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