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