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         /* Amount of bytes written to the output */
 212         uint64_t output_written;
 213         enum lttng_consumer_stream_state state;
 214         int shm_fd_is_copy;
 215         int data_read;
 216         int hangup_flush_done;
 217         enum lttng_event_output output;
 218         /* Maximum subbuffer size. */
 219         unsigned long max_sb_size;
 220
 221         /*
 222          * Still used by the kernel for MMAP output. For UST, the ustctl getter is
 223          * used for the mmap base and offset.
 224          */
 225         void *mmap_base;
 226         unsigned long mmap_len;
 227
 228         /* For UST */
 229
 230         int wait_fd;
 231         /* UID/GID of the user owning the session to which stream belongs */
 232         uid_t uid;
 233         gid_t gid;
 234         /* Network sequence number. Indicating on which relayd socket it goes. */
 235         uint64_t net_seq_idx;
 236         /* Identify if the stream is the metadata */
 237         unsigned int metadata_flag;
 238         /* Used when the stream is set for network streaming */
 239         uint64_t relayd_stream_id;
 240         /*
 241          * When sending a stream packet to a relayd, this number is used to track
 242          * the packet sent by the consumer and seen by the relayd. When sending the
 243          * data header to the relayd, this number is sent and if the transmission
 244          * was successful, it is incremented.
 245          *
 246          * Even if the full data is not fully transmitted it won't matter since
 247          * only two possible error can happen after that where either the relayd
 248          * died or a read error is detected on the stream making this value useless
 249          * after that.
 250          *
 251          * This value SHOULD be read/updated atomically or with the lock acquired.
 252          */
 253         uint64_t next_net_seq_num;
 254         /*
 255          * Lock to use the stream FDs since they are used between threads.
 256          *
 257          * This is nested INSIDE the consumer_data lock.
 258          * This is nested INSIDE the metadata cache lock.
 259          * This is nested INSIDE the channel lock.
 260          * This is nested INSIDE the channel timer lock.
 261          * This is nested OUTSIDE consumer_relayd_sock_pair lock.
 262          */
 263         pthread_mutex_t lock;
 264         /* Tracing session id */
 265         uint64_t session_id;
 266         /*
 267          * Indicates if the stream end point is still active or not (network
 268          * streaming or local file system). The thread "owning" the stream is
 269          * handling this status and can be notified of a state change through the
 270          * consumer data appropriate pipe.
 271          */
 272         enum consumer_endpoint_status endpoint_status;
 273         /* Stream name. Format is: <channel_name>_<cpu_number> */
 274         char name[LTTNG_SYMBOL_NAME_LEN];
 275         /* Internal state of libustctl. */
 276         struct ustctl_consumer_stream *ustream;
 277         struct cds_list_head send_node;
 278         /* On-disk circular buffer */
 279         uint64_t tracefile_size_current;
 280         uint64_t tracefile_count_current;
 281 };
 282
 283 /*
 284  * Internal representation of a relayd socket pair.
 285  */
 286 struct consumer_relayd_sock_pair {
 287         /* Network sequence number. */
 288         uint64_t net_seq_idx;
 289         /* Number of stream associated with this relayd */
 290         unsigned int refcount;
 291
 292         /*
 293          * This flag indicates whether or not we should destroy this object. The
 294          * destruction should ONLY occurs when this flag is set and the refcount is
 295          * set to zero.
 296          */
 297         unsigned int destroy_flag;
 298
 299         /*
 300          * Mutex protecting the control socket to avoid out of order packets
 301          * between threads sending data to the relayd. Since metadata data is sent
 302          * over that socket, at least two sendmsg() are needed (header + data)
 303          * creating a race for packets to overlap between threads using it.
 304          *
 305          * This is nested INSIDE the consumer_data lock.
 306          * This is nested INSIDE the stream lock.
 307          */
 308         pthread_mutex_t ctrl_sock_mutex;
 309
 310         /* Control socket. Command and metadata are passed over it */
 311         struct lttcomm_relayd_sock control_sock;
 312
 313         /*
 314          * We don't need a mutex at this point since we only splice or write single
 315          * large chunk of data with a header appended at the begining. Moreover,
 316          * this socket is for now only used in a single thread.
 317          */
 318         struct lttcomm_relayd_sock data_sock;
 319         struct lttng_ht_node_u64 node;
 320
 321         /* Session id on both sides for the sockets. */
 322         uint64_t relayd_session_id;
 323         uint64_t sessiond_session_id;
 324 };
 325
 326 /*
 327  * UST consumer local data to the program. One or more instance per
 328  * process.
 329  */
 330 struct lttng_consumer_local_data {
 331         /*
 332          * Function to call when data is available on a buffer.
 333          * Returns the number of bytes read, or negative error value.
 334          */
 335         ssize_t (*on_buffer_ready)(struct lttng_consumer_stream *stream,
 336                         struct lttng_consumer_local_data *ctx);
 337         /*
 338          * function to call when we receive a new channel, it receives a
 339          * newly allocated channel, depending on the return code of this
 340          * function, the new channel will be handled by the application
 341          * or the library.
 342          *
 343          * Returns:
 344          *    > 0 (success, FD is kept by application)
 345          *   == 0 (success, FD is left to library)
 346          *    < 0 (error)
 347          */
 348         int (*on_recv_channel)(struct lttng_consumer_channel *channel);
 349         /*
 350          * function to call when we receive a new stream, it receives a
 351          * newly allocated stream, depending on the return code of this
 352          * function, the new stream will be handled by the application
 353          * or the library.
 354          *
 355          * Returns:
 356          *    > 0 (success, FD is kept by application)
 357          *   == 0 (success, FD is left to library)
 358          *    < 0 (error)
 359          */
 360         int (*on_recv_stream)(struct lttng_consumer_stream *stream);
 361         /*
 362          * function to call when a stream is getting updated by the session
 363          * daemon, this function receives the sessiond key and the new
 364          * state, depending on the return code of this function the
 365          * update of state for the stream is handled by the application
 366          * or the library.
 367          *
 368          * Returns:
 369          *    > 0 (success, FD is kept by application)
 370          *   == 0 (success, FD is left to library)
 371          *    < 0 (error)
 372          */
 373         int (*on_update_stream)(uint64_t sessiond_key, uint32_t state);
 374         enum lttng_consumer_type type;
 375         /* socket to communicate errors with sessiond */
 376         int consumer_error_socket;
 377         /* socket to ask metadata to sessiond */
 378         int consumer_metadata_socket;
 379         /* socket to exchange commands with sessiond */
 380         char *consumer_command_sock_path;
 381         /* communication with splice */
 382         int consumer_thread_pipe[2];
 383         int consumer_channel_pipe[2];
 384         int consumer_splice_metadata_pipe[2];
 385         /* Data stream poll thread pipe. To transfer data stream to the thread */
 386         struct lttng_pipe *consumer_data_pipe;
 387         /* to let the signal handler wake up the fd receiver thread */
 388         int consumer_should_quit[2];
 389         /* Metadata poll thread pipe. Transfer metadata stream to it */
 390         struct lttng_pipe *consumer_metadata_pipe;
 391 };
 392
 393 /*
 394  * Library-level data. One instance per process.
 395  */
 396 struct lttng_consumer_global_data {
 397         /*
 398          * At this time, this lock is used to ensure coherence between the count
 399          * and number of element in the hash table. It's also a protection for
 400          * concurrent read/write between threads.
 401          *
 402          * This is nested OUTSIDE the stream lock.
 403          * This is nested OUTSIDE the consumer_relayd_sock_pair lock.
 404          */
 405         pthread_mutex_t lock;
 406
 407         /*
 408          * Number of streams in the data stream hash table declared outside.
 409          * Protected by consumer_data.lock.
 410          */
 411         int stream_count;
 412
 413         /* Channel hash table protected by consumer_data.lock. */
 414         struct lttng_ht *channel_ht;
 415         /*
 416          * Flag specifying if the local array of FDs needs update in the
 417          * poll function. Protected by consumer_data.lock.
 418          */
 419         unsigned int need_update;
 420         enum lttng_consumer_type type;
 421
 422         /*
 423          * Relayd socket(s) hashtable indexed by network sequence number. Each
 424          * stream has an index which associate the right relayd socket to use.
 425          */
 426         struct lttng_ht *relayd_ht;
 427
 428         /*
 429          * This hash table contains all streams (metadata and data) indexed by
 430          * session id. In other words, the ht is indexed by session id and each
 431          * bucket contains the list of associated streams.
 432          *
 433          * This HT uses the "node_session_id" of the consumer stream.
 434          */
 435         struct lttng_ht *stream_list_ht;
 436
 437         /*
 438          * This HT uses the "node_channel_id" of the consumer stream.
 439          */
 440         struct lttng_ht *stream_per_chan_id_ht;
 441 };
 442
 443 /*
 444  * Init consumer data structures.
 445  */
 446 void lttng_consumer_init(void);
 447
 448 /*
 449  * Set the error socket for communication with a session daemon.
 450  */
 451 void lttng_consumer_set_error_sock(struct lttng_consumer_local_data *ctx,
 452                 int sock);
 453
 454 /*
 455  * Set the command socket path for communication with a session daemon.
 456  */
 457 void lttng_consumer_set_command_sock_path(
 458                 struct lttng_consumer_local_data *ctx, char *sock);
 459
 460 /*
 461  * Send return code to session daemon.
 462  *
 463  * Returns the return code of sendmsg : the number of bytes transmitted or -1
 464  * on error.
 465  */
 466 int lttng_consumer_send_error(struct lttng_consumer_local_data *ctx, int cmd);
 467
 468 /*
 469  * Called from signal handler to ensure a clean exit.
 470  */
 471 void lttng_consumer_should_exit(struct lttng_consumer_local_data *ctx);
 472
 473 /*
 474  * Cleanup the daemon's socket on exit.
 475  */
 476 void lttng_consumer_cleanup(void);
 477
 478 /*
 479  * Flush pending writes to trace output disk file.
 480  */
 481 void lttng_consumer_sync_trace_file(struct lttng_consumer_stream *stream,
 482                 off_t orig_offset);
 483
 484 /*
 485  * Poll on the should_quit pipe and the command socket return -1 on error and
 486  * should exit, 0 if data is available on the command socket
 487  */
 488 int lttng_consumer_poll_socket(struct pollfd *kconsumer_sockpoll);
 489
 490 struct lttng_consumer_stream *consumer_allocate_stream(uint64_t channel_key,
 491                 uint64_t stream_key,
 492                 enum lttng_consumer_stream_state state,
 493                 const char *channel_name,
 494                 uid_t uid,
 495                 gid_t gid,
 496                 uint64_t relayd_id,
 497                 uint64_t session_id,
 498                 int cpu,
 499                 int *alloc_ret,
 500                 enum consumer_channel_type type);
 501 struct lttng_consumer_channel *consumer_allocate_channel(uint64_t key,
 502                 uint64_t session_id,
 503                 const char *pathname,
 504                 const char *name,
 505                 uid_t uid,
 506                 gid_t gid,
 507                 uint64_t relayd_id,
 508                 enum lttng_event_output output,
 509                 uint64_t tracefile_size,
 510                 uint64_t tracefile_count,
 511                 uint64_t session_id_per_pid);
 512 void consumer_del_stream(struct lttng_consumer_stream *stream,
 513                 struct lttng_ht *ht);
 514 void consumer_del_metadata_stream(struct lttng_consumer_stream *stream,
 515                 struct lttng_ht *ht);
 516 int consumer_add_channel(struct lttng_consumer_channel *channel,
 517                 struct lttng_consumer_local_data *ctx);
 518 void consumer_del_channel(struct lttng_consumer_channel *channel);
 519
 520 /* lttng-relayd consumer command */
 521 struct consumer_relayd_sock_pair *consumer_allocate_relayd_sock_pair(
 522                 uint64_t net_seq_idx);
 523 struct consumer_relayd_sock_pair *consumer_find_relayd(uint64_t key);
 524 struct lttng_consumer_channel *consumer_find_channel(uint64_t key);
 525 int consumer_handle_stream_before_relayd(struct lttng_consumer_stream *stream,
 526                 size_t data_size);
 527 void consumer_steal_stream_key(int key, struct lttng_ht *ht);
 528
 529 struct lttng_consumer_local_data *lttng_consumer_create(
 530                 enum lttng_consumer_type type,
 531                 ssize_t (*buffer_ready)(struct lttng_consumer_stream *stream,
 532                         struct lttng_consumer_local_data *ctx),
 533                 int (*recv_channel)(struct lttng_consumer_channel *channel),
 534                 int (*recv_stream)(struct lttng_consumer_stream *stream),
 535                 int (*update_stream)(uint64_t sessiond_key, uint32_t state));
 536 void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx);
 537 ssize_t lttng_consumer_on_read_subbuffer_mmap(
 538                 struct lttng_consumer_local_data *ctx,
 539                 struct lttng_consumer_stream *stream, unsigned long len,
 540                 unsigned long padding);
 541 ssize_t lttng_consumer_on_read_subbuffer_splice(
 542                 struct lttng_consumer_local_data *ctx,
 543                 struct lttng_consumer_stream *stream, unsigned long len,
 544                 unsigned long padding);
 545 int lttng_consumer_take_snapshot(struct lttng_consumer_stream *stream);
 546 int lttng_consumer_get_produced_snapshot(struct lttng_consumer_stream *stream,
 547                 unsigned long *pos);
 548 void *consumer_thread_metadata_poll(void *data);
 549 void *consumer_thread_data_poll(void *data);
 550 void *consumer_thread_sessiond_poll(void *data);
 551 void *consumer_thread_channel_poll(void *data);
 552 int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 553                 int sock, struct pollfd *consumer_sockpoll);
 554
 555 ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream,
 556                 struct lttng_consumer_local_data *ctx);
 557 int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream);
 558 int consumer_add_relayd_socket(uint64_t net_seq_idx, int sock_type,
 559                 struct lttng_consumer_local_data *ctx, int sock,
 560                 struct pollfd *consumer_sockpoll, struct lttcomm_relayd_sock *relayd_sock,
 561                 uint64_t sessiond_id);
 562 void consumer_flag_relayd_for_destroy(
 563                 struct consumer_relayd_sock_pair *relayd);
 564 int consumer_data_pending(uint64_t id);
 565 int consumer_send_status_msg(int sock, int ret_code);
 566 int consumer_send_status_channel(int sock,
 567                 struct lttng_consumer_channel *channel);
 568 void notify_thread_del_channel(struct lttng_consumer_local_data *ctx,
 569                 uint64_t key);
 570 int consumer_add_data_stream(struct lttng_consumer_stream *stream);
 571 void consumer_del_stream_for_data(struct lttng_consumer_stream *stream);
 572 int consumer_add_metadata_stream(struct lttng_consumer_stream *stream);
 573 void consumer_del_stream_for_metadata(struct lttng_consumer_stream *stream);
 574
 575 #endif /* LIB_CONSUMER_H */