| 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 | /* |
| 34 | * When the receiving thread dies, we need to have a way to make the polling |
| 35 | * thread exit eventually. If all FDs hang up (normal case when the |
| 36 | * lttng-sessiond stops), we can exit cleanly, but if there is a problem and |
| 37 | * for whatever reason some FDs remain open, the consumer should still exit |
| 38 | * eventually. |
| 39 | * |
| 40 | * If the timeout is reached, it means that during this period no events |
| 41 | * occurred on the FDs so we need to force an exit. This case should not happen |
| 42 | * but it is a safety to ensure we won't block the consumer indefinitely. |
| 43 | * |
| 44 | * The value of 2 seconds is an arbitrary choice. |
| 45 | */ |
| 46 | #define LTTNG_CONSUMER_POLL_TIMEOUT 2000 |
| 47 | |
| 48 | /* Commands for consumer */ |
| 49 | enum lttng_consumer_command { |
| 50 | LTTNG_CONSUMER_ADD_CHANNEL, |
| 51 | LTTNG_CONSUMER_ADD_STREAM, |
| 52 | /* pause, delete, active depending on fd state */ |
| 53 | LTTNG_CONSUMER_UPDATE_STREAM, |
| 54 | /* inform the consumer to quit when all fd has hang up */ |
| 55 | LTTNG_CONSUMER_STOP, |
| 56 | LTTNG_CONSUMER_ADD_RELAYD_SOCKET, |
| 57 | /* Inform the consumer to kill a specific relayd connection */ |
| 58 | LTTNG_CONSUMER_DESTROY_RELAYD, |
| 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 | struct lttng_consumer_channel { |
| 76 | struct lttng_ht_node_ulong node; |
| 77 | int key; |
| 78 | uint64_t max_sb_size; /* the subbuffer size for this channel */ |
| 79 | int refcount; /* Number of streams referencing this channel */ |
| 80 | /* For UST */ |
| 81 | int shm_fd; |
| 82 | int wait_fd; |
| 83 | void *mmap_base; |
| 84 | size_t mmap_len; |
| 85 | struct lttng_ust_shm_handle *handle; |
| 86 | int nr_streams; |
| 87 | int wait_fd_is_copy; |
| 88 | int cpucount; |
| 89 | }; |
| 90 | |
| 91 | /* Forward declaration for UST. */ |
| 92 | struct lttng_ust_lib_ring_buffer; |
| 93 | |
| 94 | /* |
| 95 | * Internal representation of the streams, sessiond_key is used to identify |
| 96 | * uniquely a stream. |
| 97 | */ |
| 98 | struct lttng_consumer_stream { |
| 99 | struct lttng_ht_node_ulong node; |
| 100 | struct lttng_ht_node_ulong waitfd_node; |
| 101 | struct lttng_consumer_channel *chan; /* associated channel */ |
| 102 | /* |
| 103 | * key is the key used by the session daemon to refer to the |
| 104 | * object in the consumer daemon. |
| 105 | */ |
| 106 | int key; |
| 107 | int shm_fd; |
| 108 | int wait_fd; |
| 109 | int out_fd; /* output file to write the data */ |
| 110 | off_t out_fd_offset; /* write position in the output file descriptor */ |
| 111 | char path_name[PATH_MAX]; /* tracefile name */ |
| 112 | enum lttng_consumer_stream_state state; |
| 113 | size_t shm_len; |
| 114 | void *mmap_base; |
| 115 | size_t mmap_len; |
| 116 | enum lttng_event_output output; /* splice or mmap */ |
| 117 | int shm_fd_is_copy; |
| 118 | int wait_fd_is_copy; |
| 119 | /* For UST */ |
| 120 | struct lttng_ust_lib_ring_buffer *buf; |
| 121 | int cpu; |
| 122 | int data_read; |
| 123 | int hangup_flush_done; |
| 124 | /* UID/GID of the user owning the session to which stream belongs */ |
| 125 | uid_t uid; |
| 126 | gid_t gid; |
| 127 | /* Network sequence number. Indicating on which relayd socket it goes. */ |
| 128 | int net_seq_idx; |
| 129 | /* Identify if the stream is the metadata */ |
| 130 | unsigned int metadata_flag; |
| 131 | /* Used when the stream is set for network streaming */ |
| 132 | uint64_t relayd_stream_id; |
| 133 | /* Next sequence number to use for trace packet */ |
| 134 | uint64_t next_net_seq_num; |
| 135 | }; |
| 136 | |
| 137 | /* |
| 138 | * Internal representation of a relayd socket pair. |
| 139 | */ |
| 140 | struct consumer_relayd_sock_pair { |
| 141 | /* Network sequence number. */ |
| 142 | int net_seq_idx; |
| 143 | /* Number of stream associated with this relayd */ |
| 144 | unsigned int refcount; |
| 145 | |
| 146 | /* |
| 147 | * This flag indicates whether or not we should destroy this object. The |
| 148 | * destruction should ONLY occurs when this flag is set and the refcount is |
| 149 | * set to zero. |
| 150 | */ |
| 151 | unsigned int destroy_flag; |
| 152 | |
| 153 | /* |
| 154 | * Mutex protecting the control socket to avoid out of order packets |
| 155 | * between threads sending data to the relayd. Since metadata data is sent |
| 156 | * over that socket, at least two sendmsg() are needed (header + data) |
| 157 | * creating a race for packets to overlap between threads using it. |
| 158 | */ |
| 159 | pthread_mutex_t ctrl_sock_mutex; |
| 160 | |
| 161 | /* Control socket. Command and metadata are passed over it */ |
| 162 | struct lttcomm_sock control_sock; |
| 163 | |
| 164 | /* |
| 165 | * We don't need a mutex at this point since we only splice or write single |
| 166 | * large chunk of data with a header appended at the begining. Moreover, |
| 167 | * this socket is for now only used in a single thread. |
| 168 | */ |
| 169 | struct lttcomm_sock data_sock; |
| 170 | struct lttng_ht_node_ulong node; |
| 171 | }; |
| 172 | |
| 173 | /* |
| 174 | * UST consumer local data to the program. One or more instance per |
| 175 | * process. |
| 176 | */ |
| 177 | struct lttng_consumer_local_data { |
| 178 | /* |
| 179 | * Function to call when data is available on a buffer. |
| 180 | * Returns the number of bytes read, or negative error value. |
| 181 | */ |
| 182 | ssize_t (*on_buffer_ready)(struct lttng_consumer_stream *stream, |
| 183 | struct lttng_consumer_local_data *ctx); |
| 184 | /* |
| 185 | * function to call when we receive a new channel, it receives a |
| 186 | * newly allocated channel, depending on the return code of this |
| 187 | * function, the new channel will be handled by the application |
| 188 | * or the library. |
| 189 | * |
| 190 | * Returns: |
| 191 | * > 0 (success, FD is kept by application) |
| 192 | * == 0 (success, FD is left to library) |
| 193 | * < 0 (error) |
| 194 | */ |
| 195 | int (*on_recv_channel)(struct lttng_consumer_channel *channel); |
| 196 | /* |
| 197 | * function to call when we receive a new stream, it receives a |
| 198 | * newly allocated stream, depending on the return code of this |
| 199 | * function, the new stream will be handled by the application |
| 200 | * or the library. |
| 201 | * |
| 202 | * Returns: |
| 203 | * > 0 (success, FD is kept by application) |
| 204 | * == 0 (success, FD is left to library) |
| 205 | * < 0 (error) |
| 206 | */ |
| 207 | int (*on_recv_stream)(struct lttng_consumer_stream *stream); |
| 208 | /* |
| 209 | * function to call when a stream is getting updated by the session |
| 210 | * daemon, this function receives the sessiond key and the new |
| 211 | * state, depending on the return code of this function the |
| 212 | * update of state for the stream is handled by the application |
| 213 | * or the library. |
| 214 | * |
| 215 | * Returns: |
| 216 | * > 0 (success, FD is kept by application) |
| 217 | * == 0 (success, FD is left to library) |
| 218 | * < 0 (error) |
| 219 | */ |
| 220 | int (*on_update_stream)(int sessiond_key, uint32_t state); |
| 221 | /* socket to communicate errors with sessiond */ |
| 222 | int consumer_error_socket; |
| 223 | /* socket to exchange commands with sessiond */ |
| 224 | char *consumer_command_sock_path; |
| 225 | /* communication with splice */ |
| 226 | int consumer_thread_pipe[2]; |
| 227 | /* pipe to wake the poll thread when necessary */ |
| 228 | int consumer_poll_pipe[2]; |
| 229 | /* to let the signal handler wake up the fd receiver thread */ |
| 230 | int consumer_should_quit[2]; |
| 231 | }; |
| 232 | |
| 233 | /* |
| 234 | * Library-level data. One instance per process. |
| 235 | */ |
| 236 | struct lttng_consumer_global_data { |
| 237 | /* |
| 238 | * At this time, this lock is used to ensure coherence between the count |
| 239 | * and number of element in the hash table. It's also a protection for |
| 240 | * concurrent read/write between threads. |
| 241 | * |
| 242 | * XXX: We need to see if this lock is still needed with the lockless RCU |
| 243 | * hash tables. |
| 244 | */ |
| 245 | pthread_mutex_t lock; |
| 246 | |
| 247 | /* |
| 248 | * Number of streams in the hash table. Protected by consumer_data.lock. |
| 249 | */ |
| 250 | int stream_count; |
| 251 | /* |
| 252 | * Hash tables of streams and channels. Protected by consumer_data.lock. |
| 253 | */ |
| 254 | struct lttng_ht *stream_ht; |
| 255 | struct lttng_ht *channel_ht; |
| 256 | /* |
| 257 | * Flag specifying if the local array of FDs needs update in the |
| 258 | * poll function. Protected by consumer_data.lock. |
| 259 | */ |
| 260 | unsigned int need_update; |
| 261 | enum lttng_consumer_type type; |
| 262 | |
| 263 | /* |
| 264 | * Relayd socket(s) hashtable indexed by network sequence number. Each |
| 265 | * stream has an index which associate the right relayd socket to use. |
| 266 | */ |
| 267 | struct lttng_ht *relayd_ht; |
| 268 | }; |
| 269 | |
| 270 | /* |
| 271 | * Init consumer data structures. |
| 272 | */ |
| 273 | extern void lttng_consumer_init(void); |
| 274 | |
| 275 | /* |
| 276 | * Set the error socket for communication with a session daemon. |
| 277 | */ |
| 278 | extern void lttng_consumer_set_error_sock( |
| 279 | struct lttng_consumer_local_data *ctx, int sock); |
| 280 | |
| 281 | /* |
| 282 | * Set the command socket path for communication with a session daemon. |
| 283 | */ |
| 284 | extern void lttng_consumer_set_command_sock_path( |
| 285 | struct lttng_consumer_local_data *ctx, char *sock); |
| 286 | |
| 287 | /* |
| 288 | * Send return code to session daemon. |
| 289 | * |
| 290 | * Returns the return code of sendmsg : the number of bytes transmitted or -1 |
| 291 | * on error. |
| 292 | */ |
| 293 | extern int lttng_consumer_send_error( |
| 294 | struct lttng_consumer_local_data *ctx, int cmd); |
| 295 | |
| 296 | /* |
| 297 | * Called from signal handler to ensure a clean exit. |
| 298 | */ |
| 299 | extern void lttng_consumer_should_exit( |
| 300 | struct lttng_consumer_local_data *ctx); |
| 301 | |
| 302 | /* |
| 303 | * Cleanup the daemon's socket on exit. |
| 304 | */ |
| 305 | extern void lttng_consumer_cleanup(void); |
| 306 | |
| 307 | /* |
| 308 | * Flush pending writes to trace output disk file. |
| 309 | */ |
| 310 | extern void lttng_consumer_sync_trace_file( |
| 311 | struct lttng_consumer_stream *stream, off_t orig_offset); |
| 312 | |
| 313 | /* |
| 314 | * Poll on the should_quit pipe and the command socket return -1 on error and |
| 315 | * should exit, 0 if data is available on the command socket |
| 316 | */ |
| 317 | extern int lttng_consumer_poll_socket(struct pollfd *kconsumer_sockpoll); |
| 318 | |
| 319 | extern int consumer_update_poll_array( |
| 320 | struct lttng_consumer_local_data *ctx, struct pollfd **pollfd, |
| 321 | struct lttng_consumer_stream **local_consumer_streams, |
| 322 | struct lttng_ht *metadata_ht); |
| 323 | |
| 324 | extern struct lttng_consumer_stream *consumer_allocate_stream( |
| 325 | int channel_key, int stream_key, |
| 326 | int shm_fd, int wait_fd, |
| 327 | enum lttng_consumer_stream_state state, |
| 328 | uint64_t mmap_len, |
| 329 | enum lttng_event_output output, |
| 330 | const char *path_name, |
| 331 | uid_t uid, |
| 332 | gid_t gid, |
| 333 | int net_index, |
| 334 | int metadata_flag); |
| 335 | extern int consumer_add_stream(struct lttng_consumer_stream *stream); |
| 336 | extern void consumer_del_stream(struct lttng_consumer_stream *stream); |
| 337 | extern void consumer_change_stream_state(int stream_key, |
| 338 | enum lttng_consumer_stream_state state); |
| 339 | extern void consumer_del_channel(struct lttng_consumer_channel *channel); |
| 340 | extern struct lttng_consumer_channel *consumer_allocate_channel( |
| 341 | int channel_key, |
| 342 | int shm_fd, int wait_fd, |
| 343 | uint64_t mmap_len, |
| 344 | uint64_t max_sb_size); |
| 345 | int consumer_add_channel(struct lttng_consumer_channel *channel); |
| 346 | |
| 347 | /* lttng-relayd consumer command */ |
| 348 | int consumer_add_relayd(struct consumer_relayd_sock_pair *relayd); |
| 349 | struct consumer_relayd_sock_pair *consumer_allocate_relayd_sock_pair( |
| 350 | int net_seq_idx); |
| 351 | struct consumer_relayd_sock_pair *consumer_find_relayd(int key); |
| 352 | int consumer_handle_stream_before_relayd(struct lttng_consumer_stream *stream, |
| 353 | size_t data_size); |
| 354 | void consumer_destroy_relayd(struct consumer_relayd_sock_pair *relayd); |
| 355 | |
| 356 | extern struct lttng_consumer_local_data *lttng_consumer_create( |
| 357 | enum lttng_consumer_type type, |
| 358 | ssize_t (*buffer_ready)(struct lttng_consumer_stream *stream, |
| 359 | struct lttng_consumer_local_data *ctx), |
| 360 | int (*recv_channel)(struct lttng_consumer_channel *channel), |
| 361 | int (*recv_stream)(struct lttng_consumer_stream *stream), |
| 362 | int (*update_stream)(int sessiond_key, uint32_t state)); |
| 363 | extern void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx); |
| 364 | extern ssize_t lttng_consumer_on_read_subbuffer_mmap( |
| 365 | struct lttng_consumer_local_data *ctx, |
| 366 | struct lttng_consumer_stream *stream, unsigned long len); |
| 367 | extern ssize_t lttng_consumer_on_read_subbuffer_splice( |
| 368 | struct lttng_consumer_local_data *ctx, |
| 369 | struct lttng_consumer_stream *stream, unsigned long len); |
| 370 | extern int lttng_consumer_take_snapshot(struct lttng_consumer_local_data *ctx, |
| 371 | struct lttng_consumer_stream *stream); |
| 372 | extern int lttng_consumer_get_produced_snapshot( |
| 373 | struct lttng_consumer_local_data *ctx, |
| 374 | struct lttng_consumer_stream *stream, |
| 375 | unsigned long *pos); |
| 376 | extern void *lttng_consumer_thread_poll_fds(void *data); |
| 377 | extern void *lttng_consumer_thread_receive_fds(void *data); |
| 378 | extern int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx, |
| 379 | int sock, struct pollfd *consumer_sockpoll); |
| 380 | |
| 381 | ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream, |
| 382 | struct lttng_consumer_local_data *ctx); |
| 383 | int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream); |
| 384 | int consumer_add_relayd_socket(int net_seq_idx, int sock_type, |
| 385 | struct lttng_consumer_local_data *ctx, int sock, |
| 386 | struct pollfd *consumer_sockpoll, struct lttcomm_sock *relayd_sock); |
| 387 | void consumer_flag_relayd_for_destroy( |
| 388 | struct consumer_relayd_sock_pair *relayd); |
| 389 | |
| 390 | #endif /* LIB_CONSUMER_H */ |