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