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 };
  53
  54 /* State of each fd in consumer */
  55 enum lttng_consumer_stream_state {
  56         LTTNG_CONSUMER_ACTIVE_STREAM,
  57         LTTNG_CONSUMER_PAUSE_STREAM,
  58         LTTNG_CONSUMER_DELETE_STREAM,
  59 };
  60
  61 enum lttng_consumer_type {
  62         LTTNG_CONSUMER_UNKNOWN = 0,
  63         LTTNG_CONSUMER_KERNEL,
  64         LTTNG_CONSUMER64_UST,
  65         LTTNG_CONSUMER32_UST,
  66 };
  67
  68 enum consumer_endpoint_status {
  69         CONSUMER_ENDPOINT_ACTIVE,
  70         CONSUMER_ENDPOINT_INACTIVE,
  71 };
  72
  73 enum consumer_channel_output {
  74         CONSUMER_CHANNEL_MMAP   = 0,
  75         CONSUMER_CHANNEL_SPLICE = 1,
  76 };
  77
  78 enum consumer_channel_type {
  79         CONSUMER_CHANNEL_TYPE_METADATA  = 0,
  80         CONSUMER_CHANNEL_TYPE_DATA              = 1,
  81 };
  82
  83 struct stream_list {
  84         struct cds_list_head head;
  85         unsigned int count;
  86 };
  87
  88 struct lttng_consumer_channel {
  89         /* HT node used for consumer_data.channel_ht */
  90         struct lttng_ht_node_ulong node;
  91         /* Indexed key. Incremented value in the consumer. */
  92         int key;
  93         /* Number of streams referencing this channel */
  94         int refcount;
  95         /* Tracing session id on the session daemon side. */
  96         uint64_t session_id;
  97         /* Channel trace file path name. */
  98         char pathname[PATH_MAX];
  99         /* Channel name. */
 100         char name[LTTNG_SYMBOL_NAME_LEN];
 101         /* UID and GID of the channel. */
 102         uid_t uid;
 103         gid_t gid;
 104         /* Relayd id of the channel. -1 if it does not apply. */
 105         int relayd_id;
 106         /*
 107          * Number of streams NOT initialized yet. This is used in order to not
 108          * delete this channel if streams are getting initialized.
 109          */
 110         unsigned int nb_init_stream_left;
 111         /* Output type (mmap or splice). */
 112         enum consumer_channel_output output;
 113         /* Channel type for stream */
 114         enum consumer_channel_type type;
 115
 116         /* For UST */
 117         struct ustctl_consumer_channel *uchan;
 118         unsigned char uuid[UUID_STR_LEN];
 119         /*
 120          * Temporary stream list used to store the streams once created and waiting
 121          * to be sent to the session daemon by receiving the
 122          * LTTNG_CONSUMER_GET_CHANNEL.
 123          */
 124         struct stream_list streams;
 125 };
 126
 127 /*
 128  * Internal representation of the streams, sessiond_key is used to identify
 129  * uniquely a stream.
 130  */
 131 struct lttng_consumer_stream {
 132         /* HT node used by the data_ht and metadata_ht */
 133         struct lttng_ht_node_ulong node;
 134         /* HT node used in consumer_data.stream_list_ht */
 135         struct lttng_ht_node_ulong node_session_id;
 136         /* Pointer to associated channel. */
 137         struct lttng_consumer_channel *chan;
 138
 139         /* Key by which the stream is indexed for 'node'. */
 140         int key;
 141         /*
 142          * File descriptor of the data output file. This can be either a file or a
 143          * socket fd for relayd streaming.
 144          */
 145         int out_fd; /* output file to write the data */
 146         /* Write position in the output file descriptor */
 147         off_t out_fd_offset;
 148         enum lttng_consumer_stream_state state;
 149         int shm_fd_is_copy;
 150         int data_read;
 151         int hangup_flush_done;
 152         enum lttng_event_output output;
 153         /* Maximum subbuffer size. */
 154         unsigned long max_sb_size;
 155
 156         /*
 157          * Still used by the kernel for MMAP output. For UST, the ustctl getter is
 158          * used for the mmap base and offset.
 159          */
 160         void *mmap_base;
 161         unsigned long mmap_len;
 162
 163         /* For UST */
 164
 165         int wait_fd;
 166         /* UID/GID of the user owning the session to which stream belongs */
 167         uid_t uid;
 168         gid_t gid;
 169         /* Network sequence number. Indicating on which relayd socket it goes. */
 170         int net_seq_idx;
 171         /* Identify if the stream is the metadata */
 172         unsigned int metadata_flag;
 173         /* Used when the stream is set for network streaming */
 174         uint64_t relayd_stream_id;
 175         /*
 176          * When sending a stream packet to a relayd, this number is used to track
 177          * the packet sent by the consumer and seen by the relayd. When sending the
 178          * data header to the relayd, this number is sent and if the transmission
 179          * was successful, it is incremented.
 180          *
 181          * Even if the full data is not fully transmitted it won't matter since
 182          * only two possible error can happen after that where either the relayd
 183          * died or a read error is detected on the stream making this value useless
 184          * after that.
 185          *
 186          * This value SHOULD be read/updated atomically or with the lock acquired.
 187          */
 188         uint64_t next_net_seq_num;
 189         /*
 190          * Lock to use the stream FDs since they are used between threads.
 191          *
 192          * This is nested INSIDE the consumer_data lock.
 193          * This is nested OUTSIDE consumer_relayd_sock_pair lock.
 194          */
 195         pthread_mutex_t lock;
 196         /* Tracing session id */
 197         uint64_t session_id;
 198         /*
 199          * Indicates if the stream end point is still active or not (network
 200          * streaming or local file system). The thread "owning" the stream is
 201          * handling this status and can be notified of a state change through the
 202          * consumer data appropriate pipe.
 203          */
 204         enum consumer_endpoint_status endpoint_status;
 205         /* Stream name. Format is: <channel_name>_<cpu_number> */
 206         char name[LTTNG_SYMBOL_NAME_LEN];
 207         /* Internal state of libustctl. */
 208         struct ustctl_consumer_stream *ustream;
 209         struct cds_list_head send_node;
 210 };
 211
 212 /*
 213  * Internal representation of a relayd socket pair.
 214  */
 215 struct consumer_relayd_sock_pair {
 216         /* Network sequence number. */
 217         int net_seq_idx;
 218         /* Number of stream associated with this relayd */
 219         unsigned int refcount;
 220
 221         /*
 222          * This flag indicates whether or not we should destroy this object. The
 223          * destruction should ONLY occurs when this flag is set and the refcount is
 224          * set to zero.
 225          */
 226         unsigned int destroy_flag;
 227
 228         /*
 229          * Mutex protecting the control socket to avoid out of order packets
 230          * between threads sending data to the relayd. Since metadata data is sent
 231          * over that socket, at least two sendmsg() are needed (header + data)
 232          * creating a race for packets to overlap between threads using it.
 233          *
 234          * This is nested INSIDE the consumer_data lock.
 235          * This is nested INSIDE the stream lock.
 236          */
 237         pthread_mutex_t ctrl_sock_mutex;
 238
 239         /* Control socket. Command and metadata are passed over it */
 240         struct lttcomm_sock control_sock;
 241
 242         /*
 243          * We don't need a mutex at this point since we only splice or write single
 244          * large chunk of data with a header appended at the begining. Moreover,
 245          * this socket is for now only used in a single thread.
 246          */
 247         struct lttcomm_sock data_sock;
 248         struct lttng_ht_node_ulong node;
 249
 250         /* Session id on both sides for the sockets. */
 251         uint64_t relayd_session_id;
 252         uint64_t sessiond_session_id;
 253 };
 254
 255 /*
 256  * UST consumer local data to the program. One or more instance per
 257  * process.
 258  */
 259 struct lttng_consumer_local_data {
 260         /*
 261          * Function to call when data is available on a buffer.
 262          * Returns the number of bytes read, or negative error value.
 263          */
 264         ssize_t (*on_buffer_ready)(struct lttng_consumer_stream *stream,
 265                         struct lttng_consumer_local_data *ctx);
 266         /*
 267          * function to call when we receive a new channel, it receives a
 268          * newly allocated channel, depending on the return code of this
 269          * function, the new channel will be handled by the application
 270          * or the library.
 271          *
 272          * Returns:
 273          *    > 0 (success, FD is kept by application)
 274          *   == 0 (success, FD is left to library)
 275          *    < 0 (error)
 276          */
 277         int (*on_recv_channel)(struct lttng_consumer_channel *channel);
 278         /*
 279          * function to call when we receive a new stream, it receives a
 280          * newly allocated stream, depending on the return code of this
 281          * function, the new stream will be handled by the application
 282          * or the library.
 283          *
 284          * Returns:
 285          *    > 0 (success, FD is kept by application)
 286          *   == 0 (success, FD is left to library)
 287          *    < 0 (error)
 288          */
 289         int (*on_recv_stream)(struct lttng_consumer_stream *stream);
 290         /*
 291          * function to call when a stream is getting updated by the session
 292          * daemon, this function receives the sessiond key and the new
 293          * state, depending on the return code of this function the
 294          * update of state for the stream is handled by the application
 295          * or the library.
 296          *
 297          * Returns:
 298          *    > 0 (success, FD is kept by application)
 299          *   == 0 (success, FD is left to library)
 300          *    < 0 (error)
 301          */
 302         int (*on_update_stream)(int sessiond_key, uint32_t state);
 303         /* socket to communicate errors with sessiond */
 304         int consumer_error_socket;
 305         /* socket to exchange commands with sessiond */
 306         char *consumer_command_sock_path;
 307         /* communication with splice */
 308         int consumer_thread_pipe[2];
 309         int consumer_splice_metadata_pipe[2];
 310         /* Data stream poll thread pipe. To transfer data stream to the thread */
 311         int consumer_data_pipe[2];
 312         /* to let the signal handler wake up the fd receiver thread */
 313         int consumer_should_quit[2];
 314         /* Metadata poll thread pipe. Transfer metadata stream to it */
 315         int consumer_metadata_pipe[2];
 316 };
 317
 318 /*
 319  * Library-level data. One instance per process.
 320  */
 321 struct lttng_consumer_global_data {
 322         /*
 323          * At this time, this lock is used to ensure coherence between the count
 324          * and number of element in the hash table. It's also a protection for
 325          * concurrent read/write between threads.
 326          *
 327          * This is nested OUTSIDE the stream lock.
 328          * This is nested OUTSIDE the consumer_relayd_sock_pair lock.
 329          */
 330         pthread_mutex_t lock;
 331
 332         /*
 333          * Number of streams in the data stream hash table declared outside.
 334          * Protected by consumer_data.lock.
 335          */
 336         int stream_count;
 337
 338         /* Channel hash table protected by consumer_data.lock. */
 339         struct lttng_ht *channel_ht;
 340         /*
 341          * Flag specifying if the local array of FDs needs update in the
 342          * poll function. Protected by consumer_data.lock.
 343          */
 344         unsigned int need_update;
 345         enum lttng_consumer_type type;
 346
 347         /*
 348          * Relayd socket(s) hashtable indexed by network sequence number. Each
 349          * stream has an index which associate the right relayd socket to use.
 350          */
 351         struct lttng_ht *relayd_ht;
 352
 353         /*
 354          * This hash table contains all streams (metadata and data) indexed by
 355          * session id. In other words, the ht is indexed by session id and each
 356          * bucket contains the list of associated streams.
 357          *
 358          * This HT uses the "node_session_id" of the consumer stream.
 359          */
 360         struct lttng_ht *stream_list_ht;
 361 };
 362
 363 /*
 364  * Init consumer data structures.
 365  */
 366 void lttng_consumer_init(void);
 367
 368 /*
 369  * Set the error socket for communication with a session daemon.
 370  */
 371 void lttng_consumer_set_error_sock(struct lttng_consumer_local_data *ctx,
 372                 int sock);
 373
 374 /*
 375  * Set the command socket path for communication with a session daemon.
 376  */
 377 void lttng_consumer_set_command_sock_path(
 378                 struct lttng_consumer_local_data *ctx, char *sock);
 379
 380 /*
 381  * Send return code to session daemon.
 382  *
 383  * Returns the return code of sendmsg : the number of bytes transmitted or -1
 384  * on error.
 385  */
 386 int lttng_consumer_send_error(struct lttng_consumer_local_data *ctx, int cmd);
 387
 388 /*
 389  * Called from signal handler to ensure a clean exit.
 390  */
 391 void lttng_consumer_should_exit(struct lttng_consumer_local_data *ctx);
 392
 393 /*
 394  * Cleanup the daemon's socket on exit.
 395  */
 396 void lttng_consumer_cleanup(void);
 397
 398 /*
 399  * Flush pending writes to trace output disk file.
 400  */
 401 void lttng_consumer_sync_trace_file(struct lttng_consumer_stream *stream,
 402                 off_t orig_offset);
 403
 404 /*
 405  * Poll on the should_quit pipe and the command socket return -1 on error and
 406  * should exit, 0 if data is available on the command socket
 407  */
 408 int lttng_consumer_poll_socket(struct pollfd *kconsumer_sockpoll);
 409
 410 struct lttng_consumer_stream *consumer_allocate_stream(int channel_key,
 411                 int stream_key,
 412                 enum lttng_consumer_stream_state state,
 413                 const char *channel_name,
 414                 uid_t uid,
 415                 gid_t gid,
 416                 int relayd_id,
 417                 uint64_t session_id,
 418                 int cpu,
 419                 int *alloc_ret,
 420                 enum consumer_channel_type type);
 421 struct lttng_consumer_channel *consumer_allocate_channel(unsigned long key,
 422                 uint64_t session_id,
 423                 const char *pathname,
 424                 const char *name,
 425                 uid_t uid,
 426                 gid_t gid,
 427                 int relayd_id,
 428                 enum lttng_event_output output);
 429 void consumer_del_stream(struct lttng_consumer_stream *stream,
 430                 struct lttng_ht *ht);
 431 void consumer_del_metadata_stream(struct lttng_consumer_stream *stream,
 432                 struct lttng_ht *ht);
 433 int consumer_add_channel(struct lttng_consumer_channel *channel);
 434 void consumer_del_channel(struct lttng_consumer_channel *channel);
 435
 436 /* lttng-relayd consumer command */
 437 struct consumer_relayd_sock_pair *consumer_allocate_relayd_sock_pair(
 438                 int net_seq_idx);
 439 struct consumer_relayd_sock_pair *consumer_find_relayd(int key);
 440 struct lttng_consumer_channel *consumer_find_channel(unsigned long key);
 441 int consumer_handle_stream_before_relayd(struct lttng_consumer_stream *stream,
 442                 size_t data_size);
 443 void consumer_steal_stream_key(int key, struct lttng_ht *ht);
 444
 445 struct lttng_consumer_local_data *lttng_consumer_create(
 446                 enum lttng_consumer_type type,
 447                 ssize_t (*buffer_ready)(struct lttng_consumer_stream *stream,
 448                         struct lttng_consumer_local_data *ctx),
 449                 int (*recv_channel)(struct lttng_consumer_channel *channel),
 450                 int (*recv_stream)(struct lttng_consumer_stream *stream),
 451                 int (*update_stream)(int sessiond_key, uint32_t state));
 452 void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx);
 453 ssize_t lttng_consumer_on_read_subbuffer_mmap(
 454                 struct lttng_consumer_local_data *ctx,
 455                 struct lttng_consumer_stream *stream, unsigned long len,
 456                 unsigned long padding);
 457 ssize_t lttng_consumer_on_read_subbuffer_splice(
 458                 struct lttng_consumer_local_data *ctx,
 459                 struct lttng_consumer_stream *stream, unsigned long len,
 460                 unsigned long padding);
 461 int lttng_consumer_take_snapshot(struct lttng_consumer_stream *stream);
 462 int lttng_consumer_get_produced_snapshot(struct lttng_consumer_stream *stream,
 463                 unsigned long *pos);
 464 void *consumer_thread_metadata_poll(void *data);
 465 void *consumer_thread_data_poll(void *data);
 466 void *consumer_thread_sessiond_poll(void *data);
 467 int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 468                 int sock, struct pollfd *consumer_sockpoll);
 469
 470 ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream,
 471                 struct lttng_consumer_local_data *ctx);
 472 int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream);
 473 int consumer_add_relayd_socket(int net_seq_idx, int sock_type,
 474                 struct lttng_consumer_local_data *ctx, int sock,
 475                 struct pollfd *consumer_sockpoll, struct lttcomm_sock *relayd_sock,
 476                 unsigned int sessiond_id);
 477 void consumer_flag_relayd_for_destroy(
 478                 struct consumer_relayd_sock_pair *relayd);
 479 int consumer_data_pending(uint64_t id);
 480 int consumer_send_status_msg(int sock, int ret_code);
 481 int consumer_send_status_channel(int sock,
 482                 struct lttng_consumer_channel *channel);
 483
 484 #endif /* LIB_CONSUMER_H */