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