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 extern struct lttng_consumer_global_data consumer_data;
  89
  90 struct stream_list {
  91         struct cds_list_head head;
  92         unsigned int count;
  93 };
  94
  95 /* Stub. */
  96 struct consumer_metadata_cache;
  97
  98 struct lttng_consumer_channel {
  99         /* HT node used for consumer_data.channel_ht */
 100         struct lttng_ht_node_u64 node;
 101         /* Indexed key. Incremented value in the consumer. */
 102         uint64_t key;
 103         /* Number of streams referencing this channel */
 104         int refcount;
 105         /* Tracing session id on the session daemon side. */
 106         uint64_t session_id;
 107         /* Channel trace file path name. */
 108         char pathname[PATH_MAX];
 109         /* Channel name. */
 110         char name[LTTNG_SYMBOL_NAME_LEN];
 111         /* UID and GID of the channel. */
 112         uid_t uid;
 113         gid_t gid;
 114         /* Relayd id of the channel. -1 if it does not apply. */
 115         int64_t relayd_id;
 116         /*
 117          * Number of streams NOT initialized yet. This is used in order to not
 118          * delete this channel if streams are getting initialized.
 119          */
 120         unsigned int nb_init_stream_left;
 121         /* Output type (mmap or splice). */
 122         enum consumer_channel_output output;
 123         /* Channel type for stream */
 124         enum consumer_channel_type type;
 125
 126         /* For UST */
 127         struct ustctl_consumer_channel *uchan;
 128         unsigned char uuid[UUID_STR_LEN];
 129         /*
 130          * Temporary stream list used to store the streams once created and waiting
 131          * to be sent to the session daemon by receiving the
 132          * LTTNG_CONSUMER_GET_CHANNEL.
 133          */
 134         struct stream_list streams;
 135         /*
 136          * Set if the channel is metadata. We keep a reference to the stream
 137          * because we have to flush data once pushed by the session daemon. For a
 138          * regular channel, this is always set to NULL.
 139          */
 140         struct lttng_consumer_stream *metadata_stream;
 141
 142         /* for UST */
 143         int wait_fd;
 144         /* Node within channel thread ht */
 145         struct lttng_ht_node_u64 wait_fd_node;
 146
 147         /* Metadata cache is metadata channel */
 148         struct consumer_metadata_cache *metadata_cache;
 149         /* For metadata periodical flush */
 150         int switch_timer_enabled;
 151         timer_t switch_timer;
 152         int switch_timer_error;
 153
 154         /* On-disk circular buffer */
 155         uint64_t tracefile_size;
 156         uint64_t tracefile_count;
 157 };
 158
 159 /*
 160  * Internal representation of the streams, sessiond_key is used to identify
 161  * uniquely a stream.
 162  */
 163 struct lttng_consumer_stream {
 164         /* HT node used by the data_ht and metadata_ht */
 165         struct lttng_ht_node_u64 node;
 166         /* stream indexed per channel key node */
 167         struct lttng_ht_node_u64 node_channel_id;
 168         /* HT node used in consumer_data.stream_list_ht */
 169         struct lttng_ht_node_u64 node_session_id;
 170         /* Pointer to associated channel. */
 171         struct lttng_consumer_channel *chan;
 172
 173         /* Key by which the stream is indexed for 'node'. */
 174         uint64_t key;
 175         /*
 176          * File descriptor of the data output file. This can be either a file or a
 177          * socket fd for relayd streaming.
 178          */
 179         int out_fd; /* output file to write the data */
 180         /* Write position in the output file descriptor */
 181         off_t out_fd_offset;
 182         enum lttng_consumer_stream_state state;
 183         int shm_fd_is_copy;
 184         int data_read;
 185         int hangup_flush_done;
 186         enum lttng_event_output output;
 187         /* Maximum subbuffer size. */
 188         unsigned long max_sb_size;
 189
 190         /*
 191          * Still used by the kernel for MMAP output. For UST, the ustctl getter is
 192          * used for the mmap base and offset.
 193          */
 194         void *mmap_base;
 195         unsigned long mmap_len;
 196
 197         /* For UST */
 198
 199         int wait_fd;
 200         /* UID/GID of the user owning the session to which stream belongs */
 201         uid_t uid;
 202         gid_t gid;
 203         /* Network sequence number. Indicating on which relayd socket it goes. */
 204         uint64_t net_seq_idx;
 205         /* Identify if the stream is the metadata */
 206         unsigned int metadata_flag;
 207         /* Used when the stream is set for network streaming */
 208         uint64_t relayd_stream_id;
 209         /*
 210          * When sending a stream packet to a relayd, this number is used to track
 211          * the packet sent by the consumer and seen by the relayd. When sending the
 212          * data header to the relayd, this number is sent and if the transmission
 213          * was successful, it is incremented.
 214          *
 215          * Even if the full data is not fully transmitted it won't matter since
 216          * only two possible error can happen after that where either the relayd
 217          * died or a read error is detected on the stream making this value useless
 218          * after that.
 219          *
 220          * This value SHOULD be read/updated atomically or with the lock acquired.
 221          */
 222         uint64_t next_net_seq_num;
 223         /*
 224          * Lock to use the stream FDs since they are used between threads.
 225          *
 226          * This is nested INSIDE the consumer_data lock.
 227          * This is nested INSIDE the metadata cache lock.
 228          * This is nested OUTSIDE consumer_relayd_sock_pair lock.
 229          */
 230         pthread_mutex_t lock;
 231         /* Tracing session id */
 232         uint64_t session_id;
 233         /*
 234          * Indicates if the stream end point is still active or not (network
 235          * streaming or local file system). The thread "owning" the stream is
 236          * handling this status and can be notified of a state change through the
 237          * consumer data appropriate pipe.
 238          */
 239         enum consumer_endpoint_status endpoint_status;
 240         /* Stream name. Format is: <channel_name>_<cpu_number> */
 241         char name[LTTNG_SYMBOL_NAME_LEN];
 242         /* Internal state of libustctl. */
 243         struct ustctl_consumer_stream *ustream;
 244         struct cds_list_head send_node;
 245         /* On-disk circular buffer */
 246         uint64_t tracefile_size_current;
 247         uint64_t tracefile_count_current;
 248 };
 249
 250 /*
 251  * Internal representation of a relayd socket pair.
 252  */
 253 struct consumer_relayd_sock_pair {
 254         /* Network sequence number. */
 255         int64_t net_seq_idx;
 256         /* Number of stream associated with this relayd */
 257         unsigned int refcount;
 258
 259         /*
 260          * This flag indicates whether or not we should destroy this object. The
 261          * destruction should ONLY occurs when this flag is set and the refcount is
 262          * set to zero.
 263          */
 264         unsigned int destroy_flag;
 265
 266         /*
 267          * Mutex protecting the control socket to avoid out of order packets
 268          * between threads sending data to the relayd. Since metadata data is sent
 269          * over that socket, at least two sendmsg() are needed (header + data)
 270          * creating a race for packets to overlap between threads using it.
 271          *
 272          * This is nested INSIDE the consumer_data lock.
 273          * This is nested INSIDE the stream lock.
 274          */
 275         pthread_mutex_t ctrl_sock_mutex;
 276
 277         /* Control socket. Command and metadata are passed over it */
 278         struct lttcomm_relayd_sock control_sock;
 279
 280         /*
 281          * We don't need a mutex at this point since we only splice or write single
 282          * large chunk of data with a header appended at the begining. Moreover,
 283          * this socket is for now only used in a single thread.
 284          */
 285         struct lttcomm_relayd_sock data_sock;
 286         struct lttng_ht_node_u64 node;
 287
 288         /* Session id on both sides for the sockets. */
 289         uint64_t relayd_session_id;
 290         uint64_t sessiond_session_id;
 291 };
 292
 293 /*
 294  * UST consumer local data to the program. One or more instance per
 295  * process.
 296  */
 297 struct lttng_consumer_local_data {
 298         /*
 299          * Function to call when data is available on a buffer.
 300          * Returns the number of bytes read, or negative error value.
 301          */
 302         ssize_t (*on_buffer_ready)(struct lttng_consumer_stream *stream,
 303                         struct lttng_consumer_local_data *ctx);
 304         /*
 305          * function to call when we receive a new channel, it receives a
 306          * newly allocated channel, depending on the return code of this
 307          * function, the new channel will be handled by the application
 308          * or the library.
 309          *
 310          * Returns:
 311          *    > 0 (success, FD is kept by application)
 312          *   == 0 (success, FD is left to library)
 313          *    < 0 (error)
 314          */
 315         int (*on_recv_channel)(struct lttng_consumer_channel *channel);
 316         /*
 317          * function to call when we receive a new stream, it receives a
 318          * newly allocated stream, depending on the return code of this
 319          * function, the new stream will be handled by the application
 320          * or the library.
 321          *
 322          * Returns:
 323          *    > 0 (success, FD is kept by application)
 324          *   == 0 (success, FD is left to library)
 325          *    < 0 (error)
 326          */
 327         int (*on_recv_stream)(struct lttng_consumer_stream *stream);
 328         /*
 329          * function to call when a stream is getting updated by the session
 330          * daemon, this function receives the sessiond key and the new
 331          * state, depending on the return code of this function the
 332          * update of state for the stream is 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_update_stream)(int sessiond_key, uint32_t state);
 341         enum lttng_consumer_type type;
 342         /* socket to communicate errors with sessiond */
 343         int consumer_error_socket;
 344         /* socket to ask metadata to sessiond */
 345         int consumer_metadata_socket;
 346         /* socket to exchange commands with sessiond */
 347         char *consumer_command_sock_path;
 348         /* communication with splice */
 349         int consumer_thread_pipe[2];
 350         int consumer_channel_pipe[2];
 351         int consumer_splice_metadata_pipe[2];
 352         /* Data stream poll thread pipe. To transfer data stream to the thread */
 353         struct lttng_pipe *consumer_data_pipe;
 354         /* to let the signal handler wake up the fd receiver thread */
 355         int consumer_should_quit[2];
 356         /* Metadata poll thread pipe. Transfer metadata stream to it */
 357         struct lttng_pipe *consumer_metadata_pipe;
 358 };
 359
 360 /*
 361  * Library-level data. One instance per process.
 362  */
 363 struct lttng_consumer_global_data {
 364         /*
 365          * At this time, this lock is used to ensure coherence between the count
 366          * and number of element in the hash table. It's also a protection for
 367          * concurrent read/write between threads.
 368          *
 369          * This is nested OUTSIDE the stream lock.
 370          * This is nested OUTSIDE the consumer_relayd_sock_pair lock.
 371          */
 372         pthread_mutex_t lock;
 373
 374         /*
 375          * Number of streams in the data stream hash table declared outside.
 376          * Protected by consumer_data.lock.
 377          */
 378         int stream_count;
 379
 380         /* Channel hash table protected by consumer_data.lock. */
 381         struct lttng_ht *channel_ht;
 382         /*
 383          * Flag specifying if the local array of FDs needs update in the
 384          * poll function. Protected by consumer_data.lock.
 385          */
 386         unsigned int need_update;
 387         enum lttng_consumer_type type;
 388
 389         /*
 390          * Relayd socket(s) hashtable indexed by network sequence number. Each
 391          * stream has an index which associate the right relayd socket to use.
 392          */
 393         struct lttng_ht *relayd_ht;
 394
 395         /*
 396          * This hash table contains all streams (metadata and data) indexed by
 397          * session id. In other words, the ht is indexed by session id and each
 398          * bucket contains the list of associated streams.
 399          *
 400          * This HT uses the "node_session_id" of the consumer stream.
 401          */
 402         struct lttng_ht *stream_list_ht;
 403
 404         /*
 405          * This HT uses the "node_channel_id" of the consumer stream.
 406          */
 407         struct lttng_ht *stream_per_chan_id_ht;
 408 };
 409
 410 /*
 411  * Init consumer data structures.
 412  */
 413 void lttng_consumer_init(void);
 414
 415 /*
 416  * Set the error socket for communication with a session daemon.
 417  */
 418 void lttng_consumer_set_error_sock(struct lttng_consumer_local_data *ctx,
 419                 int sock);
 420
 421 /*
 422  * Set the command socket path for communication with a session daemon.
 423  */
 424 void lttng_consumer_set_command_sock_path(
 425                 struct lttng_consumer_local_data *ctx, char *sock);
 426
 427 /*
 428  * Send return code to session daemon.
 429  *
 430  * Returns the return code of sendmsg : the number of bytes transmitted or -1
 431  * on error.
 432  */
 433 int lttng_consumer_send_error(struct lttng_consumer_local_data *ctx, int cmd);
 434
 435 /*
 436  * Called from signal handler to ensure a clean exit.
 437  */
 438 void lttng_consumer_should_exit(struct lttng_consumer_local_data *ctx);
 439
 440 /*
 441  * Cleanup the daemon's socket on exit.
 442  */
 443 void lttng_consumer_cleanup(void);
 444
 445 /*
 446  * Flush pending writes to trace output disk file.
 447  */
 448 void lttng_consumer_sync_trace_file(struct lttng_consumer_stream *stream,
 449                 off_t orig_offset);
 450
 451 /*
 452  * Poll on the should_quit pipe and the command socket return -1 on error and
 453  * should exit, 0 if data is available on the command socket
 454  */
 455 int lttng_consumer_poll_socket(struct pollfd *kconsumer_sockpoll);
 456
 457 struct lttng_consumer_stream *consumer_allocate_stream(uint64_t channel_key,
 458                 uint64_t stream_key,
 459                 enum lttng_consumer_stream_state state,
 460                 const char *channel_name,
 461                 uid_t uid,
 462                 gid_t gid,
 463                 uint64_t relayd_id,
 464                 uint64_t session_id,
 465                 int cpu,
 466                 int *alloc_ret,
 467                 enum consumer_channel_type type);
 468 struct lttng_consumer_channel *consumer_allocate_channel(uint64_t key,
 469                 uint64_t session_id,
 470                 const char *pathname,
 471                 const char *name,
 472                 uid_t uid,
 473                 gid_t gid,
 474                 uint64_t relayd_id,
 475                 enum lttng_event_output output,
 476                 uint64_t tracefile_size,
 477                 uint64_t tracefile_count);
 478 void consumer_del_stream(struct lttng_consumer_stream *stream,
 479                 struct lttng_ht *ht);
 480 void consumer_del_metadata_stream(struct lttng_consumer_stream *stream,
 481                 struct lttng_ht *ht);
 482 int consumer_add_channel(struct lttng_consumer_channel *channel,
 483                 struct lttng_consumer_local_data *ctx);
 484 void consumer_del_channel(struct lttng_consumer_channel *channel);
 485
 486 /* lttng-relayd consumer command */
 487 struct consumer_relayd_sock_pair *consumer_allocate_relayd_sock_pair(
 488                 int net_seq_idx);
 489 struct consumer_relayd_sock_pair *consumer_find_relayd(uint64_t key);
 490 struct lttng_consumer_channel *consumer_find_channel(uint64_t key);
 491 int consumer_handle_stream_before_relayd(struct lttng_consumer_stream *stream,
 492                 size_t data_size);
 493 void consumer_steal_stream_key(int key, struct lttng_ht *ht);
 494
 495 struct lttng_consumer_local_data *lttng_consumer_create(
 496                 enum lttng_consumer_type type,
 497                 ssize_t (*buffer_ready)(struct lttng_consumer_stream *stream,
 498                         struct lttng_consumer_local_data *ctx),
 499                 int (*recv_channel)(struct lttng_consumer_channel *channel),
 500                 int (*recv_stream)(struct lttng_consumer_stream *stream),
 501                 int (*update_stream)(int sessiond_key, uint32_t state));
 502 void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx);
 503 ssize_t lttng_consumer_on_read_subbuffer_mmap(
 504                 struct lttng_consumer_local_data *ctx,
 505                 struct lttng_consumer_stream *stream, unsigned long len,
 506                 unsigned long padding);
 507 ssize_t lttng_consumer_on_read_subbuffer_splice(
 508                 struct lttng_consumer_local_data *ctx,
 509                 struct lttng_consumer_stream *stream, unsigned long len,
 510                 unsigned long padding);
 511 int lttng_consumer_take_snapshot(struct lttng_consumer_stream *stream);
 512 int lttng_consumer_get_produced_snapshot(struct lttng_consumer_stream *stream,
 513                 unsigned long *pos);
 514 void *consumer_thread_metadata_poll(void *data);
 515 void *consumer_thread_data_poll(void *data);
 516 void *consumer_thread_sessiond_poll(void *data);
 517 void *consumer_thread_channel_poll(void *data);
 518 int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 519                 int sock, struct pollfd *consumer_sockpoll);
 520
 521 ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream,
 522                 struct lttng_consumer_local_data *ctx);
 523 int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream);
 524 int consumer_add_relayd_socket(int net_seq_idx, int sock_type,
 525                 struct lttng_consumer_local_data *ctx, int sock,
 526                 struct pollfd *consumer_sockpoll, struct lttcomm_relayd_sock *relayd_sock,
 527                 unsigned int sessiond_id);
 528 void consumer_flag_relayd_for_destroy(
 529                 struct consumer_relayd_sock_pair *relayd);
 530 int consumer_data_pending(uint64_t id);
 531 int consumer_send_status_msg(int sock, int ret_code);
 532 int consumer_send_status_channel(int sock,
 533                 struct lttng_consumer_channel *channel);
 534 void notify_thread_del_channel(struct lttng_consumer_local_data *ctx,
 535                 uint64_t key);
 536 void consumer_destroy_relayd(struct consumer_relayd_sock_pair *relayd);
 537
 538 #endif /* LIB_CONSUMER_H */