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