct lttng_consumer_stream *stream);
 911 void lttng_consumer_cleanup_relayd(struct consumer_relayd_sock_pair *relayd);
 912
 913 #endif /* LIB_CONSUMER_H */