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
 161 /*
 162  * Internal representation of the streams, sessiond_key is used to identify
 163  * uniquely a stream.
 164  */
 165 struct lttng_consumer_stream {
 166         /* HT node used by the data_ht and metadata_ht */
 167         struct lttng_ht_node_u64 node;
 168         /* stream indexed per channel key node */
 169         struct lttng_ht_node_u64 node_channel_id;
 170         /* HT node used in consumer_data.stream_list_ht */
 171         struct lttng_ht_node_u64 node_session_id;
 172         /* Pointer to associated channel. */
 173         struct lttng_consumer_channel *chan;
 174
 175         /* Key by which the stream is indexed for 'node'. */
 176         uint64_t key;
 177         /*
 178          * File descriptor of the data output file. This can be either a file or a
 179          * socket fd for relayd streaming.
 180          */
 181         int out_fd; /* output file to write the data */
 182         /* Write position in the output file descriptor */
 183         off_t out_fd_offset;
 184         enum lttng_consumer_stream_state state;
 185         int shm_fd_is_copy;
 186         int data_read;
 187         int hangup_flush_done;
 188         enum lttng_event_output output;
 189         /* Maximum subbuffer size. */
 190         unsigned long max_sb_size;
 191
 192         /*
 193          * Still used by the kernel for MMAP output. For UST, the ustctl getter is
 194          * used for the mmap base and offset.
 195          */
 196         void *mmap_base;
 197         unsigned long mmap_len;
 198
 199         /* For UST */
 200
 201         int wait_fd;
 202         /* UID/GID of the user owning the session to which stream belongs */
 203         uid_t uid;
 204         gid_t gid;
 205         /* Network sequence number. Indicating on which relayd socket it goes. */
 206         uint64_t net_seq_idx;
 207         /* Identify if the stream is the metadata */
 208         unsigned int metadata_flag;
 209         /* Used when the stream is set for network streaming */
 210         uint64_t relayd_stream_id;
 211         /*
 212          * When sending a stream packet to a relayd, this number is used to track
 213          * the packet sent by the consumer and seen by the relayd. When sending the
 214          * data header to the relayd, this number is sent and if the transmission
 215          * was successful, it is incremented.
 216          *
 217          * Even if the full data is not fully transmitted it won't matter since
 218          * only two possible error can happen after that where either the relayd
 219          * died or a read error is detected on the stream making this value useless
 220          * after that.
 221          *
 222          * This value SHOULD be read/updated atomically or with the lock acquired.
 223          */
 224         uint64_t next_net_seq_num;
 225         /*
 226          * Lock to use the stream FDs since they are used between threads.
 227          *
 228          * This is nested INSIDE the consumer_data lock.
 229          * This is nested INSIDE the metadata cache lock.
 230          * This is nested OUTSIDE consumer_relayd_sock_pair lock.
 231          */
 232         pthread_mutex_t lock;
 233         /* Tracing session id */
 234         uint64_t session_id;
 235         /*
 236          * Indicates if the stream end point is still active or not (network
 237          * streaming or local file system). The thread "owning" the stream is
 238          * handling this status and can be notified of a state change through the
 239          * consumer data appropriate pipe.
 240          */
 241         enum consumer_endpoint_status endpoint_status;
 242         /* Stream name. Format is: <channel_name>_<cpu_number> */
 243         char name[LTTNG_SYMBOL_NAME_LEN];
 244         /* Internal state of libustctl. */
 245         struct ustctl_consumer_stream *ustream;
 246         struct cds_list_head send_node;
 247         /* On-disk circular buffer */
 248         uint64_t tracefile_size_current;
 249         uint64_t tracefile_count_current;
 250 };
 251
 252 /*
 253  * Internal representation of a relayd socket pair.
 254  */
 255 struct consumer_relayd_sock_pair {
 256         /* Network sequence number. */
 257         int64_t net_seq_idx;
 258         /* Number of stream associated with this relayd */
 259         unsigned int refcount;
 260
 261         /*
 262          * This flag indicates whether or not we should destroy this object. The
 263          * destruction should ONLY occurs when this flag is set and the refcount is
 264          * set to zero.
 265          */
 266         unsigned int destroy_flag;
 267
 268         /*
 269          * Mutex protecting the control socket to avoid out of order packets
 270          * between threads sending data to the relayd. Since metadata data is sent
 271          * over that socket, at least two sendmsg() are needed (header + data)
 272          * creating a race for packets to overlap between threads using it.
 273          *
 274          * This is nested INSIDE the consumer_data lock.
 275          * This is nested INSIDE the stream lock.
 276          */
 277         pthread_mutex_t ctrl_sock_mutex;
 278
 279         /* Control socket. Command and metadata are passed over it */
 280         struct lttcomm_relayd_sock control_sock;
 281
 282         /*
 283          * We don't need a mutex at this point since we only splice or write single
 284          * large chunk of data with a header appended at the begining. Moreover,
 285          * this socket is for now only used in a single thread.
 286          */
 287         struct lttcomm_relayd_sock data_sock;
 288         struct lttng_ht_node_u64 node;
 289
 290         /* Session id on both sides for the sockets. */
 291         uint64_t relayd_session_id;
 292         uint64_t sessiond_session_id;
 293 };
 294
 295 /*
 296  * UST consumer local data to the program. One or more instance per
 297  * process.
 298  */
 299 struct lttng_consumer_local_data {
 300         /*
 301          * Function to call when data is available on a buffer.
 302          * Returns the number of bytes read, or negative error value.
 303          */
 304         ssize_t (*on_buffer_ready)(struct lttng_consumer_stream *stream,
 305                         struct lttng_consumer_local_data *ctx);
 306         /*
 307          * function to call when we receive a new channel, it receives a
 308          * newly allocated channel, depending on the return code of this
 309          * function, the new channel will be handled by the application
 310          * or the library.
 311          *
 312          * Returns:
 313          *    > 0 (success, FD is kept by application)
 314          *   == 0 (success, FD is left to library)
 315          *    < 0 (error)
 316          */
 317         int (*on_recv_channel)(struct lttng_consumer_channel *channel);
 318         /*
 319          * function to call when we receive a new stream, it receives a
 320          * newly allocated stream, depending on the return code of this
 321          * function, the new stream will be handled by the application
 322          * or the library.
 323          *
 324          * Returns:
 325          *    > 0 (success, FD is kept by application)
 326          *   == 0 (success, FD is left to library)
 327          *    < 0 (error)
 328          */
 329         int (*on_recv_stream)(struct lttng_consumer_stream *stream);
 330         /*
 331          * function to call when a stream is getting updated by the session
 332          * daemon, this function receives the sessiond key and the new
 333          * state, depending on the return code of this function the
 334          * update of state for the stream is handled by the application
 335          * or the library.
 336          *
 337          * Returns:
 338          *    > 0 (success, FD is kept by application)
 339          *   == 0 (success, FD is left to library)
 340          *    < 0 (error)
 341          */
 342         int (*on_update_stream)(int sessiond_key, uint32_t state);
 343         enum lttng_consumer_type type;
 344         /* socket to communicate errors with sessiond */
 345         int consumer_error_socket;
 346         /* socket to ask metadata to sessiond */
 347         int consumer_metadata_socket;
 348         /* socket to exchange commands with sessiond */
 349         char *consumer_command_sock_path;
 350         /* communication with splice */
 351         int consumer_thread_pipe[2];
 352         int consumer_channel_pipe[2];
 353         int consumer_splice_metadata_pipe[2];
 354         /* Data stream poll thread pipe. To transfer data stream to the thread */
 355         struct lttng_pipe *consumer_data_pipe;
 356         /* to let the signal handler wake up the fd receiver thread */
 357         int consumer_should_quit[2];
 358         /* Metadata poll thread pipe. Transfer metadata stream to it */
 359         struct lttng_pipe *consumer_metadata_pipe;
 360 };
 361
 362 /*
 363  * Library-level data. One instance per process.
 364  */
 365 struct lttng_consumer_global_data {
 366         /*
 367          * At this time, this lock is used to ensure coherence between the count
 368          * and number of element in the hash table. It's also a protection for
 369          * concurrent read/write between threads.
 370          *
 371          * This is nested OUTSIDE the stream lock.
 372          * This is nested OUTSIDE the consumer_relayd_sock_pair lock.
 373          */
 374         pthread_mutex_t lock;
 375
 376         /*
 377          * Number of streams in the data stream hash table declared outside.
 378          * Protected by consumer_data.lock.
 379          */
 380         int stream_count;
 381
 382         /* Channel hash table protected by consumer_data.lock. */
 383         struct lttng_ht *channel_ht;
 384         /*
 385          * Flag specifying if the local array of FDs needs update in the
 386          * poll function. Protected by consumer_data.lock.
 387          */
 388         unsigned int need_update;
 389         enum lttng_consumer_type type;
 390
 391         /*
 392          * Relayd socket(s) hashtable indexed by network sequence number. Each
 393          * stream has an index which associate the right relayd socket to use.
 394          */
 395         struct lttng_ht *relayd_ht;
 396
 397         /*
 398          * This hash table contains all streams (metadata and data) indexed by
 399          * session id. In other words, the ht is indexed by session id and each
 400          * bucket contains the list of associated streams.
 401          *
 402          * This HT uses the "node_session_id" of the consumer stream.
 403          */
 404         struct lttng_ht *stream_list_ht;
 405
 406         /*
 407          * This HT uses the "node_channel_id" of the consumer stream.
 408          */
 409         struct lttng_ht *stream_per_chan_id_ht;
 410 };
 411
 412 /*
 413  * Init consumer data structures.
 414  */
 415 void lttng_consumer_init(void);
 416
 417 /*
 418  * Set the error socket for communication with a session daemon.
 419  */
 420 void lttng_consumer_set_error_sock(struct lttng_consumer_local_data *ctx,
 421                 int sock);
 422
 423 /*
 424  * Set the command socket path for communication with a session daemon.
 425  */
 426 void lttng_consumer_set_command_sock_path(
 427                 struct lttng_consumer_local_data *ctx, char *sock);
 428
 429 /*
 430  * Send return code to session daemon.
 431  *
 432  * Returns the return code of sendmsg : the number of bytes transmitted or -1
 433  * on error.
 434  */
 435 int lttng_consumer_send_error(struct lttng_consumer_local_data *ctx, int cmd);
 436
 437 /*
 438  * Called from signal handler to ensure a clean exit.
 439  */
 440 void lttng_consumer_should_exit(struct lttng_consumer_local_data *ctx);
 441
 442 /*
 443  * Cleanup the daemon's socket on exit.
 444  */
 445 void lttng_consumer_cleanup(void);
 446
 447 /*
 448  * Flush pending writes to trace output disk file.
 449  */
 450 void lttng_consumer_sync_trace_file(struct lttng_consumer_stream *stream,
 451                 off_t orig_offset);
 452
 453 /*
 454  * Poll on the should_quit pipe and the command socket return -1 on error and
 455  * should exit, 0 if data is available on the command socket
 456  */
 457 int lttng_consumer_poll_socket(struct pollfd *kconsumer_sockpoll);
 458
 459 struct lttng_consumer_stream *consumer_allocate_stream(uint64_t channel_key,
 460                 uint64_t stream_key,
 461                 enum lttng_consumer_stream_state state,
 462                 const char *channel_name,
 463                 uid_t uid,
 464                 gid_t gid,
 465                 uint64_t relayd_id,
 466                 uint64_t session_id,
 467                 int cpu,
 468                 int *alloc_ret,
 469                 enum consumer_channel_type type);
 470 struct lttng_consumer_channel *consumer_allocate_channel(uint64_t key,
 471                 uint64_t session_id,
 472                 const char *pathname,
 473                 const char *name,
 474                 uid_t uid,
 475                 gid_t gid,
 476                 uint64_t relayd_id,
 477                 enum lttng_event_output output,
 478                 uint64_t tracefile_size,
 479                 uint64_t tracefile_count);
 480 void consumer_del_stream(struct lttng_consumer_stream *stream,
 481                 struct lttng_ht *ht);
 482 void consumer_del_metadata_stream(struct lttng_consumer_stream *stream,
 483                 struct lttng_ht *ht);
 484 int consumer_add_channel(struct lttng_consumer_channel *channel,
 485                 struct lttng_consumer_local_data *ctx);
 486 void consumer_del_channel(struct lttng_consumer_channel *channel);
 487
 488 /* lttng-relayd consumer command */
 489 struct consumer_relayd_sock_pair *consumer_allocate_relayd_sock_pair(
 490                 int net_seq_idx);
 491 struct consumer_relayd_sock_pair *consumer_find_relayd(uint64_t key);
 492 struct lttng_consumer_channel *consumer_find_channel(uint64_t key);
 493 int consumer_handle_stream_before_relayd(struct lttng_consumer_stream *stream,
 494                 size_t data_size);
 495 void consumer_steal_stream_key(int key, struct lttng_ht *ht);
 496
 497 struct lttng_consumer_local_data *lttng_consumer_create(
 498                 enum lttng_consumer_type type,
 499                 ssize_t (*buffer_ready)(struct lttng_consumer_stream *stream,
 500                         struct lttng_consumer_local_data *ctx),
 501                 int (*recv_channel)(struct lttng_consumer_channel *channel),
 502                 int (*recv_stream)(struct lttng_consumer_stream *stream),
 503                 int (*update_stream)(int sessiond_key, uint32_t state));
 504 void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx);
 505 ssize_t lttng_consumer_on_read_subbuffer_mmap(
 506                 struct lttng_consumer_local_data *ctx,
 507                 struct lttng_consumer_stream *stream, unsigned long len,
 508                 unsigned long padding);
 509 ssize_t lttng_consumer_on_read_subbuffer_splice(
 510                 struct lttng_consumer_local_data *ctx,
 511                 struct lttng_consumer_stream *stream, unsigned long len,
 512                 unsigned long padding);
 513 int lttng_consumer_take_snapshot(struct lttng_consumer_stream *stream);
 514 int lttng_consumer_get_produced_snapshot(struct lttng_consumer_stream *stream,
 515                 unsigned long *pos);
 516 void *consumer_thread_metadata_poll(void *data);
 517 void *consumer_thread_data_poll(void *data);
 518 void *consumer_thread_sessiond_poll(void *data);
 519 void *consumer_thread_channel_poll(void *data);
 520 int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 521                 int sock, struct pollfd *consumer_sockpoll);
 522
 523 ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream,
 524                 struct lttng_consumer_local_data *ctx);
 525 int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream);
 526 int consumer_add_relayd_socket(int net_seq_idx, int sock_type,
 527                 struct lttng_consumer_local_data *ctx, int sock,
 528                 struct pollfd *consumer_sockpoll, struct lttcomm_relayd_sock *relayd_sock,
 529                 unsigned int sessiond_id);
 530 void consumer_flag_relayd_for_destroy(
 531                 struct consumer_relayd_sock_pair *relayd);
 532 int consumer_data_pending(uint64_t id);
 533 int consumer_send_status_msg(int sock, int ret_code);
 534 int consumer_send_status_channel(int sock,
 535                 struct lttng_consumer_channel *channel);
 536 void notify_thread_del_channel(struct lttng_consumer_local_data *ctx,
 537                 uint64_t key);
 538 void consumer_destroy_relayd(struct consumer_relayd_sock_pair *relayd);
 539
 540 #endif /* LIB_CONSUMER_H */