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