| 1 | /* |
| 2 | * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca> |
| 3 | * Copyright (C) 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or |
| 6 | * modify it under the terms of the GNU General Public License |
| 7 | * as published by the Free Software Foundation; only version 2 |
| 8 | * of the License. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program; if not, write to the Free Software |
| 17 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 18 | */ |
| 19 | |
| 20 | #ifndef _LTTNG_CONSUMER_H |
| 21 | #define _LTTNG_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 | |
| 32 | /* |
| 33 | * When the receiving thread dies, we need to have a way to make the polling |
| 34 | * thread exit eventually. If all FDs hang up (normal case when the |
| 35 | * lttng-sessiond stops), we can exit cleanly, but if there is a problem and |
| 36 | * for whatever reason some FDs remain open, the consumer should still exit |
| 37 | * eventually. |
| 38 | * |
| 39 | * If the timeout is reached, it means that during this period no events |
| 40 | * occurred on the FDs so we need to force an exit. This case should not happen |
| 41 | * but it is a safety to ensure we won't block the consumer indefinitely. |
| 42 | * |
| 43 | * The value of 2 seconds is an arbitrary choice. |
| 44 | */ |
| 45 | #define LTTNG_CONSUMER_POLL_TIMEOUT 2000 |
| 46 | |
| 47 | /* Commands for consumer */ |
| 48 | enum lttng_consumer_command { |
| 49 | LTTNG_CONSUMER_ADD_CHANNEL, |
| 50 | LTTNG_CONSUMER_ADD_STREAM, |
| 51 | /* pause, delete, active depending on fd state */ |
| 52 | LTTNG_CONSUMER_UPDATE_STREAM, |
| 53 | /* inform the consumer to quit when all fd has hang up */ |
| 54 | LTTNG_CONSUMER_STOP, |
| 55 | }; |
| 56 | |
| 57 | /* State of each fd in consumer */ |
| 58 | enum lttng_consumer_stream_state { |
| 59 | LTTNG_CONSUMER_ACTIVE_STREAM, |
| 60 | LTTNG_CONSUMER_PAUSE_STREAM, |
| 61 | LTTNG_CONSUMER_DELETE_STREAM, |
| 62 | }; |
| 63 | |
| 64 | enum lttng_consumer_type { |
| 65 | LTTNG_CONSUMER_UNKNOWN = 0, |
| 66 | LTTNG_CONSUMER_KERNEL, |
| 67 | LTTNG_CONSUMER64_UST, |
| 68 | LTTNG_CONSUMER32_UST, |
| 69 | }; |
| 70 | |
| 71 | struct lttng_consumer_channel { |
| 72 | struct lttng_ht_node_ulong node; |
| 73 | int key; |
| 74 | uint64_t max_sb_size; /* the subbuffer size for this channel */ |
| 75 | int refcount; /* Number of streams referencing this channel */ |
| 76 | /* For UST */ |
| 77 | int shm_fd; |
| 78 | int wait_fd; |
| 79 | void *mmap_base; |
| 80 | size_t mmap_len; |
| 81 | struct lttng_ust_shm_handle *handle; |
| 82 | int nr_streams; |
| 83 | int wait_fd_is_copy; |
| 84 | int cpucount; |
| 85 | }; |
| 86 | |
| 87 | /* Forward declaration for UST. */ |
| 88 | struct lttng_ust_lib_ring_buffer; |
| 89 | |
| 90 | /* |
| 91 | * Internal representation of the streams, sessiond_key is used to identify |
| 92 | * uniquely a stream. |
| 93 | */ |
| 94 | struct lttng_consumer_stream { |
| 95 | struct lttng_ht_node_ulong node; |
| 96 | struct lttng_consumer_channel *chan; /* associated channel */ |
| 97 | /* |
| 98 | * key is the key used by the session daemon to refer to the |
| 99 | * object in the consumer daemon. |
| 100 | */ |
| 101 | int key; |
| 102 | int shm_fd; |
| 103 | int wait_fd; |
| 104 | int out_fd; /* output file to write the data */ |
| 105 | off_t out_fd_offset; /* write position in the output file descriptor */ |
| 106 | char path_name[PATH_MAX]; /* tracefile name */ |
| 107 | enum lttng_consumer_stream_state state; |
| 108 | size_t shm_len; |
| 109 | void *mmap_base; |
| 110 | size_t mmap_len; |
| 111 | enum lttng_event_output output; /* splice or mmap */ |
| 112 | int shm_fd_is_copy; |
| 113 | int wait_fd_is_copy; |
| 114 | /* For UST */ |
| 115 | struct lttng_ust_lib_ring_buffer *buf; |
| 116 | int cpu; |
| 117 | int data_read; |
| 118 | int hangup_flush_done; |
| 119 | /* UID/GID of the user owning the session to which stream belongs */ |
| 120 | uid_t uid; |
| 121 | gid_t gid; |
| 122 | }; |
| 123 | |
| 124 | /* |
| 125 | * UST consumer local data to the program. One or more instance per |
| 126 | * process. |
| 127 | */ |
| 128 | struct lttng_consumer_local_data { |
| 129 | /* |
| 130 | * Function to call when data is available on a buffer. |
| 131 | * Returns the number of bytes read, or negative error value. |
| 132 | */ |
| 133 | ssize_t (*on_buffer_ready)(struct lttng_consumer_stream *stream, |
| 134 | struct lttng_consumer_local_data *ctx); |
| 135 | /* |
| 136 | * function to call when we receive a new channel, it receives a |
| 137 | * newly allocated channel, depending on the return code of this |
| 138 | * function, the new channel will be handled by the application |
| 139 | * or the library. |
| 140 | * |
| 141 | * Returns: |
| 142 | * > 0 (success, FD is kept by application) |
| 143 | * == 0 (success, FD is left to library) |
| 144 | * < 0 (error) |
| 145 | */ |
| 146 | int (*on_recv_channel)(struct lttng_consumer_channel *channel); |
| 147 | /* |
| 148 | * function to call when we receive a new stream, it receives a |
| 149 | * newly allocated stream, depending on the return code of this |
| 150 | * function, the new stream will be handled by the application |
| 151 | * or the library. |
| 152 | * |
| 153 | * Returns: |
| 154 | * > 0 (success, FD is kept by application) |
| 155 | * == 0 (success, FD is left to library) |
| 156 | * < 0 (error) |
| 157 | */ |
| 158 | int (*on_recv_stream)(struct lttng_consumer_stream *stream); |
| 159 | /* |
| 160 | * function to call when a stream is getting updated by the session |
| 161 | * daemon, this function receives the sessiond key and the new |
| 162 | * state, depending on the return code of this function the |
| 163 | * update of state for the stream is handled by the application |
| 164 | * or the library. |
| 165 | * |
| 166 | * Returns: |
| 167 | * > 0 (success, FD is kept by application) |
| 168 | * == 0 (success, FD is left to library) |
| 169 | * < 0 (error) |
| 170 | */ |
| 171 | int (*on_update_stream)(int sessiond_key, uint32_t state); |
| 172 | /* socket to communicate errors with sessiond */ |
| 173 | int consumer_error_socket; |
| 174 | /* socket to exchange commands with sessiond */ |
| 175 | char *consumer_command_sock_path; |
| 176 | /* communication with splice */ |
| 177 | int consumer_thread_pipe[2]; |
| 178 | /* pipe to wake the poll thread when necessary */ |
| 179 | int consumer_poll_pipe[2]; |
| 180 | /* to let the signal handler wake up the fd receiver thread */ |
| 181 | int consumer_should_quit[2]; |
| 182 | }; |
| 183 | |
| 184 | /* |
| 185 | * Library-level data. One instance per process. |
| 186 | */ |
| 187 | struct lttng_consumer_global_data { |
| 188 | |
| 189 | /* |
| 190 | * At this time, this lock is used to ensure coherence between the count |
| 191 | * and number of element in the hash table. It's also a protection for |
| 192 | * concurrent read/write between threads. |
| 193 | * |
| 194 | * XXX: We need to see if this lock is still needed with the lockless RCU |
| 195 | * hash tables. |
| 196 | */ |
| 197 | pthread_mutex_t lock; |
| 198 | |
| 199 | /* |
| 200 | * Number of streams in the hash table. Protected by consumer_data.lock. |
| 201 | */ |
| 202 | int stream_count; |
| 203 | /* |
| 204 | * Hash tables of streams and channels. Protected by consumer_data.lock. |
| 205 | */ |
| 206 | struct lttng_ht *stream_ht; |
| 207 | struct lttng_ht *channel_ht; |
| 208 | /* |
| 209 | * Flag specifying if the local array of FDs needs update in the |
| 210 | * poll function. Protected by consumer_data.lock. |
| 211 | */ |
| 212 | unsigned int need_update; |
| 213 | enum lttng_consumer_type type; |
| 214 | }; |
| 215 | |
| 216 | /* |
| 217 | * Init consumer data structures. |
| 218 | */ |
| 219 | extern void lttng_consumer_init(void); |
| 220 | |
| 221 | /* |
| 222 | * Set the error socket for communication with a session daemon. |
| 223 | */ |
| 224 | extern void lttng_consumer_set_error_sock( |
| 225 | struct lttng_consumer_local_data *ctx, int sock); |
| 226 | |
| 227 | /* |
| 228 | * Set the command socket path for communication with a session daemon. |
| 229 | */ |
| 230 | extern void lttng_consumer_set_command_sock_path( |
| 231 | struct lttng_consumer_local_data *ctx, char *sock); |
| 232 | |
| 233 | /* |
| 234 | * Send return code to session daemon. |
| 235 | * |
| 236 | * Returns the return code of sendmsg : the number of bytes transmitted or -1 |
| 237 | * on error. |
| 238 | */ |
| 239 | extern int lttng_consumer_send_error( |
| 240 | struct lttng_consumer_local_data *ctx, int cmd); |
| 241 | |
| 242 | /* |
| 243 | * Called from signal handler to ensure a clean exit. |
| 244 | */ |
| 245 | extern void lttng_consumer_should_exit( |
| 246 | struct lttng_consumer_local_data *ctx); |
| 247 | |
| 248 | /* |
| 249 | * Cleanup the daemon's socket on exit. |
| 250 | */ |
| 251 | extern void lttng_consumer_cleanup(void); |
| 252 | |
| 253 | /* |
| 254 | * Flush pending writes to trace output disk file. |
| 255 | */ |
| 256 | extern void lttng_consumer_sync_trace_file( |
| 257 | struct lttng_consumer_stream *stream, off_t orig_offset); |
| 258 | |
| 259 | /* |
| 260 | * Poll on the should_quit pipe and the command socket return -1 on error and |
| 261 | * should exit, 0 if data is available on the command socket |
| 262 | */ |
| 263 | extern int lttng_consumer_poll_socket(struct pollfd *kconsumer_sockpoll); |
| 264 | |
| 265 | extern int consumer_update_poll_array( |
| 266 | struct lttng_consumer_local_data *ctx, struct pollfd **pollfd, |
| 267 | struct lttng_consumer_stream **local_consumer_streams); |
| 268 | |
| 269 | extern struct lttng_consumer_stream *consumer_allocate_stream( |
| 270 | int channel_key, int stream_key, |
| 271 | int shm_fd, int wait_fd, |
| 272 | enum lttng_consumer_stream_state state, |
| 273 | uint64_t mmap_len, |
| 274 | enum lttng_event_output output, |
| 275 | const char *path_name, |
| 276 | uid_t uid, |
| 277 | gid_t gid); |
| 278 | extern int consumer_add_stream(struct lttng_consumer_stream *stream); |
| 279 | extern void consumer_del_stream(struct lttng_consumer_stream *stream); |
| 280 | extern void consumer_change_stream_state(int stream_key, |
| 281 | enum lttng_consumer_stream_state state); |
| 282 | extern void consumer_del_channel(struct lttng_consumer_channel *channel); |
| 283 | extern struct lttng_consumer_channel *consumer_allocate_channel( |
| 284 | int channel_key, |
| 285 | int shm_fd, int wait_fd, |
| 286 | uint64_t mmap_len, |
| 287 | uint64_t max_sb_size); |
| 288 | int consumer_add_channel(struct lttng_consumer_channel *channel); |
| 289 | |
| 290 | extern struct lttng_consumer_local_data *lttng_consumer_create( |
| 291 | enum lttng_consumer_type type, |
| 292 | ssize_t (*buffer_ready)(struct lttng_consumer_stream *stream, |
| 293 | struct lttng_consumer_local_data *ctx), |
| 294 | int (*recv_channel)(struct lttng_consumer_channel *channel), |
| 295 | int (*recv_stream)(struct lttng_consumer_stream *stream), |
| 296 | int (*update_stream)(int sessiond_key, uint32_t state)); |
| 297 | extern void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx); |
| 298 | extern ssize_t lttng_consumer_on_read_subbuffer_mmap( |
| 299 | struct lttng_consumer_local_data *ctx, |
| 300 | struct lttng_consumer_stream *stream, unsigned long len); |
| 301 | extern ssize_t lttng_consumer_on_read_subbuffer_splice( |
| 302 | struct lttng_consumer_local_data *ctx, |
| 303 | struct lttng_consumer_stream *stream, unsigned long len); |
| 304 | extern int lttng_consumer_take_snapshot(struct lttng_consumer_local_data *ctx, |
| 305 | struct lttng_consumer_stream *stream); |
| 306 | extern int lttng_consumer_get_produced_snapshot( |
| 307 | struct lttng_consumer_local_data *ctx, |
| 308 | struct lttng_consumer_stream *stream, |
| 309 | unsigned long *pos); |
| 310 | extern void *lttng_consumer_thread_poll_fds(void *data); |
| 311 | extern void *lttng_consumer_thread_receive_fds(void *data); |
| 312 | extern int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx, |
| 313 | int sock, struct pollfd *consumer_sockpoll); |
| 314 | |
| 315 | ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream, |
| 316 | struct lttng_consumer_local_data *ctx); |
| 317 | int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream); |
| 318 | |
| 319 | #endif /* _LTTNG_CONSUMER_H */ |