node/deps/v8/src/profile-generator.cc

// Copyright 2010 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
//       notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
//       copyright notice, this list of conditions and the following
//       disclaimer in the documentation and/or other materials provided
//       with the distribution.
//     * Neither the name of Google Inc. nor the names of its
//       contributors may be used to endorse or promote products derived
//       from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#ifdef ENABLE_LOGGING_AND_PROFILING

#include "v8.h"

#include "profile-generator-inl.h"

#include "../include/v8-profiler.h"

namespace v8 {
namespace internal {


const char* CodeEntry::kEmptyNamePrefix = "";
unsigned CodeEntry::next_call_uid_ = 1;


ProfileNode* ProfileNode::FindChild(CodeEntry* entry) {
  HashMap::Entry* map_entry =
      children_.Lookup(entry, CodeEntryHash(entry), false);
  return map_entry != NULL ?
      reinterpret_cast<ProfileNode*>(map_entry->value) : NULL;
}


ProfileNode* ProfileNode::FindOrAddChild(CodeEntry* entry) {
  HashMap::Entry* map_entry =
      children_.Lookup(entry, CodeEntryHash(entry), true);
  if (map_entry->value == NULL) {
    // New node added.
    ProfileNode* new_node = new ProfileNode(tree_, entry);
    map_entry->value = new_node;
    children_list_.Add(new_node);
  }
  return reinterpret_cast<ProfileNode*>(map_entry->value);
}


double ProfileNode::GetSelfMillis() const {
  return tree_->TicksToMillis(self_ticks_);
}


double ProfileNode::GetTotalMillis() const {
  return tree_->TicksToMillis(total_ticks_);
}


void ProfileNode::Print(int indent) {
  OS::Print("%5u %5u %*c %s%s",
            total_ticks_, self_ticks_,
            indent, ' ',
            entry_->name_prefix(),
            entry_->name());
  if (entry_->resource_name()[0] != '\0')
    OS::Print(" %s:%d", entry_->resource_name(), entry_->line_number());
  OS::Print("\n");
  for (HashMap::Entry* p = children_.Start();
       p != NULL;
       p = children_.Next(p)) {
    reinterpret_cast<ProfileNode*>(p->value)->Print(indent + 2);
  }
}


namespace {

class DeleteNodesCallback {
 public:
  void AfterAllChildrenTraversed(ProfileNode* node) {
    delete node;
  }

  void AfterChildTraversed(ProfileNode*, ProfileNode*) { }
};

}  // namespace


ProfileTree::ProfileTree()
    : root_entry_(Logger::FUNCTION_TAG, "", "(root)", "", 0),
      root_(new ProfileNode(this, &root_entry_)) {
}


ProfileTree::~ProfileTree() {
  DeleteNodesCallback cb;
  TraverseDepthFirstPostOrder(&cb);
}


void ProfileTree::AddPathFromEnd(const Vector<CodeEntry*>& path) {
  ProfileNode* node = root_;
  for (CodeEntry** entry = path.start() + path.length() - 1;
       entry != path.start() - 1;
       --entry) {
    if (*entry != NULL) {
      node = node->FindOrAddChild(*entry);
    }
  }
  node->IncrementSelfTicks();
}


void ProfileTree::AddPathFromStart(const Vector<CodeEntry*>& path) {
  ProfileNode* node = root_;
  for (CodeEntry** entry = path.start();
       entry != path.start() + path.length();
       ++entry) {
    if (*entry != NULL) {
      node = node->FindOrAddChild(*entry);
    }
  }
  node->IncrementSelfTicks();
}


void ProfileTree::SetTickRatePerMs(double ticks_per_ms) {
  ms_to_ticks_scale_ = ticks_per_ms > 0 ? 1.0 / ticks_per_ms : 1.0;
}


namespace {

class Position {
 public:
  explicit Position(ProfileNode* node)
      : node(node), child_idx_(0) { }
  INLINE(ProfileNode* current_child()) {
    return node->children()->at(child_idx_);
  }
  INLINE(bool has_current_child()) {
    return child_idx_ < node->children()->length();
  }
  INLINE(void next_child()) { ++child_idx_; }

  ProfileNode* node;
 private:
  int child_idx_;
};

}  // namespace


// Non-recursive implementation of a depth-first post-order tree traversal.
template <typename Callback>
void ProfileTree::TraverseDepthFirstPostOrder(Callback* callback) {
  List<Position> stack(10);
  stack.Add(Position(root_));
  do {
    Position& current = stack.last();
    if (current.has_current_child()) {
      stack.Add(Position(current.current_child()));
    } else {
      callback->AfterAllChildrenTraversed(current.node);
      if (stack.length() > 1) {
        Position& parent = stack[stack.length() - 2];
        callback->AfterChildTraversed(parent.node, current.node);
        parent.next_child();
        // Remove child from the stack.
        stack.RemoveLast();
      }
    }
  } while (stack.length() > 1 || stack.last().has_current_child());
}


namespace {

class CalculateTotalTicksCallback {
 public:
  void AfterAllChildrenTraversed(ProfileNode* node) {
    node->IncreaseTotalTicks(node->self_ticks());
  }

  void AfterChildTraversed(ProfileNode* parent, ProfileNode* child) {
    parent->IncreaseTotalTicks(child->total_ticks());
  }
};

}  // namespace


void ProfileTree::CalculateTotalTicks() {
  CalculateTotalTicksCallback cb;
  TraverseDepthFirstPostOrder(&cb);
}


void ProfileTree::ShortPrint() {
  OS::Print("root: %u %u %.2fms %.2fms\n",
            root_->total_ticks(), root_->self_ticks(),
            root_->GetTotalMillis(), root_->GetSelfMillis());
}


void CpuProfile::AddPath(const Vector<CodeEntry*>& path) {
  top_down_.AddPathFromEnd(path);
  bottom_up_.AddPathFromStart(path);
}


void CpuProfile::CalculateTotalTicks() {
  top_down_.CalculateTotalTicks();
  bottom_up_.CalculateTotalTicks();
}


void CpuProfile::SetActualSamplingRate(double actual_sampling_rate) {
  top_down_.SetTickRatePerMs(actual_sampling_rate);
  bottom_up_.SetTickRatePerMs(actual_sampling_rate);
}


void CpuProfile::ShortPrint() {
  OS::Print("top down ");
  top_down_.ShortPrint();
  OS::Print("bottom up ");
  bottom_up_.ShortPrint();
}


void CpuProfile::Print() {
  OS::Print("[Top down]:\n");
  top_down_.Print();
  OS::Print("[Bottom up]:\n");
  bottom_up_.Print();
}


const CodeMap::CodeTreeConfig::Key CodeMap::CodeTreeConfig::kNoKey = NULL;
const CodeMap::CodeTreeConfig::Value CodeMap::CodeTreeConfig::kNoValue =
    CodeMap::CodeEntryInfo(NULL, 0);


void CodeMap::AddAlias(Address alias, Address addr) {
  CodeTree::Locator locator;
  if (tree_.Find(addr, &locator)) {
    const CodeEntryInfo& entry_info = locator.value();
    tree_.Insert(alias, &locator);
    locator.set_value(entry_info);
  }
}


CodeEntry* CodeMap::FindEntry(Address addr) {
  CodeTree::Locator locator;
  if (tree_.FindGreatestLessThan(addr, &locator)) {
    // locator.key() <= addr. Need to check that addr is within entry.
    const CodeEntryInfo& entry = locator.value();
    if (addr < (locator.key() + entry.size))
      return entry.entry;
  }
  return NULL;
}


void CodeMap::CodeTreePrinter::Call(
    const Address& key, const CodeMap::CodeEntryInfo& value) {
  OS::Print("%p %5d %s\n", key, value.size, value.entry->name());
}


void CodeMap::Print() {
  CodeTreePrinter printer;
  tree_.ForEach(&printer);
}


CpuProfilesCollection::CpuProfilesCollection()
    : function_and_resource_names_(StringsMatch),
      profiles_uids_(CpuProfilesMatch),
      current_profiles_semaphore_(OS::CreateSemaphore(1)) {
}


static void DeleteArgsCountName(char** name_ptr) {
  DeleteArray(*name_ptr);
}


static void DeleteCodeEntry(CodeEntry** entry_ptr) {
  delete *entry_ptr;
}

static void DeleteCpuProfile(CpuProfile** profile_ptr) {
  delete *profile_ptr;
}


CpuProfilesCollection::~CpuProfilesCollection() {
  delete current_profiles_semaphore_;
  current_profiles_.Iterate(DeleteCpuProfile);
  profiles_.Iterate(DeleteCpuProfile);
  code_entries_.Iterate(DeleteCodeEntry);
  args_count_names_.Iterate(DeleteArgsCountName);
  for (HashMap::Entry* p = function_and_resource_names_.Start();
       p != NULL;
       p = function_and_resource_names_.Next(p)) {
    DeleteArray(reinterpret_cast<const char*>(p->value));
  }
}


bool CpuProfilesCollection::StartProfiling(const char* title, unsigned uid) {
  ASSERT(uid > 0);
  current_profiles_semaphore_->Wait();
  for (int i = 0; i < current_profiles_.length(); ++i) {
    if (strcmp(current_profiles_[i]->title(), title) == 0) {
      // Ignore attempts to start profile with the same title.
      current_profiles_semaphore_->Signal();
      return false;
    }
  }
  current_profiles_.Add(new CpuProfile(title, uid));
  current_profiles_semaphore_->Signal();
  return true;
}


bool CpuProfilesCollection::StartProfiling(String* title, unsigned uid) {
  return StartProfiling(GetName(title), uid);
}


CpuProfile* CpuProfilesCollection::StopProfiling(const char* title,
                                                 double actual_sampling_rate) {
  const int title_len = StrLength(title);
  CpuProfile* profile = NULL;
  current_profiles_semaphore_->Wait();
  for (int i = current_profiles_.length() - 1; i >= 0; --i) {
    if (title_len == 0 || strcmp(current_profiles_[i]->title(), title) == 0) {
      profile = current_profiles_.Remove(i);
      break;
    }
  }
  current_profiles_semaphore_->Signal();

  if (profile != NULL) {
    profile->CalculateTotalTicks();
    profile->SetActualSamplingRate(actual_sampling_rate);
    profiles_.Add(profile);
    HashMap::Entry* entry =
        profiles_uids_.Lookup(reinterpret_cast<void*>(profile->uid()),
                              static_cast<uint32_t>(profile->uid()),
                              true);
    ASSERT(entry->value == NULL);
    entry->value = profile;
  }
  return profile;
}


CpuProfile* CpuProfilesCollection::StopProfiling(String* title,
                                                 double actual_sampling_rate) {
  return StopProfiling(GetName(title), actual_sampling_rate);
}


CpuProfile* CpuProfilesCollection::GetProfile(unsigned uid) {
  HashMap::Entry* entry = profiles_uids_.Lookup(reinterpret_cast<void*>(uid),
                                                static_cast<uint32_t>(uid),
                                                false);
  return entry != NULL ? reinterpret_cast<CpuProfile*>(entry->value) : NULL;
}


CodeEntry* CpuProfilesCollection::NewCodeEntry(Logger::LogEventsAndTags tag,
                                               String* name,
                                               String* resource_name,
                                               int line_number) {
  CodeEntry* entry = new CodeEntry(tag,
                                   CodeEntry::kEmptyNamePrefix,
                                   GetFunctionName(name),
                                   GetName(resource_name),
                                   line_number);
  code_entries_.Add(entry);
  return entry;
}


CodeEntry* CpuProfilesCollection::NewCodeEntry(Logger::LogEventsAndTags tag,
                                               const char* name) {
  CodeEntry* entry = new CodeEntry(tag,
                                   CodeEntry::kEmptyNamePrefix,
                                   GetFunctionName(name),
                                   "",
                                   v8::CpuProfileNode::kNoLineNumberInfo);
  code_entries_.Add(entry);
  return entry;
}


CodeEntry* CpuProfilesCollection::NewCodeEntry(Logger::LogEventsAndTags tag,
                                               const char* name_prefix,
                                               String* name) {
  CodeEntry* entry = new CodeEntry(tag,
                                   name_prefix,
                                   GetName(name),
                                   "",
                                   v8::CpuProfileNode::kNoLineNumberInfo);
  code_entries_.Add(entry);
  return entry;
}


CodeEntry* CpuProfilesCollection::NewCodeEntry(Logger::LogEventsAndTags tag,
                                               int args_count) {
  CodeEntry* entry = new CodeEntry(tag,
                                   "args_count: ",
                                   GetName(args_count),
                                   "",
                                   v8::CpuProfileNode::kNoLineNumberInfo);
  code_entries_.Add(entry);
  return entry;
}


const char* CpuProfilesCollection::GetName(String* name) {
  if (name->IsString()) {
    char* c_name =
        name->ToCString(DISALLOW_NULLS, ROBUST_STRING_TRAVERSAL).Detach();
    HashMap::Entry* cache_entry =
        function_and_resource_names_.Lookup(c_name,
                                            name->Hash(),
                                            true);
    if (cache_entry->value == NULL) {
      // New entry added.
      cache_entry->value = c_name;
    } else {
      DeleteArray(c_name);
    }
    return reinterpret_cast<const char*>(cache_entry->value);
  } else {
    return "";
  }
}


const char* CpuProfilesCollection::GetName(int args_count) {
  ASSERT(args_count >= 0);
  if (args_count_names_.length() <= args_count) {
    args_count_names_.AddBlock(
        NULL, args_count - args_count_names_.length() + 1);
  }
  if (args_count_names_[args_count] == NULL) {
    const int kMaximumNameLength = 32;
    char* name = NewArray<char>(kMaximumNameLength);
    OS::SNPrintF(Vector<char>(name, kMaximumNameLength), "%d", args_count);
    args_count_names_[args_count] = name;
  }
  return args_count_names_[args_count];
}


void CpuProfilesCollection::AddPathToCurrentProfiles(
    const Vector<CodeEntry*>& path) {
  // As starting / stopping profiles is rare relatively to this
  // method, we don't bother minimizing the duration of lock holding,
  // e.g. copying contents of the list to a local vector.
  current_profiles_semaphore_->Wait();
  for (int i = 0; i < current_profiles_.length(); ++i) {
    current_profiles_[i]->AddPath(path);
  }
  current_profiles_semaphore_->Signal();
}


void SampleRateCalculator::Tick() {
  if (--wall_time_query_countdown_ == 0)
    UpdateMeasurements(OS::TimeCurrentMillis());
}


void SampleRateCalculator::UpdateMeasurements(double current_time) {
  if (measurements_count_++ != 0) {
    const double measured_ticks_per_ms =
        (kWallTimeQueryIntervalMs * ticks_per_ms_) /
        (current_time - last_wall_time_);
    // Update the average value.
    ticks_per_ms_ +=
        (measured_ticks_per_ms - ticks_per_ms_) / measurements_count_;
    // Update the externally accessible result.
    result_ = static_cast<AtomicWord>(ticks_per_ms_ * kResultScale);
  }
  last_wall_time_ = current_time;
  wall_time_query_countdown_ =
      static_cast<unsigned>(kWallTimeQueryIntervalMs * ticks_per_ms_);
}


const char* ProfileGenerator::kAnonymousFunctionName = "(anonymous function)";
const char* ProfileGenerator::kProgramEntryName = "(program)";
const char* ProfileGenerator::kGarbageCollectorEntryName =
  "(garbage collector)";


ProfileGenerator::ProfileGenerator(CpuProfilesCollection* profiles)
    : profiles_(profiles),
      program_entry_(
          profiles->NewCodeEntry(Logger::FUNCTION_TAG, kProgramEntryName)),
      gc_entry_(
          profiles->NewCodeEntry(Logger::BUILTIN_TAG,
                                 kGarbageCollectorEntryName)) {
}


void ProfileGenerator::RecordTickSample(const TickSample& sample) {
  // Allocate space for stack frames + pc + function + vm-state.
  ScopedVector<CodeEntry*> entries(sample.frames_count + 3);
  // As actual number of decoded code entries may vary, initialize
  // entries vector with NULL values.
  CodeEntry** entry = entries.start();
  memset(entry, 0, entries.length() * sizeof(*entry));
  if (sample.pc != NULL) {
    *entry++ = code_map_.FindEntry(sample.pc);

    if (sample.function != NULL) {
      *entry = code_map_.FindEntry(sample.function);
      if (*entry != NULL && !(*entry)->is_js_function()) {
        *entry = NULL;
      } else {
        CodeEntry* pc_entry = *entries.start();
        if (pc_entry == NULL || pc_entry->is_js_function())
          *entry = NULL;
      }
      entry++;
    }

    for (const Address *stack_pos = sample.stack,
           *stack_end = stack_pos + sample.frames_count;
         stack_pos != stack_end;
         ++stack_pos) {
      *entry++ = code_map_.FindEntry(*stack_pos);
    }
  }

  if (FLAG_prof_browser_mode) {
    bool no_symbolized_entries = true;
    for (CodeEntry** e = entries.start(); e != entry; ++e) {
      if (*e != NULL) {
        no_symbolized_entries = false;
        break;
      }
    }
    // If no frames were symbolized, put the VM state entry in.
    if (no_symbolized_entries) {
      *entry++ = EntryForVMState(sample.state);
    }
  }

  profiles_->AddPathToCurrentProfiles(entries);
}

} }  // namespace v8::internal

#endif  // ENABLE_LOGGING_AND_PROFILING