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
  27 #include <lttng/lttng.h>
  28
  29 #include <common/hashtable/hashtable.h>
  30 #include <common/compat/fcntl.h>
  31 #include <common/sessiond-comm/sessiond-comm.h>
  32
  33 /* Commands for consumer */
  34 enum lttng_consumer_command {
  35         LTTNG_CONSUMER_ADD_CHANNEL,
  36         LTTNG_CONSUMER_ADD_STREAM,
  37         /* pause, delete, active depending on fd state */
  38         LTTNG_CONSUMER_UPDATE_STREAM,
  39         /* inform the consumer to quit when all fd has hang up */
  40         LTTNG_CONSUMER_STOP,
  41         LTTNG_CONSUMER_ADD_RELAYD_SOCKET,
  42         /* Inform the consumer to kill a specific relayd connection */
  43         LTTNG_CONSUMER_DESTROY_RELAYD,
  44         /* Return to the sessiond if there is data pending for a session */
  45         LTTNG_CONSUMER_DATA_PENDING,
  46 };
  47
  48 /* State of each fd in consumer */
  49 enum lttng_consumer_stream_state {
  50         LTTNG_CONSUMER_ACTIVE_STREAM,
  51         LTTNG_CONSUMER_PAUSE_STREAM,
  52         LTTNG_CONSUMER_DELETE_STREAM,
  53 };
  54
  55 enum lttng_consumer_type {
  56         LTTNG_CONSUMER_UNKNOWN = 0,
  57         LTTNG_CONSUMER_KERNEL,
  58         LTTNG_CONSUMER64_UST,
  59         LTTNG_CONSUMER32_UST,
  60 };
  61
  62 enum consumer_endpoint_status {
  63         CONSUMER_ENDPOINT_ACTIVE,
  64         CONSUMER_ENDPOINT_INACTIVE,
  65 };
  66
  67 struct lttng_consumer_channel {
  68         struct lttng_ht_node_ulong node;
  69         int key;
  70         uint64_t max_sb_size; /* the subbuffer size for this channel */
  71         int refcount; /* Number of streams referencing this channel */
  72         /*
  73          * The number of streams to receive initially. Used to guarantee that we do
  74          * not destroy a channel before receiving all its associated streams.
  75          */
  76         unsigned int nb_init_streams;
  77
  78         /* For UST */
  79         int shm_fd;
  80         int wait_fd;
  81         void *mmap_base;
  82         size_t mmap_len;
  83         struct lttng_ust_shm_handle *handle;
  84         int wait_fd_is_copy;
  85         int cpucount;
  86 };
  87
  88 /* Forward declaration for UST. */
  89 struct lttng_ust_lib_ring_buffer;
  90
  91 /*
  92  * Internal representation of the streams, sessiond_key is used to identify
  93  * uniquely a stream.
  94  */
  95 struct lttng_consumer_stream {
  96         /* HT node used by the data_ht and metadata_ht */
  97         struct lttng_ht_node_ulong node;
  98         /* HT node used in consumer_data.stream_list_ht */
  99         struct lttng_ht_node_ulong node_session_id;
 100         struct lttng_consumer_channel *chan;    /* associated channel */
 101         /*
 102          * key is the key used by the session daemon to refer to the
 103          * object in the consumer daemon.
 104          */
 105         int key;
 106         int shm_fd;
 107         int wait_fd;
 108         int out_fd; /* output file to write the data */
 109         off_t out_fd_offset; /* write position in the output file descriptor */
 110         char path_name[PATH_MAX]; /* tracefile name */
 111         enum lttng_consumer_stream_state state;
 112         size_t shm_len;
 113         void *mmap_base;
 114         size_t mmap_len;
 115         enum lttng_event_output output; /* splice or mmap */
 116         int shm_fd_is_copy;
 117         int wait_fd_is_copy;
 118         /* For UST */
 119         struct lttng_ust_lib_ring_buffer *buf;
 120         int cpu;
 121         int data_read;
 122         int hangup_flush_done;
 123         /* UID/GID of the user owning the session to which stream belongs */
 124         uid_t uid;
 125         gid_t gid;
 126         /* Network sequence number. Indicating on which relayd socket it goes. */
 127         int net_seq_idx;
 128         /* Identify if the stream is the metadata */
 129         unsigned int metadata_flag;
 130         /* Used when the stream is set for network streaming */
 131         uint64_t relayd_stream_id;
 132         /* Next sequence number to use for trace packet */
 133         uint64_t next_net_seq_num;
 134         /*
 135          * Lock to use the stream FDs since they are used between threads.
 136          *
 137          * This is nested INSIDE the consumer_data lock.
 138          * This is nested OUTSIDE consumer_relayd_sock_pair lock.
 139          */
 140         pthread_mutex_t lock;
 141         /* Tracing session id */
 142         uint64_t session_id;
 143         /*
 144          * Indicates if the stream end point is still active or not (network
 145          * streaming or local file system). The thread "owning" the stream is
 146          * handling this status and can be notified of a state change through the
 147          * consumer data appropriate pipe.
 148          */
 149         enum consumer_endpoint_status endpoint_status;
 150 };
 151
 152 /*
 153  * Internal representation of a relayd socket pair.
 154  */
 155 struct consumer_relayd_sock_pair {
 156         /* Network sequence number. */
 157         int net_seq_idx;
 158         /* Number of stream associated with this relayd */
 159         unsigned int refcount;
 160
 161         /*
 162          * This flag indicates whether or not we should destroy this object. The
 163          * destruction should ONLY occurs when this flag is set and the refcount is
 164          * set to zero.
 165          */
 166         unsigned int destroy_flag;
 167
 168         /*
 169          * Mutex protecting the control socket to avoid out of order packets
 170          * between threads sending data to the relayd. Since metadata data is sent
 171          * over that socket, at least two sendmsg() are needed (header + data)
 172          * creating a race for packets to overlap between threads using it.
 173          *
 174          * This is nested INSIDE the consumer_data lock.
 175          * This is nested INSIDE the stream lock.
 176          */
 177         pthread_mutex_t ctrl_sock_mutex;
 178
 179         /* Control socket. Command and metadata are passed over it */
 180         struct lttcomm_sock control_sock;
 181
 182         /*
 183          * We don't need a mutex at this point since we only splice or write single
 184          * large chunk of data with a header appended at the begining. Moreover,
 185          * this socket is for now only used in a single thread.
 186          */
 187         struct lttcomm_sock data_sock;
 188         struct lttng_ht_node_ulong node;
 189 };
 190
 191 /*
 192  * UST consumer local data to the program. One or more instance per
 193  * process.
 194  */
 195 struct lttng_consumer_local_data {
 196         /*
 197          * Function to call when data is available on a buffer.
 198          * Returns the number of bytes read, or negative error value.
 199          */
 200         ssize_t (*on_buffer_ready)(struct lttng_consumer_stream *stream,
 201                         struct lttng_consumer_local_data *ctx);
 202         /*
 203          * function to call when we receive a new channel, it receives a
 204          * newly allocated channel, depending on the return code of this
 205          * function, the new channel will be handled by the application
 206          * or the library.
 207          *
 208          * Returns:
 209          *    > 0 (success, FD is kept by application)
 210          *   == 0 (success, FD is left to library)
 211          *    < 0 (error)
 212          */
 213         int (*on_recv_channel)(struct lttng_consumer_channel *channel);
 214         /*
 215          * function to call when we receive a new stream, it receives a
 216          * newly allocated stream, depending on the return code of this
 217          * function, the new stream will be handled by the application
 218          * or the library.
 219          *
 220          * Returns:
 221          *    > 0 (success, FD is kept by application)
 222          *   == 0 (success, FD is left to library)
 223          *    < 0 (error)
 224          */
 225         int (*on_recv_stream)(struct lttng_consumer_stream *stream);
 226         /*
 227          * function to call when a stream is getting updated by the session
 228          * daemon, this function receives the sessiond key and the new
 229          * state, depending on the return code of this function the
 230          * update of state for the stream is handled by the application
 231          * or the library.
 232          *
 233          * Returns:
 234          *    > 0 (success, FD is kept by application)
 235          *   == 0 (success, FD is left to library)
 236          *    < 0 (error)
 237          */
 238         int (*on_update_stream)(int sessiond_key, uint32_t state);
 239         /* socket to communicate errors with sessiond */
 240         int consumer_error_socket;
 241         /* socket to exchange commands with sessiond */
 242         char *consumer_command_sock_path;
 243         /* communication with splice */
 244         int consumer_thread_pipe[2];
 245         int consumer_splice_metadata_pipe[2];
 246         /* Data stream poll thread pipe. To transfer data stream to the thread */
 247         int consumer_data_pipe[2];
 248         /* to let the signal handler wake up the fd receiver thread */
 249         int consumer_should_quit[2];
 250         /* Metadata poll thread pipe. Transfer metadata stream to it */
 251         int consumer_metadata_pipe[2];
 252 };
 253
 254 /*
 255  * Library-level data. One instance per process.
 256  */
 257 struct lttng_consumer_global_data {
 258         /*
 259          * At this time, this lock is used to ensure coherence between the count
 260          * and number of element in the hash table. It's also a protection for
 261          * concurrent read/write between threads.
 262          *
 263          * This is nested OUTSIDE the stream lock.
 264          * This is nested OUTSIDE the consumer_relayd_sock_pair lock.
 265          */
 266         pthread_mutex_t lock;
 267
 268         /*
 269          * Number of streams in the data stream hash table declared outside.
 270          * Protected by consumer_data.lock.
 271          */
 272         int stream_count;
 273
 274         /* Channel hash table protected by consumer_data.lock. */
 275         struct lttng_ht *channel_ht;
 276         /*
 277          * Flag specifying if the local array of FDs needs update in the
 278          * poll function. Protected by consumer_data.lock.
 279          */
 280         unsigned int need_update;
 281         enum lttng_consumer_type type;
 282
 283         /*
 284          * Relayd socket(s) hashtable indexed by network sequence number. Each
 285          * stream has an index which associate the right relayd socket to use.
 286          */
 287         struct lttng_ht *relayd_ht;
 288
 289         /*
 290          * This hash table contains all streams (metadata and data) indexed by
 291          * session id. In other words, the ht is indexed by session id and each
 292          * bucket contains the list of associated streams.
 293          *
 294          * This HT uses the "node_session_id" of the consumer stream.
 295          */
 296         struct lttng_ht *stream_list_ht;
 297 };
 298
 299 /*
 300  * Init consumer data structures.
 301  */
 302 extern void lttng_consumer_init(void);
 303
 304 /*
 305  * Set the error socket for communication with a session daemon.
 306  */
 307 extern void lttng_consumer_set_error_sock(
 308                 struct lttng_consumer_local_data *ctx, int sock);
 309
 310 /*
 311  * Set the command socket path for communication with a session daemon.
 312  */
 313 extern void lttng_consumer_set_command_sock_path(
 314                 struct lttng_consumer_local_data *ctx, char *sock);
 315
 316 /*
 317  * Send return code to session daemon.
 318  *
 319  * Returns the return code of sendmsg : the number of bytes transmitted or -1
 320  * on error.
 321  */
 322 extern int lttng_consumer_send_error(
 323                 struct lttng_consumer_local_data *ctx, int cmd);
 324
 325 /*
 326  * Called from signal handler to ensure a clean exit.
 327  */
 328 extern void lttng_consumer_should_exit(
 329                 struct lttng_consumer_local_data *ctx);
 330
 331 /*
 332  * Cleanup the daemon's socket on exit.
 333  */
 334 extern void lttng_consumer_cleanup(void);
 335
 336 /*
 337  * Flush pending writes to trace output disk file.
 338  */
 339 extern void lttng_consumer_sync_trace_file(
 340                 struct lttng_consumer_stream *stream, off_t orig_offset);
 341
 342 /*
 343  * Poll on the should_quit pipe and the command socket return -1 on error and
 344  * should exit, 0 if data is available on the command socket
 345  */
 346 extern int lttng_consumer_poll_socket(struct pollfd *kconsumer_sockpoll);
 347
 348 extern struct lttng_consumer_stream *consumer_allocate_stream(
 349                 int channel_key, int stream_key,
 350                 int shm_fd, int wait_fd,
 351                 enum lttng_consumer_stream_state state,
 352                 uint64_t mmap_len,
 353                 enum lttng_event_output output,
 354                 const char *path_name,
 355                 uid_t uid,
 356                 gid_t gid,
 357                 int net_index,
 358                 int metadata_flag,
 359                 uint64_t session_id,
 360                 int *alloc_ret);
 361 extern void consumer_del_stream(struct lttng_consumer_stream *stream,
 362                 struct lttng_ht *ht);
 363 extern void consumer_del_metadata_stream(struct lttng_consumer_stream *stream,
 364                 struct lttng_ht *ht);
 365 extern void consumer_del_channel(struct lttng_consumer_channel *channel);
 366 extern struct lttng_consumer_channel *consumer_allocate_channel(
 367                 int channel_key,
 368                 int shm_fd, int wait_fd,
 369                 uint64_t mmap_len,
 370                 uint64_t max_sb_size,
 371                 unsigned int nb_init_streams);
 372 int consumer_add_channel(struct lttng_consumer_channel *channel);
 373
 374 /* lttng-relayd consumer command */
 375 struct consumer_relayd_sock_pair *consumer_allocate_relayd_sock_pair(
 376                 int net_seq_idx);
 377 struct consumer_relayd_sock_pair *consumer_find_relayd(int key);
 378 int consumer_handle_stream_before_relayd(struct lttng_consumer_stream *stream,
 379                 size_t data_size);
 380 void consumer_steal_stream_key(int key, struct lttng_ht *ht);
 381
 382 extern struct lttng_consumer_local_data *lttng_consumer_create(
 383                 enum lttng_consumer_type type,
 384                 ssize_t (*buffer_ready)(struct lttng_consumer_stream *stream,
 385                         struct lttng_consumer_local_data *ctx),
 386                 int (*recv_channel)(struct lttng_consumer_channel *channel),
 387                 int (*recv_stream)(struct lttng_consumer_stream *stream),
 388                 int (*update_stream)(int sessiond_key, uint32_t state));
 389 extern void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx);
 390 extern ssize_t lttng_consumer_on_read_subbuffer_mmap(
 391                 struct lttng_consumer_local_data *ctx,
 392                 struct lttng_consumer_stream *stream, unsigned long len,
 393                 unsigned long padding);
 394 extern ssize_t lttng_consumer_on_read_subbuffer_splice(
 395                 struct lttng_consumer_local_data *ctx,
 396                 struct lttng_consumer_stream *stream, unsigned long len,
 397                 unsigned long padding);
 398 extern int lttng_consumer_take_snapshot(struct lttng_consumer_local_data *ctx,
 399                 struct lttng_consumer_stream *stream);
 400 extern int lttng_consumer_get_produced_snapshot(
 401                 struct lttng_consumer_local_data *ctx,
 402                 struct lttng_consumer_stream *stream,
 403                 unsigned long *pos);
 404 extern void *consumer_thread_metadata_poll(void *data);
 405 extern void *consumer_thread_data_poll(void *data);
 406 extern void *consumer_thread_sessiond_poll(void *data);
 407 extern int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 408                 int sock, struct pollfd *consumer_sockpoll);
 409
 410 ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream,
 411                 struct lttng_consumer_local_data *ctx);
 412 int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream);
 413 int consumer_add_relayd_socket(int net_seq_idx, int sock_type,
 414                 struct lttng_consumer_local_data *ctx, int sock,
 415                 struct pollfd *consumer_sockpoll, struct lttcomm_sock *relayd_sock);
 416 void consumer_flag_relayd_for_destroy(
 417                 struct consumer_relayd_sock_pair *relayd);
 418 int consumer_data_pending(uint64_t id);
 419 int consumer_send_status_msg(int sock, int ret_code);
 420
 421 #endif /* LIB_CONSUMER_H */