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