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         /*
 106          * Session id when requesting metadata to the session daemon for
 107          * a session with per-PID buffers.
 108          */
 109         uint64_t session_id_per_pid;
 110         /* Channel trace file path name. */
 111         char pathname[PATH_MAX];
 112         /* Channel name. */
 113         char name[LTTNG_SYMBOL_NAME_LEN];
 114         /* UID and GID of the channel. */
 115         uid_t uid;
 116         gid_t gid;
 117         /* Relayd id of the channel. -1 if it does not apply. */
 118         int64_t relayd_id;
 119         /*
 120          * Number of streams NOT initialized yet. This is used in order to not
 121          * delete this channel if streams are getting initialized.
 122          */
 123         unsigned int nb_init_stream_left;
 124         /* Output type (mmap or splice). */
 125         enum consumer_channel_output output;
 126         /* Channel type for stream */
 127         enum consumer_channel_type type;
 128
 129         /* For UST */
 130         struct ustctl_consumer_channel *uchan;
 131         unsigned char uuid[UUID_STR_LEN];
 132         /*
 133          * Temporary stream list used to store the streams once created and waiting
 134          * to be sent to the session daemon by receiving the
 135          * LTTNG_CONSUMER_GET_CHANNEL.
 136          */
 137         struct stream_list streams;
 138         /*
 139          * Set if the channel is metadata. We keep a reference to the stream
 140          * because we have to flush data once pushed by the session daemon. For a
 141          * regular channel, this is always set to NULL.
 142          */
 143         struct lttng_consumer_stream *metadata_stream;
 144
 145         /* for UST */
 146         int wait_fd;
 147         /* Node within channel thread ht */
 148         struct lttng_ht_node_u64 wait_fd_node;
 149
 150         /* Metadata cache is metadata channel */
 151         struct consumer_metadata_cache *metadata_cache;
 152         /* For metadata periodical flush */
 153         int switch_timer_enabled;
 154         timer_t switch_timer;
 155         int switch_timer_error;
 156
 157         /* On-disk circular buffer */
 158         uint64_t tracefile_size;
 159         uint64_t tracefile_count;
 160 };
 161
 162 /*
 163  * Internal representation of the streams, sessiond_key is used to identify
 164  * uniquely a stream.
 165  */
 166 struct lttng_consumer_stream {
 167         /* HT node used by the data_ht and metadata_ht */
 168         struct lttng_ht_node_u64 node;
 169         /* stream indexed per channel key node */
 170         struct lttng_ht_node_u64 node_channel_id;
 171         /* HT node used in consumer_data.stream_list_ht */
 172         struct lttng_ht_node_u64 node_session_id;
 173         /* Pointer to associated channel. */
 174         struct lttng_consumer_channel *chan;
 175
 176         /* Key by which the stream is indexed for 'node'. */
 177         uint64_t key;
 178         /*
 179          * File descriptor of the data output file. This can be either a file or a
 180          * socket fd for relayd streaming.
 181          */
 182         int out_fd; /* output file to write the data */
 183         /* Write position in the output file descriptor */
 184         off_t out_fd_offset;
 185         enum lttng_consumer_stream_state state;
 186         int shm_fd_is_copy;
 187         int data_read;
 188         int hangup_flush_done;
 189         enum lttng_event_output output;
 190         /* Maximum subbuffer size. */
 191         unsigned long max_sb_size;
 192
 193         /*
 194          * Still used by the kernel for MMAP output. For UST, the ustctl getter is
 195          * used for the mmap base and offset.
 196          */
 197         void *mmap_base;
 198         unsigned long mmap_len;
 199
 200         /* For UST */
 201
 202         int wait_fd;
 203         /* UID/GID of the user owning the session to which stream belongs */
 204         uid_t uid;
 205         gid_t gid;
 206         /* Network sequence number. Indicating on which relayd socket it goes. */
 207         uint64_t net_seq_idx;
 208         /* Identify if the stream is the metadata */
 209         unsigned int metadata_flag;
 210         /* Used when the stream is set for network streaming */
 211         uint64_t relayd_stream_id;
 212         /*
 213          * When sending a stream packet to a relayd, this number is used to track
 214          * the packet sent by the consumer and seen by the relayd. When sending the
 215          * data header to the relayd, this number is sent and if the transmission
 216          * was successful, it is incremented.
 217          *
 218          * Even if the full data is not fully transmitted it won't matter since
 219          * only two possible error can happen after that where either the relayd
 220          * died or a read error is detected on the stream making this value useless
 221          * after that.
 222          *
 223          * This value SHOULD be read/updated atomically or with the lock acquired.
 224          */
 225         uint64_t next_net_seq_num;
 226         /*
 227          * Lock to use the stream FDs since they are used between threads.
 228          *
 229          * This is nested INSIDE the consumer_data lock.
 230          * This is nested INSIDE the metadata cache lock.
 231          * This is nested OUTSIDE consumer_relayd_sock_pair lock.
 232          */
 233         pthread_mutex_t lock;
 234         /* Tracing session id */
 235         uint64_t session_id;
 236         /*
 237          * Indicates if the stream end point is still active or not (network
 238          * streaming or local file system). The thread "owning" the stream is
 239          * handling this status and can be notified of a state change through the
 240          * consumer data appropriate pipe.
 241          */
 242         enum consumer_endpoint_status endpoint_status;
 243         /* Stream name. Format is: <channel_name>_<cpu_number> */
 244         char name[LTTNG_SYMBOL_NAME_LEN];
 245         /* Internal state of libustctl. */
 246         struct ustctl_consumer_stream *ustream;
 247         struct cds_list_head send_node;
 248         /* On-disk circular buffer */
 249         uint64_t tracefile_size_current;
 250         uint64_t tracefile_count_current;
 251 };
 252
 253 /*
 254  * Internal representation of a relayd socket pair.
 255  */
 256 struct consumer_relayd_sock_pair {
 257         /* Network sequence number. */
 258         int64_t net_seq_idx;
 259         /* Number of stream associated with this relayd */
 260         unsigned int refcount;
 261
 262         /*
 263          * This flag indicates whether or not we should destroy this object. The
 264          * destruction should ONLY occurs when this flag is set and the refcount is
 265          * set to zero.
 266          */
 267         unsigned int destroy_flag;
 268
 269         /*
 270          * Mutex protecting the control socket to avoid out of order packets
 271          * between threads sending data to the relayd. Since metadata data is sent
 272          * over that socket, at least two sendmsg() are needed (header + data)
 273          * creating a race for packets to overlap between threads using it.
 274          *
 275          * This is nested INSIDE the consumer_data lock.
 276          * This is nested INSIDE the stream lock.
 277          */
 278         pthread_mutex_t ctrl_sock_mutex;
 279
 280         /* Control socket. Command and metadata are passed over it */
 281         struct lttcomm_relayd_sock control_sock;
 282
 283         /*
 284          * We don't need a mutex at this point since we only splice or write single
 285          * large chunk of data with a header appended at the begining. Moreover,
 286          * this socket is for now only used in a single thread.
 287          */
 288         struct lttcomm_relayd_sock data_sock;
 289         struct lttng_ht_node_u64 node;
 290
 291         /* Session id on both sides for the sockets. */
 292         uint64_t relayd_session_id;
 293         uint64_t sessiond_session_id;
 294 };
 295
 296 /*
 297  * UST consumer local data to the program. One or more instance per
 298  * process.
 299  */
 300 struct lttng_consumer_local_data {
 301         /*
 302          * Function to call when data is available on a buffer.
 303          * Returns the number of bytes read, or negative error value.
 304          */
 305         ssize_t (*on_buffer_ready)(struct lttng_consumer_stream *stream,
 306                         struct lttng_consumer_local_data *ctx);
 307         /*
 308          * function to call when we receive a new channel, it receives a
 309          * newly allocated channel, depending on the return code of this
 310          * function, the new channel will be handled by the application
 311          * or the library.
 312          *
 313          * Returns:
 314          *    > 0 (success, FD is kept by application)
 315          *   == 0 (success, FD is left to library)
 316          *    < 0 (error)
 317          */
 318         int (*on_recv_channel)(struct lttng_consumer_channel *channel);
 319         /*
 320          * function to call when we receive a new stream, it receives a
 321          * newly allocated stream, depending on the return code of this
 322          * function, the new stream will be handled by the application
 323          * or the library.
 324          *
 325          * Returns:
 326          *    > 0 (success, FD is kept by application)
 327          *   == 0 (success, FD is left to library)
 328          *    < 0 (error)
 329          */
 330         int (*on_recv_stream)(struct lttng_consumer_stream *stream);
 331         /*
 332          * function to call when a stream is getting updated by the session
 333          * daemon, this function receives the sessiond key and the new
 334          * state, depending on the return code of this function the
 335          * update of state for the stream is handled by the application
 336          * or the library.
 337          *
 338          * Returns:
 339          *    > 0 (success, FD is kept by application)
 340          *   == 0 (success, FD is left to library)
 341          *    < 0 (error)
 342          */
 343         int (*on_update_stream)(int sessiond_key, uint32_t state);
 344         enum lttng_consumer_type type;
 345         /* socket to communicate errors with sessiond */
 346         int consumer_error_socket;
 347         /* socket to ask metadata to sessiond */
 348         int consumer_metadata_socket;
 349         /* socket to exchange commands with sessiond */
 350         char *consumer_command_sock_path;
 351         /* communication with splice */
 352         int consumer_thread_pipe[2];
 353         int consumer_channel_pipe[2];
 354         int consumer_splice_metadata_pipe[2];
 355         /* Data stream poll thread pipe. To transfer data stream to the thread */
 356         struct lttng_pipe *consumer_data_pipe;
 357         /* to let the signal handler wake up the fd receiver thread */
 358         int consumer_should_quit[2];
 359         /* Metadata poll thread pipe. Transfer metadata stream to it */
 360         struct lttng_pipe *consumer_metadata_pipe;
 361 };
 362
 363 /*
 364  * Library-level data. One instance per process.
 365  */
 366 struct lttng_consumer_global_data {
 367         /*
 368          * At this time, this lock is used to ensure coherence between the count
 369          * and number of element in the hash table. It's also a protection for
 370          * concurrent read/write between threads.
 371          *
 372          * This is nested OUTSIDE the stream lock.
 373          * This is nested OUTSIDE the consumer_relayd_sock_pair lock.
 374          */
 375         pthread_mutex_t lock;
 376
 377         /*
 378          * Number of streams in the data stream hash table declared outside.
 379          * Protected by consumer_data.lock.
 380          */
 381         int stream_count;
 382
 383         /* Channel hash table protected by consumer_data.lock. */
 384         struct lttng_ht *channel_ht;
 385         /*
 386          * Flag specifying if the local array of FDs needs update in the
 387          * poll function. Protected by consumer_data.lock.
 388          */
 389         unsigned int need_update;
 390         enum lttng_consumer_type type;
 391
 392         /*
 393          * Relayd socket(s) hashtable indexed by network sequence number. Each
 394          * stream has an index which associate the right relayd socket to use.
 395          */
 396         struct lttng_ht *relayd_ht;
 397
 398         /*
 399          * This hash table contains all streams (metadata and data) indexed by
 400          * session id. In other words, the ht is indexed by session id and each
 401          * bucket contains the list of associated streams.
 402          *
 403          * This HT uses the "node_session_id" of the consumer stream.
 404          */
 405         struct lttng_ht *stream_list_ht;
 406
 407         /*
 408          * This HT uses the "node_channel_id" of the consumer stream.
 409          */
 410         struct lttng_ht *stream_per_chan_id_ht;
 411 };
 412
 413 /*
 414  * Init consumer data structures.
 415  */
 416 void lttng_consumer_init(void);
 417
 418 /*
 419  * Set the error socket for communication with a session daemon.
 420  */
 421 void lttng_consumer_set_error_sock(struct lttng_consumer_local_data *ctx,
 422                 int sock);
 423
 424 /*
 425  * Set the command socket path for communication with a session daemon.
 426  */
 427 void lttng_consumer_set_command_sock_path(
 428                 struct lttng_consumer_local_data *ctx, char *sock);
 429
 430 /*
 431  * Send return code to session daemon.
 432  *
 433  * Returns the return code of sendmsg : the number of bytes transmitted or -1
 434  * on error.
 435  */
 436 int lttng_consumer_send_error(struct lttng_consumer_local_data *ctx, int cmd);
 437
 438 /*
 439  * Called from signal handler to ensure a clean exit.
 440  */
 441 void lttng_consumer_should_exit(struct lttng_consumer_local_data *ctx);
 442
 443 /*
 444  * Cleanup the daemon's socket on exit.
 445  */
 446 void lttng_consumer_cleanup(void);
 447
 448 /*
 449  * Flush pending writes to trace output disk file.
 450  */
 451 void lttng_consumer_sync_trace_file(struct lttng_consumer_stream *stream,
 452                 off_t orig_offset);
 453
 454 /*
 455  * Poll on the should_quit pipe and the command socket return -1 on error and
 456  * should exit, 0 if data is available on the command socket
 457  */
 458 int lttng_consumer_poll_socket(struct pollfd *kconsumer_sockpoll);
 459
 460 struct lttng_consumer_stream *consumer_allocate_stream(uint64_t channel_key,
 461                 uint64_t stream_key,
 462                 enum lttng_consumer_stream_state state,
 463                 const char *channel_name,
 464                 uid_t uid,
 465                 gid_t gid,
 466                 uint64_t relayd_id,
 467                 uint64_t session_id,
 468                 int cpu,
 469                 int *alloc_ret,
 470                 enum consumer_channel_type type);
 471 struct lttng_consumer_channel *consumer_allocate_channel(uint64_t key,
 472                 uint64_t session_id,
 473                 const char *pathname,
 474                 const char *name,
 475                 uid_t uid,
 476                 gid_t gid,
 477                 uint64_t relayd_id,
 478                 enum lttng_event_output output,
 479                 uint64_t tracefile_size,
 480                 uint64_t tracefile_count,
 481                 uint64_t session_id_per_pid);
 482 void consumer_del_stream(struct lttng_consumer_stream *stream,
 483                 struct lttng_ht *ht);
 484 void consumer_del_metadata_stream(struct lttng_consumer_stream *stream,
 485                 struct lttng_ht *ht);
 486 int consumer_add_channel(struct lttng_consumer_channel *channel,
 487                 struct lttng_consumer_local_data *ctx);
 488 void consumer_del_channel(struct lttng_consumer_channel *channel);
 489
 490 /* lttng-relayd consumer command */
 491 struct consumer_relayd_sock_pair *consumer_allocate_relayd_sock_pair(
 492                 int net_seq_idx);
 493 struct consumer_relayd_sock_pair *consumer_find_relayd(uint64_t key);
 494 struct lttng_consumer_channel *consumer_find_channel(uint64_t key);
 495 int consumer_handle_stream_before_relayd(struct lttng_consumer_stream *stream,
 496                 size_t data_size);
 497 void consumer_steal_stream_key(int key, struct lttng_ht *ht);
 498
 499 struct lttng_consumer_local_data *lttng_consumer_create(
 500                 enum lttng_consumer_type type,
 501                 ssize_t (*buffer_ready)(struct lttng_consumer_stream *stream,
 502                         struct lttng_consumer_local_data *ctx),
 503                 int (*recv_channel)(struct lttng_consumer_channel *channel),
 504                 int (*recv_stream)(struct lttng_consumer_stream *stream),
 505                 int (*update_stream)(int sessiond_key, uint32_t state));
 506 void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx);
 507 ssize_t lttng_consumer_on_read_subbuffer_mmap(
 508                 struct lttng_consumer_local_data *ctx,
 509                 struct lttng_consumer_stream *stream, unsigned long len,
 510                 unsigned long padding);
 511 ssize_t lttng_consumer_on_read_subbuffer_splice(
 512                 struct lttng_consumer_local_data *ctx,
 513                 struct lttng_consumer_stream *stream, unsigned long len,
 514                 unsigned long padding);
 515 int lttng_consumer_take_snapshot(struct lttng_consumer_stream *stream);
 516 int lttng_consumer_get_produced_snapshot(struct lttng_consumer_stream *stream,
 517                 unsigned long *pos);
 518 void *consumer_thread_metadata_poll(void *data);
 519 void *consumer_thread_data_poll(void *data);
 520 void *consumer_thread_sessiond_poll(void *data);
 521 void *consumer_thread_channel_poll(void *data);
 522 int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 523                 int sock, struct pollfd *consumer_sockpoll);
 524
 525 ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream,
 526                 struct lttng_consumer_local_data *ctx);
 527 int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream);
 528 int consumer_add_relayd_socket(int net_seq_idx, int sock_type,
 529                 struct lttng_consumer_local_data *ctx, int sock,
 530                 struct pollfd *consumer_sockpoll, struct lttcomm_relayd_sock *relayd_sock,
 531                 unsigned int sessiond_id);
 532 void consumer_flag_relayd_for_destroy(
 533                 struct consumer_relayd_sock_pair *relayd);
 534 int consumer_data_pending(uint64_t id);
 535 int consumer_send_status_msg(int sock, int ret_code);
 536 int consumer_send_status_channel(int sock,
 537                 struct lttng_consumer_channel *channel);
 538 void notify_thread_del_channel(struct lttng_consumer_local_data *ctx,
 539                 uint64_t key);
 540
 541 #endif /* LIB_CONSUMER_H */