| Junio C Hamano | 11f1537 | 2019-03-07 03:17:00 | [diff] [blame^] | 1 | <?xml version="1.0" encoding="UTF-8"?> |
| 2 | <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" |
| 3 | "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd"> |
| 4 | <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en"> |
| 5 | <head> |
| 6 | <meta http-equiv="Content-Type" content="application/xhtml+xml; charset=UTF-8" /> |
| 7 | <meta name="generator" content="AsciiDoc 8.6.10" /> |
| 8 | <title>Trace2 API</title> |
| 9 | <style type="text/css"> |
| 10 | /* Shared CSS for AsciiDoc xhtml11 and html5 backends */ |
| 11 | |
| 12 | /* Default font. */ |
| 13 | body { |
| 14 | font-family: Georgia,serif; |
| 15 | } |
| 16 | |
| 17 | /* Title font. */ |
| 18 | h1, h2, h3, h4, h5, h6, |
| 19 | div.title, caption.title, |
| 20 | thead, p.table.header, |
| 21 | #toctitle, |
| 22 | #author, #revnumber, #revdate, #revremark, |
| 23 | #footer { |
| 24 | font-family: Arial,Helvetica,sans-serif; |
| 25 | } |
| 26 | |
| 27 | body { |
| 28 | margin: 1em 5% 1em 5%; |
| 29 | } |
| 30 | |
| 31 | a { |
| 32 | color: blue; |
| 33 | text-decoration: underline; |
| 34 | } |
| 35 | a:visited { |
| 36 | color: fuchsia; |
| 37 | } |
| 38 | |
| 39 | em { |
| 40 | font-style: italic; |
| 41 | color: navy; |
| 42 | } |
| 43 | |
| 44 | strong { |
| 45 | font-weight: bold; |
| 46 | color: #083194; |
| 47 | } |
| 48 | |
| 49 | h1, h2, h3, h4, h5, h6 { |
| 50 | color: #527bbd; |
| 51 | margin-top: 1.2em; |
| 52 | margin-bottom: 0.5em; |
| 53 | line-height: 1.3; |
| 54 | } |
| 55 | |
| 56 | h1, h2, h3 { |
| 57 | border-bottom: 2px solid silver; |
| 58 | } |
| 59 | h2 { |
| 60 | padding-top: 0.5em; |
| 61 | } |
| 62 | h3 { |
| 63 | float: left; |
| 64 | } |
| 65 | h3 + * { |
| 66 | clear: left; |
| 67 | } |
| 68 | h5 { |
| 69 | font-size: 1.0em; |
| 70 | } |
| 71 | |
| 72 | div.sectionbody { |
| 73 | margin-left: 0; |
| 74 | } |
| 75 | |
| 76 | hr { |
| 77 | border: 1px solid silver; |
| 78 | } |
| 79 | |
| 80 | p { |
| 81 | margin-top: 0.5em; |
| 82 | margin-bottom: 0.5em; |
| 83 | } |
| 84 | |
| 85 | ul, ol, li > p { |
| 86 | margin-top: 0; |
| 87 | } |
| 88 | ul > li { color: #aaa; } |
| 89 | ul > li > * { color: black; } |
| 90 | |
| 91 | .monospaced, code, pre { |
| 92 | font-family: "Courier New", Courier, monospace; |
| 93 | font-size: inherit; |
| 94 | color: navy; |
| 95 | padding: 0; |
| 96 | margin: 0; |
| 97 | } |
| 98 | pre { |
| 99 | white-space: pre-wrap; |
| 100 | } |
| 101 | |
| 102 | #author { |
| 103 | color: #527bbd; |
| 104 | font-weight: bold; |
| 105 | font-size: 1.1em; |
| 106 | } |
| 107 | #email { |
| 108 | } |
| 109 | #revnumber, #revdate, #revremark { |
| 110 | } |
| 111 | |
| 112 | #footer { |
| 113 | font-size: small; |
| 114 | border-top: 2px solid silver; |
| 115 | padding-top: 0.5em; |
| 116 | margin-top: 4.0em; |
| 117 | } |
| 118 | #footer-text { |
| 119 | float: left; |
| 120 | padding-bottom: 0.5em; |
| 121 | } |
| 122 | #footer-badges { |
| 123 | float: right; |
| 124 | padding-bottom: 0.5em; |
| 125 | } |
| 126 | |
| 127 | #preamble { |
| 128 | margin-top: 1.5em; |
| 129 | margin-bottom: 1.5em; |
| 130 | } |
| 131 | div.imageblock, div.exampleblock, div.verseblock, |
| 132 | div.quoteblock, div.literalblock, div.listingblock, div.sidebarblock, |
| 133 | div.admonitionblock { |
| 134 | margin-top: 1.0em; |
| 135 | margin-bottom: 1.5em; |
| 136 | } |
| 137 | div.admonitionblock { |
| 138 | margin-top: 2.0em; |
| 139 | margin-bottom: 2.0em; |
| 140 | margin-right: 10%; |
| 141 | color: #606060; |
| 142 | } |
| 143 | |
| 144 | div.content { /* Block element content. */ |
| 145 | padding: 0; |
| 146 | } |
| 147 | |
| 148 | /* Block element titles. */ |
| 149 | div.title, caption.title { |
| 150 | color: #527bbd; |
| 151 | font-weight: bold; |
| 152 | text-align: left; |
| 153 | margin-top: 1.0em; |
| 154 | margin-bottom: 0.5em; |
| 155 | } |
| 156 | div.title + * { |
| 157 | margin-top: 0; |
| 158 | } |
| 159 | |
| 160 | td div.title:first-child { |
| 161 | margin-top: 0.0em; |
| 162 | } |
| 163 | div.content div.title:first-child { |
| 164 | margin-top: 0.0em; |
| 165 | } |
| 166 | div.content + div.title { |
| 167 | margin-top: 0.0em; |
| 168 | } |
| 169 | |
| 170 | div.sidebarblock > div.content { |
| 171 | background: #ffffee; |
| 172 | border: 1px solid #dddddd; |
| 173 | border-left: 4px solid #f0f0f0; |
| 174 | padding: 0.5em; |
| 175 | } |
| 176 | |
| 177 | div.listingblock > div.content { |
| 178 | border: 1px solid #dddddd; |
| 179 | border-left: 5px solid #f0f0f0; |
| 180 | background: #f8f8f8; |
| 181 | padding: 0.5em; |
| 182 | } |
| 183 | |
| 184 | div.quoteblock, div.verseblock { |
| 185 | padding-left: 1.0em; |
| 186 | margin-left: 1.0em; |
| 187 | margin-right: 10%; |
| 188 | border-left: 5px solid #f0f0f0; |
| 189 | color: #888; |
| 190 | } |
| 191 | |
| 192 | div.quoteblock > div.attribution { |
| 193 | padding-top: 0.5em; |
| 194 | text-align: right; |
| 195 | } |
| 196 | |
| 197 | div.verseblock > pre.content { |
| 198 | font-family: inherit; |
| 199 | font-size: inherit; |
| 200 | } |
| 201 | div.verseblock > div.attribution { |
| 202 | padding-top: 0.75em; |
| 203 | text-align: left; |
| 204 | } |
| 205 | /* DEPRECATED: Pre version 8.2.7 verse style literal block. */ |
| 206 | div.verseblock + div.attribution { |
| 207 | text-align: left; |
| 208 | } |
| 209 | |
| 210 | div.admonitionblock .icon { |
| 211 | vertical-align: top; |
| 212 | font-size: 1.1em; |
| 213 | font-weight: bold; |
| 214 | text-decoration: underline; |
| 215 | color: #527bbd; |
| 216 | padding-right: 0.5em; |
| 217 | } |
| 218 | div.admonitionblock td.content { |
| 219 | padding-left: 0.5em; |
| 220 | border-left: 3px solid #dddddd; |
| 221 | } |
| 222 | |
| 223 | div.exampleblock > div.content { |
| 224 | border-left: 3px solid #dddddd; |
| 225 | padding-left: 0.5em; |
| 226 | } |
| 227 | |
| 228 | div.imageblock div.content { padding-left: 0; } |
| 229 | span.image img { border-style: none; vertical-align: text-bottom; } |
| 230 | a.image:visited { color: white; } |
| 231 | |
| 232 | dl { |
| 233 | margin-top: 0.8em; |
| 234 | margin-bottom: 0.8em; |
| 235 | } |
| 236 | dt { |
| 237 | margin-top: 0.5em; |
| 238 | margin-bottom: 0; |
| 239 | font-style: normal; |
| 240 | color: navy; |
| 241 | } |
| 242 | dd > *:first-child { |
| 243 | margin-top: 0.1em; |
| 244 | } |
| 245 | |
| 246 | ul, ol { |
| 247 | list-style-position: outside; |
| 248 | } |
| 249 | ol.arabic { |
| 250 | list-style-type: decimal; |
| 251 | } |
| 252 | ol.loweralpha { |
| 253 | list-style-type: lower-alpha; |
| 254 | } |
| 255 | ol.upperalpha { |
| 256 | list-style-type: upper-alpha; |
| 257 | } |
| 258 | ol.lowerroman { |
| 259 | list-style-type: lower-roman; |
| 260 | } |
| 261 | ol.upperroman { |
| 262 | list-style-type: upper-roman; |
| 263 | } |
| 264 | |
| 265 | div.compact ul, div.compact ol, |
| 266 | div.compact p, div.compact p, |
| 267 | div.compact div, div.compact div { |
| 268 | margin-top: 0.1em; |
| 269 | margin-bottom: 0.1em; |
| 270 | } |
| 271 | |
| 272 | tfoot { |
| 273 | font-weight: bold; |
| 274 | } |
| 275 | td > div.verse { |
| 276 | white-space: pre; |
| 277 | } |
| 278 | |
| 279 | div.hdlist { |
| 280 | margin-top: 0.8em; |
| 281 | margin-bottom: 0.8em; |
| 282 | } |
| 283 | div.hdlist tr { |
| 284 | padding-bottom: 15px; |
| 285 | } |
| 286 | dt.hdlist1.strong, td.hdlist1.strong { |
| 287 | font-weight: bold; |
| 288 | } |
| 289 | td.hdlist1 { |
| 290 | vertical-align: top; |
| 291 | font-style: normal; |
| 292 | padding-right: 0.8em; |
| 293 | color: navy; |
| 294 | } |
| 295 | td.hdlist2 { |
| 296 | vertical-align: top; |
| 297 | } |
| 298 | div.hdlist.compact tr { |
| 299 | margin: 0; |
| 300 | padding-bottom: 0; |
| 301 | } |
| 302 | |
| 303 | .comment { |
| 304 | background: yellow; |
| 305 | } |
| 306 | |
| 307 | .footnote, .footnoteref { |
| 308 | font-size: 0.8em; |
| 309 | } |
| 310 | |
| 311 | span.footnote, span.footnoteref { |
| 312 | vertical-align: super; |
| 313 | } |
| 314 | |
| 315 | #footnotes { |
| 316 | margin: 20px 0 20px 0; |
| 317 | padding: 7px 0 0 0; |
| 318 | } |
| 319 | |
| 320 | #footnotes div.footnote { |
| 321 | margin: 0 0 5px 0; |
| 322 | } |
| 323 | |
| 324 | #footnotes hr { |
| 325 | border: none; |
| 326 | border-top: 1px solid silver; |
| 327 | height: 1px; |
| 328 | text-align: left; |
| 329 | margin-left: 0; |
| 330 | width: 20%; |
| 331 | min-width: 100px; |
| 332 | } |
| 333 | |
| 334 | div.colist td { |
| 335 | padding-right: 0.5em; |
| 336 | padding-bottom: 0.3em; |
| 337 | vertical-align: top; |
| 338 | } |
| 339 | div.colist td img { |
| 340 | margin-top: 0.3em; |
| 341 | } |
| 342 | |
| 343 | @media print { |
| 344 | #footer-badges { display: none; } |
| 345 | } |
| 346 | |
| 347 | #toc { |
| 348 | margin-bottom: 2.5em; |
| 349 | } |
| 350 | |
| 351 | #toctitle { |
| 352 | color: #527bbd; |
| 353 | font-size: 1.1em; |
| 354 | font-weight: bold; |
| 355 | margin-top: 1.0em; |
| 356 | margin-bottom: 0.1em; |
| 357 | } |
| 358 | |
| 359 | div.toclevel0, div.toclevel1, div.toclevel2, div.toclevel3, div.toclevel4 { |
| 360 | margin-top: 0; |
| 361 | margin-bottom: 0; |
| 362 | } |
| 363 | div.toclevel2 { |
| 364 | margin-left: 2em; |
| 365 | font-size: 0.9em; |
| 366 | } |
| 367 | div.toclevel3 { |
| 368 | margin-left: 4em; |
| 369 | font-size: 0.9em; |
| 370 | } |
| 371 | div.toclevel4 { |
| 372 | margin-left: 6em; |
| 373 | font-size: 0.9em; |
| 374 | } |
| 375 | |
| 376 | span.aqua { color: aqua; } |
| 377 | span.black { color: black; } |
| 378 | span.blue { color: blue; } |
| 379 | span.fuchsia { color: fuchsia; } |
| 380 | span.gray { color: gray; } |
| 381 | span.green { color: green; } |
| 382 | span.lime { color: lime; } |
| 383 | span.maroon { color: maroon; } |
| 384 | span.navy { color: navy; } |
| 385 | span.olive { color: olive; } |
| 386 | span.purple { color: purple; } |
| 387 | span.red { color: red; } |
| 388 | span.silver { color: silver; } |
| 389 | span.teal { color: teal; } |
| 390 | span.white { color: white; } |
| 391 | span.yellow { color: yellow; } |
| 392 | |
| 393 | span.aqua-background { background: aqua; } |
| 394 | span.black-background { background: black; } |
| 395 | span.blue-background { background: blue; } |
| 396 | span.fuchsia-background { background: fuchsia; } |
| 397 | span.gray-background { background: gray; } |
| 398 | span.green-background { background: green; } |
| 399 | span.lime-background { background: lime; } |
| 400 | span.maroon-background { background: maroon; } |
| 401 | span.navy-background { background: navy; } |
| 402 | span.olive-background { background: olive; } |
| 403 | span.purple-background { background: purple; } |
| 404 | span.red-background { background: red; } |
| 405 | span.silver-background { background: silver; } |
| 406 | span.teal-background { background: teal; } |
| 407 | span.white-background { background: white; } |
| 408 | span.yellow-background { background: yellow; } |
| 409 | |
| 410 | span.big { font-size: 2em; } |
| 411 | span.small { font-size: 0.6em; } |
| 412 | |
| 413 | span.underline { text-decoration: underline; } |
| 414 | span.overline { text-decoration: overline; } |
| 415 | span.line-through { text-decoration: line-through; } |
| 416 | |
| 417 | div.unbreakable { page-break-inside: avoid; } |
| 418 | |
| 419 | |
| 420 | /* |
| 421 | * xhtml11 specific |
| 422 | * |
| 423 | * */ |
| 424 | |
| 425 | div.tableblock { |
| 426 | margin-top: 1.0em; |
| 427 | margin-bottom: 1.5em; |
| 428 | } |
| 429 | div.tableblock > table { |
| 430 | border: 3px solid #527bbd; |
| 431 | } |
| 432 | thead, p.table.header { |
| 433 | font-weight: bold; |
| 434 | color: #527bbd; |
| 435 | } |
| 436 | p.table { |
| 437 | margin-top: 0; |
| 438 | } |
| 439 | /* Because the table frame attribute is overriden by CSS in most browsers. */ |
| 440 | div.tableblock > table[frame="void"] { |
| 441 | border-style: none; |
| 442 | } |
| 443 | div.tableblock > table[frame="hsides"] { |
| 444 | border-left-style: none; |
| 445 | border-right-style: none; |
| 446 | } |
| 447 | div.tableblock > table[frame="vsides"] { |
| 448 | border-top-style: none; |
| 449 | border-bottom-style: none; |
| 450 | } |
| 451 | |
| 452 | |
| 453 | /* |
| 454 | * html5 specific |
| 455 | * |
| 456 | * */ |
| 457 | |
| 458 | table.tableblock { |
| 459 | margin-top: 1.0em; |
| 460 | margin-bottom: 1.5em; |
| 461 | } |
| 462 | thead, p.tableblock.header { |
| 463 | font-weight: bold; |
| 464 | color: #527bbd; |
| 465 | } |
| 466 | p.tableblock { |
| 467 | margin-top: 0; |
| 468 | } |
| 469 | table.tableblock { |
| 470 | border-width: 3px; |
| 471 | border-spacing: 0px; |
| 472 | border-style: solid; |
| 473 | border-color: #527bbd; |
| 474 | border-collapse: collapse; |
| 475 | } |
| 476 | th.tableblock, td.tableblock { |
| 477 | border-width: 1px; |
| 478 | padding: 4px; |
| 479 | border-style: solid; |
| 480 | border-color: #527bbd; |
| 481 | } |
| 482 | |
| 483 | table.tableblock.frame-topbot { |
| 484 | border-left-style: hidden; |
| 485 | border-right-style: hidden; |
| 486 | } |
| 487 | table.tableblock.frame-sides { |
| 488 | border-top-style: hidden; |
| 489 | border-bottom-style: hidden; |
| 490 | } |
| 491 | table.tableblock.frame-none { |
| 492 | border-style: hidden; |
| 493 | } |
| 494 | |
| 495 | th.tableblock.halign-left, td.tableblock.halign-left { |
| 496 | text-align: left; |
| 497 | } |
| 498 | th.tableblock.halign-center, td.tableblock.halign-center { |
| 499 | text-align: center; |
| 500 | } |
| 501 | th.tableblock.halign-right, td.tableblock.halign-right { |
| 502 | text-align: right; |
| 503 | } |
| 504 | |
| 505 | th.tableblock.valign-top, td.tableblock.valign-top { |
| 506 | vertical-align: top; |
| 507 | } |
| 508 | th.tableblock.valign-middle, td.tableblock.valign-middle { |
| 509 | vertical-align: middle; |
| 510 | } |
| 511 | th.tableblock.valign-bottom, td.tableblock.valign-bottom { |
| 512 | vertical-align: bottom; |
| 513 | } |
| 514 | |
| 515 | |
| 516 | /* |
| 517 | * manpage specific |
| 518 | * |
| 519 | * */ |
| 520 | |
| 521 | body.manpage h1 { |
| 522 | padding-top: 0.5em; |
| 523 | padding-bottom: 0.5em; |
| 524 | border-top: 2px solid silver; |
| 525 | border-bottom: 2px solid silver; |
| 526 | } |
| 527 | body.manpage h2 { |
| 528 | border-style: none; |
| 529 | } |
| 530 | body.manpage div.sectionbody { |
| 531 | margin-left: 3em; |
| 532 | } |
| 533 | |
| 534 | @media print { |
| 535 | body.manpage div#toc { display: none; } |
| 536 | } |
| 537 | |
| 538 | |
| 539 | </style> |
| 540 | <script type="text/javascript"> |
| 541 | /*<+'])'); |
| 584 | // Function that scans the DOM tree for header elements (the DOM2 |
| 585 | // nodeIterator API would be a better technique but not supported by all |
| 586 | // browsers). |
| 587 | var iterate = function (el) { |
| 588 | for (var i = el.firstChild; i != null; i = i.nextSibling) { |
| 589 | if (i.nodeType == 1 /* Node.ELEMENT_NODE */) { |
| 590 | var mo = re.exec(i.tagName); |
| 591 | if (mo && (i.getAttribute("class") || i.getAttribute("className")) != "float") { |
| 592 | result[result.length] = new TocEntry(i, getText(i), mo[1]-1); |
| 593 | } |
| 594 | iterate(i); |
| 595 | } |
| 596 | } |
| 597 | } |
| 598 | iterate(el); |
| 599 | return result; |
| 600 | } |
| 601 | |
| 602 | var toc = document.getElementById("toc"); |
| 603 | if (!toc) { |
| 604 | return; |
| 605 | } |
| 606 | |
| 607 | // Delete existing TOC entries in case we're reloading the TOC. |
| 608 | var tocEntriesToRemove = []; |
| 609 | var i; |
| 610 | for (i = 0; i < toc.childNodes.length; i++) { |
| 611 | var entry = toc.childNodes[i]; |
| 612 | if (entry.nodeName.toLowerCase() == 'div' |
| 613 | && entry.getAttribute("class") |
| 614 | && entry.getAttribute("class").match(/^toclevel/)) |
| 615 | tocEntriesToRemove.push(entry); |
| 616 | } |
| 617 | for (i = 0; i < tocEntriesToRemove.length; i++) { |
| 618 | toc.removeChild(tocEntriesToRemove[i]); |
| 619 | } |
| 620 | |
| 621 | // Rebuild TOC entries. |
| 622 | var entries = tocEntries(document.getElementById("content"), toclevels); |
| 623 | for (var i = 0; i < entries.length; ++i) { |
| 624 | var entry = entries[i]; |
| 625 | if (entry.element.id == "") |
| 626 | entry.element.id = "_toc_" + i; |
| 627 | var a = document.createElement("a"); |
| 628 | a.href = "#" + entry.element.id; |
| 629 | a.appendChild(document.createTextNode(entry.text)); |
| 630 | var div = document.createElement("div"); |
| 631 | div.appendChild(a); |
| 632 | div.className = "toclevel" + entry.toclevel; |
| 633 | toc.appendChild(div); |
| 634 | } |
| 635 | if (entries.length == 0) |
| 636 | toc.parentNode.removeChild(toc); |
| 637 | }, |
| 638 | |
| 639 | |
| 640 | ///////////////////////////////////////////////////////////////////// |
| 641 | // Footnotes generator |
| 642 | ///////////////////////////////////////////////////////////////////// |
| 643 | |
| 644 | /* Based on footnote generation code from: |
| 645 | * http://www.brandspankingnew.net/archive/2005/07/format_footnote.html |
| 646 | */ |
| 647 | |
| 648 | footnotes: function () { |
| 649 | // Delete existing footnote entries in case we're reloading the footnodes. |
| 650 | var i; |
| 651 | var noteholder = document.getElementById("footnotes"); |
| 652 | if (!noteholder) { |
| 653 | return; |
| 654 | } |
| 655 | var entriesToRemove = []; |
| 656 | for (i = 0; i < noteholder.childNodes.length; i++) { |
| 657 | var entry = noteholder.childNodes[i]; |
| 658 | if (entry.nodeName.toLowerCase() == 'div' && entry.getAttribute("class") == "footnote") |
| 659 | entriesToRemove.push(entry); |
| 660 | } |
| 661 | for (i = 0; i < entriesToRemove.length; i++) { |
| 662 | noteholder.removeChild(entriesToRemove[i]); |
| 663 | } |
| 664 | |
| 665 | // Rebuild footnote entries. |
| 666 | var cont = document.getElementById("content"); |
| 667 | var spans = cont.getElementsByTagName("span"); |
| 668 | var refs = {}; |
| 669 | var n = 0; |
| 670 | for (i=0; i<spans.length; i++) { |
| 671 | if (spans[i].className == "footnote") { |
| 672 | n++; |
| 673 | var note = spans[i].getAttribute("data-note"); |
| 674 | if (!note) { |
| 675 | // Use [\s\S] in place of . so multi-line matches work. |
| 676 | // Because JavaScript has no s (dotall) regex flag. |
| 677 | note = spans[i].innerHTML.match(/\s*\[([\s\S]*)]\s*/)[1]; |
| 678 | spans[i].innerHTML = |
| 679 | "[<a id='_footnoteref_" + n + "' href='#_footnote_" + n + |
| 680 | "' title='View footnote' class='footnote'>" + n + "</a>]"; |
| 681 | spans[i].setAttribute("data-note", note); |
| 682 | } |
| 683 | noteholder.innerHTML += |
| 684 | "<div class='footnote' id='_footnote_" + n + "'>" + |
| 685 | "<a href='#_footnoteref_" + n + "' title='Return to text'>" + |
| 686 | n + "</a>. " + note + "</div>"; |
| 687 | var id =spans[i].getAttribute("id"); |
| 688 | if (id != null) refs["#"+id] = n; |
| 689 | } |
| 690 | } |
| 691 | if (n == 0) |
| 692 | noteholder.parentNode.removeChild(noteholder); |
| 693 | else { |
| 694 | // Process footnoterefs. |
| 695 | for (i=0; i<spans.length; i++) { |
| 696 | if (spans[i].className == "footnoteref") { |
| 697 | var href = spans[i].getElementsByTagName("a")[0].getAttribute("href"); |
| 698 | href = href.match(/#.*/)[0]; // Because IE return full URL. |
| 699 | n = refs[href]; |
| 700 | spans[i].innerHTML = |
| 701 | "[<a href='#_footnote_" + n + |
| 702 | "' title='View footnote' class='footnote'>" + n + "</a>]"; |
| 703 | } |
| 704 | } |
| 705 | } |
| 706 | }, |
| 707 | |
| 708 | install: function(toclevels) { |
| 709 | var timerId; |
| 710 | |
| 711 | function reinstall() { |
| 712 | asciidoc.footnotes(); |
| 713 | if (toclevels) { |
| 714 | asciidoc.toc(toclevels); |
| 715 | } |
| 716 | } |
| 717 | |
| 718 | function reinstallAndRemoveTimer() { |
| 719 | clearInterval(timerId); |
| 720 | reinstall(); |
| 721 | } |
| 722 | |
| 723 | timerId = setInterval(reinstall, 500); |
| 724 | if (document.addEventListener) |
| 725 | document.addEventListener("DOMContentLoaded", reinstallAndRemoveTimer, false); |
| 726 | else |
| 727 | window.onload = reinstallAndRemoveTimer; |
| 728 | } |
| 729 | |
| 730 | } |
| 731 | asciidoc.install(); |
| 732 | /*]]>*/ |
| 733 | </script> |
| 734 | </head> |
| 735 | <body class="article"> |
| 736 | <div id="header"> |
| 737 | <h1>Trace2 API</h1> |
| 738 | </div> |
| 739 | <div id="content"> |
| 740 | <div id="preamble"> |
| 741 | <div class="sectionbody"> |
| 742 | <div class="paragraph"><p>The Trace2 API can be used to print debug, performance, and telemetry |
| 743 | information to stderr or a file. The Trace2 feature is inactive unless |
| 744 | explicitly enabled by enabling one or more Trace2 Targets.</p></div> |
| 745 | <div class="paragraph"><p>The Trace2 API is intended to replace the existing (Trace1) |
| 746 | printf-style tracing provided by the existing <code>GIT_TRACE</code> and |
| 747 | <code>GIT_TRACE_PERFORMANCE</code> facilities. During initial implementation, |
| 748 | Trace2 and Trace1 may operate in parallel.</p></div> |
| 749 | <div class="paragraph"><p>The Trace2 API defines a set of high-level messages with known fields, |
| 750 | such as (<code>start</code>: <code>argv</code>) and (<code>exit</code>: {<code>exit-code</code>, <code>elapsed-time</code>}).</p></div> |
| 751 | <div class="paragraph"><p>Trace2 instrumentation throughout the Git code base sends Trace2 |
| 752 | messages to the enabled Trace2 Targets. Targets transform these |
| 753 | messages content into purpose-specific formats and write events to |
| 754 | their data streams. In this manner, the Trace2 API can drive |
| 755 | many different types of analysis.</p></div> |
| 756 | <div class="paragraph"><p>Targets are defined using a VTable allowing easy extension to other |
| 757 | formats in the future. This might be used to define a binary format, |
| 758 | for example.</p></div> |
| 759 | </div> |
| 760 | </div> |
| 761 | <div class="sect1"> |
| 762 | <h2 id="_trace2_targets">Trace2 Targets</h2> |
| 763 | <div class="sectionbody"> |
| 764 | <div class="paragraph"><p>Trace2 defines the following set of Trace2 Targets. |
| 765 | Format details are given in a later section.</p></div> |
| 766 | <div class="dlist"><dl> |
| 767 | <dt class="hdlist1"> |
| 768 | <code>GIT_TR2</code> (NORMAL) |
| 769 | </dt> |
| 770 | <dd> |
| 771 | <p> |
| 772 | a simple printf format like GIT_TRACE. |
| 773 | </p> |
| 774 | <div class="listingblock"> |
| 775 | <div class="content"> |
| 776 | <pre><code>$ export GIT_TR2=~/log.normal |
| 777 | $ git version |
| 778 | git version 2.20.1.155.g426c96fcdb</code></pre> |
| 779 | </div></div> |
| 780 | <div class="listingblock"> |
| 781 | <div class="content"> |
| 782 | <pre><code>$ cat ~/log.normal |
| 783 | 12:28:42.620009 common-main.c:38 version 2.20.1.155.g426c96fcdb |
| 784 | 12:28:42.620989 common-main.c:39 start git version |
| 785 | 12:28:42.621101 git.c:432 cmd_name version (version) |
| 786 | 12:28:42.621215 git.c:662 exit elapsed:0.001227 code:0 |
| 787 | 12:28:42.621250 trace2/tr2_tgt_normal.c:124 atexit elapsed:0.001265 code:0</code></pre> |
| 788 | </div></div> |
| 789 | </dd> |
| 790 | <dt class="hdlist1"> |
| 791 | <code>GIT_TR2_PERF</code> (PERF) |
| 792 | </dt> |
| 793 | <dd> |
| 794 | <p> |
| 795 | a column-based format to replace GIT_TRACE_PERFORMANCE suitable for |
| 796 | development and testing, possibly to complement tools like gprof. |
| 797 | </p> |
| 798 | <div class="listingblock"> |
| 799 | <div class="content"> |
| 800 | <pre><code>$ export GIT_TR2_PERF=~/log.perf |
| 801 | $ git version |
| 802 | git version 2.20.1.155.g426c96fcdb</code></pre> |
| 803 | </div></div> |
| 804 | <div class="listingblock"> |
| 805 | <div class="content"> |
| 806 | <pre><code>$ cat ~/log.perf |
| 807 | 12:28:42.620675 common-main.c:38 | d0 | main | version | | | | | 2.20.1.155.g426c96fcdb |
| 808 | 12:28:42.621001 common-main.c:39 | d0 | main | start | | | | | git version |
| 809 | 12:28:42.621111 git.c:432 | d0 | main | cmd_name | | | | | version (version) |
| 810 | 12:28:42.621225 git.c:662 | d0 | main | exit | | 0.001227 | | | code:0 |
| 811 | 12:28:42.621259 trace2/tr2_tgt_perf.c:211 | d0 | main | atexit | | 0.001265 | | | code:0</code></pre> |
| 812 | </div></div> |
| 813 | </dd> |
| 814 | <dt class="hdlist1"> |
| 815 | <code>GIT_TR2_EVENT</code> (EVENT) |
| 816 | </dt> |
| 817 | <dd> |
| 818 | <p> |
| 819 | a JSON-based format of event data suitable for telemetry analysis. |
| 820 | </p> |
| 821 | <div class="listingblock"> |
| 822 | <div class="content"> |
| 823 | <pre><code>$ export GIT_TR2_EVENT=~/log.event |
| 824 | $ git version |
| 825 | git version 2.20.1.155.g426c96fcdb</code></pre> |
| 826 | </div></div> |
| 827 | <div class="listingblock"> |
| 828 | <div class="content"> |
| 829 | <pre><code>$ cat ~/log.event |
| 830 | {"event":"version","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.620713","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"} |
| 831 | {"event":"start","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621027","file":"common-main.c","line":39,"argv":["git","version"]} |
| 832 | {"event":"cmd_name","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621122","file":"git.c","line":432,"name":"version","hierarchy":"version"} |
| 833 | {"event":"exit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621236","file":"git.c","line":662,"t_abs":0.001227,"code":0} |
| 834 | {"event":"atexit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621268","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}</code></pre> |
| 835 | </div></div> |
| 836 | </dd> |
| 837 | </dl></div> |
| 838 | </div> |
| 839 | </div> |
| 840 | <div class="sect1"> |
| 841 | <h2 id="_enabling_a_target">Enabling a Target</h2> |
| 842 | <div class="sectionbody"> |
| 843 | <div class="paragraph"><p>A Trace2 Target is enabled when the corresponding environment variable |
| 844 | (<code>GIT_TR2</code>, <code>GIT_TR2_PERF</code>, or <code>GIT_TR2_EVENT</code>) is set. The following |
| 845 | values are recognized.</p></div> |
| 846 | <div class="dlist"><dl> |
| 847 | <dt class="hdlist1"> |
| 848 | <code>0</code> |
| 849 | </dt> |
| 850 | <dt class="hdlist1"> |
| 851 | <code>false</code> |
| 852 | </dt> |
| 853 | <dd> |
| 854 | <p> |
| 855 | Disables the target. |
| 856 | </p> |
| 857 | </dd> |
| 858 | <dt class="hdlist1"> |
| 859 | <code>1</code> |
| 860 | </dt> |
| 861 | <dt class="hdlist1"> |
| 862 | <code>true</code> |
| 863 | </dt> |
| 864 | <dd> |
| 865 | <p> |
| 866 | Enables the target and writes stream to <code>STDERR</code>. |
| 867 | </p> |
| 868 | </dd> |
| 869 | <dt class="hdlist1"> |
| 870 | <code>[2-9]</code> |
| 871 | </dt> |
| 872 | <dd> |
| 873 | <p> |
| 874 | Enables the target and writes to the already opened file descriptor. |
| 875 | </p> |
| 876 | </dd> |
| 877 | <dt class="hdlist1"> |
| 878 | <code><absolute-pathname></code> |
| 879 | </dt> |
| 880 | <dd> |
| 881 | <p> |
| 882 | Enables the target, opens and writes to the file in append mode. |
| 883 | </p> |
| 884 | </dd> |
| 885 | <dt class="hdlist1"> |
| 886 | <code>af_unix:[<socket_type>:]<absolute-pathname></code> |
| 887 | </dt> |
| 888 | <dd> |
| 889 | <p> |
| 890 | Enables the target, opens and writes to a Unix Domain Socket |
| 891 | (on platforms that support them). |
| 892 | </p> |
| 893 | <div class="paragraph"><p>Socket type can be either <code>stream</code> or <code>dgram</code>. If the socket type is |
| 894 | omitted, Git will try both.</p></div> |
| 895 | </dd> |
| 896 | </dl></div> |
| 897 | </div> |
| 898 | </div> |
| 899 | <div class="sect1"> |
| 900 | <h2 id="_trace2_api">Trace2 API</h2> |
| 901 | <div class="sectionbody"> |
| 902 | <div class="paragraph"><p>All public Trace2 functions and macros are defined in <code>trace2.h</code> and |
| 903 | <code>trace2.c</code>. All public symbols are prefixed with <code>trace2_</code>.</p></div> |
| 904 | <div class="paragraph"><p>There are no public Trace2 data structures.</p></div> |
| 905 | <div class="paragraph"><p>The Trace2 code also defines a set of private functions and data types |
| 906 | in the <code>trace2/</code> directory. These symbols are prefixed with <code>tr2_</code> |
| 907 | and should only be used by functions in <code>trace2.c</code>.</p></div> |
| 908 | </div> |
| 909 | </div> |
| 910 | <div class="sect1"> |
| 911 | <h2 id="_conventions_for_public_functions_and_macros">Conventions for Public Functions and Macros</h2> |
| 912 | <div class="sectionbody"> |
| 913 | <div class="paragraph"><p>The functions defined by the Trace2 API are declared and documented |
| 914 | in <code>trace2.h</code>. It defines the API functions and wrapper macros for |
| 915 | Trace2.</p></div> |
| 916 | <div class="paragraph"><p>Some functions have a <code>_fl()</code> suffix to indicate that they take <code>file</code> |
| 917 | and <code>line-number</code> arguments.</p></div> |
| 918 | <div class="paragraph"><p>Some functions have a <code>_va_fl()</code> suffix to indicate that they also |
| 919 | take a <code>va_list</code> argument.</p></div> |
| 920 | <div class="paragraph"><p>Some functions have a <code>_printf_fl()</code> suffix to indicate that they also |
| 921 | take a varargs argument.</p></div> |
| 922 | <div class="paragraph"><p>There are CPP wrapper macros and ifdefs to hide most of these details. |
| 923 | See <code>trace2.h</code> for more details. The following discussion will only |
| 924 | describe the simplified forms.</p></div> |
| 925 | </div> |
| 926 | </div> |
| 927 | <div class="sect1"> |
| 928 | <h2 id="_public_api">Public API</h2> |
| 929 | <div class="sectionbody"> |
| 930 | <div class="paragraph"><p>All Trace2 API functions send a messsage to all of the active |
| 931 | Trace2 Targets. This section describes the set of available |
| 932 | messages.</p></div> |
| 933 | <div class="paragraph"><p>It helps to divide these functions into groups for discussion |
| 934 | purposes.</p></div> |
| 935 | <div class="sect2"> |
| 936 | <h3 id="_basic_command_messages">Basic Command Messages</h3> |
| 937 | <div class="paragraph"><p>These are concerned with the lifetime of the overall git process.</p></div> |
| 938 | <div class="dlist"><dl> |
| 939 | <dt class="hdlist1"> |
| 940 | <code>void trace2_initialize()</code> |
| 941 | </dt> |
| 942 | <dd> |
| 943 | <p> |
| 944 | Determines if any Trace2 Targets should be enabled and |
| 945 | initializes the Trace2 facility. This includes starting the |
| 946 | elapsed time clocks and thread local storage (TLS). |
| 947 | </p> |
| 948 | <div class="paragraph"><p>This function emits a "version" message containing the version of git |
| 949 | and the Trace2 protocol.</p></div> |
| 950 | <div class="paragraph"><p>This function should be called from <code>main()</code> as early as possible in |
| 951 | the life of the process.</p></div> |
| 952 | </dd> |
| 953 | <dt class="hdlist1"> |
| 954 | <code>int trace2_is_enabled()</code> |
| 955 | </dt> |
| 956 | <dd> |
| 957 | <p> |
| 958 | Returns 1 if Trace2 is enabled (at least one target is |
| 959 | active). |
| 960 | </p> |
| 961 | </dd> |
| 962 | <dt class="hdlist1"> |
| 963 | <code>void trace2_cmd_start(int argc, const char **argv)</code> |
| 964 | </dt> |
| 965 | <dd> |
| 966 | <p> |
| 967 | Emits a "start" message containing the process command line |
| 968 | arguments. |
| 969 | </p> |
| 970 | </dd> |
| 971 | <dt class="hdlist1"> |
| 972 | <code>int trace2_cmd_exit(int exit_code)</code> |
| 973 | </dt> |
| 974 | <dd> |
| 975 | <p> |
| 976 | Emits an "exit" message containing the process exit-code and |
| 977 | elapsed time. |
| 978 | </p> |
| 979 | <div class="paragraph"><p>Returns the exit-code.</p></div> |
| 980 | </dd> |
| 981 | <dt class="hdlist1"> |
| 982 | <code>void trace2_cmd_error(const char *fmt, va_list ap)</code> |
| 983 | </dt> |
| 984 | <dd> |
| 985 | <p> |
| 986 | Emits an "error" message containing a formatted error message. |
| 987 | </p> |
| 988 | </dd> |
| 989 | <dt class="hdlist1"> |
| 990 | <code>void trace2_cmd_path(const char *pathname)</code> |
| 991 | </dt> |
| 992 | <dd> |
| 993 | <p> |
| 994 | Emits a "cmd_path" message with the full pathname of the |
| 995 | current process. |
| 996 | </p> |
| 997 | </dd> |
| 998 | </dl></div> |
| 999 | </div> |
| 1000 | <div class="sect2"> |
| 1001 | <h3 id="_command_detail_messages">Command Detail Messages</h3> |
| 1002 | <div class="paragraph"><p>These are concerned with describing the specific Git command |
| 1003 | after the command line, config, and environment are inspected.</p></div> |
| 1004 | <div class="dlist"><dl> |
| 1005 | <dt class="hdlist1"> |
| 1006 | <code>void trace2_cmd_name(const char *name)</code> |
| 1007 | </dt> |
| 1008 | <dd> |
| 1009 | <p> |
| 1010 | Emits a "cmd_name" message with the canonical name of the |
| 1011 | command, for example "status" or "checkout". |
| 1012 | </p> |
| 1013 | </dd> |
| 1014 | <dt class="hdlist1"> |
| 1015 | <code>void trace2_cmd_mode(const char *mode)</code> |
| 1016 | </dt> |
| 1017 | <dd> |
| 1018 | <p> |
| 1019 | Emits a "cmd_mode" message with a qualifier name to further |
| 1020 | describe the current git command. |
| 1021 | </p> |
| 1022 | <div class="paragraph"><p>This message is intended to be used with git commands having multiple |
| 1023 | major modes. For example, a "checkout" command can checkout a new |
| 1024 | branch or it can checkout a single file, so the checkout code could |
| 1025 | emit a cmd_mode message of "branch" or "file".</p></div> |
| 1026 | </dd> |
| 1027 | <dt class="hdlist1"> |
| 1028 | <code>void trace2_cmd_alias(const char *alias, const char **argv_expansion)</code> |
| 1029 | </dt> |
| 1030 | <dd> |
| 1031 | <p> |
| 1032 | Emits an "alias" message containing the alias used and the |
| 1033 | argument expansion. |
| 1034 | </p> |
| 1035 | </dd> |
| 1036 | <dt class="hdlist1"> |
| 1037 | <code>void trace2_def_param(const char *parameter, const char *value)</code> |
| 1038 | </dt> |
| 1039 | <dd> |
| 1040 | <p> |
| 1041 | Emits a "def_param" message containing a key/value pair. |
| 1042 | </p> |
| 1043 | <div class="paragraph"><p>This message is intended to report some global aspect of the current |
| 1044 | command, such as a configuration setting or command line switch that |
| 1045 | significantly affects program performance or behavior, such as |
| 1046 | <code>core.abbrev</code>, <code>status.showUntrackedFiles</code>, or <code>--no-ahead-behind</code>.</p></div> |
| 1047 | </dd> |
| 1048 | <dt class="hdlist1"> |
| 1049 | <code>void trace2_cmd_list_config()</code> |
| 1050 | </dt> |
| 1051 | <dd> |
| 1052 | <p> |
| 1053 | Emits a "def_param" messages for "important" configuration |
| 1054 | settings. |
| 1055 | </p> |
| 1056 | <div class="paragraph"><p>The environment variable <code>GIT_TR2_CONFIG_PARAMS</code> can be set to a |
| 1057 | list of patterns of important configuration settings, for example: |
| 1058 | <code>core.*,remote.*.url</code>. This function will iterate over all config |
| 1059 | settings and emit a "def_param" message for each match.</p></div> |
| 1060 | </dd> |
| 1061 | <dt class="hdlist1"> |
| 1062 | <code>void trace2_cmd_set_config(const char *key, const char *value)</code> |
| 1063 | </dt> |
| 1064 | <dd> |
| 1065 | <p> |
| 1066 | Emits a "def_param" message for a specific configuration |
| 1067 | setting IFF it matches the <code>GIT_TR2_CONFIG_PARAMS</code> pattern. |
| 1068 | </p> |
| 1069 | <div class="paragraph"><p>This is used to hook into <code>git_config_set()</code> and catch any |
| 1070 | configuration changes and update a value previously reported by |
| 1071 | <code>trace2_cmd_list_config()</code>.</p></div> |
| 1072 | </dd> |
| 1073 | <dt class="hdlist1"> |
| 1074 | <code>void trace2_def_repo(struct repository *repo)</code> |
| 1075 | </dt> |
| 1076 | <dd> |
| 1077 | <p> |
| 1078 | Registers a repository with the Trace2 layer. Assigns a |
| 1079 | unique "repo-id" to <code>repo->trace2_repo_id</code>. |
| 1080 | </p> |
| 1081 | <div class="paragraph"><p>Emits a "worktree" messages containing the repo-id and the worktree |
| 1082 | pathname.</p></div> |
| 1083 | <div class="paragraph"><p>Region and data messages (described later) may refer to this repo-id.</p></div> |
| 1084 | <div class="paragraph"><p>The main/top-level repository will have repo-id value 1 (aka "r1").</p></div> |
| 1085 | <div class="paragraph"><p>The repo-id field is in anticipation of future in-proc submodule |
| 1086 | repositories.</p></div> |
| 1087 | </dd> |
| 1088 | </dl></div> |
| 1089 | </div> |
| 1090 | <div class="sect2"> |
| 1091 | <h3 id="_child_process_messages">Child Process Messages</h3> |
| 1092 | <div class="paragraph"><p>These are concerned with the various spawned child processes, |
| 1093 | including shell scripts, git commands, editors, pagers, and hooks.</p></div> |
| 1094 | <div class="dlist"><dl> |
| 1095 | <dt class="hdlist1"> |
| 1096 | <code>void trace2_child_start(struct child_process *cmd)</code> |
| 1097 | </dt> |
| 1098 | <dd> |
| 1099 | <p> |
| 1100 | Emits a "child_start" message containing the "child-id", |
| 1101 | "child-argv", and "child-classification". |
| 1102 | </p> |
| 1103 | <div class="paragraph"><p>Before calling this, set <code>cmd->trace2_child_class</code> to a name |
| 1104 | describing the type of child process, for example "editor".</p></div> |
| 1105 | <div class="paragraph"><p>This function assigns a unique "child-id" to <code>cmd->trace2_child_id</code>. |
| 1106 | This field is used later during the "child_exit" message to associate |
| 1107 | it with the "child_start" message.</p></div> |
| 1108 | <div class="paragraph"><p>This function should be called before spawning the child process.</p></div> |
| 1109 | </dd> |
| 1110 | <dt class="hdlist1"> |
| 1111 | <code>void trace2_child_exit(struct child_proess *cmd, int child_exit_code)</code> |
| 1112 | </dt> |
| 1113 | <dd> |
| 1114 | <p> |
| 1115 | Emits a "child_exit" message containing the "child-id", |
| 1116 | the child’s elapsed time and exit-code. |
| 1117 | </p> |
| 1118 | <div class="paragraph"><p>The reported elapsed time includes the process creation overhead and |
| 1119 | time spend waiting for it to exit, so it may be slightly longer than |
| 1120 | the time reported by the child itself.</p></div> |
| 1121 | <div class="paragraph"><p>This function should be called after reaping the child process.</p></div> |
| 1122 | </dd> |
| 1123 | <dt class="hdlist1"> |
| 1124 | <code>int trace2_exec(const char *exe, const char **argv)</code> |
| 1125 | </dt> |
| 1126 | <dd> |
| 1127 | <p> |
| 1128 | Emits a "exec" message containing the "exec-id" and the |
| 1129 | argv of the new process. |
| 1130 | </p> |
| 1131 | <div class="paragraph"><p>This function should be called before calling one of the <code>exec()</code> |
| 1132 | variants, such as <code>execvp()</code>.</p></div> |
| 1133 | <div class="paragraph"><p>This function returns a unique "exec-id". This value is used later |
| 1134 | if the exec() fails and a "exec-result" message is necessary.</p></div> |
| 1135 | </dd> |
| 1136 | <dt class="hdlist1"> |
| 1137 | <code>void trace2_exec_result(int exec_id, int error_code)</code> |
| 1138 | </dt> |
| 1139 | <dd> |
| 1140 | <p> |
| 1141 | Emits a "exec_result" message containing the "exec-id" |
| 1142 | and the error code. |
| 1143 | </p> |
| 1144 | <div class="paragraph"><p>On Unix-based systems, <code>exec()</code> does not return if successful. |
| 1145 | This message is used to indicate that the <code>exec()</code> failed and |
| 1146 | that the current program is continuing.</p></div> |
| 1147 | </dd> |
| 1148 | </dl></div> |
| 1149 | </div> |
| 1150 | <div class="sect2"> |
| 1151 | <h3 id="_git_thread_messages">Git Thread Messages</h3> |
| 1152 | <div class="paragraph"><p>These messages are concerned with Git thread usage.</p></div> |
| 1153 | <div class="dlist"><dl> |
| 1154 | <dt class="hdlist1"> |
| 1155 | <code>void trace2_thread_start(const char *thread_name)</code> |
| 1156 | </dt> |
| 1157 | <dd> |
| 1158 | <p> |
| 1159 | Emits a "thread_start" message. |
| 1160 | </p> |
| 1161 | <div class="paragraph"><p>The <code>thread_name</code> field should be a descriptive name, such as the |
| 1162 | unique name of the thread-proc. A unique "thread-id" will be added |
| 1163 | to the name to uniquely identify thread instances.</p></div> |
| 1164 | <div class="paragraph"><p>Region and data messages (described later) may refer to this thread |
| 1165 | name.</p></div> |
| 1166 | <div class="paragraph"><p>This function must be called by the thread-proc of the new thread |
| 1167 | (so that TLS data is properly initialized) and not by the caller |
| 1168 | of <code>pthread_create()</code>.</p></div> |
| 1169 | </dd> |
| 1170 | <dt class="hdlist1"> |
| 1171 | <code>void trace2_thread_exit()</code> |
| 1172 | </dt> |
| 1173 | <dd> |
| 1174 | <p> |
| 1175 | Emits a "thread_exit" message containing the thread name |
| 1176 | and the thread elapsed time. |
| 1177 | </p> |
| 1178 | <div class="paragraph"><p>This function must be called by the thread-proc before it returns |
| 1179 | (so that the coorect TLS data is used and cleaned up. It should |
| 1180 | not be called by the caller of <code>pthread_join()</code>.</p></div> |
| 1181 | </dd> |
| 1182 | </dl></div> |
| 1183 | </div> |
| 1184 | <div class="sect2"> |
| 1185 | <h3 id="_region_and_data_messages">Region and Data Messages</h3> |
| 1186 | <div class="paragraph"><p>These are concerned with recording performance data |
| 1187 | over regions or spans of code.</p></div> |
| 1188 | <div class="dlist"><dl> |
| 1189 | <dt class="hdlist1"> |
| 1190 | <code>void trace2_region_enter(const char *category, const char *label, const struct repository *repo)</code> |
| 1191 | </dt> |
| 1192 | <dt class="hdlist1"> |
| 1193 | <code>void trace2_region_enter_printf(const char *category, const char *label, const struct repository *repo, const char *fmt, ...)</code> |
| 1194 | </dt> |
| 1195 | <dt class="hdlist1"> |
| 1196 | <code>void trace2_region_enter_printf_va(const char *category, const char *label, const struct repository *repo, const char *fmt, va_list ap)</code> |
| 1197 | </dt> |
| 1198 | <dd> |
| 1199 | <p> |
| 1200 | Emits a thread-relative "region_enter" message with optional |
| 1201 | printf string. |
| 1202 | </p> |
| 1203 | <div class="paragraph"><p>This function pushes a new region nesting stack level on the current |
| 1204 | thread and starts a clock for the new stack frame.</p></div> |
| 1205 | <div class="paragraph"><p>The <code>category</code> field is an arbitrary category name used to classify |
| 1206 | regions by feature area, such as "status" or "index". At this time |
| 1207 | it is only just printed along with the rest of the message. It may |
| 1208 | be used in the future to filter messages.</p></div> |
| 1209 | <div class="paragraph"><p>The <code>label</code> field is an arbitrary label used to describe the activity |
| 1210 | being started, such as "read_recursive" or "do_read_index".</p></div> |
| 1211 | <div class="paragraph"><p>The <code>repo</code> field, if set, will be used to get the "repo-id", so that |
| 1212 | recursive oerations can be attributed to the correct repository.</p></div> |
| 1213 | </dd> |
| 1214 | <dt class="hdlist1"> |
| 1215 | <code>void trace2_region_leave(const char *category, const char *label, const struct repository *repo)</code> |
| 1216 | </dt> |
| 1217 | <dt class="hdlist1"> |
| 1218 | <code>void trace2_region_leave_printf(const char *category, const char *label, const struct repository *repo, const char *fmt, ...)</code> |
| 1219 | </dt> |
| 1220 | <dt class="hdlist1"> |
| 1221 | <code>void trace2_region_leave_printf_va(const char *category, const char *label, const struct repository *repo, const char *fmt, va_list ap)</code> |
| 1222 | </dt> |
| 1223 | <dd> |
| 1224 | <p> |
| 1225 | Emits a thread-relative "region_leave" message with optional |
| 1226 | printf string. |
| 1227 | </p> |
| 1228 | <div class="paragraph"><p>This function pops the region nesting stack on the current thread |
| 1229 | and reports the elapsed time of the stack frame.</p></div> |
| 1230 | <div class="paragraph"><p>The <code>category</code>, <code>label</code>, and <code>repo</code> fields are the same as above. |
| 1231 | The <code>category</code> and <code>label</code> do not need to match the correpsonding |
| 1232 | "region_enter" message, but it makes the data stream easier to |
| 1233 | understand.</p></div> |
| 1234 | </dd> |
| 1235 | <dt class="hdlist1"> |
| 1236 | <code>void trace2_data_string(const char *category, const struct repository *repo, const char *key, const char * value)</code> |
| 1237 | </dt> |
| 1238 | <dt class="hdlist1"> |
| 1239 | <code>void trace2_data_intmax(const char *category, const struct repository *repo, const char *key, intmax value)</code> |
| 1240 | </dt> |
| 1241 | <dt class="hdlist1"> |
| 1242 | <code>void trace2_data_json(const char *category, const struct repository *repo, const char *key, const struct json_writer *jw)</code> |
| 1243 | </dt> |
| 1244 | <dd> |
| 1245 | <p> |
| 1246 | Emits a region- and thread-relative "data" or "data_json" message. |
| 1247 | </p> |
| 1248 | <div class="paragraph"><p>This is a key/value pair message containing information about the |
| 1249 | current thread, region stack, and repository. This could be used |
| 1250 | to print the number of files in a directory during a multi-threaded |
| 1251 | recursive tree walk.</p></div> |
| 1252 | </dd> |
| 1253 | <dt class="hdlist1"> |
| 1254 | <code>void trace2_printf(const char *fmt, ...)</code> |
| 1255 | </dt> |
| 1256 | <dt class="hdlist1"> |
| 1257 | <code>void trace2_printf_va(const char *fmt, va_list ap)</code> |
| 1258 | </dt> |
| 1259 | <dd> |
| 1260 | <p> |
| 1261 | Emits a region- and thread-relative "printf" message. |
| 1262 | </p> |
| 1263 | </dd> |
| 1264 | </dl></div> |
| 1265 | </div> |
| 1266 | </div> |
| 1267 | </div> |
| 1268 | <div class="sect1"> |
| 1269 | <h2 id="_trace2_target_formats">Trace2 Target Formats</h2> |
| 1270 | <div class="sectionbody"> |
| 1271 | <div class="sect2"> |
| 1272 | <h3 id="_normal_format">NORMAL Format</h3> |
| 1273 | <div class="paragraph"><p>NORMAL format is enabled when the <code>GIT_TR2</code> environment variable is |
| 1274 | set.</p></div> |
| 1275 | <div class="paragraph"><p>Events are written as lines of the form:</p></div> |
| 1276 | <div class="listingblock"> |
| 1277 | <div class="content"> |
| 1278 | <pre><code>[<time> SP <filename>:<line> SP+] <event-name> [[SP] <event-message>] LF</code></pre> |
| 1279 | </div></div> |
| 1280 | <div class="dlist"><dl> |
| 1281 | <dt class="hdlist1"> |
| 1282 | <code><event-name></code> |
| 1283 | </dt> |
| 1284 | <dd> |
| 1285 | <p> |
| 1286 | is the event name. |
| 1287 | </p> |
| 1288 | </dd> |
| 1289 | <dt class="hdlist1"> |
| 1290 | <code><event-message></code> |
| 1291 | </dt> |
| 1292 | <dd> |
| 1293 | <p> |
| 1294 | is a free-form printf message intended for human consumption. |
| 1295 | </p> |
| 1296 | <div class="paragraph"><p>Note that this may contain embedded LF or CRLF characters that are |
| 1297 | not escaped, so the event may spill across multiple lines.</p></div> |
| 1298 | </dd> |
| 1299 | </dl></div> |
| 1300 | <div class="paragraph"><p>If <code>GIT_TR2_BRIEF</code> is true, the <code>time</code>, <code>filename</code>, and <code>line</code> fields |
| 1301 | are omitted.</p></div> |
| 1302 | <div class="paragraph"><p>This target is intended to be more of a summary (like GIT_TRACE) and |
| 1303 | less detailed than the other targets. It ignores thread, region, and |
| 1304 | data messages, for example.</p></div> |
| 1305 | </div> |
| 1306 | <div class="sect2"> |
| 1307 | <h3 id="_perf_format">PERF Format</h3> |
| 1308 | <div class="paragraph"><p>PERF format is enabled when the <code>GIT_TR2_PERF</code> environment variable |
| 1309 | is set.</p></div> |
| 1310 | <div class="paragraph"><p>Events are written as lines of the form:</p></div> |
| 1311 | <div class="listingblock"> |
| 1312 | <div class="content"> |
| 1313 | <pre><code>[<time> SP <filename>:<line> SP+ |
| 1314 | BAR SP] d<depth> SP |
| 1315 | BAR SP <thread-name> SP+ |
| 1316 | BAR SP <event-name> SP+ |
| 1317 | BAR SP [r<repo-id>] SP+ |
| 1318 | BAR SP [<t_abs>] SP+ |
| 1319 | BAR SP [<t_rel>] SP+ |
| 1320 | BAR SP [<category>] SP+ |
| 1321 | BAR SP DOTS* <perf-event-message> |
| 1322 | LF</code></pre> |
| 1323 | </div></div> |
| 1324 | <div class="dlist"><dl> |
| 1325 | <dt class="hdlist1"> |
| 1326 | <code><depth></code> |
| 1327 | </dt> |
| 1328 | <dd> |
| 1329 | <p> |
| 1330 | is the git process depth. This is the number of parent |
| 1331 | git processes. A top-level git command has depth value "d0". |
| 1332 | A child of it has depth value "d1". A second level child |
| 1333 | has depth value "d2" and so on. |
| 1334 | </p> |
| 1335 | </dd> |
| 1336 | <dt class="hdlist1"> |
| 1337 | <code><thread-name></code> |
| 1338 | </dt> |
| 1339 | <dd> |
| 1340 | <p> |
| 1341 | is a unique name for the thread. The primary thread |
| 1342 | is called "main". Other thread names are of the form "th%d:%s" |
| 1343 | and include a unique number and the name of the thread-proc. |
| 1344 | </p> |
| 1345 | </dd> |
| 1346 | <dt class="hdlist1"> |
| 1347 | <code><event-name></code> |
| 1348 | </dt> |
| 1349 | <dd> |
| 1350 | <p> |
| 1351 | is the event name. |
| 1352 | </p> |
| 1353 | </dd> |
| 1354 | <dt class="hdlist1"> |
| 1355 | <code><repo-id></code> |
| 1356 | </dt> |
| 1357 | <dd> |
| 1358 | <p> |
| 1359 | when present, is a number indicating the repository |
| 1360 | in use. A <code>def_repo</code> event is emitted when a repository is |
| 1361 | opened. This defines the repo-id and associated worktree. |
| 1362 | Subsequent repo-specific events will reference this repo-id. |
| 1363 | </p> |
| 1364 | <div class="paragraph"><p>Currently, this is always "r1" for the main repository. |
| 1365 | This field is in anticipation of in-proc submodules in the future.</p></div> |
| 1366 | </dd> |
| 1367 | <dt class="hdlist1"> |
| 1368 | <code><t_abs></code> |
| 1369 | </dt> |
| 1370 | <dd> |
| 1371 | <p> |
| 1372 | when present, is the absolute time in seconds since the |
| 1373 | program started. |
| 1374 | </p> |
| 1375 | </dd> |
| 1376 | <dt class="hdlist1"> |
| 1377 | <code><t_rel></code> |
| 1378 | </dt> |
| 1379 | <dd> |
| 1380 | <p> |
| 1381 | when present, is time in seconds relative to the start of |
| 1382 | the current region. For a thread-exit event, it is the elapsed |
| 1383 | time of the thread. |
| 1384 | </p> |
| 1385 | </dd> |
| 1386 | <dt class="hdlist1"> |
| 1387 | <code><category></code> |
| 1388 | </dt> |
| 1389 | <dd> |
| 1390 | <p> |
| 1391 | is present on region and data events and is used to |
| 1392 | indicate a broad category, such as "index" or "status". |
| 1393 | </p> |
| 1394 | </dd> |
| 1395 | <dt class="hdlist1"> |
| 1396 | <code><perf-event-message></code> |
| 1397 | </dt> |
| 1398 | <dd> |
| 1399 | <p> |
| 1400 | is a free-form printf message intended for human consumption. |
| 1401 | </p> |
| 1402 | </dd> |
| 1403 | </dl></div> |
| 1404 | <div class="listingblock"> |
| 1405 | <div class="content"> |
| 1406 | <pre><code>15:33:33.532712 wt-status.c:2310 | d0 | main | region_enter | r1 | 0.126064 | | status | label:print |
| 1407 | 15:33:33.532712 wt-status.c:2331 | d0 | main | region_leave | r1 | 0.127568 | 0.001504 | status | label:print</code></pre> |
| 1408 | </div></div> |
| 1409 | <div class="paragraph"><p>If <code>GIT_TR2_PERF_BRIEF</code> is true, the <code>time</code>, <code>file</code>, and <code>line</code> |
| 1410 | fields are omitted.</p></div> |
| 1411 | <div class="listingblock"> |
| 1412 | <div class="content"> |
| 1413 | <pre><code>d0 | main | region_leave | r1 | 0.011717 | 0.009122 | index | label:preload</code></pre> |
| 1414 | </div></div> |
| 1415 | <div class="paragraph"><p>The PERF target is intended for interactive performance analysis |
| 1416 | during development and is quite noisy.</p></div> |
| 1417 | </div> |
| 1418 | <div class="sect2"> |
| 1419 | <h3 id="_event_format">EVENT Format</h3> |
| 1420 | <div class="paragraph"><p>EVENT format is enabled when the <code>GIT_TR2_EVENT</code> environment |
| 1421 | variable is set.</p></div> |
| 1422 | <div class="paragraph"><p>Each event is a JSON-object containing multiple key/value pairs |
| 1423 | written as a single line and followed by a LF.</p></div> |
| 1424 | <div class="listingblock"> |
| 1425 | <div class="content"> |
| 1426 | <pre><code>'{' <key> ':' <value> [',' <key> ':' <value>]* '}' LF</code></pre> |
| 1427 | </div></div> |
| 1428 | <div class="paragraph"><p>Some key/value pairs are common to all events and some are |
| 1429 | event-specific.</p></div> |
| 1430 | <div class="sect3"> |
| 1431 | <h4 id="_common_key_value_pairs">Common Key/Value Pairs</h4> |
| 1432 | <div class="paragraph"><p>The following key/value pairs are common to all events:</p></div> |
| 1433 | <div class="listingblock"> |
| 1434 | <div class="content"> |
| 1435 | <pre><code>{ |
| 1436 | "event":"version", |
| 1437 | "sid":"1547659722619736-11614", |
| 1438 | "thread":"main", |
| 1439 | "time":"2019-01-16 17:28:42.620713", |
| 1440 | "file":"common-main.c", |
| 1441 | "line":38, |
| 1442 | ... |
| 1443 | }</code></pre> |
| 1444 | </div></div> |
| 1445 | <div class="dlist"><dl> |
| 1446 | <dt class="hdlist1"> |
| 1447 | <code>"event":<event></code> |
| 1448 | </dt> |
| 1449 | <dd> |
| 1450 | <p> |
| 1451 | is the event name. |
| 1452 | </p> |
| 1453 | </dd> |
| 1454 | <dt class="hdlist1"> |
| 1455 | <code>"sid":<sid></code> |
| 1456 | </dt> |
| 1457 | <dd> |
| 1458 | <p> |
| 1459 | is the session-id. This is a unique string to identify the |
| 1460 | process instance to allow all events emitted by a process to |
| 1461 | be identified. A session-id is used instead of a PID because |
| 1462 | PIDs are recycled by the OS. For child git processes, the |
| 1463 | session-id is prepended with the session-id of the parent git |
| 1464 | process to allow parent-child relationships to be identified |
| 1465 | during post-processing. |
| 1466 | </p> |
| 1467 | </dd> |
| 1468 | <dt class="hdlist1"> |
| 1469 | <code>"thread":<thread></code> |
| 1470 | </dt> |
| 1471 | <dd> |
| 1472 | <p> |
| 1473 | is the thread name. |
| 1474 | </p> |
| 1475 | </dd> |
| 1476 | <dt class="hdlist1"> |
| 1477 | <code>"time":<time></code> |
| 1478 | </dt> |
| 1479 | <dd> |
| 1480 | <p> |
| 1481 | is the UTC time of the event. |
| 1482 | </p> |
| 1483 | </dd> |
| 1484 | <dt class="hdlist1"> |
| 1485 | <code>"file":<filename></code> |
| 1486 | </dt> |
| 1487 | <dd> |
| 1488 | <p> |
| 1489 | is source file generating the event. |
| 1490 | </p> |
| 1491 | </dd> |
| 1492 | <dt class="hdlist1"> |
| 1493 | <code>"line":<line-number></code> |
| 1494 | </dt> |
| 1495 | <dd> |
| 1496 | <p> |
| 1497 | is the integer source line number generating the event. |
| 1498 | </p> |
| 1499 | </dd> |
| 1500 | <dt class="hdlist1"> |
| 1501 | <code>"repo":<repo-id></code> |
| 1502 | </dt> |
| 1503 | <dd> |
| 1504 | <p> |
| 1505 | when present, is the integer repo-id as described previously. |
| 1506 | </p> |
| 1507 | </dd> |
| 1508 | </dl></div> |
| 1509 | <div class="paragraph"><p>If <code>GIT_TR2_EVENT_BRIEF</code> is true, the <code>file</code> and <code>line</code> fields are omitted |
| 1510 | from all events and the <code>time</code> field is only present on the "start" and |
| 1511 | "atexit" events.</p></div> |
| 1512 | </div> |
| 1513 | <div class="sect3"> |
| 1514 | <h4 id="_event_specific_key_value_pairs">Event-Specific Key/Value Pairs</h4> |
| 1515 | <div class="dlist"><dl> |
| 1516 | <dt class="hdlist1"> |
| 1517 | <code>"version"</code> |
| 1518 | </dt> |
| 1519 | <dd> |
| 1520 | <p> |
| 1521 | This event gives the version of the executable and the EVENT format. |
| 1522 | </p> |
| 1523 | <div class="listingblock"> |
| 1524 | <div class="content"> |
| 1525 | <pre><code>{ |
| 1526 | "event":"version", |
| 1527 | ... |
| 1528 | "evt":"1", # EVENT format version |
| 1529 | "exe":"2.20.1.155.g426c96fcdb" # git version |
| 1530 | }</code></pre> |
| 1531 | </div></div> |
| 1532 | </dd> |
| 1533 | <dt class="hdlist1"> |
| 1534 | <code>"start"</code> |
| 1535 | </dt> |
| 1536 | <dd> |
| 1537 | <p> |
| 1538 | This event contains the complete argv received by main(). |
| 1539 | </p> |
| 1540 | <div class="listingblock"> |
| 1541 | <div class="content"> |
| 1542 | <pre><code>{ |
| 1543 | "event":"start", |
| 1544 | ... |
| 1545 | "argv":["git","version"] |
| 1546 | }</code></pre> |
| 1547 | </div></div> |
| 1548 | </dd> |
| 1549 | <dt class="hdlist1"> |
| 1550 | <code>"exit"</code> |
| 1551 | </dt> |
| 1552 | <dd> |
| 1553 | <p> |
| 1554 | This event is emitted when git calls <code>exit()</code>. |
| 1555 | </p> |
| 1556 | <div class="listingblock"> |
| 1557 | <div class="content"> |
| 1558 | <pre><code>{ |
| 1559 | "event":"exit", |
| 1560 | ... |
| 1561 | "t_abs":0.001227, # elapsed time in seconds |
| 1562 | "code":0 # exit code |
| 1563 | }</code></pre> |
| 1564 | </div></div> |
| 1565 | </dd> |
| 1566 | <dt class="hdlist1"> |
| 1567 | <code>"atexit"</code> |
| 1568 | </dt> |
| 1569 | <dd> |
| 1570 | <p> |
| 1571 | This event is emitted by the Trace2 <code>atexit</code> routine during |
| 1572 | final shutdown. It should be the last event emitted by the |
| 1573 | process. |
| 1574 | </p> |
| 1575 | <div class="paragraph"><p>(The elapsed time reported here is greater than the time reported in |
| 1576 | the "exit" event because it runs after all other atexit tasks have |
| 1577 | completed.)</p></div> |
| 1578 | <div class="listingblock"> |
| 1579 | <div class="content"> |
| 1580 | <pre><code>{ |
| 1581 | "event":"atexit", |
| 1582 | ... |
| 1583 | "t_abs":0.001227, # elapsed time in seconds |
| 1584 | "code":0 # exit code |
| 1585 | }</code></pre> |
| 1586 | </div></div> |
| 1587 | </dd> |
| 1588 | <dt class="hdlist1"> |
| 1589 | <code>"signal"</code> |
| 1590 | </dt> |
| 1591 | <dd> |
| 1592 | <p> |
| 1593 | This event is emitted when the program is terminated by a user |
| 1594 | signal. Depending on the platform, the signal event may |
| 1595 | prevent the "atexit" event from being generated. |
| 1596 | </p> |
| 1597 | <div class="listingblock"> |
| 1598 | <div class="content"> |
| 1599 | <pre><code>{ |
| 1600 | "event":"signal", |
| 1601 | ... |
| 1602 | "t_abs":0.001227, # elapsed time in seconds |
| 1603 | "signal":13 # SIGTERM, SIGINT, etc. |
| 1604 | }</code></pre> |
| 1605 | </div></div> |
| 1606 | </dd> |
| 1607 | <dt class="hdlist1"> |
| 1608 | <code>"error"</code> |
| 1609 | </dt> |
| 1610 | <dd> |
| 1611 | <p> |
| 1612 | This event is emitted when one of the <code>error()</code>, <code>die()</code>, |
| 1613 | or <code>usage()</code> functions are called. |
| 1614 | </p> |
| 1615 | <div class="listingblock"> |
| 1616 | <div class="content"> |
| 1617 | <pre><code>{ |
| 1618 | "event":"error", |
| 1619 | ... |
| 1620 | "msg":"invalid option: --cahced", # formatted error message |
| 1621 | "fmt":"invalid option: %s" # error format string |
| 1622 | }</code></pre> |
| 1623 | </div></div> |
| 1624 | <div class="paragraph"><p>The error event may be emitted more than once. The format string |
| 1625 | allows post-processors to group errors by type without worrying |
| 1626 | about specific error arguments.</p></div> |
| 1627 | </dd> |
| 1628 | <dt class="hdlist1"> |
| 1629 | <code>"cmd_path"</code> |
| 1630 | </dt> |
| 1631 | <dd> |
| 1632 | <p> |
| 1633 | This event contains the discovered full path of the git |
| 1634 | executable (on platforms that are configured to resolve it). |
| 1635 | </p> |
| 1636 | <div class="listingblock"> |
| 1637 | <div class="content"> |
| 1638 | <pre><code>{ |
| 1639 | "event":"cmd_path", |
| 1640 | ... |
| 1641 | "path":"C:/work/gfw/git.exe" |
| 1642 | }</code></pre> |
| 1643 | </div></div> |
| 1644 | </dd> |
| 1645 | <dt class="hdlist1"> |
| 1646 | <code>"cmd_name"</code> |
| 1647 | </dt> |
| 1648 | <dd> |
| 1649 | <p> |
| 1650 | This event contains the command name for this git process |
| 1651 | and the hierarchy of commands from parent git processes. |
| 1652 | </p> |
| 1653 | <div class="listingblock"> |
| 1654 | <div class="content"> |
| 1655 | <pre><code>{ |
| 1656 | "event":"cmd_name", |
| 1657 | ... |
| 1658 | "name":"pack-objects", |
| 1659 | "hierarchy":"push/pack-objects" |
| 1660 | }</code></pre> |
| 1661 | </div></div> |
| 1662 | <div class="paragraph"><p>Normally, the "name" field contains the canonical name of the |
| 1663 | command. When a canonical name is not available, one of |
| 1664 | these special values are used:</p></div> |
| 1665 | <div class="listingblock"> |
| 1666 | <div class="content"> |
| 1667 | <pre><code>"_query_" # "git --html-path" |
| 1668 | "_run_dashed_" # when "git foo" tries to run "git-foo" |
| 1669 | "_run_shell_alias_" # alias expansion to a shell command |
| 1670 | "_run_git_alias_" # alias expansion to a git command |
| 1671 | "_usage_" # usage error</code></pre> |
| 1672 | </div></div> |
| 1673 | </dd> |
| 1674 | <dt class="hdlist1"> |
| 1675 | <code>"cmd_mode"</code> |
| 1676 | </dt> |
| 1677 | <dd> |
| 1678 | <p> |
| 1679 | This event, when present, describes the command variant This |
| 1680 | event may be emitted more than once. |
| 1681 | </p> |
| 1682 | <div class="listingblock"> |
| 1683 | <div class="content"> |
| 1684 | <pre><code>{ |
| 1685 | "event":"cmd_mode", |
| 1686 | ... |
| 1687 | "name":"branch" |
| 1688 | }</code></pre> |
| 1689 | </div></div> |
| 1690 | <div class="paragraph"><p>The "name" field is an arbitrary string to describe the command mode. |
| 1691 | For example, checkout can checkout a branch or an individual file. |
| 1692 | And these variations typically have different performance |
| 1693 | characteristics that are not comparable.</p></div> |
| 1694 | </dd> |
| 1695 | <dt class="hdlist1"> |
| 1696 | <code>"alias"</code> |
| 1697 | </dt> |
| 1698 | <dd> |
| 1699 | <p> |
| 1700 | This event is present when an alias is expanded. |
| 1701 | </p> |
| 1702 | <div class="listingblock"> |
| 1703 | <div class="content"> |
| 1704 | <pre><code>{ |
| 1705 | "event":"alias", |
| 1706 | ... |
| 1707 | "alias":"l", # registered alias |
| 1708 | "argv":["log","--graph"] # alias expansion |
| 1709 | }</code></pre> |
| 1710 | </div></div> |
| 1711 | </dd> |
| 1712 | <dt class="hdlist1"> |
| 1713 | <code>"child_start"</code> |
| 1714 | </dt> |
| 1715 | <dd> |
| 1716 | <p> |
| 1717 | This event describes a child process that is about to be |
| 1718 | spawned. |
| 1719 | </p> |
| 1720 | <div class="listingblock"> |
| 1721 | <div class="content"> |
| 1722 | <pre><code>{ |
| 1723 | "event":"child_start", |
| 1724 | ... |
| 1725 | "child_id":2, |
| 1726 | "child_class":"?", |
| 1727 | "use_shell":false, |
| 1728 | "argv":["git","rev-list","--objects","--stdin","--not","--all","--quiet"] |
| 1729 | |
| 1730 | "hook_name":"<hook_name>" # present when child_class is "hook" |
| 1731 | "cd":"<path>" # present when cd is required |
| 1732 | }</code></pre> |
| 1733 | </div></div> |
| 1734 | <div class="paragraph"><p>The "child_id" field can be used to match this child_start with the |
| 1735 | corresponding child_exit event.</p></div> |
| 1736 | <div class="paragraph"><p>The "child_class" field is a rough classification, such as "editor", |
| 1737 | "pager", "transport/*", and "hook". Unclassified children are classified |
| 1738 | with "?".</p></div> |
| 1739 | </dd> |
| 1740 | <dt class="hdlist1"> |
| 1741 | <code>"child_exit"</code> |
| 1742 | </dt> |
| 1743 | <dd> |
| 1744 | <p> |
| 1745 | This event is generated after the current process has returned |
| 1746 | from the waitpid() and collected the exit information from the |
| 1747 | child. |
| 1748 | </p> |
| 1749 | <div class="listingblock"> |
| 1750 | <div class="content"> |
| 1751 | <pre><code>{ |
| 1752 | "event":"child_exit", |
| 1753 | ... |
| 1754 | "child_id":2, |
| 1755 | "pid":14708, # child PID |
| 1756 | "code":0, # child exit-code |
| 1757 | "t_rel":0.110605 # observed run-time of child process |
| 1758 | }</code></pre> |
| 1759 | </div></div> |
| 1760 | <div class="paragraph"><p>Note that the session-id of the child process is not available to |
| 1761 | the current/spawning process, so the child’s PID is reported here as |
| 1762 | a hint for post-processing. (But it is only a hint because the child |
| 1763 | proces may be a shell script which doesn’t have a session-id.)</p></div> |
| 1764 | <div class="paragraph"><p>Note that the <code>t_rel</code> field contains the observed run time in seconds |
| 1765 | for the child process (starting before the fork/exec/spawn and |
| 1766 | stopping after the waitpid() and includes OS process creation overhead). |
| 1767 | So this time will be slightly larger than the atexit time reported by |
| 1768 | the child process itself.</p></div> |
| 1769 | </dd> |
| 1770 | <dt class="hdlist1"> |
| 1771 | <code>"exec"</code> |
| 1772 | </dt> |
| 1773 | <dd> |
| 1774 | <p> |
| 1775 | This event is generated before git attempts to <code>exec()</code> |
| 1776 | another command rather than starting a child process. |
| 1777 | </p> |
| 1778 | <div class="listingblock"> |
| 1779 | <div class="content"> |
| 1780 | <pre><code>{ |
| 1781 | "event":"exec", |
| 1782 | ... |
| 1783 | "exec_id":0, |
| 1784 | "exe":"git", |
| 1785 | "argv":["foo", "bar"] |
| 1786 | }</code></pre> |
| 1787 | </div></div> |
| 1788 | <div class="paragraph"><p>The "exec_id" field is a command-unique id and is only useful if the |
| 1789 | <code>exec()</code> fails and a corresponding exec_result event is generated.</p></div> |
| 1790 | </dd> |
| 1791 | <dt class="hdlist1"> |
| 1792 | <code>"exec_result"</code> |
| 1793 | </dt> |
| 1794 | <dd> |
| 1795 | <p> |
| 1796 | This event is generated if the <code>exec()</code> fails and control |
| 1797 | returns to the current git command. |
| 1798 | </p> |
| 1799 | <div class="listingblock"> |
| 1800 | <div class="content"> |
| 1801 | <pre><code>{ |
| 1802 | "event":"exec_result", |
| 1803 | ... |
| 1804 | "exec_id":0, |
| 1805 | "code":1 # error code (errno) from exec() |
| 1806 | }</code></pre> |
| 1807 | </div></div> |
| 1808 | </dd> |
| 1809 | <dt class="hdlist1"> |
| 1810 | <code>"thread_start"</code> |
| 1811 | </dt> |
| 1812 | <dd> |
| 1813 | <p> |
| 1814 | This event is generated when a thread is started. It is |
| 1815 | generated from <strong>within</strong> the new thread’s thread-proc (for TLS |
| 1816 | reasons). |
| 1817 | </p> |
| 1818 | <div class="listingblock"> |
| 1819 | <div class="content"> |
| 1820 | <pre><code>{ |
| 1821 | "event":"thread_start", |
| 1822 | ... |
| 1823 | "thread":"th02:preload_thread" # thread name |
| 1824 | }</code></pre> |
| 1825 | </div></div> |
| 1826 | </dd> |
| 1827 | <dt class="hdlist1"> |
| 1828 | <code>"thread_exit"</code> |
| 1829 | </dt> |
| 1830 | <dd> |
| 1831 | <p> |
| 1832 | This event is generated when a thread exits. It is generated |
| 1833 | from <strong>within</strong> the thread’s thread-proc (for TLS reasons). |
| 1834 | </p> |
| 1835 | <div class="listingblock"> |
| 1836 | <div class="content"> |
| 1837 | <pre><code>{ |
| 1838 | "event":"thread_exit", |
| 1839 | ... |
| 1840 | "thread":"th02:preload_thread", # thread name |
| 1841 | "t_rel":0.007328 # thread elapsed time |
| 1842 | }</code></pre> |
| 1843 | </div></div> |
| 1844 | </dd> |
| 1845 | <dt class="hdlist1"> |
| 1846 | <code>"def_param"</code> |
| 1847 | </dt> |
| 1848 | <dd> |
| 1849 | <p> |
| 1850 | This event is generated to log a global parameter. |
| 1851 | </p> |
| 1852 | <div class="listingblock"> |
| 1853 | <div class="content"> |
| 1854 | <pre><code>{ |
| 1855 | "event":"def_param", |
| 1856 | ... |
| 1857 | "param":"core.abbrev", |
| 1858 | "value":"7" |
| 1859 | }</code></pre> |
| 1860 | </div></div> |
| 1861 | </dd> |
| 1862 | <dt class="hdlist1"> |
| 1863 | <code>"def_repo"</code> |
| 1864 | </dt> |
| 1865 | <dd> |
| 1866 | <p> |
| 1867 | This event defines a repo-id and associates it with the root |
| 1868 | of the worktree. |
| 1869 | </p> |
| 1870 | <div class="listingblock"> |
| 1871 | <div class="content"> |
| 1872 | <pre><code>{ |
| 1873 | "event":"def_repo", |
| 1874 | ... |
| 1875 | "repo":1, |
| 1876 | "worktree":"/Users/jeffhost/work/gfw" |
| 1877 | }</code></pre> |
| 1878 | </div></div> |
| 1879 | <div class="paragraph"><p>As stated earlier, the repo-id is currently always 1, so there will |
| 1880 | only be one def_repo event. Later, if in-proc submodules are |
| 1881 | supported, a def_repo event should be emitted for each submodule |
| 1882 | visited.</p></div> |
| 1883 | </dd> |
| 1884 | <dt class="hdlist1"> |
| 1885 | <code>"region_enter"</code> |
| 1886 | </dt> |
| 1887 | <dd> |
| 1888 | <p> |
| 1889 | This event is generated when entering a region. |
| 1890 | </p> |
| 1891 | <div class="listingblock"> |
| 1892 | <div class="content"> |
| 1893 | <pre><code>{ |
| 1894 | "event":"region_enter", |
| 1895 | ... |
| 1896 | "repo":1, # optional |
| 1897 | "nesting":1, # current region stack depth |
| 1898 | "category":"index", # optional |
| 1899 | "label":"do_read_index", # optional |
| 1900 | "msg":".git/index" # optional |
| 1901 | }</code></pre> |
| 1902 | </div></div> |
| 1903 | <div class="paragraph"><p>The <code>category</code> field may be used in a future enhancement to |
| 1904 | do category-based filtering.</p></div> |
| 1905 | <div class="paragraph"><p>The <code>GIT_TR2_EVENT_NESTING</code> environment variable can be used to |
| 1906 | filter deeply nested regions and data events. It defaults to "2".</p></div> |
| 1907 | </dd> |
| 1908 | <dt class="hdlist1"> |
| 1909 | <code>"region_leave"</code> |
| 1910 | </dt> |
| 1911 | <dd> |
| 1912 | <p> |
| 1913 | This event is generated when leaving a region. |
| 1914 | </p> |
| 1915 | <div class="listingblock"> |
| 1916 | <div class="content"> |
| 1917 | <pre><code>{ |
| 1918 | "event":"region_leave", |
| 1919 | ... |
| 1920 | "repo":1, # optional |
| 1921 | "t_rel":0.002876, # time spent in region in seconds |
| 1922 | "nesting":1, # region stack depth |
| 1923 | "category":"index", # optional |
| 1924 | "label":"do_read_index", # optional |
| 1925 | "msg":".git/index" # optional |
| 1926 | }</code></pre> |
| 1927 | </div></div> |
| 1928 | </dd> |
| 1929 | <dt class="hdlist1"> |
| 1930 | <code>"data"</code> |
| 1931 | </dt> |
| 1932 | <dd> |
| 1933 | <p> |
| 1934 | This event is generated to log a thread- and region-local |
| 1935 | key/value pair. |
| 1936 | </p> |
| 1937 | <div class="listingblock"> |
| 1938 | <div class="content"> |
| 1939 | <pre><code>{ |
| 1940 | "event":"data", |
| 1941 | ... |
| 1942 | "repo":1, # optional |
| 1943 | "t_abs":0.024107, # absolute elapsed time |
| 1944 | "t_rel":0.001031, # elapsed time in region/thread |
| 1945 | "nesting":2, # region stack depth |
| 1946 | "category":"index", |
| 1947 | "key":"read/cache_nr", |
| 1948 | "value":"3552" |
| 1949 | }</code></pre> |
| 1950 | </div></div> |
| 1951 | <div class="paragraph"><p>The "value" field may be an integer or a string.</p></div> |
| 1952 | </dd> |
| 1953 | <dt class="hdlist1"> |
| 1954 | <code>"data-json"</code> |
| 1955 | </dt> |
| 1956 | <dd> |
| 1957 | <p> |
| 1958 | This event is generated to log a pre-formatted JSON string |
| 1959 | containing structured data. |
| 1960 | </p> |
| 1961 | <div class="listingblock"> |
| 1962 | <div class="content"> |
| 1963 | <pre><code>{ |
| 1964 | "event":"data_json", |
| 1965 | ... |
| 1966 | "repo":1, # optional |
| 1967 | "t_abs":0.015905, |
| 1968 | "t_rel":0.015905, |
| 1969 | "nesting":1, |
| 1970 | "category":"process", |
| 1971 | "key":"windows/ancestry", |
| 1972 | "value":["bash.exe","bash.exe"] |
| 1973 | }</code></pre> |
| 1974 | </div></div> |
| 1975 | </dd> |
| 1976 | </dl></div> |
| 1977 | </div> |
| 1978 | </div> |
| 1979 | </div> |
| 1980 | </div> |
| 1981 | <div class="sect1"> |
| 1982 | <h2 id="_example_trace2_api_usage">Example Trace2 API Usage</h2> |
| 1983 | <div class="sectionbody"> |
| 1984 | <div class="paragraph"><p>Here is a hypothetical usage of the Trace2 API showing the intended |
| 1985 | usage (without worrying about the actual Git details).</p></div> |
| 1986 | <div class="dlist"><dl> |
| 1987 | <dt class="hdlist1"> |
| 1988 | Initialization |
| 1989 | </dt> |
| 1990 | <dd> |
| 1991 | <p> |
| 1992 | Initialization happens in <code>main()</code>. Behind the scenes, an |
| 1993 | <code>atexit</code> and <code>signal</code> handler are registered. |
| 1994 | </p> |
| 1995 | <div class="listingblock"> |
| 1996 | <div class="content"> |
| 1997 | <pre><code>int main(int argc, const char **argv) |
| 1998 | { |
| 1999 | int exit_code; |
| 2000 | |
| 2001 | trace2_initialize(); |
| 2002 | trace2_cmd_start(argv); |
| 2003 | |
| 2004 | exit_code = cmd_main(argc, argv); |
| 2005 | |
| 2006 | trace2_cmd_exit(exit_code); |
| 2007 | |
| 2008 | return exit_code; |
| 2009 | }</code></pre> |
| 2010 | </div></div> |
| 2011 | </dd> |
| 2012 | <dt class="hdlist1"> |
| 2013 | Command Details |
| 2014 | </dt> |
| 2015 | <dd> |
| 2016 | <p> |
| 2017 | After the basics are established, additional command |
| 2018 | information can be sent to Trace2 as it is discovered. |
| 2019 | </p> |
| 2020 | <div class="listingblock"> |
| 2021 | <div class="content"> |
| 2022 | <pre><code>int cmd_checkout(int argc, const char **argv) |
| 2023 | { |
| 2024 | trace2_cmd_name("checkout"); |
| 2025 | trace2_cmd_mode("branch"); |
| 2026 | trace2_def_repo(the_repository); |
| 2027 | |
| 2028 | // emit "def_param" messages for "interesting" config settings. |
| 2029 | trace2_cmd_list_config(); |
| 2030 | |
| 2031 | if (do_something()) |
| 2032 | trace2_cmd_error("Path '%s': cannot do something", path); |
| 2033 | |
| 2034 | return 0; |
| 2035 | }</code></pre> |
| 2036 | </div></div> |
| 2037 | </dd> |
| 2038 | <dt class="hdlist1"> |
| 2039 | Child Processes |
| 2040 | </dt> |
| 2041 | <dd> |
| 2042 | <p> |
| 2043 | Wrap code spawning child processes. |
| 2044 | </p> |
| 2045 | <div class="listingblock"> |
| 2046 | <div class="content"> |
| 2047 | <pre><code>void run_child(...) |
| 2048 | { |
| 2049 | int child_exit_code; |
| 2050 | struct child_process cmd = CHILD_PROCESS_INIT; |
| 2051 | ... |
| 2052 | cmd.trace2_child_class = "editor"; |
| 2053 | |
| 2054 | trace2_child_start(&cmd); |
| 2055 | child_exit_code = spawn_child_and_wait_for_it(); |
| 2056 | trace2_child_exit(&cmd, child_exit_code); |
| 2057 | }</code></pre> |
| 2058 | </div></div> |
| 2059 | <div class="paragraph"><p>For example, the following fetch command spawned ssh, index-pack, |
| 2060 | rev-list, and gc. This example also shows that fetch took |
| 2061 | 5.199 seconds and of that 4.932 was in ssh.</p></div> |
| 2062 | <div class="listingblock"> |
| 2063 | <div class="content"> |
| 2064 | <pre><code>$ export GIT_TR2_BRIEF=1 |
| 2065 | $ export GIT_TR2=~/log.normal |
| 2066 | $ git fetch origin |
| 2067 | ...</code></pre> |
| 2068 | </div></div> |
| 2069 | <div class="listingblock"> |
| 2070 | <div class="content"> |
| 2071 | <pre><code>$ cat ~/log.normal |
| 2072 | version 2.20.1.vfs.1.1.47.g534dbe1ad1 |
| 2073 | start git fetch origin |
| 2074 | worktree /Users/jeffhost/work/gfw |
| 2075 | cmd_name fetch (fetch) |
| 2076 | child_start[0] ssh git@github.com ... |
| 2077 | child_start[1] git index-pack ... |
| 2078 | ... (Trace2 events from child processes omitted) |
| 2079 | child_exit[1] pid:14707 code:0 elapsed:0.076353 |
| 2080 | child_exit[0] pid:14706 code:0 elapsed:4.931869 |
| 2081 | child_start[2] git rev-list ... |
| 2082 | ... (Trace2 events from child process omitted) |
| 2083 | child_exit[2] pid:14708 code:0 elapsed:0.110605 |
| 2084 | child_start[3] git gc --auto |
| 2085 | ... (Trace2 events from child process omitted) |
| 2086 | child_exit[3] pid:14709 code:0 elapsed:0.006240 |
| 2087 | exit elapsed:5.198503 code:0 |
| 2088 | atexit elapsed:5.198541 code:0</code></pre> |
| 2089 | </div></div> |
| 2090 | <div class="paragraph"><p>When a git process is a (direct or indirect) child of another |
| 2091 | git process, it inherits Trace2 context information. This |
| 2092 | allows the child to print the command hierarchy. This example |
| 2093 | shows gc as child[3] of fetch. When the gc process reports |
| 2094 | its name as "gc", it also reports the hierarchy as "fetch/gc". |
| 2095 | (In this example, trace2 messages from the child process is |
| 2096 | indented for clarity.)</p></div> |
| 2097 | <div class="listingblock"> |
| 2098 | <div class="content"> |
| 2099 | <pre><code>$ export GIT_TR2_BRIEF=1 |
| 2100 | $ export GIT_TR2=~/log.normal |
| 2101 | $ git fetch origin |
| 2102 | ...</code></pre> |
| 2103 | </div></div> |
| 2104 | <div class="listingblock"> |
| 2105 | <div class="content"> |
| 2106 | <pre><code>$ cat ~/log.normal |
| 2107 | version 2.20.1.160.g5676107ecd.dirty |
| 2108 | start git fetch official |
| 2109 | worktree /Users/jeffhost/work/gfw |
| 2110 | cmd_name fetch (fetch) |
| 2111 | ... |
| 2112 | child_start[3] git gc --auto |
| 2113 | version 2.20.1.160.g5676107ecd.dirty |
| 2114 | start /Users/jeffhost/work/gfw/git gc --auto |
| 2115 | worktree /Users/jeffhost/work/gfw |
| 2116 | cmd_name gc (fetch/gc) |
| 2117 | exit elapsed:0.001959 code:0 |
| 2118 | atexit elapsed:0.001997 code:0 |
| 2119 | child_exit[3] pid:20303 code:0 elapsed:0.007564 |
| 2120 | exit elapsed:3.868938 code:0 |
| 2121 | atexit elapsed:3.868970 code:0</code></pre> |
| 2122 | </div></div> |
| 2123 | </dd> |
| 2124 | <dt class="hdlist1"> |
| 2125 | Regions |
| 2126 | </dt> |
| 2127 | <dd> |
| 2128 | <p> |
| 2129 | Regions can be use to time an interesting section of code. |
| 2130 | </p> |
| 2131 | <div class="listingblock"> |
| 2132 | <div class="content"> |
| 2133 | <pre><code>void wt_status_collect(struct wt_status *s) |
| 2134 | { |
| 2135 | trace2_region_enter("status", "worktrees", s->repo); |
| 2136 | wt_status_collect_changes_worktree(s); |
| 2137 | trace2_region_leave("status", "worktrees", s->repo); |
| 2138 | |
| 2139 | trace2_region_enter("status", "index", s->repo); |
| 2140 | wt_status_collect_changes_index(s); |
| 2141 | trace2_region_leave("status", "index", s->repo); |
| 2142 | |
| 2143 | trace2_region_enter("status", "untracked", s->repo); |
| 2144 | wt_status_collect_untracked(s); |
| 2145 | trace2_region_leave("status", "untracked", s->repo); |
| 2146 | } |
| 2147 | |
| 2148 | void wt_status_print(struct wt_status *s) |
| 2149 | { |
| 2150 | trace2_region_enter("status", "print", s->repo); |
| 2151 | switch (s->status_format) { |
| 2152 | ... |
| 2153 | } |
| 2154 | trace2_region_leave("status", "print", s->repo); |
| 2155 | }</code></pre> |
| 2156 | </div></div> |
| 2157 | <div class="paragraph"><p>In this example, scanning for untracked files ran from +0.012568 to |
| 2158 | +0.027149 (since the process started) and took 0.014581 seconds.</p></div> |
| 2159 | <div class="listingblock"> |
| 2160 | <div class="content"> |
| 2161 | <pre><code>$ export GIT_TR2_PERF_BRIEF=1 |
| 2162 | $ export GIT_TR2_PERF=~/log.perf |
| 2163 | $ git status |
| 2164 | ... |
| 2165 | |
| 2166 | $ cat ~/log.perf |
| 2167 | d0 | main | version | | | | | 2.20.1.160.g5676107ecd.dirty |
| 2168 | d0 | main | start | | | | | git status |
| 2169 | d0 | main | def_repo | r1 | | | | worktree:/Users/jeffhost/work/gfw |
| 2170 | d0 | main | cmd_name | | | | | status (status) |
| 2171 | ... |
| 2172 | d0 | main | region_enter | r1 | 0.010988 | | status | label:worktrees |
| 2173 | d0 | main | region_leave | r1 | 0.011236 | 0.000248 | status | label:worktrees |
| 2174 | d0 | main | region_enter | r1 | 0.011260 | | status | label:index |
| 2175 | d0 | main | region_leave | r1 | 0.012542 | 0.001282 | status | label:index |
| 2176 | d0 | main | region_enter | r1 | 0.012568 | | status | label:untracked |
| 2177 | d0 | main | region_leave | r1 | 0.027149 | 0.014581 | status | label:untracked |
| 2178 | d0 | main | region_enter | r1 | 0.027411 | | status | label:print |
| 2179 | d0 | main | region_leave | r1 | 0.028741 | 0.001330 | status | label:print |
| 2180 | d0 | main | exit | | 0.028778 | | | code:0 |
| 2181 | d0 | main | atexit | | 0.028809 | | | code:0</code></pre> |
| 2182 | </div></div> |
| 2183 | <div class="paragraph"><p>Regions may be nested. This causes messages to be indented in the |
| 2184 | PERF target, for example. |
| 2185 | Elapsed times are relative to the start of the correpsonding nesting |
| 2186 | level as expected. For example, if we add region message to:</p></div> |
| 2187 | <div class="listingblock"> |
| 2188 | <div class="content"> |
| 2189 | <pre><code>static enum path_treatment read_directory_recursive(struct dir_struct *dir, |
| 2190 | struct index_state *istate, const char *base, int baselen, |
| 2191 | struct untracked_cache_dir *untracked, int check_only, |
| 2192 | int stop_at_first_file, const struct pathspec *pathspec) |
| 2193 | { |
| 2194 | enum path_treatment state, subdir_state, dir_state = path_none; |
| 2195 | |
| 2196 | trace2_region_enter_printf("dir", "read_recursive", NULL, "%.*s", baselen, base); |
| 2197 | ... |
| 2198 | trace2_region_leave_printf("dir", "read_recursive", NULL, "%.*s", baselen, base); |
| 2199 | return dir_state; |
| 2200 | }</code></pre> |
| 2201 | </div></div> |
| 2202 | <div class="paragraph"><p>We can further investigate the time spent scanning for untracked files.</p></div> |
| 2203 | <div class="listingblock"> |
| 2204 | <div class="content"> |
| 2205 | <pre><code>$ export GIT_TR2_PERF_BRIEF=1 |
| 2206 | $ export GIT_TR2_PERF=~/log.perf |
| 2207 | $ git status |
| 2208 | ... |
| 2209 | $ cat ~/log.perf |
| 2210 | d0 | main | version | | | | | 2.20.1.162.gb4ccea44db.dirty |
| 2211 | d0 | main | start | | | | | git status |
| 2212 | d0 | main | def_repo | r1 | | | | worktree:/Users/jeffhost/work/gfw |
| 2213 | d0 | main | cmd_name | | | | | status (status) |
| 2214 | ... |
| 2215 | d0 | main | region_enter | r1 | 0.015047 | | status | label:untracked |
| 2216 | d0 | main | region_enter | | 0.015132 | | dir | ..label:read_recursive |
| 2217 | d0 | main | region_enter | | 0.016341 | | dir | ....label:read_recursive vcs-svn/ |
| 2218 | d0 | main | region_leave | | 0.016422 | 0.000081 | dir | ....label:read_recursive vcs-svn/ |
| 2219 | d0 | main | region_enter | | 0.016446 | | dir | ....label:read_recursive xdiff/ |
| 2220 | d0 | main | region_leave | | 0.016522 | 0.000076 | dir | ....label:read_recursive xdiff/ |
| 2221 | d0 | main | region_enter | | 0.016612 | | dir | ....label:read_recursive git-gui/ |
| 2222 | d0 | main | region_enter | | 0.016698 | | dir | ......label:read_recursive git-gui/po/ |
| 2223 | d0 | main | region_enter | | 0.016810 | | dir | ........label:read_recursive git-gui/po/glossary/ |
| 2224 | d0 | main | region_leave | | 0.016863 | 0.000053 | dir | ........label:read_recursive git-gui/po/glossary/ |
| 2225 | ... |
| 2226 | d0 | main | region_enter | | 0.031876 | | dir | ....label:read_recursive builtin/ |
| 2227 | d0 | main | region_leave | | 0.032270 | 0.000394 | dir | ....label:read_recursive builtin/ |
| 2228 | d0 | main | region_leave | | 0.032414 | 0.017282 | dir | ..label:read_recursive |
| 2229 | d0 | main | region_leave | r1 | 0.032454 | 0.017407 | status | label:untracked |
| 2230 | ... |
| 2231 | d0 | main | exit | | 0.034279 | | | code:0 |
| 2232 | d0 | main | atexit | | 0.034322 | | | code:0</code></pre> |
| 2233 | </div></div> |
| 2234 | <div class="paragraph"><p>Trace2 regions are similar to the existing trace_performance_enter() |
| 2235 | and trace_performance_leave() routines, but are thread safe and |
| 2236 | maintain per-thread stacks of timers.</p></div> |
| 2237 | </dd> |
| 2238 | <dt class="hdlist1"> |
| 2239 | Data Messages |
| 2240 | </dt> |
| 2241 | <dd> |
| 2242 | <p> |
| 2243 | Data messages added to a region. |
| 2244 | </p> |
| 2245 | <div class="listingblock"> |
| 2246 | <div class="content"> |
| 2247 | <pre><code>int read_index_from(struct index_state *istate, const char *path, |
| 2248 | const char *gitdir) |
| 2249 | { |
| 2250 | trace2_region_enter_printf("index", "do_read_index", the_repository, "%s", path); |
| 2251 | |
| 2252 | ... |
| 2253 | |
| 2254 | trace2_data_intmax("index", the_repository, "read/version", istate->version); |
| 2255 | trace2_data_intmax("index", the_repository, "read/cache_nr", istate->cache_nr); |
| 2256 | |
| 2257 | trace2_region_leave_printf("index", "do_read_index", the_repository, "%s", path); |
| 2258 | }</code></pre> |
| 2259 | </div></div> |
| 2260 | <div class="paragraph"><p>This example shows that the index contained 3552 entries.</p></div> |
| 2261 | <div class="listingblock"> |
| 2262 | <div class="content"> |
| 2263 | <pre><code>$ export GIT_TR2_PERF_BRIEF=1 |
| 2264 | $ export GIT_TR2_PERF=~/log.perf |
| 2265 | $ git status |
| 2266 | ... |
| 2267 | $ cat ~/log.perf |
| 2268 | d0 | main | version | | | | | 2.20.1.156.gf9916ae094.dirty |
| 2269 | d0 | main | start | | | | | git status |
| 2270 | d0 | main | def_repo | r1 | | | | worktree:/Users/jeffhost/work/gfw |
| 2271 | d0 | main | cmd_name | | | | | status (status) |
| 2272 | d0 | main | region_enter | r1 | 0.001791 | | index | label:do_read_index .git/index |
| 2273 | d0 | main | data | r1 | 0.002494 | 0.000703 | index | ..read/version:2 |
| 2274 | d0 | main | data | r1 | 0.002520 | 0.000729 | index | ..read/cache_nr:3552 |
| 2275 | d0 | main | region_leave | r1 | 0.002539 | 0.000748 | index | label:do_read_index .git/index |
| 2276 | ...</code></pre> |
| 2277 | </div></div> |
| 2278 | </dd> |
| 2279 | <dt class="hdlist1"> |
| 2280 | Thread Events |
| 2281 | </dt> |
| 2282 | <dd> |
| 2283 | <p> |
| 2284 | Thread messages added to a thread-proc. |
| 2285 | </p> |
| 2286 | <div class="paragraph"><p>For example, the multithreaded preload-index code can be |
| 2287 | instrumented with a region around the thread pool and then |
| 2288 | per-thread start and exit events within the threadproc.</p></div> |
| 2289 | <div class="listingblock"> |
| 2290 | <div class="content"> |
| 2291 | <pre><code>static void *preload_thread(void *_data) |
| 2292 | { |
| 2293 | // start the per-thread clock and emit a message. |
| 2294 | trace2_thread_start("preload_thread"); |
| 2295 | |
| 2296 | // report which chunk of the array this thread was assigned. |
| 2297 | trace2_data_intmax("index", the_repository, "offset", p->offset); |
| 2298 | trace2_data_intmax("index", the_repository, "count", nr); |
| 2299 | |
| 2300 | do { |
| 2301 | ... |
| 2302 | } while (--nr > 0); |
| 2303 | ... |
| 2304 | |
| 2305 | // report elapsed time taken by this thread. |
| 2306 | trace2_thread_exit(); |
| 2307 | return NULL; |
| 2308 | } |
| 2309 | |
| 2310 | void preload_index(struct index_state *index, |
| 2311 | const struct pathspec *pathspec, |
| 2312 | unsigned int refresh_flags) |
| 2313 | { |
| 2314 | trace2_region_enter("index", "preload", the_repository); |
| 2315 | |
| 2316 | for (i = 0; i < threads; i++) { |
| 2317 | ... /* create thread */ |
| 2318 | } |
| 2319 | |
| 2320 | for (i = 0; i < threads; i++) { |
| 2321 | ... /* join thread */ |
| 2322 | } |
| 2323 | |
| 2324 | trace2_region_leave("index", "preload", the_repository); |
| 2325 | }</code></pre> |
| 2326 | </div></div> |
| 2327 | <div class="paragraph"><p>In this example preload_index() was executed by the <code>main</code> thread |
| 2328 | and started the <code>preload</code> region. Seven threads, named |
| 2329 | <code>th01:preload_thread</code> through <code>th07:preload_thread</code>, were started. |
| 2330 | Events from each thread are atomically appended to the shared target |
| 2331 | stream as they occur so they may appear in random order with respect |
| 2332 | other threads. Finally, the main thread waits for the threads to |
| 2333 | finish and leaves the region.</p></div> |
| 2334 | <div class="paragraph"><p>Data events are tagged with the active thread name. They are used |
| 2335 | to report the per-thread parameters.</p></div> |
| 2336 | <div class="listingblock"> |
| 2337 | <div class="content"> |
| 2338 | <pre><code>$ export GIT_TR2_PERF_BRIEF=1 |
| 2339 | $ export GIT_TR2_PERF=~/log.perf |
| 2340 | $ git status |
| 2341 | ... |
| 2342 | $ cat ~/log.perf |
| 2343 | ... |
| 2344 | d0 | main | region_enter | r1 | 0.002595 | | index | label:preload |
| 2345 | d0 | th01:preload_thread | thread_start | | 0.002699 | | | |
| 2346 | d0 | th02:preload_thread | thread_start | | 0.002721 | | | |
| 2347 | d0 | th01:preload_thread | data | r1 | 0.002736 | 0.000037 | index | offset:0 |
| 2348 | d0 | th02:preload_thread | data | r1 | 0.002751 | 0.000030 | index | offset:2032 |
| 2349 | d0 | th03:preload_thread | thread_start | | 0.002711 | | | |
| 2350 | d0 | th06:preload_thread | thread_start | | 0.002739 | | | |
| 2351 | d0 | th01:preload_thread | data | r1 | 0.002766 | 0.000067 | index | count:508 |
| 2352 | d0 | th06:preload_thread | data | r1 | 0.002856 | 0.000117 | index | offset:2540 |
| 2353 | d0 | th03:preload_thread | data | r1 | 0.002824 | 0.000113 | index | offset:1016 |
| 2354 | d0 | th04:preload_thread | thread_start | | 0.002710 | | | |
| 2355 | d0 | th02:preload_thread | data | r1 | 0.002779 | 0.000058 | index | count:508 |
| 2356 | d0 | th06:preload_thread | data | r1 | 0.002966 | 0.000227 | index | count:508 |
| 2357 | d0 | th07:preload_thread | thread_start | | 0.002741 | | | |
| 2358 | d0 | th07:preload_thread | data | r1 | 0.003017 | 0.000276 | index | offset:3048 |
| 2359 | d0 | th05:preload_thread | thread_start | | 0.002712 | | | |
| 2360 | d0 | th05:preload_thread | data | r1 | 0.003067 | 0.000355 | index | offset:1524 |
| 2361 | d0 | th05:preload_thread | data | r1 | 0.003090 | 0.000378 | index | count:508 |
| 2362 | d0 | th07:preload_thread | data | r1 | 0.003037 | 0.000296 | index | count:504 |
| 2363 | d0 | th03:preload_thread | data | r1 | 0.002971 | 0.000260 | index | count:508 |
| 2364 | d0 | th04:preload_thread | data | r1 | 0.002983 | 0.000273 | index | offset:508 |
| 2365 | d0 | th04:preload_thread | data | r1 | 0.007311 | 0.004601 | index | count:508 |
| 2366 | d0 | th05:preload_thread | thread_exit | | 0.008781 | 0.006069 | | |
| 2367 | d0 | th01:preload_thread | thread_exit | | 0.009561 | 0.006862 | | |
| 2368 | d0 | th03:preload_thread | thread_exit | | 0.009742 | 0.007031 | | |
| 2369 | d0 | th06:preload_thread | thread_exit | | 0.009820 | 0.007081 | | |
| 2370 | d0 | th02:preload_thread | thread_exit | | 0.010274 | 0.007553 | | |
| 2371 | d0 | th07:preload_thread | thread_exit | | 0.010477 | 0.007736 | | |
| 2372 | d0 | th04:preload_thread | thread_exit | | 0.011657 | 0.008947 | | |
| 2373 | d0 | main | region_leave | r1 | 0.011717 | 0.009122 | index | label:preload |
| 2374 | ... |
| 2375 | d0 | main | exit | | 0.029996 | | | code:0 |
| 2376 | d0 | main | atexit | | 0.030027 | | | code:0</code></pre> |
| 2377 | </div></div> |
| 2378 | <div class="paragraph"><p>In this example, the preload region took 0.009122 seconds. The 7 threads |
| 2379 | took between 0.006069 and 0.008947 seconds to work on their portion of |
| 2380 | the index. Thread "th01" worked on 508 items at offset 0. Thread "th02" |
| 2381 | worked on 508 items at offset 2032. Thread "th04" worked on 508 itemts |
| 2382 | at offset 508.</p></div> |
| 2383 | <div class="paragraph"><p>This example also shows that thread names are assigned in a racy manner |
| 2384 | as each thread starts and allocates TLS storage.</p></div> |
| 2385 | </dd> |
| 2386 | </dl></div> |
| 2387 | </div> |
| 2388 | </div> |
| 2389 | <div class="sect1"> |
| 2390 | <h2 id="_future_work">Future Work</h2> |
| 2391 | <div class="sectionbody"> |
| 2392 | <div class="sect2"> |
| 2393 | <h3 id="_relationship_to_the_existing_trace_api_api_trace_txt">Relationship to the Existing Trace Api (api-trace.txt)</h3> |
| 2394 | <div class="paragraph"><p>There are a few issues to resolve before we can completely |
| 2395 | switch to Trace2.</p></div> |
| 2396 | <div class="ulist"><ul> |
| 2397 | <li> |
| 2398 | <p> |
| 2399 | Updating existing tests that assume GIT_TRACE format messages. |
| 2400 | </p> |
| 2401 | </li> |
| 2402 | <li> |
| 2403 | <p> |
| 2404 | How to best handle custom GIT_TRACE_<key> messages? |
| 2405 | </p> |
| 2406 | <div class="ulist"><ul> |
| 2407 | <li> |
| 2408 | <p> |
| 2409 | The GIT_TRACE_<key> mechanism allows each <key> to write to a |
| 2410 | different file (in addition to just stderr). |
| 2411 | </p> |
| 2412 | </li> |
| 2413 | <li> |
| 2414 | <p> |
| 2415 | Do we want to maintain that ability or simply write to the existing |
| 2416 | Trace2 targets (and convert <key> to a "category"). |
| 2417 | </p> |
| 2418 | </li> |
| 2419 | </ul></div> |
| 2420 | </li> |
| 2421 | </ul></div> |
| 2422 | </div> |
| 2423 | </div> |
| 2424 | </div> |
| 2425 | </div> |
| 2426 | <div id="footnotes"><hr /></div> |
| 2427 | <div id="footer"> |
| 2428 | <div id="footer-text"> |
| 2429 | Last updated |
| 2430 | 2019-03-07 12:16:20 JST |
| 2431 | </div> |
| 2432 | </div> |
| 2433 | </body> |
| 2434 | </html> |
