| 1 | #LyX 1.5.5 created this file. For more info see http://www.lyx.org/ |
| 2 | \lyxformat 276 |
| 3 | \begin_document |
| 4 | \begin_header |
| 5 | \textclass article |
| 6 | \language english |
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| 27 | \tocdepth 3 |
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| 29 | \defskip medskip |
| 30 | \quotes_language english |
| 31 | \papercolumns 1 |
| 32 | \papersides 1 |
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| 35 | \output_changes false |
| 36 | \author "" |
| 37 | \author "" |
| 38 | \end_header |
| 39 | |
| 40 | \begin_body |
| 41 | |
| 42 | \begin_layout Title |
| 43 | A Set of APIs for a Third-Generation Trace Viewer |
| 44 | \end_layout |
| 45 | |
| 46 | \begin_layout Author |
| 47 | \noindent |
| 48 | Pierre-Marc Fournier, Michel Dagenais, Mathieu Desnoyers |
| 49 | \newline |
| 50 | |
| 51 | \family typewriter |
| 52 | \size footnotesize |
| 53 | <pierre-marc.fournier _at_ polymtl.ca> |
| 54 | \family default |
| 55 | \size default |
| 56 | |
| 57 | \newline |
| 58 | |
| 59 | \newline |
| 60 | CASI Lab |
| 61 | \newline |
| 62 | École Polytechnique de Montréal |
| 63 | \newline |
| 64 | |
| 65 | \newline |
| 66 | WORK IN PROGRESS |
| 67 | \end_layout |
| 68 | |
| 69 | \begin_layout Section |
| 70 | Introduction |
| 71 | \end_layout |
| 72 | |
| 73 | \begin_layout Standard |
| 74 | This document proposes some APIs for a trace viewing and analysis infrastructure. |
| 75 | \end_layout |
| 76 | |
| 77 | \begin_layout Standard |
| 78 | Design choices were made based on the experience acquired by the design, |
| 79 | development and use of two previous generations of trace viewers, respectively |
| 80 | the Trace Visualizer from the Linux Trace Toolkit and its successor, the |
| 81 | LTTV from the LTTng tracing toolkit. |
| 82 | \end_layout |
| 83 | |
| 84 | \begin_layout Section |
| 85 | Goals |
| 86 | \end_layout |
| 87 | |
| 88 | \begin_layout Itemize |
| 89 | Provide an infrastructure for fast, interactive visualization and analysis |
| 90 | of huge traces (>10 GB) on standard workstations |
| 91 | \begin_inset Foot |
| 92 | status open |
| 93 | |
| 94 | \begin_layout Standard |
| 95 | Efficiency is of great importance. |
| 96 | It is tempting to think that as computers get faster, it will be possible |
| 97 | to run more complex analyses on traces in a shorter time. |
| 98 | In fact, the size of the traces grows as computers get more powerful, because |
| 99 | they do more operations than before in the same amount of time and therefore |
| 100 | generate more events. |
| 101 | The current tendency to parallelize systems is another factor that results |
| 102 | in bigger traces. |
| 103 | \end_layout |
| 104 | |
| 105 | \end_inset |
| 106 | |
| 107 | |
| 108 | \end_layout |
| 109 | |
| 110 | \begin_layout Itemize |
| 111 | Support live trace processing |
| 112 | \end_layout |
| 113 | |
| 114 | \begin_layout Itemize |
| 115 | Allow merging of traces of different formats |
| 116 | \end_layout |
| 117 | |
| 118 | \begin_layout Itemize |
| 119 | Design with both command line utilities (C language) and graphical interfaces |
| 120 | (Java and others) in mind, sharing code and standardizing interfaces as |
| 121 | much as possible |
| 122 | \end_layout |
| 123 | |
| 124 | \begin_deeper |
| 125 | \begin_layout Standard |
| 126 | Both command-line interfaces and graphical interfaces have an important |
| 127 | role to play in trace analysis. |
| 128 | While graphical interfaces allow for complex views, command-line utilities |
| 129 | can be used quickly in more environments; they can also be more convenient |
| 130 | in some circumstances. |
| 131 | A good design should be such that they can share code and APIs. |
| 132 | \end_layout |
| 133 | |
| 134 | \end_deeper |
| 135 | \begin_layout Section |
| 136 | General aspects |
| 137 | \end_layout |
| 138 | |
| 139 | \begin_layout Itemize |
| 140 | All data structures must be accessed through API methods, in order to allow |
| 141 | for internal change without breaking compatibility. |
| 142 | \end_layout |
| 143 | |
| 144 | \begin_layout Itemize |
| 145 | The APIs in this document are described as C functions and datatypes. |
| 146 | When an operation applies to an abstraction that should be an object in |
| 147 | an object-oriented language, it is specified as the first argument of the |
| 148 | function. |
| 149 | In such languages, this first argument should be removed, as it will be |
| 150 | passed implicitly. |
| 151 | \end_layout |
| 152 | |
| 153 | \begin_layout Subsection |
| 154 | Time |
| 155 | \end_layout |
| 156 | |
| 157 | \begin_layout Standard |
| 158 | The framework needs to represent points in the time line and time ranges. |
| 159 | This is done by two data structures, respectively: |
| 160 | \end_layout |
| 161 | |
| 162 | \begin_layout Itemize |
| 163 | struct trace_time |
| 164 | \end_layout |
| 165 | |
| 166 | \begin_layout Itemize |
| 167 | struct trace_time_range |
| 168 | \end_layout |
| 169 | |
| 170 | \begin_layout Standard |
| 171 | The preferred representation for times is seconds. |
| 172 | \end_layout |
| 173 | |
| 174 | \begin_layout Standard |
| 175 | Ranges are a span between two points in time. |
| 176 | They are represented as these two points. |
| 177 | One or both of them can have the special value |
| 178 | \emph on |
| 179 | infinity |
| 180 | \emph default |
| 181 | . |
| 182 | \end_layout |
| 183 | |
| 184 | \begin_layout Section |
| 185 | Reading traces |
| 186 | \end_layout |
| 187 | |
| 188 | \begin_layout Subsection |
| 189 | Overview |
| 190 | \end_layout |
| 191 | |
| 192 | \begin_layout Subsubsection |
| 193 | Timestamps |
| 194 | \end_layout |
| 195 | |
| 196 | \begin_layout Standard |
| 197 | Timestamps, at the framework level, should be in an architecture-independent |
| 198 | format. |
| 199 | One possibility would be to have them stored in seconds (with decimals). |
| 200 | Offsetting, if necessary, could be handled by the traceset (trace merging) |
| 201 | level. |
| 202 | An uncertainty value should accompany the timestamp. |
| 203 | Timestamps in cycles should be available if they are provided by the tracer. |
| 204 | \end_layout |
| 205 | |
| 206 | \begin_layout Subsection |
| 207 | Low-level trace reading API |
| 208 | \end_layout |
| 209 | |
| 210 | \begin_layout Standard |
| 211 | The goal of this API is to provide a uniform way for the framework to access |
| 212 | the events recorded in a trace, in an encoding-independant way. |
| 213 | \end_layout |
| 214 | |
| 215 | \begin_layout Subsubsection |
| 216 | Factory methods |
| 217 | \end_layout |
| 218 | |
| 219 | \begin_layout Itemize |
| 220 | void get_supported_formats(void) |
| 221 | \end_layout |
| 222 | |
| 223 | \begin_deeper |
| 224 | \begin_layout Standard |
| 225 | Arguments: none |
| 226 | \end_layout |
| 227 | |
| 228 | \begin_layout Standard |
| 229 | Return: |
| 230 | \end_layout |
| 231 | |
| 232 | \begin_layout Itemize |
| 233 | a list of supported formats |
| 234 | \end_layout |
| 235 | |
| 236 | \end_deeper |
| 237 | \begin_layout Itemize |
| 238 | open_trace() |
| 239 | \end_layout |
| 240 | |
| 241 | \begin_deeper |
| 242 | \begin_layout Standard |
| 243 | Arguments: |
| 244 | \end_layout |
| 245 | |
| 246 | \begin_layout Itemize |
| 247 | trace URL |
| 248 | \end_layout |
| 249 | |
| 250 | \begin_deeper |
| 251 | \begin_layout Itemize |
| 252 | local file name |
| 253 | \end_layout |
| 254 | |
| 255 | \begin_layout Itemize |
| 256 | other special url to establish a network connection |
| 257 | \end_layout |
| 258 | |
| 259 | \begin_layout Itemize |
| 260 | etc... |
| 261 | \end_layout |
| 262 | |
| 263 | \end_deeper |
| 264 | \begin_layout Itemize |
| 265 | trace format (optional, for cases where auto detection would not work or |
| 266 | be ambiguous) |
| 267 | \end_layout |
| 268 | |
| 269 | \begin_layout Standard |
| 270 | Return: |
| 271 | \end_layout |
| 272 | |
| 273 | \begin_layout Itemize |
| 274 | a trace handle |
| 275 | \end_layout |
| 276 | |
| 277 | \end_deeper |
| 278 | \begin_layout Subsubsection |
| 279 | Trace methods |
| 280 | \end_layout |
| 281 | |
| 282 | \begin_layout Itemize |
| 283 | bool close(struct trace *tr) |
| 284 | \end_layout |
| 285 | |
| 286 | \begin_layout Itemize |
| 287 | struct event *current_event(struct trace *) |
| 288 | \end_layout |
| 289 | |
| 290 | \begin_deeper |
| 291 | \begin_layout Standard |
| 292 | Arguments: none |
| 293 | \end_layout |
| 294 | |
| 295 | \begin_layout Standard |
| 296 | Return: |
| 297 | \end_layout |
| 298 | |
| 299 | \begin_layout Itemize |
| 300 | the event currently pointed by the position pointer |
| 301 | \end_layout |
| 302 | |
| 303 | \end_deeper |
| 304 | \begin_layout Itemize |
| 305 | bool advance(struct trace *tr) |
| 306 | \end_layout |
| 307 | |
| 308 | \begin_deeper |
| 309 | \begin_layout Standard |
| 310 | Advance the position pointer to the next event in the trace. |
| 311 | \end_layout |
| 312 | |
| 313 | \begin_layout Standard |
| 314 | Arguments: none |
| 315 | \end_layout |
| 316 | |
| 317 | \begin_layout Standard |
| 318 | Return values: |
| 319 | \end_layout |
| 320 | |
| 321 | \begin_layout Itemize |
| 322 | The result: |
| 323 | \end_layout |
| 324 | |
| 325 | \begin_deeper |
| 326 | \begin_layout Itemize |
| 327 | Success |
| 328 | \end_layout |
| 329 | |
| 330 | \begin_layout Itemize |
| 331 | Final end of trace (end of a non-live trace or of a completed live trace) |
| 332 | \end_layout |
| 333 | |
| 334 | \begin_layout Itemize |
| 335 | No more events for now (end of a still running live trace) |
| 336 | \end_layout |
| 337 | |
| 338 | \end_deeper |
| 339 | \end_deeper |
| 340 | \begin_layout Itemize |
| 341 | bool seek_time(struct trace *tr, struct trace_cursor *cur) |
| 342 | \end_layout |
| 343 | |
| 344 | \begin_deeper |
| 345 | \begin_layout Standard |
| 346 | Arguments: |
| 347 | \end_layout |
| 348 | |
| 349 | \begin_layout Itemize |
| 350 | The time to seek to |
| 351 | \end_layout |
| 352 | |
| 353 | \begin_layout Standard |
| 354 | Return: none |
| 355 | \end_layout |
| 356 | |
| 357 | \end_deeper |
| 358 | \begin_layout Itemize |
| 359 | struct trace_cursor *trace_new_cursor_beginning(struct trace *tr) |
| 360 | \end_layout |
| 361 | |
| 362 | \begin_deeper |
| 363 | \begin_layout Standard |
| 364 | Return a new cursor associated to the trace, positioned at its beginning |
| 365 | \end_layout |
| 366 | |
| 367 | \end_deeper |
| 368 | \begin_layout Itemize |
| 369 | struct trace_cursor *trace_cursor_copy(struct trace_cursor *cur) |
| 370 | \end_layout |
| 371 | |
| 372 | \begin_layout Itemize |
| 373 | void trace_cursor_destroy(struct trace_cursor_destroy *) |
| 374 | \end_layout |
| 375 | |
| 376 | \begin_layout Itemize |
| 377 | struct trace_time get_time_start(struct trace *tr) |
| 378 | \end_layout |
| 379 | |
| 380 | \begin_deeper |
| 381 | \begin_layout Standard |
| 382 | Arguments: none |
| 383 | \end_layout |
| 384 | |
| 385 | \begin_layout Standard |
| 386 | Return: |
| 387 | \end_layout |
| 388 | |
| 389 | \begin_layout Itemize |
| 390 | the timestamp of the first event in the trace |
| 391 | \end_layout |
| 392 | |
| 393 | \end_deeper |
| 394 | \begin_layout Itemize |
| 395 | struct trace_time get_time_end(struct trace *tr) |
| 396 | \end_layout |
| 397 | |
| 398 | \begin_deeper |
| 399 | \begin_layout Standard |
| 400 | Arguments: none |
| 401 | \end_layout |
| 402 | |
| 403 | \begin_layout Standard |
| 404 | Return: |
| 405 | \end_layout |
| 406 | |
| 407 | \begin_layout Itemize |
| 408 | the timestamp of the last event in the trace |
| 409 | \end_layout |
| 410 | |
| 411 | \end_deeper |
| 412 | \begin_layout Itemize |
| 413 | register_callback_new_event(struct trace *tr, struct trace_time after, void |
| 414 | (*cb)(void)) |
| 415 | \end_layout |
| 416 | |
| 417 | \begin_deeper |
| 418 | \begin_layout Standard |
| 419 | Register a callback that is called when a new event becomes available in |
| 420 | a live trace. |
| 421 | It is also called when the live trace ends. |
| 422 | \end_layout |
| 423 | |
| 424 | \begin_layout Standard |
| 425 | Arguments: |
| 426 | \end_layout |
| 427 | |
| 428 | \begin_layout Itemize |
| 429 | after (timestamp) : call only if the event occurent later than |
| 430 | \emph on |
| 431 | after |
| 432 | \end_layout |
| 433 | |
| 434 | \begin_layout Itemize |
| 435 | cb: the callback function |
| 436 | \begin_inset Note Note |
| 437 | status open |
| 438 | |
| 439 | \begin_layout Standard |
| 440 | specify its args and return val |
| 441 | \end_layout |
| 442 | |
| 443 | \end_inset |
| 444 | |
| 445 | |
| 446 | \end_layout |
| 447 | |
| 448 | \begin_layout Standard |
| 449 | Return: |
| 450 | \end_layout |
| 451 | |
| 452 | \begin_layout Itemize |
| 453 | Result (success or failure) |
| 454 | \end_layout |
| 455 | |
| 456 | \end_deeper |
| 457 | \begin_layout Subsection |
| 458 | High-level trace reading API |
| 459 | \end_layout |
| 460 | |
| 461 | \begin_layout Standard |
| 462 | The goal of this API is to provide a uniform way for analyses and views |
| 463 | to obtain trace events from a traceset (merge of many traces or a single |
| 464 | trace), regardless of the system they were recorded on and of the tracer |
| 465 | used. |
| 466 | \end_layout |
| 467 | |
| 468 | \begin_layout Itemize |
| 469 | struct request_handle *traceset_new_event_request(struct traceset *tr, struct |
| 470 | trace_time t1, struct trace_time t2, struct event_filter *filter, void |
| 471 | (*cb)(void *data, ), void *data) |
| 472 | \end_layout |
| 473 | |
| 474 | \begin_deeper |
| 475 | \begin_layout Standard |
| 476 | Request a range of events |
| 477 | \end_layout |
| 478 | |
| 479 | \begin_layout Standard |
| 480 | Arguments: |
| 481 | \end_layout |
| 482 | |
| 483 | \begin_layout Itemize |
| 484 | tr: the traceset |
| 485 | \end_layout |
| 486 | |
| 487 | \begin_layout Itemize |
| 488 | t1: start timestamp |
| 489 | \end_layout |
| 490 | |
| 491 | \begin_layout Itemize |
| 492 | t2: stop timestamp (special value for infinity, for live traces) |
| 493 | \end_layout |
| 494 | |
| 495 | \begin_layout Itemize |
| 496 | filter: filter with complex expressions |
| 497 | \end_layout |
| 498 | |
| 499 | \begin_layout Itemize |
| 500 | data: private pointer to be passed to the callback |
| 501 | \end_layout |
| 502 | |
| 503 | \begin_layout Standard |
| 504 | Return: |
| 505 | \end_layout |
| 506 | |
| 507 | \begin_layout Itemize |
| 508 | handle to the request for cancelling it |
| 509 | \end_layout |
| 510 | |
| 511 | \end_deeper |
| 512 | \begin_layout Itemize |
| 513 | void event_request_cancel(struct request_handle *req) |
| 514 | \end_layout |
| 515 | |
| 516 | \begin_deeper |
| 517 | \begin_layout Standard |
| 518 | Arguments: |
| 519 | \end_layout |
| 520 | |
| 521 | \begin_layout Itemize |
| 522 | req: the handle to the request |
| 523 | \end_layout |
| 524 | |
| 525 | \end_deeper |
| 526 | \begin_layout Subsection |
| 527 | State management |
| 528 | \end_layout |
| 529 | |
| 530 | \begin_layout Standard |
| 531 | States are key/value pairs associated with a time range. |
| 532 | Keys can be (and generally are) duplicated as long as they do not apply |
| 533 | to overlapping ranges. |
| 534 | \end_layout |
| 535 | |
| 536 | \begin_layout Standard |
| 537 | Keys are character strings. |
| 538 | \end_layout |
| 539 | |
| 540 | \begin_layout Standard |
| 541 | Values may be of various types: |
| 542 | \end_layout |
| 543 | |
| 544 | \begin_layout Itemize |
| 545 | string |
| 546 | \end_layout |
| 547 | |
| 548 | \begin_layout Itemize |
| 549 | uint32 |
| 550 | \end_layout |
| 551 | |
| 552 | \begin_layout Itemize |
| 553 | int32 |
| 554 | \end_layout |
| 555 | |
| 556 | \begin_layout Itemize |
| 557 | blob (binary block of arbitrary length) |
| 558 | \end_layout |
| 559 | |
| 560 | \begin_layout Itemize |
| 561 | float32 |
| 562 | \end_layout |
| 563 | |
| 564 | \begin_layout Itemize |
| 565 | float64 |
| 566 | \end_layout |
| 567 | |
| 568 | \begin_layout Standard |
| 569 | The state information must be persistent between executions of the framework. |
| 570 | \end_layout |
| 571 | |
| 572 | \begin_layout Standard |
| 573 | It is possible to assign a state to the range -infinity..infinity to indicate |
| 574 | that it is global to the trace, regardless of . |
| 575 | \end_layout |
| 576 | |
| 577 | \begin_layout Standard |
| 578 | The key names should be hierarchical. |
| 579 | \end_layout |
| 580 | |
| 581 | \begin_layout Subsubsection |
| 582 | State accessing API |
| 583 | \end_layout |
| 584 | |
| 585 | \begin_layout Itemize |
| 586 | struct state_value *state_get_value_at_time(char *key, struct trace_time |
| 587 | time) |
| 588 | \end_layout |
| 589 | |
| 590 | \begin_deeper |
| 591 | \begin_layout Standard |
| 592 | Request the value of a given key at a point in time |
| 593 | \end_layout |
| 594 | |
| 595 | \begin_layout Standard |
| 596 | Arguments: |
| 597 | \end_layout |
| 598 | |
| 599 | \begin_layout Itemize |
| 600 | var: the state variables (string) |
| 601 | \end_layout |
| 602 | |
| 603 | \begin_layout Itemize |
| 604 | time: the timestamp |
| 605 | \end_layout |
| 606 | |
| 607 | \begin_layout Standard |
| 608 | Return value: |
| 609 | \end_layout |
| 610 | |
| 611 | \begin_layout Itemize |
| 612 | The state value |
| 613 | \end_layout |
| 614 | |
| 615 | \end_deeper |
| 616 | \begin_layout Itemize |
| 617 | struct state_value_range **state_get_values_in_range(char *key, struct state_val |
| 618 | ue *val, struct trace_time_range range) |
| 619 | \end_layout |
| 620 | |
| 621 | \begin_deeper |
| 622 | \begin_layout Standard |
| 623 | Request all the states changes of a given set of state variables between |
| 624 | two time indexes |
| 625 | \end_layout |
| 626 | |
| 627 | \begin_layout Standard |
| 628 | Arguments: |
| 629 | \end_layout |
| 630 | |
| 631 | \begin_layout Itemize |
| 632 | key: the key |
| 633 | \end_layout |
| 634 | |
| 635 | \begin_layout Itemize |
| 636 | range: the time range |
| 637 | \end_layout |
| 638 | |
| 639 | \end_deeper |
| 640 | \begin_layout Itemize |
| 641 | Other functions for getting values for a set of keys at once? |
| 642 | \end_layout |
| 643 | |
| 644 | \begin_layout Subsubsection |
| 645 | State setting API |
| 646 | \end_layout |
| 647 | |
| 648 | \begin_layout Itemize |
| 649 | set a particular state |
| 650 | \end_layout |
| 651 | |
| 652 | \begin_layout Itemize |
| 653 | delete some states |
| 654 | \end_layout |
| 655 | |
| 656 | \begin_layout Section |
| 657 | Describing event types |
| 658 | \end_layout |
| 659 | |
| 660 | \begin_layout Subsection |
| 661 | Overview |
| 662 | \end_layout |
| 663 | |
| 664 | \begin_layout Standard |
| 665 | Because tracepoints may be created dynamically, information about the descriptio |
| 666 | n of events is just as dynamic. |
| 667 | In this context, one simple way to communicate the event description informatio |
| 668 | n to upper layers would be to send them as events, as it is done in recent |
| 669 | versions of LTTV. |
| 670 | The core events used to describe other events are the only ones whose descripti |
| 671 | on is hardcoded in the framework. |
| 672 | \end_layout |
| 673 | |
| 674 | \begin_layout Standard |
| 675 | These event-type-describing events could then be received and interpreted |
| 676 | by the Event Description Service, which would be a client to the high-level |
| 677 | tracing API at the same level as normal views and analyses. |
| 678 | It would store the information and allow the other views and analyses to |
| 679 | access it via this API. |
| 680 | \end_layout |
| 681 | |
| 682 | \begin_layout Standard |
| 683 | Each event has a timestamp, a name and arguments of various types. |
| 684 | The framework should support the following types: |
| 685 | \end_layout |
| 686 | |
| 687 | \begin_layout Itemize |
| 688 | uint32 |
| 689 | \end_layout |
| 690 | |
| 691 | \begin_layout Itemize |
| 692 | uint64 |
| 693 | \end_layout |
| 694 | |
| 695 | \begin_layout Itemize |
| 696 | int32 |
| 697 | \end_layout |
| 698 | |
| 699 | \begin_layout Itemize |
| 700 | int64 |
| 701 | \end_layout |
| 702 | |
| 703 | \begin_layout Itemize |
| 704 | string |
| 705 | \end_layout |
| 706 | |
| 707 | \begin_layout Subsection |
| 708 | Events-describing events |
| 709 | \end_layout |
| 710 | |
| 711 | \begin_layout Itemize |
| 712 | Event type declaration event |
| 713 | \end_layout |
| 714 | |
| 715 | \begin_deeper |
| 716 | \begin_layout Standard |
| 717 | Announce the existence of an event type |
| 718 | \end_layout |
| 719 | |
| 720 | \begin_layout Itemize |
| 721 | event type name |
| 722 | \end_layout |
| 723 | |
| 724 | \end_deeper |
| 725 | \begin_layout Itemize |
| 726 | Argument declaration event |
| 727 | \end_layout |
| 728 | |
| 729 | \begin_deeper |
| 730 | \begin_layout Standard |
| 731 | Announce the existence of an event argument |
| 732 | \end_layout |
| 733 | |
| 734 | \begin_layout Itemize |
| 735 | event type name |
| 736 | \end_layout |
| 737 | |
| 738 | \begin_layout Itemize |
| 739 | name |
| 740 | \end_layout |
| 741 | |
| 742 | \begin_layout Itemize |
| 743 | type |
| 744 | \end_layout |
| 745 | |
| 746 | \end_deeper |
| 747 | \begin_layout Itemize |
| 748 | Event destruction |
| 749 | \end_layout |
| 750 | |
| 751 | \begin_deeper |
| 752 | \begin_layout Standard |
| 753 | Announce that an event type ceased to exist |
| 754 | \end_layout |
| 755 | |
| 756 | \begin_layout Itemize |
| 757 | event type name |
| 758 | \end_layout |
| 759 | |
| 760 | \end_deeper |
| 761 | \begin_layout Subsection |
| 762 | Event type description API |
| 763 | \end_layout |
| 764 | |
| 765 | \begin_layout Standard |
| 766 | The event type description service provides the following functions. |
| 767 | \end_layout |
| 768 | |
| 769 | \begin_layout Itemize |
| 770 | GArray<struct event_type *> *traceset_get_all_event_types(struct traceset |
| 771 | *ts) |
| 772 | \end_layout |
| 773 | |
| 774 | \begin_deeper |
| 775 | \begin_layout Standard |
| 776 | Get the list of all the event types |
| 777 | \end_layout |
| 778 | |
| 779 | \begin_layout Standard |
| 780 | Arguments: |
| 781 | \end_layout |
| 782 | |
| 783 | \begin_layout Itemize |
| 784 | ts: the traceset of which we want the event types |
| 785 | \end_layout |
| 786 | |
| 787 | \begin_layout Standard |
| 788 | Return value: |
| 789 | \end_layout |
| 790 | |
| 791 | \begin_layout Itemize |
| 792 | A GArray of of struct event_type. |
| 793 | The GArray must be gfree()'d by the caller when it is done reading it. |
| 794 | \end_layout |
| 795 | |
| 796 | \end_deeper |
| 797 | \begin_layout Itemize |
| 798 | struct event_type *traceset_get_event_type_by_name(struct traceset *ts, |
| 799 | char *name) |
| 800 | \end_layout |
| 801 | |
| 802 | \begin_deeper |
| 803 | \begin_layout Standard |
| 804 | Find an event type by name |
| 805 | \end_layout |
| 806 | |
| 807 | \begin_layout Standard |
| 808 | Arguments: |
| 809 | \end_layout |
| 810 | |
| 811 | \begin_layout Itemize |
| 812 | ts: the traceset of which we want the event type |
| 813 | \end_layout |
| 814 | |
| 815 | \begin_layout Itemize |
| 816 | name: the name of the of the event type we are looking for |
| 817 | \end_layout |
| 818 | |
| 819 | \begin_layout Standard |
| 820 | Return value: |
| 821 | \end_layout |
| 822 | |
| 823 | \begin_layout Itemize |
| 824 | A pointer to the event type (must not be free'd) or NULL if not found |
| 825 | \end_layout |
| 826 | |
| 827 | \end_deeper |
| 828 | \begin_layout Itemize |
| 829 | GArray<struct event arg *> *event_type_get_all_args(struct event_type *evtype) |
| 830 | \end_layout |
| 831 | |
| 832 | \begin_deeper |
| 833 | \begin_layout Standard |
| 834 | Get the list of arguments of an event |
| 835 | \end_layout |
| 836 | |
| 837 | \begin_layout Standard |
| 838 | Arguments: |
| 839 | \end_layout |
| 840 | |
| 841 | \begin_layout Itemize |
| 842 | eventype: the event type of which we want the arguments |
| 843 | \end_layout |
| 844 | |
| 845 | \begin_layout Standard |
| 846 | Return value: |
| 847 | \end_layout |
| 848 | |
| 849 | \begin_layout Itemize |
| 850 | A GArray of struct event_args. |
| 851 | The GArray must be gfree()'d by the caller when it is done reading it. |
| 852 | \end_layout |
| 853 | |
| 854 | \end_deeper |
| 855 | \begin_layout Itemize |
| 856 | struct event_arg *event_type_get_arg_by_name(struct event_type *evtype) |
| 857 | \end_layout |
| 858 | |
| 859 | \begin_deeper |
| 860 | \begin_layout Standard |
| 861 | Find an argument by name |
| 862 | \end_layout |
| 863 | |
| 864 | \end_deeper |
| 865 | \begin_layout Itemize |
| 866 | Functions for accessing struct event_arg fields |
| 867 | \end_layout |
| 868 | |
| 869 | \begin_layout Section |
| 870 | Inspecting events |
| 871 | \end_layout |
| 872 | |
| 873 | \begin_layout Subsection |
| 874 | Overview |
| 875 | \end_layout |
| 876 | |
| 877 | \begin_layout Standard |
| 878 | Events contain the following information. |
| 879 | \end_layout |
| 880 | |
| 881 | \begin_layout Itemize |
| 882 | Timestamp |
| 883 | \end_layout |
| 884 | |
| 885 | \begin_layout Itemize |
| 886 | Event type identifier - an event id (integer) - hidden to the API users, |
| 887 | manipulated as pointers/references to struct event_type |
| 888 | \end_layout |
| 889 | |
| 890 | \begin_layout Itemize |
| 891 | A reference to the trace it was in |
| 892 | \end_layout |
| 893 | |
| 894 | \begin_layout Subsection |
| 895 | Event inspecting API |
| 896 | \end_layout |
| 897 | |
| 898 | \begin_layout Itemize |
| 899 | struct event_type *event_get_type(struct traceset *ts, struct event *ev) |
| 900 | \end_layout |
| 901 | |
| 902 | \begin_deeper |
| 903 | \begin_layout Standard |
| 904 | get the event type corresponding to an event |
| 905 | \end_layout |
| 906 | |
| 907 | \begin_layout Standard |
| 908 | Arguments: |
| 909 | \end_layout |
| 910 | |
| 911 | \begin_layout Itemize |
| 912 | ts: |
| 913 | \end_layout |
| 914 | |
| 915 | \begin_layout Itemize |
| 916 | ev: |
| 917 | \end_layout |
| 918 | |
| 919 | \begin_layout Standard |
| 920 | Return value: |
| 921 | \end_layout |
| 922 | |
| 923 | \begin_layout Itemize |
| 924 | The event type or NULL if no information |
| 925 | \end_layout |
| 926 | |
| 927 | \end_deeper |
| 928 | \begin_layout Itemize |
| 929 | struct trace_time event_get_time(struct event *ev) |
| 930 | \end_layout |
| 931 | |
| 932 | \begin_deeper |
| 933 | \begin_layout Standard |
| 934 | get the event time |
| 935 | \end_layout |
| 936 | |
| 937 | \end_deeper |
| 938 | \begin_layout Itemize |
| 939 | struct trace *event_get_trace(struct event *ev) |
| 940 | \end_layout |
| 941 | |
| 942 | \begin_layout Itemize |
| 943 | get the name of the machine on which the event occured or other location |
| 944 | information |
| 945 | \end_layout |
| 946 | |
| 947 | \begin_layout Itemize |
| 948 | get information on the type of tracing technology that was used |
| 949 | \end_layout |
| 950 | |
| 951 | \begin_layout Itemize |
| 952 | get the corresponding tracepoint (machine/tracing technology/name/location |
| 953 | in code(if available)) |
| 954 | \end_layout |
| 955 | |
| 956 | \begin_layout Itemize |
| 957 | uint32 event_read_arg_uint32(struct event *ev, struct event_arg *arg) |
| 958 | \end_layout |
| 959 | |
| 960 | \begin_layout Itemize |
| 961 | int32 event_read_arg_int32(struct event *ev, struct event_arg *arg) |
| 962 | \end_layout |
| 963 | |
| 964 | \begin_layout Itemize |
| 965 | uint64 event_read_arg_uint64(struct event *ev, struct event_arg *arg) |
| 966 | \end_layout |
| 967 | |
| 968 | \begin_layout Itemize |
| 969 | int64 event_read_arg_int64(struct event *ev, struct event_arg *arg) |
| 970 | \end_layout |
| 971 | |
| 972 | \begin_layout Itemize |
| 973 | float32 event_read_arg_float32(struct event *ev, struct event_arg *arg) |
| 974 | \end_layout |
| 975 | |
| 976 | \begin_layout Itemize |
| 977 | float64 event_read_arg_float64(struct event *ev, struct event_arg *arg) |
| 978 | \end_layout |
| 979 | |
| 980 | \begin_layout Section |
| 981 | Filtering events |
| 982 | \end_layout |
| 983 | |
| 984 | \begin_layout Standard |
| 985 | A filtering API is proposed. |
| 986 | \end_layout |
| 987 | |
| 988 | \begin_layout Section |
| 989 | Controlling the tracing of a system |
| 990 | \end_layout |
| 991 | |
| 992 | \begin_layout Subsection |
| 993 | Overview |
| 994 | \end_layout |
| 995 | |
| 996 | \begin_layout Standard |
| 997 | The goal of this API is to provide a portable way of controlling tracing |
| 998 | of heterogenous systems. |
| 999 | \end_layout |
| 1000 | |
| 1001 | \begin_layout Standard |
| 1002 | It should enable to do the following actions. |
| 1003 | \end_layout |
| 1004 | |
| 1005 | \begin_layout Itemize |
| 1006 | Set the parameters of a trace (channels, buffering, destination of data |
| 1007 | (file, network, process)...) |
| 1008 | \end_layout |
| 1009 | |
| 1010 | \begin_layout Itemize |
| 1011 | Control the recording of events (start, stop, pause the trace) |
| 1012 | \end_layout |
| 1013 | |
| 1014 | \begin_layout Itemize |
| 1015 | Create tracepoints (on dynamic tracers) and control which tracepoints are |
| 1016 | activated (some may be at trace level, others might only permit system |
| 1017 | level) |
| 1018 | \end_layout |
| 1019 | |
| 1020 | \begin_layout Subsection |
| 1021 | Trace control API |
| 1022 | \end_layout |
| 1023 | |
| 1024 | \begin_layout Itemize |
| 1025 | List the static tracepoints available on a system |
| 1026 | \end_layout |
| 1027 | |
| 1028 | \begin_deeper |
| 1029 | \begin_layout Standard |
| 1030 | These may be static tracepoints (active or inactive) or dynamic tracepoints |
| 1031 | (active or proposed). |
| 1032 | \end_layout |
| 1033 | |
| 1034 | \end_deeper |
| 1035 | \begin_layout Itemize |
| 1036 | Add a new dynamic tracepoint |
| 1037 | \end_layout |
| 1038 | |
| 1039 | \begin_layout Itemize |
| 1040 | Activate a tracepoint |
| 1041 | \end_layout |
| 1042 | |
| 1043 | \begin_layout Itemize |
| 1044 | Deactivate a tracepoint |
| 1045 | \end_layout |
| 1046 | |
| 1047 | \begin_layout Itemize |
| 1048 | List available probes |
| 1049 | \end_layout |
| 1050 | |
| 1051 | \begin_layout Itemize |
| 1052 | Connect a probe to a tracepoint |
| 1053 | \end_layout |
| 1054 | |
| 1055 | \begin_layout Itemize |
| 1056 | Start tracing |
| 1057 | \end_layout |
| 1058 | |
| 1059 | \begin_layout Itemize |
| 1060 | Stop tracing |
| 1061 | \end_layout |
| 1062 | |
| 1063 | \begin_layout Itemize |
| 1064 | \begin_inset Note Greyedout |
| 1065 | status open |
| 1066 | |
| 1067 | \begin_layout Standard |
| 1068 | others missing... |
| 1069 | \end_layout |
| 1070 | |
| 1071 | \end_inset |
| 1072 | |
| 1073 | |
| 1074 | \end_layout |
| 1075 | |
| 1076 | \end_body |
| 1077 | \end_document |