| 1 | /* |
| 2 | * SPDX-License-Identifier: MIT |
| 3 | * |
| 4 | * Copyright (C) 2010-2019 EfficiOS Inc. and Linux Foundation |
| 5 | */ |
| 6 | |
| 7 | #ifndef BABELTRACE2_TRACE_IR_EVENT_H |
| 8 | #define BABELTRACE2_TRACE_IR_EVENT_H |
| 9 | |
| 10 | #ifndef __BT_IN_BABELTRACE_H |
| 11 | # error "Please include <babeltrace2/babeltrace.h> instead." |
| 12 | #endif |
| 13 | |
| 14 | #include <babeltrace2/types.h> |
| 15 | |
| 16 | #ifdef __cplusplus |
| 17 | extern "C" { |
| 18 | #endif |
| 19 | |
| 20 | /*! |
| 21 | @defgroup api-tir-ev Event |
| 22 | @ingroup api-tir |
| 23 | |
| 24 | @brief |
| 25 | Trace event. |
| 26 | |
| 27 | An <strong><em>event</em></strong> represents a trace event record. |
| 28 | |
| 29 | An event is an instance of an \bt_ev_cls: |
| 30 | |
| 31 | @image html trace-structure.png |
| 32 | |
| 33 | In the illustration above, notice that: |
| 34 | |
| 35 | - A \bt_stream is a conceptual \ref api-msg-seq "sequence of messages", |
| 36 | some of which are \bt_p_ev_msg. |
| 37 | - An event message contains an \bt_ev. |
| 38 | - An event is an instance of an event class. |
| 39 | - The \ref api-tir-ev-prop-payload "payload field" of an event is an |
| 40 | instance of the \ref api-tir-ev-cls-prop-p-fc "payload field class" |
| 41 | which an event class contains. |
| 42 | |
| 43 | Borrow the class of an event with bt_event_borrow_class() and |
| 44 | bt_event_borrow_class_const(). |
| 45 | |
| 46 | An event is a \ref api-tir "trace IR" data object. |
| 47 | |
| 48 | You cannot directly create an event: there's no |
| 49 | <code>bt_event_create()</code> function. The \bt_name library |
| 50 | creates an event within an \bt_ev_msg from an \bt_ev_cls. |
| 51 | Therefore, to fill the fields of an event, you must first |
| 52 | borrow the event from an event message with |
| 53 | bt_message_event_borrow_event(). |
| 54 | |
| 55 | An event is a \ref api-fund-unique-object "unique object": it belongs to |
| 56 | an \bt_ev_msg. |
| 57 | |
| 58 | Some library functions \ref api-fund-freezing "freeze" events on |
| 59 | success. The documentation of those functions indicate this |
| 60 | postcondition. |
| 61 | |
| 62 | The type of an event is #bt_event. |
| 63 | |
| 64 | An event conceptually belongs to a \bt_stream. Borrow the stream of an |
| 65 | event with bt_event_borrow_stream() and bt_event_borrow_stream_const(). |
| 66 | |
| 67 | If the event's stream's class |
| 68 | \ref api-tir-stream-cls-prop-supports-pkt "supports packets", |
| 69 | the event also belongs to a \bt_pkt. In that case, borrow the packet of |
| 70 | an event with bt_event_borrow_packet() and |
| 71 | bt_event_borrow_packet_const(). |
| 72 | |
| 73 | Because a stream or a packet could contain millions of events, there are |
| 74 | no actual links from a stream or from a packet to its events. |
| 75 | |
| 76 | <h1>Properties</h1> |
| 77 | |
| 78 | An event has the following properties: |
| 79 | |
| 80 | <dl> |
| 81 | <dt>\anchor api-tir-ev-prop-payload Payload field</dt> |
| 82 | <dd> |
| 83 | Event's payload \bt_field. |
| 84 | |
| 85 | The payload of an event contains its main trace data. |
| 86 | |
| 87 | The \ref api-tir-fc "class" of an event's payload field is set |
| 88 | at the event's \ref api-tir-ev-cls "class" level. See |
| 89 | bt_event_class_set_payload_field_class(), |
| 90 | bt_event_class_borrow_payload_field_class(), and |
| 91 | bt_event_class_borrow_payload_field_class_const(). |
| 92 | |
| 93 | Use bt_event_borrow_payload_field() and |
| 94 | bt_event_borrow_payload_field_const(). |
| 95 | </dd> |
| 96 | |
| 97 | <dt>\anchor api-tir-ev-prop-spec-ctx Specific context field</dt> |
| 98 | <dd> |
| 99 | Event's specific context \bt_field. |
| 100 | |
| 101 | The specific context of an event contains |
| 102 | any contextual data of which the layout is specific to the |
| 103 | event's \ref api-tir-ev-cls "class" and which does not belong to the |
| 104 | payload. |
| 105 | |
| 106 | The \ref api-tir-fc "class" of an event's specific context field is |
| 107 | set at the event's \ref api-tir-ev-cls "class" level. See |
| 108 | bt_event_class_set_specific_context_field_class() |
| 109 | bt_event_class_borrow_specific_context_field_class(), |
| 110 | and bt_event_class_borrow_specific_context_field_class_const() |
| 111 | |
| 112 | Use bt_event_borrow_specific_context_field() and |
| 113 | bt_event_borrow_specific_context_field_const(). |
| 114 | </dd> |
| 115 | |
| 116 | <dt>\anchor api-tir-ev-prop-common-ctx Common context field</dt> |
| 117 | <dd> |
| 118 | Event's common context \bt_field. |
| 119 | |
| 120 | The common context of an event contains contextual data of which the |
| 121 | layout is common to all the \bt_p_ev_cls of the |
| 122 | event's stream's \ref api-tir-stream-cls "class". |
| 123 | |
| 124 | The \ref api-tir-fc "class" of an event's common context field is set |
| 125 | at the event's \bt_stream_cls level. See |
| 126 | bt_stream_class_set_event_common_context_field_class() |
| 127 | bt_stream_class_borrow_event_common_context_field_class(), |
| 128 | and bt_stream_class_borrow_event_common_context_field_class_const(). |
| 129 | |
| 130 | Use bt_event_borrow_common_context_field() and |
| 131 | bt_event_borrow_common_context_field_const(). |
| 132 | </dd> |
| 133 | </dl> |
| 134 | */ |
| 135 | |
| 136 | /*! @{ */ |
| 137 | |
| 138 | /*! |
| 139 | @name Type |
| 140 | @{ |
| 141 | |
| 142 | @typedef struct bt_event bt_event; |
| 143 | |
| 144 | @brief |
| 145 | Event. |
| 146 | |
| 147 | @} |
| 148 | */ |
| 149 | |
| 150 | /*! |
| 151 | @name Class access |
| 152 | @{ |
| 153 | */ |
| 154 | |
| 155 | /*! |
| 156 | @brief |
| 157 | Borrows the \ref api-tir-ev-cls "class" of the event \bt_p{event}. |
| 158 | |
| 159 | @param[in] event |
| 160 | Event of which to borrow the class. |
| 161 | |
| 162 | @returns |
| 163 | \em Borrowed reference of the class of \bt_p{event}. |
| 164 | |
| 165 | @bt_pre_not_null{event} |
| 166 | |
| 167 | @sa bt_event_borrow_class_const() — |
| 168 | \c const version of this function. |
| 169 | */ |
| 170 | extern bt_event_class *bt_event_borrow_class(bt_event *event); |
| 171 | |
| 172 | /*! |
| 173 | @brief |
| 174 | Borrows the \ref api-tir-ev-cls "class" of the event \bt_p{event} |
| 175 | (\c const version). |
| 176 | |
| 177 | See bt_event_borrow_class(). |
| 178 | */ |
| 179 | extern const bt_event_class *bt_event_borrow_class_const( |
| 180 | const bt_event *event); |
| 181 | |
| 182 | /*! @} */ |
| 183 | |
| 184 | /*! |
| 185 | @name Stream access |
| 186 | @{ |
| 187 | */ |
| 188 | |
| 189 | /*! |
| 190 | @brief |
| 191 | Borrows the \bt_stream conceptually containing the event |
| 192 | \bt_p{event}. |
| 193 | |
| 194 | @param[in] event |
| 195 | Event of which to borrow the stream conceptually containing it. |
| 196 | |
| 197 | @returns |
| 198 | \em Borrowed reference of the stream conceptually containing |
| 199 | \bt_p{event}. |
| 200 | |
| 201 | @bt_pre_not_null{event} |
| 202 | |
| 203 | @sa bt_event_borrow_stream_const() — |
| 204 | \c const version of this function. |
| 205 | */ |
| 206 | extern bt_stream *bt_event_borrow_stream(bt_event *event); |
| 207 | |
| 208 | /*! |
| 209 | @brief |
| 210 | Borrows the \bt_stream conceptually containing the event |
| 211 | \bt_p{event} (\c const version). |
| 212 | |
| 213 | See bt_event_borrow_stream(). |
| 214 | */ |
| 215 | extern const bt_stream *bt_event_borrow_stream_const( |
| 216 | const bt_event *event); |
| 217 | |
| 218 | /*! @} */ |
| 219 | |
| 220 | /*! |
| 221 | @name Packet access |
| 222 | @{ |
| 223 | */ |
| 224 | |
| 225 | /*! |
| 226 | @brief |
| 227 | Borrows the \bt_pkt conceptually containing the event |
| 228 | \bt_p{event}. |
| 229 | |
| 230 | @attention |
| 231 | Only call this function if bt_stream_class_supports_packets() |
| 232 | returns #BT_TRUE for the \bt_stream_cls of \bt_p{event}. |
| 233 | |
| 234 | @param[in] event |
| 235 | Event of which to borrow the packet conceptually containing it. |
| 236 | |
| 237 | @returns |
| 238 | \em Borrowed reference of the packet conceptually containing |
| 239 | \bt_p{event}. |
| 240 | |
| 241 | @bt_pre_not_null{event} |
| 242 | |
| 243 | @sa bt_event_borrow_packet_const() — |
| 244 | \c const version of this function. |
| 245 | */ |
| 246 | extern bt_packet *bt_event_borrow_packet(bt_event *event); |
| 247 | |
| 248 | /*! |
| 249 | @brief |
| 250 | Borrows the \bt_pkt conceptually containing the event |
| 251 | \bt_p{event} (\c const version). |
| 252 | |
| 253 | See bt_event_borrow_packet(). |
| 254 | */ |
| 255 | extern const bt_packet *bt_event_borrow_packet_const( |
| 256 | const bt_event *event); |
| 257 | |
| 258 | /*! @} */ |
| 259 | |
| 260 | /*! |
| 261 | @name Properties |
| 262 | @{ |
| 263 | */ |
| 264 | |
| 265 | /*! |
| 266 | @brief |
| 267 | Borrows the payload \bt_field of the event \bt_p{event}. |
| 268 | |
| 269 | See the \ref api-tir-ev-prop-payload "payload field" property. |
| 270 | |
| 271 | @param[in] event |
| 272 | Event of which to borrow the payload field. |
| 273 | |
| 274 | @returns |
| 275 | \em Borrowed reference of the payload field of \bt_p{event}, |
| 276 | or \c NULL if none. |
| 277 | |
| 278 | @bt_pre_not_null{event} |
| 279 | |
| 280 | @sa bt_event_borrow_payload_field_const() — |
| 281 | \c const version of this function. |
| 282 | */ |
| 283 | extern bt_field *bt_event_borrow_payload_field(bt_event *event); |
| 284 | |
| 285 | /*! |
| 286 | @brief |
| 287 | Borrows the payload \bt_field of the event \bt_p{event} |
| 288 | (\c const version). |
| 289 | |
| 290 | See bt_event_borrow_payload_field(). |
| 291 | */ |
| 292 | extern const bt_field *bt_event_borrow_payload_field_const( |
| 293 | const bt_event *event); |
| 294 | |
| 295 | /*! |
| 296 | @brief |
| 297 | Borrows the specific context \bt_field of the event \bt_p{event}. |
| 298 | |
| 299 | See the \ref api-tir-ev-prop-spec-ctx "specific context field" property. |
| 300 | |
| 301 | @param[in] event |
| 302 | Event of which to borrow the specific context field. |
| 303 | |
| 304 | @returns |
| 305 | \em Borrowed reference of the specific context field of |
| 306 | \bt_p{event}, or \c NULL if none. |
| 307 | |
| 308 | @bt_pre_not_null{event} |
| 309 | |
| 310 | @sa bt_event_borrow_specific_context_field_const() — |
| 311 | \c const version of this function. |
| 312 | */ |
| 313 | extern bt_field * |
| 314 | bt_event_borrow_specific_context_field(bt_event *event); |
| 315 | |
| 316 | /*! |
| 317 | @brief |
| 318 | Borrows the specific context \bt_field of the event \bt_p{event} |
| 319 | (\c const version). |
| 320 | |
| 321 | See bt_event_borrow_specific_context_field(). |
| 322 | */ |
| 323 | extern const bt_field *bt_event_borrow_specific_context_field_const( |
| 324 | const bt_event *event); |
| 325 | |
| 326 | /*! |
| 327 | @brief |
| 328 | Borrows the common context \bt_field of the event \bt_p{event}. |
| 329 | |
| 330 | See the \ref api-tir-ev-prop-common-ctx "common context field" property. |
| 331 | |
| 332 | @param[in] event |
| 333 | Event of which to borrow the common context field. |
| 334 | |
| 335 | @returns |
| 336 | \em Borrowed reference of the common context field of |
| 337 | \bt_p{event}, or \c NULL if none. |
| 338 | |
| 339 | @bt_pre_not_null{event} |
| 340 | |
| 341 | @sa bt_event_borrow_specific_context_field_const() — |
| 342 | \c const version of this function. |
| 343 | */ |
| 344 | extern bt_field * |
| 345 | bt_event_borrow_common_context_field(bt_event *event); |
| 346 | |
| 347 | /*! |
| 348 | @brief |
| 349 | Borrows the common context \bt_field of the event \bt_p{event} |
| 350 | (\c const version). |
| 351 | |
| 352 | See bt_event_borrow_common_context_field(). |
| 353 | */ |
| 354 | extern const bt_field *bt_event_borrow_common_context_field_const( |
| 355 | const bt_event *event); |
| 356 | |
| 357 | /*! @} */ |
| 358 | |
| 359 | /*! @} */ |
| 360 | |
| 361 | #ifdef __cplusplus |
| 362 | } |
| 363 | #endif |
| 364 | |
| 365 | #endif /* BABELTRACE2_TRACE_IR_EVENT_H */ |