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
  35 /* Commands for consumer */
  36 enum lttng_consumer_command {
  37         LTTNG_CONSUMER_ADD_CHANNEL,
  38         LTTNG_CONSUMER_ADD_STREAM,
  39         /* pause, delete, active depending on fd state */
  40         LTTNG_CONSUMER_UPDATE_STREAM,
  41         /* inform the consumer to quit when all fd has hang up */
  42         LTTNG_CONSUMER_STOP,
  43         LTTNG_CONSUMER_ADD_RELAYD_SOCKET,
  44         /* Inform the consumer to kill a specific relayd connection */
  45         LTTNG_CONSUMER_DESTROY_RELAYD,
  46         /* Return to the sessiond if there is data pending for a session */
  47         LTTNG_CONSUMER_DATA_PENDING,
  48         /* Consumer creates a channel and returns it to sessiond. */
  49         LTTNG_CONSUMER_ASK_CHANNEL_CREATION,
  50         LTTNG_CONSUMER_GET_CHANNEL,
  51         LTTNG_CONSUMER_DESTROY_CHANNEL,
  52         LTTNG_CONSUMER_PUSH_METADATA,
  53         LTTNG_CONSUMER_CLOSE_METADATA,
  54         LTTNG_CONSUMER_SETUP_METADATA,
  55         LTTNG_CONSUMER_FLUSH_CHANNEL,
  56 };
  57
  58 /* State of each fd in consumer */
  59 enum lttng_consumer_stream_state {
  60         LTTNG_CONSUMER_ACTIVE_STREAM,
  61         LTTNG_CONSUMER_PAUSE_STREAM,
  62         LTTNG_CONSUMER_DELETE_STREAM,
  63 };
  64
  65 enum lttng_consumer_type {
  66         LTTNG_CONSUMER_UNKNOWN = 0,
  67         LTTNG_CONSUMER_KERNEL,
  68         LTTNG_CONSUMER64_UST,
  69         LTTNG_CONSUMER32_UST,
  70 };
  71
  72 enum consumer_endpoint_status {
  73         CONSUMER_ENDPOINT_ACTIVE,
  74         CONSUMER_ENDPOINT_INACTIVE,
  75 };
  76
  77 enum consumer_channel_output {
  78         CONSUMER_CHANNEL_MMAP   = 0,
  79         CONSUMER_CHANNEL_SPLICE = 1,
  80 };
  81
  82 enum consumer_channel_type {
  83         CONSUMER_CHANNEL_TYPE_METADATA  = 0,
  84         CONSUMER_CHANNEL_TYPE_DATA      = 1,
  85 };
  86
  87 struct stream_list {
  88         struct cds_list_head head;
  89         unsigned int count;
  90 };
  91
  92 /* Stub. */
  93 struct consumer_metadata_cache;
  94
  95 struct lttng_consumer_channel {
  96         /* HT node used for consumer_data.channel_ht */
  97         struct lttng_ht_node_u64 node;
  98         /* Indexed key. Incremented value in the consumer. */
  99         uint64_t key;
 100         /* Number of streams referencing this channel */
 101         int refcount;
 102         /* Tracing session id on the session daemon side. */
 103         uint64_t session_id;
 104         /* Channel trace file path name. */
 105         char pathname[PATH_MAX];
 106         /* Channel name. */
 107         char name[LTTNG_SYMBOL_NAME_LEN];
 108         /* UID and GID of the channel. */
 109         uid_t uid;
 110         gid_t gid;
 111         /* Relayd id of the channel. -1 if it does not apply. */
 112         int64_t relayd_id;
 113         /*
 114          * Number of streams NOT initialized yet. This is used in order to not
 115          * delete this channel if streams are getting initialized.
 116          */
 117         unsigned int nb_init_stream_left;
 118         /* Output type (mmap or splice). */
 119         enum consumer_channel_output output;
 120         /* Channel type for stream */
 121         enum consumer_channel_type type;
 122
 123         /* For UST */
 124         struct ustctl_consumer_channel *uchan;
 125         unsigned char uuid[UUID_STR_LEN];
 126         /*
 127          * Temporary stream list used to store the streams once created and waiting
 128          * to be sent to the session daemon by receiving the
 129          * LTTNG_CONSUMER_GET_CHANNEL.
 130          */
 131         struct stream_list streams;
 132         /*
 133          * Set if the channel is metadata. We keep a reference to the stream
 134          * because we have to flush data once pushed by the session daemon. For a
 135          * regular channel, this is always set to NULL.
 136          */
 137         struct lttng_consumer_stream *metadata_stream;
 138
 139         /* for UST */
 140         int wait_fd;
 141         /* Node within channel thread ht */
 142         struct lttng_ht_node_u64 wait_fd_node;
 143
 144         /* Metadata cache is metadata channel */
 145         struct consumer_metadata_cache *metadata_cache;
 146         /* For metadata periodical flush */
 147         int switch_timer_enabled;
 148         timer_t switch_timer;
 149         int switch_timer_error;
 150
 151         /* On-disk circular buffer */
 152         uint64_t tracefile_size;
 153         uint64_t tracefile_count;
 154 };
 155
 156 /*
 157  * Internal representation of the streams, sessiond_key is used to identify
 158  * uniquely a stream.
 159  */
 160 struct lttng_consumer_stream {
 161         /* HT node used by the data_ht and metadata_ht */
 162         struct lttng_ht_node_u64 node;
 163         /* stream indexed per channel key node */
 164         struct lttng_ht_node_u64 node_channel_id;
 165         /* HT node used in consumer_data.stream_list_ht */
 166         struct lttng_ht_node_u64 node_session_id;
 167         /* Pointer to associated channel. */
 168         struct lttng_consumer_channel *chan;
 169
 170         /* Key by which the stream is indexed for 'node'. */
 171         uint64_t key;
 172         /*
 173          * File descriptor of the data output file. This can be either a file or a
 174          * socket fd for relayd streaming.
 175          */
 176         int out_fd; /* output file to write the data */
 177         /* Write position in the output file descriptor */
 178         off_t out_fd_offset;
 179         enum lttng_consumer_stream_state state;
 180         int shm_fd_is_copy;
 181         int data_read;
 182         int hangup_flush_done;
 183         enum lttng_event_output output;
 184         /* Maximum subbuffer size. */
 185         unsigned long max_sb_size;
 186
 187         /*
 188          * Still used by the kernel for MMAP output. For UST, the ustctl getter is
 189          * used for the mmap base and offset.
 190          */
 191         void *mmap_base;
 192         unsigned long mmap_len;
 193
 194         /* For UST */
 195
 196         int wait_fd;
 197         /* UID/GID of the user owning the session to which stream belongs */
 198         uid_t uid;
 199         gid_t gid;
 200         /* Network sequence number. Indicating on which relayd socket it goes. */
 201         uint64_t net_seq_idx;
 202         /* Identify if the stream is the metadata */
 203         unsigned int metadata_flag;
 204         /* Used when the stream is set for network streaming */
 205         uint64_t relayd_stream_id;
 206         /*
 207          * When sending a stream packet to a relayd, this number is used to track
 208          * the packet sent by the consumer and seen by the relayd. When sending the
 209          * data header to the relayd, this number is sent and if the transmission
 210          * was successful, it is incremented.
 211          *
 212          * Even if the full data is not fully transmitted it won't matter since
 213          * only two possible error can happen after that where either the relayd
 214          * died or a read error is detected on the stream making this value useless
 215          * after that.
 216          *
 217          * This value SHOULD be read/updated atomically or with the lock acquired.
 218          */
 219         uint64_t next_net_seq_num;
 220         /*
 221          * Lock to use the stream FDs since they are used between threads.
 222          *
 223          * This is nested INSIDE the consumer_data lock.
 224          * This is nested OUTSIDE consumer_relayd_sock_pair lock.
 225          */
 226         pthread_mutex_t lock;
 227         /* Tracing session id */
 228         uint64_t session_id;
 229         /*
 230          * Indicates if the stream end point is still active or not (network
 231          * streaming or local file system). The thread "owning" the stream is
 232          * handling this status and can be notified of a state change through the
 233          * consumer data appropriate pipe.
 234          */
 235         enum consumer_endpoint_status endpoint_status;
 236         /* Stream name. Format is: <channel_name>_<cpu_number> */
 237         char name[LTTNG_SYMBOL_NAME_LEN];
 238         /* Internal state of libustctl. */
 239         struct ustctl_consumer_stream *ustream;
 240         struct cds_list_head send_node;
 241         /* On-disk circular buffer */
 242         uint64_t tracefile_size_current;
 243         uint64_t tracefile_count_current;
 244 };
 245
 246 /*
 247  * Internal representation of a relayd socket pair.
 248  */
 249 struct consumer_relayd_sock_pair {
 250         /* Network sequence number. */
 251         int64_t net_seq_idx;
 252         /* Number of stream associated with this relayd */
 253         unsigned int refcount;
 254
 255         /*
 256          * This flag indicates whether or not we should destroy this object. The
 257          * destruction should ONLY occurs when this flag is set and the refcount is
 258          * set to zero.
 259          */
 260         unsigned int destroy_flag;
 261
 262         /*
 263          * Mutex protecting the control socket to avoid out of order packets
 264          * between threads sending data to the relayd. Since metadata data is sent
 265          * over that socket, at least two sendmsg() are needed (header + data)
 266          * creating a race for packets to overlap between threads using it.
 267          *
 268          * This is nested INSIDE the consumer_data lock.
 269          * This is nested INSIDE the stream lock.
 270          */
 271         pthread_mutex_t ctrl_sock_mutex;
 272
 273         /* Control socket. Command and metadata are passed over it */
 274         struct lttcomm_relayd_sock control_sock;
 275
 276         /*
 277          * We don't need a mutex at this point since we only splice or write single
 278          * large chunk of data with a header appended at the begining. Moreover,
 279          * this socket is for now only used in a single thread.
 280          */
 281         struct lttcomm_relayd_sock data_sock;
 282         struct lttng_ht_node_u64 node;
 283
 284         /* Session id on both sides for the sockets. */
 285         uint64_t relayd_session_id;
 286         uint64_t sessiond_session_id;
 287 };
 288
 289 /*
 290  * UST consumer local data to the program. One or more instance per
 291  * process.
 292  */
 293 struct lttng_consumer_local_data {
 294         /*
 295          * Function to call when data is available on a buffer.
 296          * Returns the number of bytes read, or negative error value.
 297          */
 298         ssize_t (*on_buffer_ready)(struct lttng_consumer_stream *stream,
 299                         struct lttng_consumer_local_data *ctx);
 300         /*
 301          * function to call when we receive a new channel, it receives a
 302          * newly allocated channel, depending on the return code of this
 303          * function, the new channel will be handled by the application
 304          * or the library.
 305          *
 306          * Returns:
 307          *    > 0 (success, FD is kept by application)
 308          *   == 0 (success, FD is left to library)
 309          *    < 0 (error)
 310          */
 311         int (*on_recv_channel)(struct lttng_consumer_channel *channel);
 312         /*
 313          * function to call when we receive a new stream, it receives a
 314          * newly allocated stream, depending on the return code of this
 315          * function, the new stream 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_stream)(struct lttng_consumer_stream *stream);
 324         /*
 325          * function to call when a stream is getting updated by the session
 326          * daemon, this function receives the sessiond key and the new
 327          * state, depending on the return code of this function the
 328          * update of state for the stream is handled by the application
 329          * or the library.
 330          *
 331          * Returns:
 332          *    > 0 (success, FD is kept by application)
 333          *   == 0 (success, FD is left to library)
 334          *    < 0 (error)
 335          */
 336         int (*on_update_stream)(int sessiond_key, uint32_t state);
 337         enum lttng_consumer_type type;
 338         /* socket to communicate errors with sessiond */
 339         int consumer_error_socket;
 340         /* socket to ask metadata to sessiond */
 341         int consumer_metadata_socket;
 342         /* socket to exchange commands with sessiond */
 343         char *consumer_command_sock_path;
 344         /* communication with splice */
 345         int consumer_thread_pipe[2];
 346         int consumer_channel_pipe[2];
 347         int consumer_splice_metadata_pipe[2];
 348         /* Data stream poll thread pipe. To transfer data stream to the thread */
 349         int consumer_data_pipe[2];
 350         /* to let the signal handler wake up the fd receiver thread */
 351         int consumer_should_quit[2];
 352         /* Metadata poll thread pipe. Transfer metadata stream to it */
 353         int consumer_metadata_pipe[2];
 354 };
 355
 356 /*
 357  * Library-level data. One instance per process.
 358  */
 359 struct lttng_consumer_global_data {
 360         /*
 361          * At this time, this lock is used to ensure coherence between the count
 362          * and number of element in the hash table. It's also a protection for
 363          * concurrent read/write between threads.
 364          *
 365          * This is nested OUTSIDE the stream lock.
 366          * This is nested OUTSIDE the consumer_relayd_sock_pair lock.
 367          */
 368         pthread_mutex_t lock;
 369
 370         /*
 371          * Number of streams in the data stream hash table declared outside.
 372          * Protected by consumer_data.lock.
 373          */
 374         int stream_count;
 375
 376         /* Channel hash table protected by consumer_data.lock. */
 377         struct lttng_ht *channel_ht;
 378         /*
 379          * Flag specifying if the local array of FDs needs update in the
 380          * poll function. Protected by consumer_data.lock.
 381          */
 382         unsigned int need_update;
 383         enum lttng_consumer_type type;
 384
 385         /*
 386          * Relayd socket(s) hashtable indexed by network sequence number. Each
 387          * stream has an index which associate the right relayd socket to use.
 388          */
 389         struct lttng_ht *relayd_ht;
 390
 391         /*
 392          * This hash table contains all streams (metadata and data) indexed by
 393          * session id. In other words, the ht is indexed by session id and each
 394          * bucket contains the list of associated streams.
 395          *
 396          * This HT uses the "node_session_id" of the consumer stream.
 397          */
 398         struct lttng_ht *stream_list_ht;
 399
 400         /*
 401          * This HT uses the "node_channel_id" of the consumer stream.
 402          */
 403         struct lttng_ht *stream_per_chan_id_ht;
 404 };
 405
 406 /*
 407  * Init consumer data structures.
 408  */
 409 void lttng_consumer_init(void);
 410
 411 /*
 412  * Set the error socket for communication with a session daemon.
 413  */
 414 void lttng_consumer_set_error_sock(struct lttng_consumer_local_data *ctx,
 415                 int sock);
 416
 417 /*
 418  * Set the command socket path for communication with a session daemon.
 419  */
 420 void lttng_consumer_set_command_sock_path(
 421                 struct lttng_consumer_local_data *ctx, char *sock);
 422
 423 /*
 424  * Send return code to session daemon.
 425  *
 426  * Returns the return code of sendmsg : the number of bytes transmitted or -1
 427  * on error.
 428  */
 429 int lttng_consumer_send_error(struct lttng_consumer_local_data *ctx, int cmd);
 430
 431 /*
 432  * Called from signal handler to ensure a clean exit.
 433  */
 434 void lttng_consumer_should_exit(struct lttng_consumer_local_data *ctx);
 435
 436 /*
 437  * Cleanup the daemon's socket on exit.
 438  */
 439 void lttng_consumer_cleanup(void);
 440
 441 /*
 442  * Flush pending writes to trace output disk file.
 443  */
 444 void lttng_consumer_sync_trace_file(struct lttng_consumer_stream *stream,
 445                 off_t orig_offset);
 446
 447 /*
 448  * Poll on the should_quit pipe and the command socket return -1 on error and
 449  * should exit, 0 if data is available on the command socket
 450  */
 451 int lttng_consumer_poll_socket(struct pollfd *kconsumer_sockpoll);
 452
 453 struct lttng_consumer_stream *consumer_allocate_stream(uint64_t channel_key,
 454                 uint64_t stream_key,
 455                 enum lttng_consumer_stream_state state,
 456                 const char *channel_name,
 457                 uid_t uid,
 458                 gid_t gid,
 459                 int relayd_id,
 460                 uint64_t session_id,
 461                 int cpu,
 462                 int *alloc_ret,
 463                 enum consumer_channel_type type);
 464 struct lttng_consumer_channel *consumer_allocate_channel(uint64_t key,
 465                 uint64_t session_id,
 466                 const char *pathname,
 467                 const char *name,
 468                 uid_t uid,
 469                 gid_t gid,
 470                 int relayd_id,
 471                 enum lttng_event_output output,
 472                 uint64_t tracefile_size,
 473                 uint64_t tracefile_count);
 474 void consumer_del_stream(struct lttng_consumer_stream *stream,
 475                 struct lttng_ht *ht);
 476 void consumer_del_metadata_stream(struct lttng_consumer_stream *stream,
 477                 struct lttng_ht *ht);
 478 int consumer_add_channel(struct lttng_consumer_channel *channel,
 479                 struct lttng_consumer_local_data *ctx);
 480 void consumer_del_channel(struct lttng_consumer_channel *channel);
 481
 482 /* lttng-relayd consumer command */
 483 struct consumer_relayd_sock_pair *consumer_allocate_relayd_sock_pair(
 484                 int net_seq_idx);
 485 struct consumer_relayd_sock_pair *consumer_find_relayd(uint64_t key);
 486 struct lttng_consumer_channel *consumer_find_channel(uint64_t key);
 487 int consumer_handle_stream_before_relayd(struct lttng_consumer_stream *stream,
 488                 size_t data_size);
 489 void consumer_steal_stream_key(int key, struct lttng_ht *ht);
 490
 491 struct lttng_consumer_local_data *lttng_consumer_create(
 492                 enum lttng_consumer_type type,
 493                 ssize_t (*buffer_ready)(struct lttng_consumer_stream *stream,
 494                         struct lttng_consumer_local_data *ctx),
 495                 int (*recv_channel)(struct lttng_consumer_channel *channel),
 496                 int (*recv_stream)(struct lttng_consumer_stream *stream),
 497                 int (*update_stream)(int sessiond_key, uint32_t state));
 498 void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx);
 499 ssize_t lttng_consumer_on_read_subbuffer_mmap(
 500                 struct lttng_consumer_local_data *ctx,
 501                 struct lttng_consumer_stream *stream, unsigned long len,
 502                 unsigned long padding);
 503 ssize_t lttng_consumer_on_read_subbuffer_splice(
 504                 struct lttng_consumer_local_data *ctx,
 505                 struct lttng_consumer_stream *stream, unsigned long len,
 506                 unsigned long padding);
 507 int lttng_consumer_take_snapshot(struct lttng_consumer_stream *stream);
 508 int lttng_consumer_get_produced_snapshot(struct lttng_consumer_stream *stream,
 509                 unsigned long *pos);
 510 void *consumer_thread_metadata_poll(void *data);
 511 void *consumer_thread_data_poll(void *data);
 512 void *consumer_thread_sessiond_poll(void *data);
 513 void *consumer_thread_channel_poll(void *data);
 514 int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 515                 int sock, struct pollfd *consumer_sockpoll);
 516
 517 ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream,
 518                 struct lttng_consumer_local_data *ctx);
 519 int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream);
 520 int consumer_add_relayd_socket(int net_seq_idx, int sock_type,
 521                 struct lttng_consumer_local_data *ctx, int sock,
 522                 struct pollfd *consumer_sockpoll, struct lttcomm_relayd_sock *relayd_sock,
 523                 unsigned int sessiond_id);
 524 void consumer_flag_relayd_for_destroy(
 525                 struct consumer_relayd_sock_pair *relayd);
 526 int consumer_data_pending(uint64_t id);
 527 int consumer_send_status_msg(int sock, int ret_code);
 528 int consumer_send_status_channel(int sock,
 529                 struct lttng_consumer_channel *channel);
 530 void notify_thread_del_channel(struct lttng_consumer_local_data *ctx,
 531                 uint64_t key);
 532
 533 #endif /* LIB_CONSUMER_H */