src/common/consumer.h

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