1// Copyright 2012 the V8 project authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include "src/profiler/profile-generator.h"
6
7#include "src/base/adapters.h"
8#include "src/debug/debug.h"
9#include "src/deoptimizer.h"
10#include "src/global-handles.h"
11#include "src/objects-inl.h"
12#include "src/profiler/cpu-profiler.h"
13#include "src/profiler/profile-generator-inl.h"
14#include "src/tracing/trace-event.h"
15#include "src/tracing/traced-value.h"
16#include "src/unicode.h"
17
18namespace v8 {
19namespace internal {
20
21
22JITLineInfoTable::JITLineInfoTable() {}
23
24
25JITLineInfoTable::~JITLineInfoTable() {}
26
27
28void JITLineInfoTable::SetPosition(int pc_offset, int line) {
29  DCHECK(pc_offset >= 0);
30  DCHECK(line > 0);  // The 1-based number of the source line.
31  if (GetSourceLineNumber(pc_offset) != line) {
32    pc_offset_map_.insert(std::make_pair(pc_offset, line));
33  }
34}
35
36
37int JITLineInfoTable::GetSourceLineNumber(int pc_offset) const {
38  PcOffsetMap::const_iterator it = pc_offset_map_.lower_bound(pc_offset);
39  if (it == pc_offset_map_.end()) {
40    if (pc_offset_map_.empty()) return v8::CpuProfileNode::kNoLineNumberInfo;
41    return (--pc_offset_map_.end())->second;
42  }
43  return it->second;
44}
45
46
47const char* const CodeEntry::kEmptyNamePrefix = "";
48const char* const CodeEntry::kEmptyResourceName = "";
49const char* const CodeEntry::kEmptyBailoutReason = "";
50const char* const CodeEntry::kNoDeoptReason = "";
51
52const char* const CodeEntry::kProgramEntryName = "(program)";
53const char* const CodeEntry::kIdleEntryName = "(idle)";
54const char* const CodeEntry::kGarbageCollectorEntryName = "(garbage collector)";
55const char* const CodeEntry::kUnresolvedFunctionName = "(unresolved function)";
56
57base::LazyDynamicInstance<CodeEntry, CodeEntry::ProgramEntryCreateTrait>::type
58    CodeEntry::kProgramEntry = LAZY_DYNAMIC_INSTANCE_INITIALIZER;
59
60base::LazyDynamicInstance<CodeEntry, CodeEntry::IdleEntryCreateTrait>::type
61    CodeEntry::kIdleEntry = LAZY_DYNAMIC_INSTANCE_INITIALIZER;
62
63base::LazyDynamicInstance<CodeEntry, CodeEntry::GCEntryCreateTrait>::type
64    CodeEntry::kGCEntry = LAZY_DYNAMIC_INSTANCE_INITIALIZER;
65
66base::LazyDynamicInstance<CodeEntry,
67                          CodeEntry::UnresolvedEntryCreateTrait>::type
68    CodeEntry::kUnresolvedEntry = LAZY_DYNAMIC_INSTANCE_INITIALIZER;
69
70CodeEntry* CodeEntry::ProgramEntryCreateTrait::Create() {
71  return new CodeEntry(Logger::FUNCTION_TAG, CodeEntry::kProgramEntryName);
72}
73
74CodeEntry* CodeEntry::IdleEntryCreateTrait::Create() {
75  return new CodeEntry(Logger::FUNCTION_TAG, CodeEntry::kIdleEntryName);
76}
77
78CodeEntry* CodeEntry::GCEntryCreateTrait::Create() {
79  return new CodeEntry(Logger::BUILTIN_TAG,
80                       CodeEntry::kGarbageCollectorEntryName);
81}
82
83CodeEntry* CodeEntry::UnresolvedEntryCreateTrait::Create() {
84  return new CodeEntry(Logger::FUNCTION_TAG,
85                       CodeEntry::kUnresolvedFunctionName);
86}
87
88CodeEntry::~CodeEntry() {
89  delete line_info_;
90  for (auto location : inline_locations_) {
91    for (auto entry : location.second) {
92      delete entry;
93    }
94  }
95}
96
97
98uint32_t CodeEntry::GetHash() const {
99  uint32_t hash = ComputeIntegerHash(tag(), v8::internal::kZeroHashSeed);
100  if (script_id_ != v8::UnboundScript::kNoScriptId) {
101    hash ^= ComputeIntegerHash(static_cast<uint32_t>(script_id_),
102                               v8::internal::kZeroHashSeed);
103    hash ^= ComputeIntegerHash(static_cast<uint32_t>(position_),
104                               v8::internal::kZeroHashSeed);
105  } else {
106    hash ^= ComputeIntegerHash(
107        static_cast<uint32_t>(reinterpret_cast<uintptr_t>(name_prefix_)),
108        v8::internal::kZeroHashSeed);
109    hash ^= ComputeIntegerHash(
110        static_cast<uint32_t>(reinterpret_cast<uintptr_t>(name_)),
111        v8::internal::kZeroHashSeed);
112    hash ^= ComputeIntegerHash(
113        static_cast<uint32_t>(reinterpret_cast<uintptr_t>(resource_name_)),
114        v8::internal::kZeroHashSeed);
115    hash ^= ComputeIntegerHash(line_number_, v8::internal::kZeroHashSeed);
116  }
117  return hash;
118}
119
120
121bool CodeEntry::IsSameFunctionAs(CodeEntry* entry) const {
122  if (this == entry) return true;
123  if (script_id_ != v8::UnboundScript::kNoScriptId) {
124    return script_id_ == entry->script_id_ && position_ == entry->position_;
125  }
126  return name_prefix_ == entry->name_prefix_ && name_ == entry->name_ &&
127         resource_name_ == entry->resource_name_ &&
128         line_number_ == entry->line_number_;
129}
130
131
132void CodeEntry::SetBuiltinId(Builtins::Name id) {
133  bit_field_ = TagField::update(bit_field_, CodeEventListener::BUILTIN_TAG);
134  bit_field_ = BuiltinIdField::update(bit_field_, id);
135}
136
137
138int CodeEntry::GetSourceLine(int pc_offset) const {
139  if (line_info_ && !line_info_->empty()) {
140    return line_info_->GetSourceLineNumber(pc_offset);
141  }
142  return v8::CpuProfileNode::kNoLineNumberInfo;
143}
144
145void CodeEntry::AddInlineStack(int pc_offset,
146                               std::vector<CodeEntry*> inline_stack) {
147  inline_locations_.insert(std::make_pair(pc_offset, std::move(inline_stack)));
148}
149
150const std::vector<CodeEntry*>* CodeEntry::GetInlineStack(int pc_offset) const {
151  auto it = inline_locations_.find(pc_offset);
152  return it != inline_locations_.end() ? &it->second : NULL;
153}
154
155void CodeEntry::AddDeoptInlinedFrames(
156    int deopt_id, std::vector<CpuProfileDeoptFrame> inlined_frames) {
157  deopt_inlined_frames_.insert(
158      std::make_pair(deopt_id, std::move(inlined_frames)));
159}
160
161bool CodeEntry::HasDeoptInlinedFramesFor(int deopt_id) const {
162  return deopt_inlined_frames_.find(deopt_id) != deopt_inlined_frames_.end();
163}
164
165void CodeEntry::FillFunctionInfo(SharedFunctionInfo* shared) {
166  if (!shared->script()->IsScript()) return;
167  Script* script = Script::cast(shared->script());
168  set_script_id(script->id());
169  set_position(shared->start_position());
170  set_bailout_reason(GetBailoutReason(shared->disable_optimization_reason()));
171}
172
173CpuProfileDeoptInfo CodeEntry::GetDeoptInfo() {
174  DCHECK(has_deopt_info());
175
176  CpuProfileDeoptInfo info;
177  info.deopt_reason = deopt_reason_;
178  DCHECK_NE(kNoDeoptimizationId, deopt_id_);
179  if (deopt_inlined_frames_.find(deopt_id_) == deopt_inlined_frames_.end()) {
180    info.stack.push_back(CpuProfileDeoptFrame(
181        {script_id_, static_cast<size_t>(std::max(0, position()))}));
182  } else {
183    info.stack = deopt_inlined_frames_[deopt_id_];
184  }
185  return info;
186}
187
188
189void ProfileNode::CollectDeoptInfo(CodeEntry* entry) {
190  deopt_infos_.push_back(entry->GetDeoptInfo());
191  entry->clear_deopt_info();
192}
193
194
195ProfileNode* ProfileNode::FindChild(CodeEntry* entry) {
196  base::HashMap::Entry* map_entry =
197      children_.Lookup(entry, CodeEntryHash(entry));
198  return map_entry != NULL ?
199      reinterpret_cast<ProfileNode*>(map_entry->value) : NULL;
200}
201
202
203ProfileNode* ProfileNode::FindOrAddChild(CodeEntry* entry) {
204  base::HashMap::Entry* map_entry =
205      children_.LookupOrInsert(entry, CodeEntryHash(entry));
206  ProfileNode* node = reinterpret_cast<ProfileNode*>(map_entry->value);
207  if (!node) {
208    node = new ProfileNode(tree_, entry, this);
209    map_entry->value = node;
210    children_list_.Add(node);
211  }
212  return node;
213}
214
215
216void ProfileNode::IncrementLineTicks(int src_line) {
217  if (src_line == v8::CpuProfileNode::kNoLineNumberInfo) return;
218  // Increment a hit counter of a certain source line.
219  // Add a new source line if not found.
220  base::HashMap::Entry* e =
221      line_ticks_.LookupOrInsert(reinterpret_cast<void*>(src_line), src_line);
222  DCHECK(e);
223  e->value = reinterpret_cast<void*>(reinterpret_cast<uintptr_t>(e->value) + 1);
224}
225
226
227bool ProfileNode::GetLineTicks(v8::CpuProfileNode::LineTick* entries,
228                               unsigned int length) const {
229  if (entries == NULL || length == 0) return false;
230
231  unsigned line_count = line_ticks_.occupancy();
232
233  if (line_count == 0) return true;
234  if (length < line_count) return false;
235
236  v8::CpuProfileNode::LineTick* entry = entries;
237
238  for (base::HashMap::Entry *p = line_ticks_.Start(); p != NULL;
239       p = line_ticks_.Next(p), entry++) {
240    entry->line =
241        static_cast<unsigned int>(reinterpret_cast<uintptr_t>(p->key));
242    entry->hit_count =
243        static_cast<unsigned int>(reinterpret_cast<uintptr_t>(p->value));
244  }
245
246  return true;
247}
248
249
250void ProfileNode::Print(int indent) {
251  base::OS::Print("%5u %*s %s%s %d #%d", self_ticks_, indent, "",
252                  entry_->name_prefix(), entry_->name(), entry_->script_id(),
253                  id());
254  if (entry_->resource_name()[0] != '\0')
255    base::OS::Print(" %s:%d", entry_->resource_name(), entry_->line_number());
256  base::OS::Print("\n");
257  for (size_t i = 0; i < deopt_infos_.size(); ++i) {
258    CpuProfileDeoptInfo& info = deopt_infos_[i];
259    base::OS::Print("%*s;;; deopted at script_id: %d position: %" PRIuS
260                    " with reason '%s'.\n",
261                    indent + 10, "", info.stack[0].script_id,
262                    info.stack[0].position, info.deopt_reason);
263    for (size_t index = 1; index < info.stack.size(); ++index) {
264      base::OS::Print("%*s;;;     Inline point: script_id %d position: %" PRIuS
265                      ".\n",
266                      indent + 10, "", info.stack[index].script_id,
267                      info.stack[index].position);
268    }
269  }
270  const char* bailout_reason = entry_->bailout_reason();
271  if (bailout_reason != GetBailoutReason(BailoutReason::kNoReason) &&
272      bailout_reason != CodeEntry::kEmptyBailoutReason) {
273    base::OS::Print("%*s bailed out due to '%s'\n", indent + 10, "",
274                    bailout_reason);
275  }
276  for (base::HashMap::Entry* p = children_.Start(); p != NULL;
277       p = children_.Next(p)) {
278    reinterpret_cast<ProfileNode*>(p->value)->Print(indent + 2);
279  }
280}
281
282
283class DeleteNodesCallback {
284 public:
285  void BeforeTraversingChild(ProfileNode*, ProfileNode*) { }
286
287  void AfterAllChildrenTraversed(ProfileNode* node) {
288    delete node;
289  }
290
291  void AfterChildTraversed(ProfileNode*, ProfileNode*) { }
292};
293
294ProfileTree::ProfileTree(Isolate* isolate)
295    : root_entry_(CodeEventListener::FUNCTION_TAG, "(root)"),
296      next_node_id_(1),
297      root_(new ProfileNode(this, &root_entry_, nullptr)),
298      isolate_(isolate),
299      next_function_id_(1),
300      function_ids_(ProfileNode::CodeEntriesMatch) {}
301
302ProfileTree::~ProfileTree() {
303  DeleteNodesCallback cb;
304  TraverseDepthFirst(&cb);
305}
306
307
308unsigned ProfileTree::GetFunctionId(const ProfileNode* node) {
309  CodeEntry* code_entry = node->entry();
310  base::HashMap::Entry* entry =
311      function_ids_.LookupOrInsert(code_entry, code_entry->GetHash());
312  if (!entry->value) {
313    entry->value = reinterpret_cast<void*>(next_function_id_++);
314  }
315  return static_cast<unsigned>(reinterpret_cast<uintptr_t>(entry->value));
316}
317
318ProfileNode* ProfileTree::AddPathFromEnd(const std::vector<CodeEntry*>& path,
319                                         int src_line, bool update_stats) {
320  ProfileNode* node = root_;
321  CodeEntry* last_entry = NULL;
322  for (auto it = path.rbegin(); it != path.rend(); ++it) {
323    if (*it == NULL) continue;
324    last_entry = *it;
325    node = node->FindOrAddChild(*it);
326  }
327  if (last_entry && last_entry->has_deopt_info()) {
328    node->CollectDeoptInfo(last_entry);
329  }
330  if (update_stats) {
331    node->IncrementSelfTicks();
332    if (src_line != v8::CpuProfileNode::kNoLineNumberInfo) {
333      node->IncrementLineTicks(src_line);
334    }
335  }
336  return node;
337}
338
339
340struct NodesPair {
341  NodesPair(ProfileNode* src, ProfileNode* dst)
342      : src(src), dst(dst) { }
343  ProfileNode* src;
344  ProfileNode* dst;
345};
346
347
348class Position {
349 public:
350  explicit Position(ProfileNode* node)
351      : node(node), child_idx_(0) { }
352  INLINE(ProfileNode* current_child()) {
353    return node->children()->at(child_idx_);
354  }
355  INLINE(bool has_current_child()) {
356    return child_idx_ < node->children()->length();
357  }
358  INLINE(void next_child()) { ++child_idx_; }
359
360  ProfileNode* node;
361 private:
362  int child_idx_;
363};
364
365
366// Non-recursive implementation of a depth-first post-order tree traversal.
367template <typename Callback>
368void ProfileTree::TraverseDepthFirst(Callback* callback) {
369  List<Position> stack(10);
370  stack.Add(Position(root_));
371  while (stack.length() > 0) {
372    Position& current = stack.last();
373    if (current.has_current_child()) {
374      callback->BeforeTraversingChild(current.node, current.current_child());
375      stack.Add(Position(current.current_child()));
376    } else {
377      callback->AfterAllChildrenTraversed(current.node);
378      if (stack.length() > 1) {
379        Position& parent = stack[stack.length() - 2];
380        callback->AfterChildTraversed(parent.node, current.node);
381        parent.next_child();
382      }
383      // Remove child from the stack.
384      stack.RemoveLast();
385    }
386  }
387}
388
389using v8::tracing::TracedValue;
390
391CpuProfile::CpuProfile(CpuProfiler* profiler, const char* title,
392                       bool record_samples)
393    : title_(title),
394      record_samples_(record_samples),
395      start_time_(base::TimeTicks::HighResolutionNow()),
396      top_down_(profiler->isolate()),
397      profiler_(profiler),
398      streaming_next_sample_(0) {
399  auto value = TracedValue::Create();
400  value->SetDouble("startTime",
401                   (start_time_ - base::TimeTicks()).InMicroseconds());
402  TRACE_EVENT_SAMPLE_WITH_ID1(TRACE_DISABLED_BY_DEFAULT("v8.cpu_profiler"),
403                              "Profile", this, "data", std::move(value));
404}
405
406void CpuProfile::AddPath(base::TimeTicks timestamp,
407                         const std::vector<CodeEntry*>& path, int src_line,
408                         bool update_stats) {
409  ProfileNode* top_frame_node =
410      top_down_.AddPathFromEnd(path, src_line, update_stats);
411  if (record_samples_ && !timestamp.IsNull()) {
412    timestamps_.Add(timestamp);
413    samples_.Add(top_frame_node);
414  }
415  const int kSamplesFlushCount = 100;
416  const int kNodesFlushCount = 10;
417  if (samples_.length() - streaming_next_sample_ >= kSamplesFlushCount ||
418      top_down_.pending_nodes_count() >= kNodesFlushCount) {
419    StreamPendingTraceEvents();
420  }
421}
422
423namespace {
424
425void BuildNodeValue(const ProfileNode* node, TracedValue* value) {
426  const CodeEntry* entry = node->entry();
427  value->BeginDictionary("callFrame");
428  value->SetString("functionName", entry->name());
429  if (*entry->resource_name()) {
430    value->SetString("url", entry->resource_name());
431  }
432  value->SetInteger("scriptId", entry->script_id());
433  if (entry->line_number()) {
434    value->SetInteger("lineNumber", entry->line_number() - 1);
435  }
436  if (entry->column_number()) {
437    value->SetInteger("columnNumber", entry->column_number() - 1);
438  }
439  value->EndDictionary();
440  value->SetInteger("id", node->id());
441  if (node->parent()) {
442    value->SetInteger("parent", node->parent()->id());
443  }
444  const char* deopt_reason = entry->bailout_reason();
445  if (deopt_reason && deopt_reason[0] && strcmp(deopt_reason, "no reason")) {
446    value->SetString("deoptReason", deopt_reason);
447  }
448}
449
450}  // namespace
451
452void CpuProfile::StreamPendingTraceEvents() {
453  std::vector<const ProfileNode*> pending_nodes = top_down_.TakePendingNodes();
454  if (pending_nodes.empty() && !samples_.length()) return;
455  auto value = TracedValue::Create();
456
457  if (!pending_nodes.empty() || streaming_next_sample_ != samples_.length()) {
458    value->BeginDictionary("cpuProfile");
459    if (!pending_nodes.empty()) {
460      value->BeginArray("nodes");
461      for (auto node : pending_nodes) {
462        value->BeginDictionary();
463        BuildNodeValue(node, value.get());
464        value->EndDictionary();
465      }
466      value->EndArray();
467    }
468    if (streaming_next_sample_ != samples_.length()) {
469      value->BeginArray("samples");
470      for (int i = streaming_next_sample_; i < samples_.length(); ++i) {
471        value->AppendInteger(samples_[i]->id());
472      }
473      value->EndArray();
474    }
475    value->EndDictionary();
476  }
477  if (streaming_next_sample_ != samples_.length()) {
478    value->BeginArray("timeDeltas");
479    base::TimeTicks lastTimestamp =
480        streaming_next_sample_ ? timestamps_[streaming_next_sample_ - 1]
481                               : start_time();
482    for (int i = streaming_next_sample_; i < timestamps_.length(); ++i) {
483      value->AppendInteger(
484          static_cast<int>((timestamps_[i] - lastTimestamp).InMicroseconds()));
485      lastTimestamp = timestamps_[i];
486    }
487    value->EndArray();
488    DCHECK(samples_.length() == timestamps_.length());
489    streaming_next_sample_ = samples_.length();
490  }
491
492  TRACE_EVENT_SAMPLE_WITH_ID1(TRACE_DISABLED_BY_DEFAULT("v8.cpu_profiler"),
493                              "ProfileChunk", this, "data", std::move(value));
494}
495
496void CpuProfile::FinishProfile() {
497  end_time_ = base::TimeTicks::HighResolutionNow();
498  StreamPendingTraceEvents();
499  auto value = TracedValue::Create();
500  value->SetDouble("endTime", (end_time_ - base::TimeTicks()).InMicroseconds());
501  TRACE_EVENT_SAMPLE_WITH_ID1(TRACE_DISABLED_BY_DEFAULT("v8.cpu_profiler"),
502                              "ProfileChunk", this, "data", std::move(value));
503}
504
505void CpuProfile::Print() {
506  base::OS::Print("[Top down]:\n");
507  top_down_.Print();
508}
509
510void CodeMap::AddCode(Address addr, CodeEntry* entry, unsigned size) {
511  DeleteAllCoveredCode(addr, addr + size);
512  code_map_.insert({addr, CodeEntryInfo(entry, size)});
513}
514
515void CodeMap::DeleteAllCoveredCode(Address start, Address end) {
516  auto left = code_map_.upper_bound(start);
517  if (left != code_map_.begin()) {
518    --left;
519    if (left->first + left->second.size <= start) ++left;
520  }
521  auto right = left;
522  while (right != code_map_.end() && right->first < end) ++right;
523  code_map_.erase(left, right);
524}
525
526CodeEntry* CodeMap::FindEntry(Address addr) {
527  auto it = code_map_.upper_bound(addr);
528  if (it == code_map_.begin()) return nullptr;
529  --it;
530  Address end_address = it->first + it->second.size;
531  return addr < end_address ? it->second.entry : nullptr;
532}
533
534void CodeMap::MoveCode(Address from, Address to) {
535  if (from == to) return;
536  auto it = code_map_.find(from);
537  if (it == code_map_.end()) return;
538  CodeEntryInfo info = it->second;
539  code_map_.erase(it);
540  AddCode(to, info.entry, info.size);
541}
542
543void CodeMap::Print() {
544  for (auto it = code_map_.begin(); it != code_map_.end(); ++it) {
545    base::OS::Print("%p %5d %s\n", static_cast<void*>(it->first),
546                    it->second.size, it->second.entry->name());
547  }
548}
549
550CpuProfilesCollection::CpuProfilesCollection(Isolate* isolate)
551    : resource_names_(isolate->heap()),
552      profiler_(nullptr),
553      current_profiles_semaphore_(1) {}
554
555static void DeleteCpuProfile(CpuProfile** profile_ptr) {
556  delete *profile_ptr;
557}
558
559
560CpuProfilesCollection::~CpuProfilesCollection() {
561  finished_profiles_.Iterate(DeleteCpuProfile);
562  current_profiles_.Iterate(DeleteCpuProfile);
563}
564
565
566bool CpuProfilesCollection::StartProfiling(const char* title,
567                                           bool record_samples) {
568  current_profiles_semaphore_.Wait();
569  if (current_profiles_.length() >= kMaxSimultaneousProfiles) {
570    current_profiles_semaphore_.Signal();
571    return false;
572  }
573  for (int i = 0; i < current_profiles_.length(); ++i) {
574    if (strcmp(current_profiles_[i]->title(), title) == 0) {
575      // Ignore attempts to start profile with the same title...
576      current_profiles_semaphore_.Signal();
577      // ... though return true to force it collect a sample.
578      return true;
579    }
580  }
581  current_profiles_.Add(new CpuProfile(profiler_, title, record_samples));
582  current_profiles_semaphore_.Signal();
583  return true;
584}
585
586
587CpuProfile* CpuProfilesCollection::StopProfiling(const char* title) {
588  const int title_len = StrLength(title);
589  CpuProfile* profile = nullptr;
590  current_profiles_semaphore_.Wait();
591  for (int i = current_profiles_.length() - 1; i >= 0; --i) {
592    if (title_len == 0 || strcmp(current_profiles_[i]->title(), title) == 0) {
593      profile = current_profiles_.Remove(i);
594      break;
595    }
596  }
597  current_profiles_semaphore_.Signal();
598
599  if (!profile) return nullptr;
600  profile->FinishProfile();
601  finished_profiles_.Add(profile);
602  return profile;
603}
604
605
606bool CpuProfilesCollection::IsLastProfile(const char* title) {
607  // Called from VM thread, and only it can mutate the list,
608  // so no locking is needed here.
609  if (current_profiles_.length() != 1) return false;
610  return StrLength(title) == 0
611      || strcmp(current_profiles_[0]->title(), title) == 0;
612}
613
614
615void CpuProfilesCollection::RemoveProfile(CpuProfile* profile) {
616  // Called from VM thread for a completed profile.
617  for (int i = 0; i < finished_profiles_.length(); i++) {
618    if (profile == finished_profiles_[i]) {
619      finished_profiles_.Remove(i);
620      return;
621    }
622  }
623  UNREACHABLE();
624}
625
626void CpuProfilesCollection::AddPathToCurrentProfiles(
627    base::TimeTicks timestamp, const std::vector<CodeEntry*>& path,
628    int src_line, bool update_stats) {
629  // As starting / stopping profiles is rare relatively to this
630  // method, we don't bother minimizing the duration of lock holding,
631  // e.g. copying contents of the list to a local vector.
632  current_profiles_semaphore_.Wait();
633  for (int i = 0; i < current_profiles_.length(); ++i) {
634    current_profiles_[i]->AddPath(timestamp, path, src_line, update_stats);
635  }
636  current_profiles_semaphore_.Signal();
637}
638
639ProfileGenerator::ProfileGenerator(CpuProfilesCollection* profiles)
640    : profiles_(profiles) {}
641
642void ProfileGenerator::RecordTickSample(const TickSample& sample) {
643  std::vector<CodeEntry*> entries;
644  // Conservatively reserve space for stack frames + pc + function + vm-state.
645  // There could in fact be more of them because of inlined entries.
646  entries.reserve(sample.frames_count + 3);
647
648  // The ProfileNode knows nothing about all versions of generated code for
649  // the same JS function. The line number information associated with
650  // the latest version of generated code is used to find a source line number
651  // for a JS function. Then, the detected source line is passed to
652  // ProfileNode to increase the tick count for this source line.
653  int src_line = v8::CpuProfileNode::kNoLineNumberInfo;
654  bool src_line_not_found = true;
655
656  if (sample.pc != nullptr) {
657    if (sample.has_external_callback && sample.state == EXTERNAL) {
658      // Don't use PC when in external callback code, as it can point
659      // inside callback's code, and we will erroneously report
660      // that a callback calls itself.
661      entries.push_back(FindEntry(sample.external_callback_entry));
662    } else {
663      CodeEntry* pc_entry = FindEntry(sample.pc);
664      // If there is no pc_entry we're likely in native code.
665      // Find out, if top of stack was pointing inside a JS function
666      // meaning that we have encountered a frameless invocation.
667      if (!pc_entry && !sample.has_external_callback) {
668        pc_entry = FindEntry(sample.tos);
669      }
670      // If pc is in the function code before it set up stack frame or after the
671      // frame was destroyed SafeStackFrameIterator incorrectly thinks that
672      // ebp contains return address of the current function and skips caller's
673      // frame. Check for this case and just skip such samples.
674      if (pc_entry) {
675        int pc_offset = static_cast<int>(reinterpret_cast<Address>(sample.pc) -
676                                         pc_entry->instruction_start());
677        src_line = pc_entry->GetSourceLine(pc_offset);
678        if (src_line == v8::CpuProfileNode::kNoLineNumberInfo) {
679          src_line = pc_entry->line_number();
680        }
681        src_line_not_found = false;
682        entries.push_back(pc_entry);
683
684        if (pc_entry->builtin_id() == Builtins::kFunctionPrototypeApply ||
685            pc_entry->builtin_id() == Builtins::kFunctionPrototypeCall) {
686          // When current function is either the Function.prototype.apply or the
687          // Function.prototype.call builtin the top frame is either frame of
688          // the calling JS function or internal frame.
689          // In the latter case we know the caller for sure but in the
690          // former case we don't so we simply replace the frame with
691          // 'unresolved' entry.
692          if (!sample.has_external_callback) {
693            entries.push_back(CodeEntry::unresolved_entry());
694          }
695        }
696      }
697    }
698
699    for (unsigned i = 0; i < sample.frames_count; ++i) {
700      Address stack_pos = reinterpret_cast<Address>(sample.stack[i]);
701      CodeEntry* entry = FindEntry(stack_pos);
702      if (entry) {
703        // Find out if the entry has an inlining stack associated.
704        int pc_offset =
705            static_cast<int>(stack_pos - entry->instruction_start());
706        const std::vector<CodeEntry*>* inline_stack =
707            entry->GetInlineStack(pc_offset);
708        if (inline_stack) {
709          entries.insert(entries.end(), inline_stack->rbegin(),
710                         inline_stack->rend());
711        }
712        // Skip unresolved frames (e.g. internal frame) and get source line of
713        // the first JS caller.
714        if (src_line_not_found) {
715          src_line = entry->GetSourceLine(pc_offset);
716          if (src_line == v8::CpuProfileNode::kNoLineNumberInfo) {
717            src_line = entry->line_number();
718          }
719          src_line_not_found = false;
720        }
721      }
722      entries.push_back(entry);
723    }
724  }
725
726  if (FLAG_prof_browser_mode) {
727    bool no_symbolized_entries = true;
728    for (auto e : entries) {
729      if (e != NULL) {
730        no_symbolized_entries = false;
731        break;
732      }
733    }
734    // If no frames were symbolized, put the VM state entry in.
735    if (no_symbolized_entries) {
736      entries.push_back(EntryForVMState(sample.state));
737    }
738  }
739
740  profiles_->AddPathToCurrentProfiles(sample.timestamp, entries, src_line,
741                                      sample.update_stats);
742}
743
744CodeEntry* ProfileGenerator::FindEntry(void* address) {
745  return code_map_.FindEntry(reinterpret_cast<Address>(address));
746}
747
748CodeEntry* ProfileGenerator::EntryForVMState(StateTag tag) {
749  switch (tag) {
750    case GC:
751      return CodeEntry::gc_entry();
752    case JS:
753    case COMPILER:
754    // DOM events handlers are reported as OTHER / EXTERNAL entries.
755    // To avoid confusing people, let's put all these entries into
756    // one bucket.
757    case OTHER:
758    case EXTERNAL:
759      return CodeEntry::program_entry();
760    case IDLE:
761      return CodeEntry::idle_entry();
762    default: return NULL;
763  }
764}
765
766}  // namespace internal
767}  // namespace v8
768