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         LTTNG_CONSUMER_SNAPSHOT_CHANNEL,
  58         LTTNG_CONSUMER_SNAPSHOT_METADATA,
  59 };
  60
  61 /* State of each fd in consumer */
  62 enum lttng_consumer_stream_state {
  63         LTTNG_CONSUMER_ACTIVE_STREAM,
  64         LTTNG_CONSUMER_PAUSE_STREAM,
  65         LTTNG_CONSUMER_DELETE_STREAM,
  66 };
  67
  68 enum lttng_consumer_type {
  69         LTTNG_CONSUMER_UNKNOWN = 0,
  70         LTTNG_CONSUMER_KERNEL,
  71         LTTNG_CONSUMER64_UST,
  72         LTTNG_CONSUMER32_UST,
  73 };
  74
  75 enum consumer_endpoint_status {
  76         CONSUMER_ENDPOINT_ACTIVE,
  77         CONSUMER_ENDPOINT_INACTIVE,
  78 };
  79
  80 enum consumer_channel_output {
  81         CONSUMER_CHANNEL_MMAP   = 0,
  82         CONSUMER_CHANNEL_SPLICE = 1,
  83 };
  84
  85 enum consumer_channel_type {
  86         CONSUMER_CHANNEL_TYPE_METADATA  = 0,
  87         CONSUMER_CHANNEL_TYPE_DATA      = 1,
  88 };
  89
  90 extern struct lttng_consumer_global_data consumer_data;
  91
  92 struct stream_list {
  93         struct cds_list_head head;
  94         unsigned int count;
  95 };
  96
  97 /* Stub. */
  98 struct consumer_metadata_cache;
  99
 100 struct lttng_consumer_channel {
 101         /* HT node used for consumer_data.channel_ht */
 102         struct lttng_ht_node_u64 node;
 103         /* Indexed key. Incremented value in the consumer. */
 104         uint64_t key;
 105         /* Number of streams referencing this channel */
 106         int refcount;
 107         /* Tracing session id on the session daemon side. */
 108         uint64_t session_id;
 109         /*
 110          * Session id when requesting metadata to the session daemon for
 111          * a session with per-PID buffers.
 112          */
 113         uint64_t session_id_per_pid;
 114         /* Channel trace file path name. */
 115         char pathname[PATH_MAX];
 116         /* Channel name. */
 117         char name[LTTNG_SYMBOL_NAME_LEN];
 118         /* UID and GID of the channel. */
 119         uid_t uid;
 120         gid_t gid;
 121         /* Relayd id of the channel. -1ULL if it does not apply. */
 122         uint64_t relayd_id;
 123         /*
 124          * Number of streams NOT initialized yet. This is used in order to not
 125          * delete this channel if streams are getting initialized.
 126          */
 127         unsigned int nb_init_stream_left;
 128         /* Output type (mmap or splice). */
 129         enum consumer_channel_output output;
 130         /* Channel type for stream */
 131         enum consumer_channel_type type;
 132
 133         /* For UST */
 134         struct ustctl_consumer_channel *uchan;
 135         unsigned char uuid[UUID_STR_LEN];
 136         /*
 137          * Temporary stream list used to store the streams once created and waiting
 138          * to be sent to the session daemon by receiving the
 139          * LTTNG_CONSUMER_GET_CHANNEL.
 140          */
 141         struct stream_list streams;
 142
 143         /*
 144          * List of streams in no monitor mode for this channel. Used ONLY for
 145          * snapshots recording.
 146          */
 147         struct stream_list stream_no_monitor_list;
 148
 149         /*
 150          * Set if the channel is metadata. We keep a reference to the stream
 151          * because we have to flush data once pushed by the session daemon. For a
 152          * regular channel, this is always set to NULL.
 153          */
 154         struct lttng_consumer_stream *metadata_stream;
 155
 156         /* for UST */
 157         int wait_fd;
 158         /* Node within channel thread ht */
 159         struct lttng_ht_node_u64 wait_fd_node;
 160
 161         /* Metadata cache is metadata channel */
 162         struct consumer_metadata_cache *metadata_cache;
 163         /* For metadata periodical flush */
 164         int switch_timer_enabled;
 165         timer_t switch_timer;
 166         int switch_timer_error;
 167
 168         /* On-disk circular buffer */
 169         uint64_t tracefile_size;
 170         uint64_t tracefile_count;
 171         /*
 172          * Monitor or not the streams of this channel meaning this indicates if the
 173          * streams should be sent to the data/metadata thread or added to the no
 174          * monitor list of the channel.
 175          */
 176         unsigned int monitor;
 177 };
 178
 179 /*
 180  * Internal representation of the streams, sessiond_key is used to identify
 181  * uniquely a stream.
 182  */
 183 struct lttng_consumer_stream {
 184         /* HT node used by the data_ht and metadata_ht */
 185         struct lttng_ht_node_u64 node;
 186         /* stream indexed per channel key node */
 187         struct lttng_ht_node_u64 node_channel_id;
 188         /* HT node used in consumer_data.stream_list_ht */
 189         struct lttng_ht_node_u64 node_session_id;
 190         /* Pointer to associated channel. */
 191         struct lttng_consumer_channel *chan;
 192
 193         /* Key by which the stream is indexed for 'node'. */
 194         uint64_t key;
 195         /*
 196          * File descriptor of the data output file. This can be either a file or a
 197          * socket fd for relayd streaming.
 198          */
 199         int out_fd; /* output file to write the data */
 200         /* Write position in the output file descriptor */
 201         off_t out_fd_offset;
 202         enum lttng_consumer_stream_state state;
 203         int shm_fd_is_copy;
 204         int data_read;
 205         int hangup_flush_done;
 206         enum lttng_event_output output;
 207         /* Maximum subbuffer size. */
 208         unsigned long max_sb_size;
 209
 210         /*
 211          * Still used by the kernel for MMAP output. For UST, the ustctl getter is
 212          * used for the mmap base and offset.
 213          */
 214         void *mmap_base;
 215         unsigned long mmap_len;
 216
 217         /* For UST */
 218
 219         int wait_fd;
 220         /* UID/GID of the user owning the session to which stream belongs */
 221         uid_t uid;
 222         gid_t gid;
 223         /* Network sequence number. Indicating on which relayd socket it goes. */
 224         uint64_t net_seq_idx;
 225         /* Identify if the stream is the metadata */
 226         unsigned int metadata_flag;
 227         /* Used when the stream is set for network streaming */
 228         uint64_t relayd_stream_id;
 229         /*
 230          * When sending a stream packet to a relayd, this number is used to track
 231          * the packet sent by the consumer and seen by the relayd. When sending the
 232          * data header to the relayd, this number is sent and if the transmission
 233          * was successful, it is incremented.
 234          *
 235          * Even if the full data is not fully transmitted it won't matter since
 236          * only two possible error can happen after that where either the relayd
 237          * died or a read error is detected on the stream making this value useless
 238          * after that.
 239          *
 240          * This value SHOULD be read/updated atomically or with the lock acquired.
 241          */
 242         uint64_t next_net_seq_num;
 243         /*
 244          * Lock to use the stream FDs since they are used between threads.
 245          *
 246          * This is nested INSIDE the consumer_data lock.
 247          * This is nested INSIDE the metadata cache lock.
 248          * This is nested OUTSIDE consumer_relayd_sock_pair lock.
 249          */
 250         pthread_mutex_t lock;
 251         /* Tracing session id */
 252         uint64_t session_id;
 253         /*
 254          * Indicates if the stream end point is still active or not (network
 255          * streaming or local file system). The thread "owning" the stream is
 256          * handling this status and can be notified of a state change through the
 257          * consumer data appropriate pipe.
 258          */
 259         enum consumer_endpoint_status endpoint_status;
 260         /* Stream name. Format is: <channel_name>_<cpu_number> */
 261         char name[LTTNG_SYMBOL_NAME_LEN];
 262         /* Internal state of libustctl. */
 263         struct ustctl_consumer_stream *ustream;
 264         struct cds_list_head send_node;
 265         /* On-disk circular buffer */
 266         uint64_t tracefile_size_current;
 267         uint64_t tracefile_count_current;
 268
 269         /* Node for the no monitor stream list in a channel. */
 270         struct cds_list_head no_monitor_node;
 271 };
 272
 273 /*
 274  * Internal representation of a relayd socket pair.
 275  */
 276 struct consumer_relayd_sock_pair {
 277         /* Network sequence number. */
 278         uint64_t net_seq_idx;
 279         /* Number of stream associated with this relayd */
 280         unsigned int refcount;
 281
 282         /*
 283          * This flag indicates whether or not we should destroy this object. The
 284          * destruction should ONLY occurs when this flag is set and the refcount is
 285          * set to zero.
 286          */
 287         unsigned int destroy_flag;
 288
 289         /*
 290          * Mutex protecting the control socket to avoid out of order packets
 291          * between threads sending data to the relayd. Since metadata data is sent
 292          * over that socket, at least two sendmsg() are needed (header + data)
 293          * creating a race for packets to overlap between threads using it.
 294          *
 295          * This is nested INSIDE the consumer_data lock.
 296          * This is nested INSIDE the stream lock.
 297          */
 298         pthread_mutex_t ctrl_sock_mutex;
 299
 300         /* Control socket. Command and metadata are passed over it */
 301         struct lttcomm_relayd_sock control_sock;
 302
 303         /*
 304          * We don't need a mutex at this point since we only splice or write single
 305          * large chunk of data with a header appended at the begining. Moreover,
 306          * this socket is for now only used in a single thread.
 307          */
 308         struct lttcomm_relayd_sock data_sock;
 309         struct lttng_ht_node_u64 node;
 310
 311         /* Session id on both sides for the sockets. */
 312         uint64_t relayd_session_id;
 313         uint64_t sessiond_session_id;
 314 };
 315
 316 /*
 317  * UST consumer local data to the program. One or more instance per
 318  * process.
 319  */
 320 struct lttng_consumer_local_data {
 321         /*
 322          * Function to call when data is available on a buffer.
 323          * Returns the number of bytes read, or negative error value.
 324          */
 325         ssize_t (*on_buffer_ready)(struct lttng_consumer_stream *stream,
 326                         struct lttng_consumer_local_data *ctx);
 327         /*
 328          * function to call when we receive a new channel, it receives a
 329          * newly allocated channel, depending on the return code of this
 330          * function, the new channel will be 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_recv_channel)(struct lttng_consumer_channel *channel);
 339         /*
 340          * function to call when we receive a new stream, it receives a
 341          * newly allocated stream, depending on the return code of this
 342          * function, the new stream will be handled by the application
 343          * or the library.
 344          *
 345          * Returns:
 346          *    > 0 (success, FD is kept by application)
 347          *   == 0 (success, FD is left to library)
 348          *    < 0 (error)
 349          */
 350         int (*on_recv_stream)(struct lttng_consumer_stream *stream);
 351         /*
 352          * function to call when a stream is getting updated by the session
 353          * daemon, this function receives the sessiond key and the new
 354          * state, depending on the return code of this function the
 355          * update of state for the stream is handled by the application
 356          * or the library.
 357          *
 358          * Returns:
 359          *    > 0 (success, FD is kept by application)
 360          *   == 0 (success, FD is left to library)
 361          *    < 0 (error)
 362          */
 363         int (*on_update_stream)(int sessiond_key, uint32_t state);
 364         enum lttng_consumer_type type;
 365         /* socket to communicate errors with sessiond */
 366         int consumer_error_socket;
 367         /* socket to ask metadata to sessiond */
 368         int consumer_metadata_socket;
 369         /* socket to exchange commands with sessiond */
 370         char *consumer_command_sock_path;
 371         /* communication with splice */
 372         int consumer_thread_pipe[2];
 373         int consumer_channel_pipe[2];
 374         int consumer_splice_metadata_pipe[2];
 375         /* Data stream poll thread pipe. To transfer data stream to the thread */
 376         struct lttng_pipe *consumer_data_pipe;
 377         /* to let the signal handler wake up the fd receiver thread */
 378         int consumer_should_quit[2];
 379         /* Metadata poll thread pipe. Transfer metadata stream to it */
 380         struct lttng_pipe *consumer_metadata_pipe;
 381 };
 382
 383 /*
 384  * Library-level data. One instance per process.
 385  */
 386 struct lttng_consumer_global_data {
 387         /*
 388          * At this time, this lock is used to ensure coherence between the count
 389          * and number of element in the hash table. It's also a protection for
 390          * concurrent read/write between threads.
 391          *
 392          * This is nested OUTSIDE the stream lock.
 393          * This is nested OUTSIDE the consumer_relayd_sock_pair lock.
 394          */
 395         pthread_mutex_t lock;
 396
 397         /*
 398          * Number of streams in the data stream hash table declared outside.
 399          * Protected by consumer_data.lock.
 400          */
 401         int stream_count;
 402
 403         /* Channel hash table protected by consumer_data.lock. */
 404         struct lttng_ht *channel_ht;
 405         /*
 406          * Flag specifying if the local array of FDs needs update in the
 407          * poll function. Protected by consumer_data.lock.
 408          */
 409         unsigned int need_update;
 410         enum lttng_consumer_type type;
 411
 412         /*
 413          * Relayd socket(s) hashtable indexed by network sequence number. Each
 414          * stream has an index which associate the right relayd socket to use.
 415          */
 416         struct lttng_ht *relayd_ht;
 417
 418         /*
 419          * This hash table contains all streams (metadata and data) indexed by
 420          * session id. In other words, the ht is indexed by session id and each
 421          * bucket contains the list of associated streams.
 422          *
 423          * This HT uses the "node_session_id" of the consumer stream.
 424          */
 425         struct lttng_ht *stream_list_ht;
 426
 427         /*
 428          * This HT uses the "node_channel_id" of the consumer stream.
 429          */
 430         struct lttng_ht *stream_per_chan_id_ht;
 431 };
 432
 433 /*
 434  * Init consumer data structures.
 435  */
 436 void lttng_consumer_init(void);
 437
 438 /*
 439  * Set the error socket for communication with a session daemon.
 440  */
 441 void lttng_consumer_set_error_sock(struct lttng_consumer_local_data *ctx,
 442                 int sock);
 443
 444 /*
 445  * Set the command socket path for communication with a session daemon.
 446  */
 447 void lttng_consumer_set_command_sock_path(
 448                 struct lttng_consumer_local_data *ctx, char *sock);
 449
 450 /*
 451  * Send return code to session daemon.
 452  *
 453  * Returns the return code of sendmsg : the number of bytes transmitted or -1
 454  * on error.
 455  */
 456 int lttng_consumer_send_error(struct lttng_consumer_local_data *ctx, int cmd);
 457
 458 /*
 459  * Called from signal handler to ensure a clean exit.
 460  */
 461 void lttng_consumer_should_exit(struct lttng_consumer_local_data *ctx);
 462
 463 /*
 464  * Cleanup the daemon's socket on exit.
 465  */
 466 void lttng_consumer_cleanup(void);
 467
 468 /*
 469  * Flush pending writes to trace output disk file.
 470  */
 471 void lttng_consumer_sync_trace_file(struct lttng_consumer_stream *stream,
 472                 off_t orig_offset);
 473
 474 /*
 475  * Poll on the should_quit pipe and the command socket return -1 on error and
 476  * should exit, 0 if data is available on the command socket
 477  */
 478 int lttng_consumer_poll_socket(struct pollfd *kconsumer_sockpoll);
 479
 480 struct lttng_consumer_stream *consumer_allocate_stream(uint64_t channel_key,
 481                 uint64_t stream_key,
 482                 enum lttng_consumer_stream_state state,
 483                 const char *channel_name,
 484                 uid_t uid,
 485                 gid_t gid,
 486                 uint64_t relayd_id,
 487                 uint64_t session_id,
 488                 int cpu,
 489                 int *alloc_ret,
 490                 enum consumer_channel_type type);
 491 struct lttng_consumer_channel *consumer_allocate_channel(uint64_t key,
 492                 uint64_t session_id,
 493                 const char *pathname,
 494                 const char *name,
 495                 uid_t uid,
 496                 gid_t gid,
 497                 uint64_t relayd_id,
 498                 enum lttng_event_output output,
 499                 uint64_t tracefile_size,
 500                 uint64_t tracefile_count,
 501                 uint64_t session_id_per_pid,
 502                 unsigned int monitor);
 503 void consumer_del_stream(struct lttng_consumer_stream *stream,
 504                 struct lttng_ht *ht);
 505 void consumer_del_metadata_stream(struct lttng_consumer_stream *stream,
 506                 struct lttng_ht *ht);
 507 int consumer_add_channel(struct lttng_consumer_channel *channel,
 508                 struct lttng_consumer_local_data *ctx);
 509 void consumer_del_channel(struct lttng_consumer_channel *channel);
 510
 511 /* lttng-relayd consumer command */
 512 struct consumer_relayd_sock_pair *consumer_allocate_relayd_sock_pair(
 513                 uint64_t net_seq_idx);
 514 struct consumer_relayd_sock_pair *consumer_find_relayd(uint64_t key);
 515 struct lttng_consumer_channel *consumer_find_channel(uint64_t key);
 516 int consumer_handle_stream_before_relayd(struct lttng_consumer_stream *stream,
 517                 size_t data_size);
 518 void consumer_steal_stream_key(int key, struct lttng_ht *ht);
 519
 520 struct lttng_consumer_local_data *lttng_consumer_create(
 521                 enum lttng_consumer_type type,
 522                 ssize_t (*buffer_ready)(struct lttng_consumer_stream *stream,
 523                         struct lttng_consumer_local_data *ctx),
 524                 int (*recv_channel)(struct lttng_consumer_channel *channel),
 525                 int (*recv_stream)(struct lttng_consumer_stream *stream),
 526                 int (*update_stream)(int sessiond_key, uint32_t state));
 527 void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx);
 528 ssize_t lttng_consumer_on_read_subbuffer_mmap(
 529                 struct lttng_consumer_local_data *ctx,
 530                 struct lttng_consumer_stream *stream, unsigned long len,
 531                 unsigned long padding);
 532 ssize_t lttng_consumer_on_read_subbuffer_splice(
 533                 struct lttng_consumer_local_data *ctx,
 534                 struct lttng_consumer_stream *stream, unsigned long len,
 535                 unsigned long padding);
 536 int lttng_consumer_take_snapshot(struct lttng_consumer_stream *stream);
 537 int lttng_consumer_get_produced_snapshot(struct lttng_consumer_stream *stream,
 538                 unsigned long *pos);
 539 void *consumer_thread_metadata_poll(void *data);
 540 void *consumer_thread_data_poll(void *data);
 541 void *consumer_thread_sessiond_poll(void *data);
 542 void *consumer_thread_channel_poll(void *data);
 543 int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 544                 int sock, struct pollfd *consumer_sockpoll);
 545
 546 ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream,
 547                 struct lttng_consumer_local_data *ctx);
 548 int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream);
 549 int consumer_add_relayd_socket(uint64_t net_seq_idx, int sock_type,
 550                 struct lttng_consumer_local_data *ctx, int sock,
 551                 struct pollfd *consumer_sockpoll, struct lttcomm_relayd_sock *relayd_sock,
 552                 unsigned int sessiond_id);
 553 void consumer_flag_relayd_for_destroy(
 554                 struct consumer_relayd_sock_pair *relayd);
 555 int consumer_data_pending(uint64_t id);
 556 int consumer_send_status_msg(int sock, int ret_code);
 557 int consumer_send_status_channel(int sock,
 558                 struct lttng_consumer_channel *channel);
 559 void notify_thread_del_channel(struct lttng_consumer_local_data *ctx,
 560                 uint64_t key);
 561 void consumer_destroy_relayd(struct consumer_relayd_sock_pair *relayd);
 562
 563 #endif /* LIB_CONSUMER_H */