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