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         /* Channel trace file path name. */
 110         char pathname[PATH_MAX];
 111         /* Channel name. */
 112         char name[LTTNG_SYMBOL_NAME_LEN];
 113         /* UID and GID of the channel. */
 114         uid_t uid;
 115         gid_t gid;
 116         /* Relayd id of the channel. -1 if it does not apply. */
 117         int64_t relayd_id;
 118         /*
 119          * Number of streams NOT initialized yet. This is used in order to not
 120          * delete this channel if streams are getting initialized.
 121          */
 122         unsigned int nb_init_stream_left;
 123         /* Output type (mmap or splice). */
 124         enum consumer_channel_output output;
 125         /* Channel type for stream */
 126         enum consumer_channel_type type;
 127
 128         /* For UST */
 129         struct ustctl_consumer_channel *uchan;
 130         unsigned char uuid[UUID_STR_LEN];
 131         /*
 132          * Temporary stream list used to store the streams once created and waiting
 133          * to be sent to the session daemon by receiving the
 134          * LTTNG_CONSUMER_GET_CHANNEL.
 135          */
 136         struct stream_list streams;
 137         /*
 138          * Set if the channel is metadata. We keep a reference to the stream
 139          * because we have to flush data once pushed by the session daemon. For a
 140          * regular channel, this is always set to NULL.
 141          */
 142         struct lttng_consumer_stream *metadata_stream;
 143
 144         /* for UST */
 145         int wait_fd;
 146         /* Node within channel thread ht */
 147         struct lttng_ht_node_u64 wait_fd_node;
 148
 149         /* Metadata cache is metadata channel */
 150         struct consumer_metadata_cache *metadata_cache;
 151         /* For metadata periodical flush */
 152         int switch_timer_enabled;
 153         timer_t switch_timer;
 154         int switch_timer_error;
 155
 156         /* On-disk circular buffer */
 157         uint64_t tracefile_size;
 158         uint64_t tracefile_count;
 159         /*
 160          * Monitor or not the streams of this channel meaning this indicates if the
 161          * streams should be sent to the data/metadata thread or added to the no
 162          * monitor list of the channel.
 163          */
 164         unsigned int monitor;
 165 };
 166
 167 /*
 168  * Internal representation of the streams, sessiond_key is used to identify
 169  * uniquely a stream.
 170  */
 171 struct lttng_consumer_stream {
 172         /* HT node used by the data_ht and metadata_ht */
 173         struct lttng_ht_node_u64 node;
 174         /* stream indexed per channel key node */
 175         struct lttng_ht_node_u64 node_channel_id;
 176         /* HT node used in consumer_data.stream_list_ht */
 177         struct lttng_ht_node_u64 node_session_id;
 178         /* Pointer to associated channel. */
 179         struct lttng_consumer_channel *chan;
 180
 181         /* Key by which the stream is indexed for 'node'. */
 182         uint64_t key;
 183         /*
 184          * File descriptor of the data output file. This can be either a file or a
 185          * socket fd for relayd streaming.
 186          */
 187         int out_fd; /* output file to write the data */
 188         /* Write position in the output file descriptor */
 189         off_t out_fd_offset;
 190         enum lttng_consumer_stream_state state;
 191         int shm_fd_is_copy;
 192         int data_read;
 193         int hangup_flush_done;
 194         enum lttng_event_output output;
 195         /* Maximum subbuffer size. */
 196         unsigned long max_sb_size;
 197
 198         /*
 199          * Still used by the kernel for MMAP output. For UST, the ustctl getter is
 200          * used for the mmap base and offset.
 201          */
 202         void *mmap_base;
 203         unsigned long mmap_len;
 204
 205         /* For UST */
 206
 207         int wait_fd;
 208         /* UID/GID of the user owning the session to which stream belongs */
 209         uid_t uid;
 210         gid_t gid;
 211         /* Network sequence number. Indicating on which relayd socket it goes. */
 212         uint64_t net_seq_idx;
 213         /* Identify if the stream is the metadata */
 214         unsigned int metadata_flag;
 215         /* Used when the stream is set for network streaming */
 216         uint64_t relayd_stream_id;
 217         /*
 218          * When sending a stream packet to a relayd, this number is used to track
 219          * the packet sent by the consumer and seen by the relayd. When sending the
 220          * data header to the relayd, this number is sent and if the transmission
 221          * was successful, it is incremented.
 222          *
 223          * Even if the full data is not fully transmitted it won't matter since
 224          * only two possible error can happen after that where either the relayd
 225          * died or a read error is detected on the stream making this value useless
 226          * after that.
 227          *
 228          * This value SHOULD be read/updated atomically or with the lock acquired.
 229          */
 230         uint64_t next_net_seq_num;
 231         /*
 232          * Lock to use the stream FDs since they are used between threads.
 233          *
 234          * This is nested INSIDE the consumer_data lock.
 235          * This is nested INSIDE the metadata cache lock.
 236          * This is nested OUTSIDE consumer_relayd_sock_pair lock.
 237          */
 238         pthread_mutex_t lock;
 239         /* Tracing session id */
 240         uint64_t session_id;
 241         /*
 242          * Indicates if the stream end point is still active or not (network
 243          * streaming or local file system). The thread "owning" the stream is
 244          * handling this status and can be notified of a state change through the
 245          * consumer data appropriate pipe.
 246          */
 247         enum consumer_endpoint_status endpoint_status;
 248         /* Stream name. Format is: <channel_name>_<cpu_number> */
 249         char name[LTTNG_SYMBOL_NAME_LEN];
 250         /* Internal state of libustctl. */
 251         struct ustctl_consumer_stream *ustream;
 252         struct cds_list_head send_node;
 253         /* On-disk circular buffer */
 254         uint64_t tracefile_size_current;
 255         uint64_t tracefile_count_current;
 256 };
 257
 258 /*
 259  * Internal representation of a relayd socket pair.
 260  */
 261 struct consumer_relayd_sock_pair {
 262         /* Network sequence number. */
 263         int64_t net_seq_idx;
 264         /* Number of stream associated with this relayd */
 265         unsigned int refcount;
 266
 267         /*
 268          * This flag indicates whether or not we should destroy this object. The
 269          * destruction should ONLY occurs when this flag is set and the refcount is
 270          * set to zero.
 271          */
 272         unsigned int destroy_flag;
 273
 274         /*
 275          * Mutex protecting the control socket to avoid out of order packets
 276          * between threads sending data to the relayd. Since metadata data is sent
 277          * over that socket, at least two sendmsg() are needed (header + data)
 278          * creating a race for packets to overlap between threads using it.
 279          *
 280          * This is nested INSIDE the consumer_data lock.
 281          * This is nested INSIDE the stream lock.
 282          */
 283         pthread_mutex_t ctrl_sock_mutex;
 284
 285         /* Control socket. Command and metadata are passed over it */
 286         struct lttcomm_relayd_sock control_sock;
 287
 288         /*
 289          * We don't need a mutex at this point since we only splice or write single
 290          * large chunk of data with a header appended at the begining. Moreover,
 291          * this socket is for now only used in a single thread.
 292          */
 293         struct lttcomm_relayd_sock data_sock;
 294         struct lttng_ht_node_u64 node;
 295
 296         /* Session id on both sides for the sockets. */
 297         uint64_t relayd_session_id;
 298         uint64_t sessiond_session_id;
 299 };
 300
 301 /*
 302  * UST consumer local data to the program. One or more instance per
 303  * process.
 304  */
 305 struct lttng_consumer_local_data {
 306         /*
 307          * Function to call when data is available on a buffer.
 308          * Returns the number of bytes read, or negative error value.
 309          */
 310         ssize_t (*on_buffer_ready)(struct lttng_consumer_stream *stream,
 311                         struct lttng_consumer_local_data *ctx);
 312         /*
 313          * function to call when we receive a new channel, it receives a
 314          * newly allocated channel, depending on the return code of this
 315          * function, the new channel will be handled by the application
 316          * or the library.
 317          *
 318          * Returns:
 319          *    > 0 (success, FD is kept by application)
 320          *   == 0 (success, FD is left to library)
 321          *    < 0 (error)
 322          */
 323         int (*on_recv_channel)(struct lttng_consumer_channel *channel);
 324         /*
 325          * function to call when we receive a new stream, it receives a
 326          * newly allocated stream, depending on the return code of this
 327          * function, the new stream will be handled by the application
 328          * or the library.
 329          *
 330          * Returns:
 331          *    > 0 (success, FD is kept by application)
 332          *   == 0 (success, FD is left to library)
 333          *    < 0 (error)
 334          */
 335         int (*on_recv_stream)(struct lttng_consumer_stream *stream);
 336         /*
 337          * function to call when a stream is getting updated by the session
 338          * daemon, this function receives the sessiond key and the new
 339          * state, depending on the return code of this function the
 340          * update of state for the stream is 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_update_stream)(int sessiond_key, uint32_t state);
 349         enum lttng_consumer_type type;
 350         /* socket to communicate errors with sessiond */
 351         int consumer_error_socket;
 352         /* socket to ask metadata to sessiond */
 353         int consumer_metadata_socket;
 354         /* socket to exchange commands with sessiond */
 355         char *consumer_command_sock_path;
 356         /* communication with splice */
 357         int consumer_thread_pipe[2];
 358         int consumer_channel_pipe[2];
 359         int consumer_splice_metadata_pipe[2];
 360         /* Data stream poll thread pipe. To transfer data stream to the thread */
 361         struct lttng_pipe *consumer_data_pipe;
 362         /* to let the signal handler wake up the fd receiver thread */
 363         int consumer_should_quit[2];
 364         /* Metadata poll thread pipe. Transfer metadata stream to it */
 365         struct lttng_pipe *consumer_metadata_pipe;
 366 };
 367
 368 /*
 369  * Library-level data. One instance per process.
 370  */
 371 struct lttng_consumer_global_data {
 372         /*
 373          * At this time, this lock is used to ensure coherence between the count
 374          * and number of element in the hash table. It's also a protection for
 375          * concurrent read/write between threads.
 376          *
 377          * This is nested OUTSIDE the stream lock.
 378          * This is nested OUTSIDE the consumer_relayd_sock_pair lock.
 379          */
 380         pthread_mutex_t lock;
 381
 382         /*
 383          * Number of streams in the data stream hash table declared outside.
 384          * Protected by consumer_data.lock.
 385          */
 386         int stream_count;
 387
 388         /* Channel hash table protected by consumer_data.lock. */
 389         struct lttng_ht *channel_ht;
 390         /*
 391          * Flag specifying if the local array of FDs needs update in the
 392          * poll function. Protected by consumer_data.lock.
 393          */
 394         unsigned int need_update;
 395         enum lttng_consumer_type type;
 396
 397         /*
 398          * Relayd socket(s) hashtable indexed by network sequence number. Each
 399          * stream has an index which associate the right relayd socket to use.
 400          */
 401         struct lttng_ht *relayd_ht;
 402
 403         /*
 404          * This hash table contains all streams (metadata and data) indexed by
 405          * session id. In other words, the ht is indexed by session id and each
 406          * bucket contains the list of associated streams.
 407          *
 408          * This HT uses the "node_session_id" of the consumer stream.
 409          */
 410         struct lttng_ht *stream_list_ht;
 411
 412         /*
 413          * This HT uses the "node_channel_id" of the consumer stream.
 414          */
 415         struct lttng_ht *stream_per_chan_id_ht;
 416 };
 417
 418 /*
 419  * Init consumer data structures.
 420  */
 421 void lttng_consumer_init(void);
 422
 423 /*
 424  * Set the error socket for communication with a session daemon.
 425  */
 426 void lttng_consumer_set_error_sock(struct lttng_consumer_local_data *ctx,
 427                 int sock);
 428
 429 /*
 430  * Set the command socket path for communication with a session daemon.
 431  */
 432 void lttng_consumer_set_command_sock_path(
 433                 struct lttng_consumer_local_data *ctx, char *sock);
 434
 435 /*
 436  * Send return code to session daemon.
 437  *
 438  * Returns the return code of sendmsg : the number of bytes transmitted or -1
 439  * on error.
 440  */
 441 int lttng_consumer_send_error(struct lttng_consumer_local_data *ctx, int cmd);
 442
 443 /*
 444  * Called from signal handler to ensure a clean exit.
 445  */
 446 void lttng_consumer_should_exit(struct lttng_consumer_local_data *ctx);
 447
 448 /*
 449  * Cleanup the daemon's socket on exit.
 450  */
 451 void lttng_consumer_cleanup(void);
 452
 453 /*
 454  * Flush pending writes to trace output disk file.
 455  */
 456 void lttng_consumer_sync_trace_file(struct lttng_consumer_stream *stream,
 457                 off_t orig_offset);
 458
 459 /*
 460  * Poll on the should_quit pipe and the command socket return -1 on error and
 461  * should exit, 0 if data is available on the command socket
 462  */
 463 int lttng_consumer_poll_socket(struct pollfd *kconsumer_sockpoll);
 464
 465 struct lttng_consumer_stream *consumer_allocate_stream(uint64_t channel_key,
 466                 uint64_t stream_key,
 467                 enum lttng_consumer_stream_state state,
 468                 const char *channel_name,
 469                 uid_t uid,
 470                 gid_t gid,
 471                 uint64_t relayd_id,
 472                 uint64_t session_id,
 473                 int cpu,
 474                 int *alloc_ret,
 475                 enum consumer_channel_type type);
 476 struct lttng_consumer_channel *consumer_allocate_channel(uint64_t key,
 477                 uint64_t session_id,
 478                 const char *pathname,
 479                 const char *name,
 480                 uid_t uid,
 481                 gid_t gid,
 482                 uint64_t relayd_id,
 483                 enum lttng_event_output output,
 484                 uint64_t tracefile_size,
 485                 uint64_t tracefile_count,
 486                 unsigned int monitor);
 487 void consumer_del_stream(struct lttng_consumer_stream *stream,
 488                 struct lttng_ht *ht);
 489 void consumer_del_metadata_stream(struct lttng_consumer_stream *stream,
 490                 struct lttng_ht *ht);
 491 int consumer_add_channel(struct lttng_consumer_channel *channel,
 492                 struct lttng_consumer_local_data *ctx);
 493 void consumer_del_channel(struct lttng_consumer_channel *channel);
 494
 495 /* lttng-relayd consumer command */
 496 struct consumer_relayd_sock_pair *consumer_allocate_relayd_sock_pair(
 497                 int net_seq_idx);
 498 struct consumer_relayd_sock_pair *consumer_find_relayd(uint64_t key);
 499 struct lttng_consumer_channel *consumer_find_channel(uint64_t key);
 500 int consumer_handle_stream_before_relayd(struct lttng_consumer_stream *stream,
 501                 size_t data_size);
 502 void consumer_steal_stream_key(int key, struct lttng_ht *ht);
 503
 504 struct lttng_consumer_local_data *lttng_consumer_create(
 505                 enum lttng_consumer_type type,
 506                 ssize_t (*buffer_ready)(struct lttng_consumer_stream *stream,
 507                         struct lttng_consumer_local_data *ctx),
 508                 int (*recv_channel)(struct lttng_consumer_channel *channel),
 509                 int (*recv_stream)(struct lttng_consumer_stream *stream),
 510                 int (*update_stream)(int sessiond_key, uint32_t state));
 511 void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx);
 512 ssize_t lttng_consumer_on_read_subbuffer_mmap(
 513                 struct lttng_consumer_local_data *ctx,
 514                 struct lttng_consumer_stream *stream, unsigned long len,
 515                 unsigned long padding);
 516 ssize_t lttng_consumer_on_read_subbuffer_splice(
 517                 struct lttng_consumer_local_data *ctx,
 518                 struct lttng_consumer_stream *stream, unsigned long len,
 519                 unsigned long padding);
 520 int lttng_consumer_take_snapshot(struct lttng_consumer_stream *stream);
 521 int lttng_consumer_get_produced_snapshot(struct lttng_consumer_stream *stream,
 522                 unsigned long *pos);
 523 void *consumer_thread_metadata_poll(void *data);
 524 void *consumer_thread_data_poll(void *data);
 525 void *consumer_thread_sessiond_poll(void *data);
 526 void *consumer_thread_channel_poll(void *data);
 527 int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 528                 int sock, struct pollfd *consumer_sockpoll);
 529
 530 ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream,
 531                 struct lttng_consumer_local_data *ctx);
 532 int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream);
 533 int consumer_add_relayd_socket(int net_seq_idx, int sock_type,
 534                 struct lttng_consumer_local_data *ctx, int sock,
 535                 struct pollfd *consumer_sockpoll, struct lttcomm_relayd_sock *relayd_sock,
 536                 unsigned int sessiond_id);
 537 void consumer_flag_relayd_for_destroy(
 538                 struct consumer_relayd_sock_pair *relayd);
 539 int consumer_data_pending(uint64_t id);
 540 int consumer_send_status_msg(int sock, int ret_code);
 541 int consumer_send_status_channel(int sock,
 542                 struct lttng_consumer_channel *channel);
 543 void notify_thread_del_channel(struct lttng_consumer_local_data *ctx,
 544                 uint64_t key);
 545 void consumer_destroy_relayd(struct consumer_relayd_sock_pair *relayd);
 546
 547 #endif /* LIB_CONSUMER_H */