DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Header

Mercurial (b6d82b1a6b02)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 * vim: set ts=8 sts=2 et sw=2 tw=80:
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "vm/GeckoProfiler-inl.h"

#include "mozilla/ArrayUtils.h"
#include "mozilla/DebugOnly.h"
#include "mozilla/Sprintf.h"

#include "jsnum.h"

#include "gc/GC.h"
#include "gc/PublicIterators.h"
#include "jit/BaselineFrame.h"
#include "jit/BaselineJIT.h"
#include "jit/JitcodeMap.h"
#include "jit/JitFrames.h"
#include "jit/JitRealm.h"
#include "jit/JSJitFrameIter.h"
#include "js/TraceLoggerAPI.h"
#include "util/StringBuffer.h"
#include "vm/JSScript.h"

#include "gc/Marking-inl.h"
#include "vm/JSScript-inl.h"

using namespace js;

using mozilla::DebugOnly;

GeckoProfilerThread::GeckoProfilerThread()
    : profilingStack_(nullptr), profilingStackIfEnabled_(nullptr) {}

GeckoProfilerRuntime::GeckoProfilerRuntime(JSRuntime* rt)
    : rt(rt),
      strings_(),
      slowAssertions(false),
      enabled_(false),
      eventMarker_(nullptr) {
  MOZ_ASSERT(rt != nullptr);
}

void GeckoProfilerThread::setProfilingStack(ProfilingStack* profilingStack,
                                            bool enabled) {
  profilingStack_ = profilingStack;
  profilingStackIfEnabled_ = enabled ? profilingStack : nullptr;
}

void GeckoProfilerRuntime::setEventMarker(void (*fn)(const char*)) {
  eventMarker_ = fn;
}

// Get a pointer to the top-most profiling frame, given the exit frame pointer.
static void* GetTopProfilingJitFrame(Activation* act) {
  if (!act || !act->isJit()) {
    return nullptr;
  }

  jit::JitActivation* jitActivation = act->asJit();

  // If there is no exit frame set, just return.
  if (!jitActivation->hasExitFP()) {
    return nullptr;
  }

  // Skip wasm frames that might be in the way.
  OnlyJSJitFrameIter iter(jitActivation);
  if (iter.done()) {
    return nullptr;
  }

  jit::JSJitProfilingFrameIterator jitIter(
      (jit::CommonFrameLayout*)iter.frame().fp());
  MOZ_ASSERT(!jitIter.done());
  return jitIter.fp();
}

void GeckoProfilerRuntime::enable(bool enabled) {
  JSContext* cx = rt->mainContextFromAnyThread();
  MOZ_ASSERT(cx->geckoProfiler().infraInstalled());

  if (enabled_ == enabled) {
    return;
  }

  /*
   * Ensure all future generated code will be instrumented, or that all
   * currently instrumented code is discarded
   */
  ReleaseAllJITCode(rt->defaultFreeOp());

  // This function is called when the Gecko profiler makes a new Sampler
  // (and thus, a new circular buffer). Set all current entries in the
  // JitcodeGlobalTable as expired and reset the buffer range start.
  if (rt->hasJitRuntime() && rt->jitRuntime()->hasJitcodeGlobalTable()) {
    rt->jitRuntime()->getJitcodeGlobalTable()->setAllEntriesAsExpired();
  }
  rt->setProfilerSampleBufferRangeStart(0);

  // Ensure that lastProfilingFrame is null for the main thread.
  if (cx->jitActivation) {
    cx->jitActivation->setLastProfilingFrame(nullptr);
    cx->jitActivation->setLastProfilingCallSite(nullptr);
  }

  // Reset the tracelogger, if toggled on
  JS::ResetTraceLogger();

  enabled_ = enabled;

  /* Toggle Gecko Profiler-related jumps on baseline jitcode.
   * The call to |ReleaseAllJITCode| above will release most baseline jitcode,
   * but not jitcode for scripts with active frames on the stack.  These scripts
   * need to have their profiler state toggled so they behave properly.
   */
  jit::ToggleBaselineProfiling(cx, enabled);

  // Update lastProfilingFrame to point to the top-most JS jit-frame currently
  // on stack.
  if (cx->jitActivation) {
    // Walk through all activations, and set their lastProfilingFrame
    // appropriately.
    if (enabled) {
      Activation* act = cx->activation();
      void* lastProfilingFrame = GetTopProfilingJitFrame(act);

      jit::JitActivation* jitActivation = cx->jitActivation;
      while (jitActivation) {
        jitActivation->setLastProfilingFrame(lastProfilingFrame);
        jitActivation->setLastProfilingCallSite(nullptr);

        jitActivation = jitActivation->prevJitActivation();
        lastProfilingFrame = GetTopProfilingJitFrame(jitActivation);
      }
    } else {
      jit::JitActivation* jitActivation = cx->jitActivation;
      while (jitActivation) {
        jitActivation->setLastProfilingFrame(nullptr);
        jitActivation->setLastProfilingCallSite(nullptr);
        jitActivation = jitActivation->prevJitActivation();
      }
    }
  }

  // WebAssembly code does not need to be released, but profiling string
  // labels have to be generated so that they are available during async
  // profiling stack iteration.
  for (RealmsIter r(rt); !r.done(); r.next()) {
    r->wasm.ensureProfilingLabels(enabled);
  }

#ifdef JS_STRUCTURED_SPEW
  // Enable the structured spewer if the environment variable is set.
  if (enabled) {
    cx->spewer().enableSpewing();
  } else {
    cx->spewer().disableSpewing();
  }
#endif
}

/* Lookup the string for the function/script, creating one if necessary */
const char* GeckoProfilerRuntime::profileString(JSContext* cx,
                                                JSScript* script) {
  ProfileStringMap::AddPtr s = strings().lookupForAdd(script);

  if (!s) {
    UniqueChars str = allocProfileString(cx, script);
    if (!str) {
      return nullptr;
    }
    if (!strings().add(s, script, std::move(str))) {
      ReportOutOfMemory(cx);
      return nullptr;
    }
  }

  return s->value().get();
}

void GeckoProfilerRuntime::onScriptFinalized(JSScript* script) {
  /*
   * This function is called whenever a script is destroyed, regardless of
   * whether profiling has been turned on, so don't invoke a function on an
   * invalid hash set. Also, even if profiling was enabled but then turned
   * off, we still want to remove the string, so no check of enabled() is
   * done.
   */
  if (ProfileStringMap::Ptr entry = strings().lookup(script)) {
    strings().remove(entry);
  }
}

void GeckoProfilerRuntime::markEvent(const char* event) {
  MOZ_ASSERT(enabled());
  if (eventMarker_) {
    JS::AutoSuppressGCAnalysis nogc;
    eventMarker_(event);
  }
}

bool GeckoProfilerThread::enter(JSContext* cx, JSScript* script) {
  const char* dynamicString =
      cx->runtime()->geckoProfiler().profileString(cx, script);
  if (dynamicString == nullptr) {
    return false;
  }

#ifdef DEBUG
  // In debug builds, assert the JS profiling stack frames already on the
  // stack have a non-null pc. Only look at the top frames to avoid quadratic
  // behavior.
  uint32_t sp = profilingStack_->stackPointer;
  if (sp > 0 && sp - 1 < profilingStack_->stackCapacity()) {
    size_t start = (sp > 4) ? sp - 4 : 0;
    for (size_t i = start; i < sp - 1; i++) {
      MOZ_ASSERT_IF(profilingStack_->frames[i].isJsFrame(),
                    profilingStack_->frames[i].pc());
    }
  }
#endif

  profilingStack_->pushJsFrame("", dynamicString, script, script->code());
  return true;
}

void GeckoProfilerThread::exit(JSContext* cx, JSScript* script) {
  profilingStack_->pop();

#ifdef DEBUG
  /* Sanity check to make sure push/pop balanced */
  uint32_t sp = profilingStack_->stackPointer;
  if (sp < profilingStack_->stackCapacity()) {
    JSRuntime* rt = script->runtimeFromMainThread();
    const char* dynamicString = rt->geckoProfiler().profileString(cx, script);
    /* Can't fail lookup because we should already be in the set */
    MOZ_ASSERT(dynamicString);

    // Bug 822041
    if (!profilingStack_->frames[sp].isJsFrame()) {
      fprintf(stderr, "--- ABOUT TO FAIL ASSERTION ---\n");
      fprintf(stderr, " frames=%p size=%u/%u\n", (void*)profilingStack_->frames,
              uint32_t(profilingStack_->stackPointer),
              profilingStack_->stackCapacity());
      for (int32_t i = sp; i >= 0; i--) {
        ProfilingStackFrame& frame = profilingStack_->frames[i];
        if (frame.isJsFrame()) {
          fprintf(stderr, "  [%d] JS %s\n", i, frame.dynamicString());
        } else {
          fprintf(stderr, "  [%d] Label %s\n", i, frame.dynamicString());
        }
      }
    }

    ProfilingStackFrame& frame = profilingStack_->frames[sp];
    MOZ_ASSERT(frame.isJsFrame());
    MOZ_ASSERT(frame.script() == script);
    MOZ_ASSERT(strcmp((const char*)frame.dynamicString(), dynamicString) == 0);
  }
#endif
}

/*
 * Serializes the script/function pair into a "descriptive string" which is
 * allowed to fail. This function cannot trigger a GC because it could finalize
 * some scripts, resize the hash table of profile strings, and invalidate the
 * AddPtr held while invoking allocProfileString.
 */
/* static */
UniqueChars GeckoProfilerRuntime::allocProfileString(JSContext* cx,
                                                     JSScript* script) {
  // Note: this profiler string is regexp-matched by
  // devtools/client/profiler/cleopatra/js/parserWorker.js.

  // If the script has a function, try calculating its name.
  bool hasName = false;
  size_t nameLength = 0;
  UniqueChars nameStr;
  JSFunction* func = script->functionDelazifying();
  if (func && func->displayAtom()) {
    nameStr = StringToNewUTF8CharsZ(cx, *func->displayAtom());
    if (!nameStr) {
      return nullptr;
    }

    nameLength = strlen(nameStr.get());
    hasName = true;
  }

  // Calculate filename length.
  const char* filenameStr = script->filename() ? script->filename() : "(null)";
  size_t filenameLength = strlen(filenameStr);

  // Calculate line + column length.
  bool hasLineAndColumn = false;
  size_t lineAndColumnLength = 0;
  char lineAndColumnStr[30];
  if (hasName || script->functionNonDelazifying() || script->isForEval()) {
    lineAndColumnLength = SprintfLiteral(lineAndColumnStr, "%u:%u",
                                         script->lineno(), script->column());
    hasLineAndColumn = true;
  }

  // Full profile string for scripts with functions is:
  //      FuncName (FileName:Lineno:Column)
  // Full profile string for scripts without functions is:
  //      FileName:Lineno:Column
  // Full profile string for scripts without functions and without lines is:
  //      FileName

  // Calculate full string length.
  size_t fullLength = 0;
  if (hasName) {
    MOZ_ASSERT(hasLineAndColumn);
    fullLength = nameLength + 2 + filenameLength + 1 + lineAndColumnLength + 1;
  } else if (hasLineAndColumn) {
    fullLength = filenameLength + 1 + lineAndColumnLength;
  } else {
    fullLength = filenameLength;
  }

  // Allocate string.
  UniqueChars str(cx->pod_malloc<char>(fullLength + 1));
  if (!str) {
    return nullptr;
  }

  size_t cur = 0;

  // Fill string with function name if needed.
  if (hasName) {
    memcpy(str.get() + cur, nameStr.get(), nameLength);
    cur += nameLength;
    str[cur++] = ' ';
    str[cur++] = '(';
  }

  // Fill string with filename chars.
  memcpy(str.get() + cur, filenameStr, filenameLength);
  cur += filenameLength;

  // Fill line + column chars.
  if (hasLineAndColumn) {
    str[cur++] = ':';
    memcpy(str.get() + cur, lineAndColumnStr, lineAndColumnLength);
    cur += lineAndColumnLength;
  }

  // Terminal ')' if necessary.
  if (hasName) {
    str[cur++] = ')';
  }

  MOZ_ASSERT(cur == fullLength);
  str[cur] = 0;

  return str;
}

void GeckoProfilerThread::trace(JSTracer* trc) {
  if (profilingStack_) {
    size_t size = profilingStack_->stackSize();
    for (size_t i = 0; i < size; i++) {
      profilingStack_->frames[i].trace(trc);
    }
  }
}

void GeckoProfilerRuntime::fixupStringsMapAfterMovingGC() {
  for (ProfileStringMap::Enum e(strings()); !e.empty(); e.popFront()) {
    JSScript* script = e.front().key();
    if (IsForwarded(script)) {
      script = Forwarded(script);
      e.rekeyFront(script);
    }
  }
}

#ifdef JSGC_HASH_TABLE_CHECKS
void GeckoProfilerRuntime::checkStringsMapAfterMovingGC() {
  for (auto r = strings().all(); !r.empty(); r.popFront()) {
    JSScript* script = r.front().key();
    CheckGCThingAfterMovingGC(script);
    auto ptr = strings().lookup(script);
    MOZ_RELEASE_ASSERT(ptr.found() && &*ptr == &r.front());
  }
}
#endif

void ProfilingStackFrame::trace(JSTracer* trc) {
  if (isJsFrame()) {
    JSScript* s = rawScript();
    TraceNullableRoot(trc, &s, "ProfilingStackFrame script");
    spOrScript = s;
  }
}

GeckoProfilerBaselineOSRMarker::GeckoProfilerBaselineOSRMarker(
    JSContext* cx,
    bool hasProfilerFrame MOZ_GUARD_OBJECT_NOTIFIER_PARAM_IN_IMPL)
    : profiler(&cx->geckoProfiler()) {
  MOZ_GUARD_OBJECT_NOTIFIER_INIT;
  if (!hasProfilerFrame || !cx->runtime()->geckoProfiler().enabled()) {
    profiler = nullptr;
    return;
  }

  uint32_t sp = profiler->profilingStack_->stackPointer;
  if (sp >= profiler->profilingStack_->stackCapacity()) {
    profiler = nullptr;
    return;
  }

  spBefore_ = sp;
  if (sp == 0) {
    return;
  }

  ProfilingStackFrame& frame = profiler->profilingStack_->frames[sp - 1];
  MOZ_ASSERT(!frame.isOSRFrame());
  frame.setIsOSRFrame(true);
}

GeckoProfilerBaselineOSRMarker::~GeckoProfilerBaselineOSRMarker() {
  if (profiler == nullptr) {
    return;
  }

  uint32_t sp = profiler->stackPointer();
  MOZ_ASSERT(spBefore_ == sp);
  if (sp == 0) {
    return;
  }

  ProfilingStackFrame& frame = profiler->stack()[sp - 1];
  MOZ_ASSERT(frame.isOSRFrame());
  frame.setIsOSRFrame(false);
}

JS_PUBLIC_API JSScript* ProfilingStackFrame::script() const {
  MOZ_ASSERT(isJsFrame());
  auto script = reinterpret_cast<JSScript*>(spOrScript.operator void*());
  if (!script) {
    return nullptr;
  }

  // If profiling is supressed then we can't trust the script pointers to be
  // valid as they could be in the process of being moved by a compacting GC
  // (although it's still OK to get the runtime from them).
  JSContext* cx = script->runtimeFromAnyThread()->mainContextFromAnyThread();
  if (!cx->isProfilerSamplingEnabled()) {
    return nullptr;
  }

  MOZ_ASSERT(!IsForwarded(script));
  return script;
}

JS_FRIEND_API jsbytecode* ProfilingStackFrame::pc() const {
  MOZ_ASSERT(isJsFrame());
  if (pcOffsetIfJS_ == NullPCOffset) {
    return nullptr;
  }

  JSScript* script = this->script();
  return script ? script->offsetToPC(pcOffsetIfJS_) : nullptr;
}

/* static */
int32_t ProfilingStackFrame::pcToOffset(JSScript* aScript, jsbytecode* aPc) {
  return aPc ? aScript->pcToOffset(aPc) : NullPCOffset;
}

void ProfilingStackFrame::setPC(jsbytecode* pc) {
  MOZ_ASSERT(isJsFrame());
  JSScript* script = this->script();
  MOZ_ASSERT(
      script);  // This should not be called while profiling is suppressed.
  pcOffsetIfJS_ = pcToOffset(script, pc);
}

JS_FRIEND_API void js::SetContextProfilingStack(
    JSContext* cx, ProfilingStack* profilingStack) {
  cx->geckoProfiler().setProfilingStack(
      profilingStack, cx->runtime()->geckoProfiler().enabled());
}

JS_FRIEND_API void js::EnableContextProfilingStack(JSContext* cx,
                                                   bool enabled) {
  cx->geckoProfiler().enable(enabled);
  cx->runtime()->geckoProfiler().enable(enabled);
}

JS_FRIEND_API void js::RegisterContextProfilingEventMarker(
    JSContext* cx, void (*fn)(const char*)) {
  MOZ_ASSERT(cx->runtime()->geckoProfiler().enabled());
  cx->runtime()->geckoProfiler().setEventMarker(fn);
}

AutoSuppressProfilerSampling::AutoSuppressProfilerSampling(
    JSContext* cx MOZ_GUARD_OBJECT_NOTIFIER_PARAM_IN_IMPL)
    : cx_(cx), previouslyEnabled_(cx->isProfilerSamplingEnabled()) {
  MOZ_GUARD_OBJECT_NOTIFIER_INIT;
  if (previouslyEnabled_) {
    cx_->disableProfilerSampling();
  }
}

AutoSuppressProfilerSampling::~AutoSuppressProfilerSampling() {
  if (previouslyEnabled_) {
    cx_->enableProfilerSampling();
  }
}

namespace JS {

// clang-format off

// ProfilingSubcategory_X:
// One enum for each category X, listing that category's subcategories. This
// allows the sProfilingCategoryInfo macro construction below to look up a
// per-category index for a subcategory.
#define SUBCATEGORY_ENUMS_BEGIN_CATEGORY(name, labelAsString, color) \
  enum class ProfilingSubcategory_##name : uint32_t {
#define SUBCATEGORY_ENUMS_SUBCATEGORY(category, name, labelAsString) \
    name,
#define SUBCATEGORY_ENUMS_END_CATEGORY \
  };
PROFILING_CATEGORY_LIST(SUBCATEGORY_ENUMS_BEGIN_CATEGORY,
                        SUBCATEGORY_ENUMS_SUBCATEGORY,
                        SUBCATEGORY_ENUMS_END_CATEGORY)
#undef SUBCATEGORY_ENUMS_BEGIN_CATEGORY
#undef SUBCATEGORY_ENUMS_SUBCATEGORY
#undef SUBCATEGORY_ENUMS_END_CATEGORY

// sProfilingCategoryPairInfo:
// A list of ProfilingCategoryPairInfos with the same order as
// ProfilingCategoryPair, which can be used to map a ProfilingCategoryPair to
// its information.
#define CATEGORY_INFO_BEGIN_CATEGORY(name, labelAsString, color)
#define CATEGORY_INFO_SUBCATEGORY(category, name, labelAsString) \
  {ProfilingCategory::category,                                  \
   uint32_t(ProfilingSubcategory_##category::name), labelAsString},
#define CATEGORY_INFO_END_CATEGORY
const ProfilingCategoryPairInfo sProfilingCategoryPairInfo[] = {
  PROFILING_CATEGORY_LIST(CATEGORY_INFO_BEGIN_CATEGORY,
                          CATEGORY_INFO_SUBCATEGORY,
                          CATEGORY_INFO_END_CATEGORY)
};
#undef CATEGORY_INFO_BEGIN_CATEGORY
#undef CATEGORY_INFO_SUBCATEGORY
#undef CATEGORY_INFO_END_CATEGORY

// clang-format on

JS_FRIEND_API const ProfilingCategoryPairInfo& GetProfilingCategoryPairInfo(
    ProfilingCategoryPair aCategoryPair) {
  static_assert(
      MOZ_ARRAY_LENGTH(sProfilingCategoryPairInfo) ==
          uint32_t(ProfilingCategoryPair::COUNT),
      "sProfilingCategoryPairInfo and ProfilingCategory need to have the "
      "same order and the same length");

  uint32_t categoryPairIndex = uint32_t(aCategoryPair);
  MOZ_RELEASE_ASSERT(categoryPairIndex <=
                     uint32_t(ProfilingCategoryPair::LAST));
  return sProfilingCategoryPairInfo[categoryPairIndex];
}

}  // namespace JS