| 1 | /* |
| 2 | * SPDX-License-Identifier: MIT |
| 3 | * |
| 4 | * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 5 | * |
| 6 | * Holds LTTng per-session event registry. |
| 7 | */ |
| 8 | |
| 9 | #ifndef _LTTNG_UST_EVENTS_H |
| 10 | #define _LTTNG_UST_EVENTS_H |
| 11 | |
| 12 | #include <urcu/list.h> |
| 13 | #include <urcu/hlist.h> |
| 14 | #include <stddef.h> |
| 15 | #include <stdint.h> |
| 16 | #include <lttng/ust-abi.h> |
| 17 | #include <lttng/ust-tracer.h> |
| 18 | #include <lttng/ust-endian.h> |
| 19 | #include <float.h> |
| 20 | #include <errno.h> |
| 21 | #include <urcu/ref.h> |
| 22 | #include <pthread.h> |
| 23 | |
| 24 | #ifdef __cplusplus |
| 25 | extern "C" { |
| 26 | #endif |
| 27 | |
| 28 | #define LTTNG_UST_UUID_LEN 16 |
| 29 | |
| 30 | /* |
| 31 | * Tracepoint provider version. Compatibility based on the major number. |
| 32 | * Older tracepoint providers can always register to newer lttng-ust |
| 33 | * library, but the opposite is rejected: a newer tracepoint provider is |
| 34 | * rejected by an older lttng-ust library. |
| 35 | */ |
| 36 | #define LTTNG_UST_PROVIDER_MAJOR 2 |
| 37 | #define LTTNG_UST_PROVIDER_MINOR 0 |
| 38 | |
| 39 | struct lttng_ust_channel_buffer; |
| 40 | struct lttng_ust_session; |
| 41 | struct lttng_ust_lib_ring_buffer_ctx; |
| 42 | struct lttng_ust_event_field; |
| 43 | |
| 44 | /* |
| 45 | * Data structures used by tracepoint event declarations, and by the |
| 46 | * tracer. |
| 47 | */ |
| 48 | |
| 49 | /* Type description */ |
| 50 | |
| 51 | enum lttng_ust_type { |
| 52 | lttng_ust_type_integer, |
| 53 | lttng_ust_type_string, |
| 54 | lttng_ust_type_float, |
| 55 | lttng_ust_type_dynamic, |
| 56 | lttng_ust_type_enum, |
| 57 | lttng_ust_type_array, |
| 58 | lttng_ust_type_sequence, |
| 59 | lttng_ust_type_struct, |
| 60 | NR_LTTNG_UST_TYPE, |
| 61 | }; |
| 62 | |
| 63 | enum lttng_ust_string_encoding { |
| 64 | lttng_ust_string_encoding_none = 0, |
| 65 | lttng_ust_string_encoding_UTF8 = 1, |
| 66 | lttng_ust_string_encoding_ASCII = 2, |
| 67 | NR_LTTNG_UST_STRING_ENCODING, |
| 68 | }; |
| 69 | |
| 70 | struct lttng_ust_enum_value { |
| 71 | unsigned long long value; |
| 72 | unsigned int signedness:1; |
| 73 | }; |
| 74 | |
| 75 | enum lttng_ust_enum_entry_option { |
| 76 | LTTNG_UST_ENUM_ENTRY_OPTION_IS_AUTO = 1U << 0, |
| 77 | }; |
| 78 | |
| 79 | /* |
| 80 | * Enumeration entry description |
| 81 | * |
| 82 | * IMPORTANT: this structure is part of the ABI between the probe and |
| 83 | * UST. Fields need to be only added at the end, never reordered, never |
| 84 | * removed. |
| 85 | * |
| 86 | * The field @struct_size should be used to determine the size of the |
| 87 | * structure. It should be queried before using additional fields added |
| 88 | * at the end of the structure. |
| 89 | */ |
| 90 | |
| 91 | struct lttng_ust_enum_entry { |
| 92 | uint32_t struct_size; |
| 93 | |
| 94 | struct lttng_ust_enum_value start, end; /* start and end are inclusive */ |
| 95 | const char *string; |
| 96 | unsigned int options; |
| 97 | |
| 98 | /* End of base ABI. Fields below should be used after checking struct_size. */ |
| 99 | }; |
| 100 | |
| 101 | /* |
| 102 | * struct lttng_ust_type_common is fixed-size. Its children inherits |
| 103 | * from it by embedding struct lttng_ust_type_common as its first field. |
| 104 | */ |
| 105 | struct lttng_ust_type_common { |
| 106 | enum lttng_ust_type type; |
| 107 | }; |
| 108 | |
| 109 | struct lttng_ust_type_integer { |
| 110 | struct lttng_ust_type_common parent; |
| 111 | uint32_t struct_size; |
| 112 | unsigned int size; /* in bits */ |
| 113 | unsigned short alignment; /* in bits */ |
| 114 | unsigned int signedness:1; |
| 115 | unsigned int reverse_byte_order:1; |
| 116 | unsigned int base; /* 2, 8, 10, 16, for pretty print */ |
| 117 | }; |
| 118 | |
| 119 | #define lttng_ust_type_integer_define(_type, _byte_order, _base) \ |
| 120 | ((struct lttng_ust_type_common *) __LTTNG_COMPOUND_LITERAL(struct lttng_ust_type_integer, { \ |
| 121 | .parent = { \ |
| 122 | .type = lttng_ust_type_integer, \ |
| 123 | }, \ |
| 124 | .struct_size = sizeof(struct lttng_ust_type_integer), \ |
| 125 | .size = sizeof(_type) * CHAR_BIT, \ |
| 126 | .alignment = lttng_alignof(_type) * CHAR_BIT, \ |
| 127 | .signedness = lttng_is_signed_type(_type), \ |
| 128 | .reverse_byte_order = _byte_order != BYTE_ORDER, \ |
| 129 | .base = _base, \ |
| 130 | })) |
| 131 | |
| 132 | struct lttng_ust_type_float { |
| 133 | struct lttng_ust_type_common parent; |
| 134 | uint32_t struct_size; |
| 135 | unsigned int exp_dig; /* exponent digits, in bits */ |
| 136 | unsigned int mant_dig; /* mantissa digits, in bits */ |
| 137 | unsigned short alignment; /* in bits */ |
| 138 | unsigned int reverse_byte_order:1; |
| 139 | }; |
| 140 | |
| 141 | /* |
| 142 | * Only float and double are supported. long double is not supported at |
| 143 | * the moment. |
| 144 | */ |
| 145 | #define lttng_ust_float_mant_dig(_type) \ |
| 146 | (sizeof(_type) == sizeof(float) ? FLT_MANT_DIG \ |
| 147 | : (sizeof(_type) == sizeof(double) ? DBL_MANT_DIG \ |
| 148 | : 0)) |
| 149 | |
| 150 | #define lttng_ust_type_float_define(_type) \ |
| 151 | ((struct lttng_ust_type_common *) __LTTNG_COMPOUND_LITERAL(struct lttng_ust_type_float, { \ |
| 152 | .parent = { \ |
| 153 | .type = lttng_ust_type_float, \ |
| 154 | }, \ |
| 155 | .struct_size = sizeof(struct lttng_ust_type_float), \ |
| 156 | .exp_dig = sizeof(_type) * CHAR_BIT \ |
| 157 | - lttng_ust_float_mant_dig(_type), \ |
| 158 | .mant_dig = lttng_ust_float_mant_dig(_type), \ |
| 159 | .alignment = lttng_alignof(_type) * CHAR_BIT, \ |
| 160 | .reverse_byte_order = BYTE_ORDER != FLOAT_WORD_ORDER, \ |
| 161 | })) |
| 162 | |
| 163 | |
| 164 | struct lttng_ust_type_string { |
| 165 | struct lttng_ust_type_common parent; |
| 166 | uint32_t struct_size; |
| 167 | enum lttng_ust_string_encoding encoding; |
| 168 | }; |
| 169 | |
| 170 | struct lttng_ust_type_enum { |
| 171 | struct lttng_ust_type_common parent; |
| 172 | uint32_t struct_size; |
| 173 | struct lttng_ust_enum_desc *desc; /* Enumeration mapping */ |
| 174 | struct lttng_ust_type_common *container_type; |
| 175 | }; |
| 176 | |
| 177 | struct lttng_ust_type_array { |
| 178 | struct lttng_ust_type_common parent; |
| 179 | uint32_t struct_size; |
| 180 | struct lttng_ust_type_common *elem_type; |
| 181 | unsigned int length; /* Num. elems. */ |
| 182 | unsigned int alignment; |
| 183 | enum lttng_ust_string_encoding encoding; |
| 184 | }; |
| 185 | |
| 186 | struct lttng_ust_type_sequence { |
| 187 | struct lttng_ust_type_common parent; |
| 188 | uint32_t struct_size; |
| 189 | const char *length_name; /* Length field name. */ |
| 190 | struct lttng_ust_type_common *elem_type; |
| 191 | unsigned int alignment; /* Alignment before elements. */ |
| 192 | enum lttng_ust_string_encoding encoding; |
| 193 | }; |
| 194 | |
| 195 | struct lttng_ust_type_struct { |
| 196 | struct lttng_ust_type_common parent; |
| 197 | uint32_t struct_size; |
| 198 | unsigned int nr_fields; |
| 199 | struct lttng_ust_event_field **fields; /* Array of pointers to fields. */ |
| 200 | unsigned int alignment; |
| 201 | }; |
| 202 | |
| 203 | /* |
| 204 | * Enumeration description |
| 205 | * |
| 206 | * IMPORTANT: this structure is part of the ABI between the probe and |
| 207 | * UST. Fields need to be only added at the end, never reordered, never |
| 208 | * removed. |
| 209 | * |
| 210 | * The field @struct_size should be used to determine the size of the |
| 211 | * structure. It should be queried before using additional fields added |
| 212 | * at the end of the structure. |
| 213 | */ |
| 214 | |
| 215 | struct lttng_ust_enum_desc { |
| 216 | uint32_t struct_size; |
| 217 | |
| 218 | const char *name; |
| 219 | struct lttng_ust_enum_entry **entries; |
| 220 | unsigned int nr_entries; |
| 221 | |
| 222 | /* End of base ABI. Fields below should be used after checking struct_size. */ |
| 223 | }; |
| 224 | |
| 225 | /* |
| 226 | * Event field description |
| 227 | * |
| 228 | * IMPORTANT: this structure is part of the ABI between the probe and |
| 229 | * UST. Fields need to be only added at the end, never reordered, never |
| 230 | * removed. |
| 231 | * |
| 232 | * The field @struct_size should be used to determine the size of the |
| 233 | * structure. It should be queried before using additional fields added |
| 234 | * at the end of the structure. |
| 235 | */ |
| 236 | |
| 237 | struct lttng_ust_event_field { |
| 238 | uint32_t struct_size; |
| 239 | |
| 240 | const char *name; |
| 241 | struct lttng_ust_type_common *type; |
| 242 | unsigned int nowrite:1, /* do not write into trace */ |
| 243 | nofilter:1; /* do not consider for filter */ |
| 244 | |
| 245 | /* End of base ABI. Fields below should be used after checking struct_size. */ |
| 246 | }; |
| 247 | |
| 248 | |
| 249 | /* |
| 250 | * IMPORTANT: this structure is part of the ABI between the probe and |
| 251 | * UST. Fields need to be only added at the end, never reordered, never |
| 252 | * removed. |
| 253 | * |
| 254 | * The field @struct_size should be used to determine the size of the |
| 255 | * structure. It should be queried before using additional fields added |
| 256 | * at the end of the structure. |
| 257 | */ |
| 258 | struct lttng_ust_event_desc { |
| 259 | uint32_t struct_size; /* Size of this structure. */ |
| 260 | |
| 261 | const char *name; |
| 262 | void (*probe_callback)(void); |
| 263 | struct lttng_event_ctx *ctx; /* context */ |
| 264 | struct lttng_ust_event_field **fields; /* event payload */ |
| 265 | unsigned int nr_fields; |
| 266 | const int **loglevel; |
| 267 | const char *signature; /* Argument types/names received */ |
| 268 | const char **model_emf_uri; |
| 269 | |
| 270 | /* End of base ABI. Fields below should be used after checking struct_size. */ |
| 271 | }; |
| 272 | |
| 273 | /* |
| 274 | * IMPORTANT: this structure is part of the ABI between the probe and |
| 275 | * UST. Fields need to be only added at the end, never reordered, never |
| 276 | * removed. |
| 277 | * |
| 278 | * The field @struct_size should be used to determine the size of the |
| 279 | * structure. It should be queried before using additional fields added |
| 280 | * at the end of the structure. |
| 281 | */ |
| 282 | struct lttng_ust_probe_desc { |
| 283 | uint32_t struct_size; /* Size of this structure. */ |
| 284 | |
| 285 | const char *provider; |
| 286 | struct lttng_ust_event_desc **event_desc; |
| 287 | unsigned int nr_events; |
| 288 | struct cds_list_head head; /* chain registered probes */ |
| 289 | struct cds_list_head lazy_init_head; |
| 290 | int lazy; /* lazy registration */ |
| 291 | uint32_t major; |
| 292 | uint32_t minor; |
| 293 | |
| 294 | /* End of base ABI. Fields below should be used after checking struct_size. */ |
| 295 | }; |
| 296 | |
| 297 | /* Data structures used by the tracer. */ |
| 298 | |
| 299 | /* |
| 300 | * Bytecode interpreter return value masks. |
| 301 | */ |
| 302 | enum lttng_ust_bytecode_interpreter_ret { |
| 303 | LTTNG_UST_BYTECODE_INTERPRETER_DISCARD = 0, |
| 304 | LTTNG_UST_BYTECODE_INTERPRETER_RECORD_FLAG = (1ULL << 0), |
| 305 | /* Other bits are kept for future use. */ |
| 306 | }; |
| 307 | |
| 308 | struct lttng_interpreter_output; |
| 309 | struct lttng_ust_bytecode_runtime_private; |
| 310 | |
| 311 | /* |
| 312 | * IMPORTANT: this structure is part of the ABI between the probe and |
| 313 | * UST. Fields need to be only added at the end, never reordered, never |
| 314 | * removed. |
| 315 | * |
| 316 | * The field @struct_size should be used to determine the size of the |
| 317 | * structure. It should be queried before using additional fields added |
| 318 | * at the end of the structure. |
| 319 | */ |
| 320 | struct lttng_ust_bytecode_runtime { |
| 321 | uint32_t struct_size; /* Size of this structure. */ |
| 322 | |
| 323 | struct lttng_ust_bytecode_runtime_private *priv; |
| 324 | /* Associated bytecode */ |
| 325 | union { |
| 326 | uint64_t (*filter)(void *interpreter_data, |
| 327 | const char *interpreter_stack_data); |
| 328 | uint64_t (*capture)(void *interpreter_data, |
| 329 | const char *interpreter_stack_data, |
| 330 | struct lttng_interpreter_output *interpreter_output); |
| 331 | } interpreter_funcs; |
| 332 | struct cds_list_head node; /* list of bytecode runtime in event */ |
| 333 | |
| 334 | /* End of base ABI. Fields below should be used after checking struct_size. */ |
| 335 | }; |
| 336 | |
| 337 | /* |
| 338 | * lttng_event structure is referred to by the tracing fast path. It |
| 339 | * must be kept small. |
| 340 | * |
| 341 | * IMPORTANT: this structure is part of the ABI between the probe and |
| 342 | * UST. Fields need to be only added at the end, never reordered, never |
| 343 | * removed. |
| 344 | */ |
| 345 | |
| 346 | struct lttng_ust_ctx; |
| 347 | struct lttng_ust_event_common_private; |
| 348 | |
| 349 | enum lttng_ust_event_type { |
| 350 | LTTNG_UST_EVENT_TYPE_RECORDER = 0, |
| 351 | LTTNG_UST_EVENT_TYPE_NOTIFIER = 1, |
| 352 | }; |
| 353 | |
| 354 | /* |
| 355 | * IMPORTANT: this structure is part of the ABI between the probe and |
| 356 | * UST. Fields need to be only added at the end, never reordered, never |
| 357 | * removed. |
| 358 | * |
| 359 | * struct lttng_ust_event_common is the common ancestor of the various |
| 360 | * public event actions. Inheritance is done by composition: The parent |
| 361 | * has a pointer to its child, and the child has a pointer to its |
| 362 | * parent. Inheritance of those public structures is done by composition |
| 363 | * to ensure both parent and child structures can be extended. |
| 364 | * |
| 365 | * The field @struct_size should be used to determine the size of the |
| 366 | * structure. It should be queried before using additional fields added |
| 367 | * at the end of the structure. |
| 368 | */ |
| 369 | struct lttng_ust_event_common { |
| 370 | uint32_t struct_size; /* Size of this structure. */ |
| 371 | |
| 372 | struct lttng_ust_event_common_private *priv; /* Private event interface */ |
| 373 | |
| 374 | enum lttng_ust_event_type type; |
| 375 | void *child; /* Pointer to child, for inheritance by aggregation. */ |
| 376 | |
| 377 | int enabled; |
| 378 | int has_enablers_without_bytecode; |
| 379 | /* list of struct lttng_ust_bytecode_runtime, sorted by seqnum */ |
| 380 | struct cds_list_head filter_bytecode_runtime_head; |
| 381 | |
| 382 | /* End of base ABI. Fields below should be used after checking struct_size. */ |
| 383 | }; |
| 384 | |
| 385 | struct lttng_ust_event_recorder_private; |
| 386 | |
| 387 | /* |
| 388 | * IMPORTANT: this structure is part of the ABI between the probe and |
| 389 | * UST. Fields need to be only added at the end, never reordered, never |
| 390 | * removed. |
| 391 | * |
| 392 | * struct lttng_ust_event_recorder is the action for recording events |
| 393 | * into a ring buffer. It inherits from struct lttng_ust_event_common |
| 394 | * by composition to ensure both parent and child structure are |
| 395 | * extensible. |
| 396 | * |
| 397 | * The field @struct_size should be used to determine the size of the |
| 398 | * structure. It should be queried before using additional fields added |
| 399 | * at the end of the structure. |
| 400 | */ |
| 401 | struct lttng_ust_event_recorder { |
| 402 | uint32_t struct_size; /* Size of this structure. */ |
| 403 | |
| 404 | struct lttng_ust_event_common *parent; /* Inheritance by aggregation. */ |
| 405 | struct lttng_ust_event_recorder_private *priv; /* Private event record interface */ |
| 406 | |
| 407 | unsigned int id; |
| 408 | struct lttng_ust_channel_buffer *chan; |
| 409 | struct lttng_ust_ctx *ctx; |
| 410 | |
| 411 | /* End of base ABI. Fields below should be used after checking struct_size. */ |
| 412 | }; |
| 413 | |
| 414 | struct lttng_ust_event_notifier_private; |
| 415 | |
| 416 | /* |
| 417 | * IMPORTANT: this structure is part of the ABI between the probe and |
| 418 | * UST. Fields need to be only added at the end, never reordered, never |
| 419 | * removed. |
| 420 | * |
| 421 | * struct lttng_ust_event_notifier is the action for sending |
| 422 | * notifications. It inherits from struct lttng_ust_event_common |
| 423 | * by composition to ensure both parent and child structure are |
| 424 | * extensible. |
| 425 | * |
| 426 | * The field @struct_size should be used to determine the size of the |
| 427 | * structure. It should be queried before using additional fields added |
| 428 | * at the end of the structure. |
| 429 | */ |
| 430 | struct lttng_ust_event_notifier { |
| 431 | uint32_t struct_size; /* Size of this structure. */ |
| 432 | |
| 433 | struct lttng_ust_event_common *parent; /* Inheritance by aggregation. */ |
| 434 | struct lttng_ust_event_notifier_private *priv; /* Private event notifier interface */ |
| 435 | |
| 436 | void (*notification_send)(struct lttng_ust_event_notifier *event_notifier, |
| 437 | const char *stack_data); |
| 438 | struct cds_list_head capture_bytecode_runtime_head; |
| 439 | |
| 440 | /* End of base ABI. Fields below should be used after checking struct_size. */ |
| 441 | }; |
| 442 | |
| 443 | struct lttng_ust_lib_ring_buffer_channel; |
| 444 | struct lttng_ust_channel_ops_private; |
| 445 | |
| 446 | /* |
| 447 | * IMPORTANT: this structure is part of the ABI between the probe and |
| 448 | * UST. Fields need to be only added at the end, never reordered, never |
| 449 | * removed. |
| 450 | * |
| 451 | * The field @struct_size should be used to determine the size of the |
| 452 | * structure. It should be queried before using additional fields added |
| 453 | * at the end of the structure. |
| 454 | */ |
| 455 | struct lttng_ust_channel_ops { |
| 456 | uint32_t struct_size; |
| 457 | |
| 458 | struct lttng_ust_channel_ops_private *priv; /* Private channel ops interface */ |
| 459 | |
| 460 | int (*event_reserve)(struct lttng_ust_lib_ring_buffer_ctx *ctx, |
| 461 | uint32_t event_id); |
| 462 | void (*event_commit)(struct lttng_ust_lib_ring_buffer_ctx *ctx); |
| 463 | void (*event_write)(struct lttng_ust_lib_ring_buffer_ctx *ctx, |
| 464 | const void *src, size_t len); |
| 465 | void (*event_strcpy)(struct lttng_ust_lib_ring_buffer_ctx *ctx, |
| 466 | const char *src, size_t len); |
| 467 | |
| 468 | /* End of base ABI. Fields below should be used after checking struct_size. */ |
| 469 | }; |
| 470 | |
| 471 | enum lttng_ust_channel_type { |
| 472 | LTTNG_UST_CHANNEL_TYPE_BUFFER = 0, |
| 473 | }; |
| 474 | |
| 475 | struct lttng_ust_channel_common_private; |
| 476 | |
| 477 | /* |
| 478 | * IMPORTANT: this structure is part of the ABI between the probe and |
| 479 | * UST. Fields need to be only added at the end, never reordered, never |
| 480 | * removed. |
| 481 | * |
| 482 | * The field @struct_size should be used to determine the size of the |
| 483 | * structure. It should be queried before using additional fields added |
| 484 | * at the end of the structure. |
| 485 | */ |
| 486 | struct lttng_ust_channel_common { |
| 487 | uint32_t struct_size; /* Size of this structure. */ |
| 488 | |
| 489 | struct lttng_ust_channel_common_private *priv; /* Private channel interface */ |
| 490 | |
| 491 | enum lttng_ust_channel_type type; |
| 492 | void *child; /* Pointer to child, for inheritance by aggregation. */ |
| 493 | |
| 494 | int enabled; |
| 495 | struct lttng_ust_session *session; |
| 496 | |
| 497 | /* End of base ABI. Fields below should be used after checking struct_size. */ |
| 498 | }; |
| 499 | |
| 500 | struct lttng_ust_channel_buffer_private; |
| 501 | |
| 502 | /* |
| 503 | * IMPORTANT: this structure is part of the ABI between the probe and |
| 504 | * UST. Fields need to be only added at the end, never reordered, never |
| 505 | * removed. |
| 506 | * |
| 507 | * The field @struct_size should be used to determine the size of the |
| 508 | * structure. It should be queried before using additional fields added |
| 509 | * at the end of the structure. |
| 510 | */ |
| 511 | struct lttng_ust_channel_buffer { |
| 512 | uint32_t struct_size; /* Size of this structure. */ |
| 513 | |
| 514 | struct lttng_ust_channel_common *parent; /* Inheritance by aggregation. */ |
| 515 | struct lttng_ust_channel_buffer_private *priv; /* Private channel buffer interface */ |
| 516 | |
| 517 | struct lttng_ust_channel_ops *ops; |
| 518 | struct lttng_ust_lib_ring_buffer_channel *chan; /* Channel buffers */ |
| 519 | struct lttng_ust_shm_handle *handle; /* shared-memory handle */ |
| 520 | |
| 521 | /* End of base ABI. Fields below should be used after checking struct_size. */ |
| 522 | }; |
| 523 | |
| 524 | /* |
| 525 | * IMPORTANT: this structure is part of the ABI between the probe and |
| 526 | * UST. Fields need to be only added at the end, never reordered, never |
| 527 | * removed. |
| 528 | * |
| 529 | * The field @struct_size should be used to determine the size of the |
| 530 | * structure. It should be queried before using additional fields added |
| 531 | * at the end of the structure. |
| 532 | */ |
| 533 | struct lttng_ust_stack_ctx { |
| 534 | uint32_t struct_size; /* Size of this structure */ |
| 535 | |
| 536 | struct lttng_ust_event_recorder *event_recorder; |
| 537 | struct lttng_ust_ctx *event_ctx; /* RCU dereferenced. */ |
| 538 | |
| 539 | /* End of base ABI. Fields below should be used after checking struct_size. */ |
| 540 | }; |
| 541 | |
| 542 | struct lttng_ust_session_private; |
| 543 | |
| 544 | /* |
| 545 | * IMPORTANT: this structure is part of the ABI between the probe and |
| 546 | * UST. Fields need to be only added at the end, never reordered, never |
| 547 | * removed. |
| 548 | * |
| 549 | * The field @struct_size should be used to determine the size of the |
| 550 | * structure. It should be queried before using additional fields added |
| 551 | * at the end of the structure. |
| 552 | */ |
| 553 | struct lttng_ust_session { |
| 554 | uint32_t struct_size; /* Size of this structure */ |
| 555 | |
| 556 | struct lttng_ust_session_private *priv; /* Private session interface */ |
| 557 | |
| 558 | int active; /* Is trace session active ? */ |
| 559 | |
| 560 | /* End of base ABI. Fields below should be used after checking struct_size. */ |
| 561 | }; |
| 562 | |
| 563 | int lttng_ust_probe_register(struct lttng_ust_probe_desc *desc); |
| 564 | void lttng_ust_probe_unregister(struct lttng_ust_probe_desc *desc); |
| 565 | |
| 566 | /* |
| 567 | * Applications that change their procname and need the new value to be |
| 568 | * reflected in the procname event context have to call this function to clear |
| 569 | * the internally cached value. This should not be called from a signal |
| 570 | * handler. |
| 571 | */ |
| 572 | void lttng_ust_context_procname_reset(void); |
| 573 | |
| 574 | #ifdef __cplusplus |
| 575 | } |
| 576 | #endif |
| 577 | |
| 578 | #endif /* _LTTNG_UST_EVENTS_H */ |