src/cpu-profiler.cc

// Copyright 2012 the V8 project authors. All rights reserved.
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// 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
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// 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,
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#include "v8.h"

#include "cpu-profiler-inl.h"

#include "compiler.h"
#include "frames-inl.h"
#include "hashmap.h"
#include "log-inl.h"
#include "vm-state-inl.h"

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

namespace v8 {
namespace internal {

static const int kTickSamplesBufferChunkSize = 64 * KB;
static const int kTickSamplesBufferChunksCount = 16;
static const int kProfilerStackSize = 64 * KB;


ProfilerEventsProcessor::ProfilerEventsProcessor(ProfileGenerator* generator)
    : Thread(Thread::Options("v8:ProfEvntProc", kProfilerStackSize)),
      generator_(generator),
      running_(true),
      ticks_buffer_(sizeof(TickSampleEventRecord),
                    kTickSamplesBufferChunkSize,
                    kTickSamplesBufferChunksCount),
      last_code_event_id_(0), last_processed_code_event_id_(0) {
}


void ProfilerEventsProcessor::Enqueue(const CodeEventsContainer& event) {
  event.generic.order = ++last_code_event_id_;
  events_buffer_.Enqueue(event);
}


void ProfilerEventsProcessor::AddCurrentStack(Isolate* isolate) {
  TickSampleEventRecord record(last_code_event_id_);
  TickSample* sample = &record.sample;
  sample->state = isolate->current_vm_state();
  sample->pc = reinterpret_cast<Address>(sample);  // Not NULL.
  for (StackTraceFrameIterator it(isolate);
       !it.done() && sample->frames_count < TickSample::kMaxFramesCount;
       it.Advance()) {
    sample->stack[sample->frames_count++] = it.frame()->pc();
  }
  ticks_from_vm_buffer_.Enqueue(record);
}


void ProfilerEventsProcessor::StopSynchronously() {
  if (!running_) return;
  running_ = false;
  Join();
}


bool ProfilerEventsProcessor::ProcessCodeEvent() {
  CodeEventsContainer record;
  if (events_buffer_.Dequeue(&record)) {
    switch (record.generic.type) {
#define PROFILER_TYPE_CASE(type, clss)                          \
      case CodeEventRecord::type:                               \
        record.clss##_.UpdateCodeMap(generator_->code_map());   \
        break;

      CODE_EVENTS_TYPE_LIST(PROFILER_TYPE_CASE)

#undef PROFILER_TYPE_CASE
      default: return true;  // Skip record.
    }
    last_processed_code_event_id_ = record.generic.order;
    return true;
  }
  return false;
}


bool ProfilerEventsProcessor::ProcessTicks() {
  while (true) {
    if (!ticks_from_vm_buffer_.IsEmpty()
        && ticks_from_vm_buffer_.Peek()->order ==
           last_processed_code_event_id_) {
      TickSampleEventRecord record;
      ticks_from_vm_buffer_.Dequeue(&record);
      generator_->RecordTickSample(record.sample);
    }

    const TickSampleEventRecord* rec =
        TickSampleEventRecord::cast(ticks_buffer_.StartDequeue());
    if (rec == NULL) return !ticks_from_vm_buffer_.IsEmpty();
    // Make a local copy of tick sample record to ensure that it won't
    // be modified as we are processing it. This is possible as the
    // sampler writes w/o any sync to the queue, so if the processor
    // will get far behind, a record may be modified right under its
    // feet.
    TickSampleEventRecord record = *rec;
    if (record.order != last_processed_code_event_id_) return true;

    // A paranoid check to make sure that we don't get a memory overrun
    // in case of frames_count having a wild value.
    if (record.sample.frames_count < 0
        || record.sample.frames_count > TickSample::kMaxFramesCount)
      record.sample.frames_count = 0;
    generator_->RecordTickSample(record.sample);
    ticks_buffer_.FinishDequeue();
  }
}


void ProfilerEventsProcessor::Run() {
  while (running_) {
    // Process ticks until we have any.
    if (ProcessTicks()) {
      // All ticks of the current last_processed_code_event_id_ are processed,
      // proceed to the next code event.
      ProcessCodeEvent();
    }
    YieldCPU();
  }

  // Process remaining tick events.
  ticks_buffer_.FlushResidualRecords();
  do {
    ProcessTicks();
  } while (ProcessCodeEvent());
}


int CpuProfiler::GetProfilesCount() {
  // The count of profiles doesn't depend on a security token.
  return profiles_->profiles()->length();
}


CpuProfile* CpuProfiler::GetProfile(int index) {
  return profiles_->profiles()->at(index);
}


TickSample* CpuProfiler::TickSampleEvent() {
  if (is_profiling_) return processor_->TickSampleEvent();
  return NULL;
}


void CpuProfiler::DeleteAllProfiles() {
  if (is_profiling_) StopProcessor();
  ResetProfiles();
}


void CpuProfiler::DeleteProfile(CpuProfile* profile) {
  profiles_->RemoveProfile(profile);
  delete profile;
}


static bool FilterOutCodeCreateEvent(Logger::LogEventsAndTags tag) {
  return FLAG_prof_browser_mode
      && (tag != Logger::CALLBACK_TAG
          && tag != Logger::FUNCTION_TAG
          && tag != Logger::LAZY_COMPILE_TAG
          && tag != Logger::REG_EXP_TAG
          && tag != Logger::SCRIPT_TAG);
}


void CpuProfiler::CallbackEvent(Name* name, Address entry_point) {
  if (FilterOutCodeCreateEvent(Logger::CALLBACK_TAG)) return;
  CodeEventsContainer evt_rec(CodeEventRecord::CODE_CREATION);
  CodeCreateEventRecord* rec = &evt_rec.CodeCreateEventRecord_;
  rec->start = entry_point;
  rec->entry = profiles_->NewCodeEntry(
      Logger::CALLBACK_TAG,
      profiles_->GetName(name));
  rec->size = 1;
  rec->shared = NULL;
  processor_->Enqueue(evt_rec);
}


void CpuProfiler::CodeCreateEvent(Logger::LogEventsAndTags tag,
                                  Code* code,
                                  const char* name) {
  if (FilterOutCodeCreateEvent(tag)) return;
  CodeEventsContainer evt_rec(CodeEventRecord::CODE_CREATION);
  CodeCreateEventRecord* rec = &evt_rec.CodeCreateEventRecord_;
  rec->start = code->address();
  rec->entry = profiles_->NewCodeEntry(tag, profiles_->GetFunctionName(name));
  rec->size = code->ExecutableSize();
  rec->shared = NULL;
  processor_->Enqueue(evt_rec);
}


void CpuProfiler::CodeCreateEvent(Logger::LogEventsAndTags tag,
                                  Code* code,
                                  Name* name) {
  if (FilterOutCodeCreateEvent(tag)) return;
  CodeEventsContainer evt_rec(CodeEventRecord::CODE_CREATION);
  CodeCreateEventRecord* rec = &evt_rec.CodeCreateEventRecord_;
  rec->start = code->address();
  rec->entry = profiles_->NewCodeEntry(tag, profiles_->GetFunctionName(name));
  rec->size = code->ExecutableSize();
  rec->shared = NULL;
  processor_->Enqueue(evt_rec);
}


void CpuProfiler::CodeCreateEvent(Logger::LogEventsAndTags tag,
                                  Code* code,
                                  SharedFunctionInfo* shared,
                                  CompilationInfo* info,
                                  Name* name) {
  if (FilterOutCodeCreateEvent(tag)) return;
  CodeEventsContainer evt_rec(CodeEventRecord::CODE_CREATION);
  CodeCreateEventRecord* rec = &evt_rec.CodeCreateEventRecord_;
  rec->start = code->address();
  rec->entry = profiles_->NewCodeEntry(tag, profiles_->GetFunctionName(name));
  if (info) {
    rec->entry->set_no_frame_ranges(info->ReleaseNoFrameRanges());
  }
  if (shared->script()->IsScript()) {
    ASSERT(Script::cast(shared->script()));
    Script* script = Script::cast(shared->script());
    rec->entry->set_script_id(script->id()->value());
  }
  rec->size = code->ExecutableSize();
  rec->shared = shared->address();
  processor_->Enqueue(evt_rec);
}


void CpuProfiler::CodeCreateEvent(Logger::LogEventsAndTags tag,
                                  Code* code,
                                  SharedFunctionInfo* shared,
                                  CompilationInfo* info,
                                  String* source, int line) {
  if (FilterOutCodeCreateEvent(tag)) return;
  CodeEventsContainer evt_rec(CodeEventRecord::CODE_CREATION);
  CodeCreateEventRecord* rec = &evt_rec.CodeCreateEventRecord_;
  rec->start = code->address();
  rec->entry = profiles_->NewCodeEntry(
      tag,
      profiles_->GetFunctionName(shared->DebugName()),
      CodeEntry::kEmptyNamePrefix,
      profiles_->GetName(source),
      line);
  if (info) {
    rec->entry->set_no_frame_ranges(info->ReleaseNoFrameRanges());
  }
  ASSERT(Script::cast(shared->script()));
  Script* script = Script::cast(shared->script());
  rec->entry->set_script_id(script->id()->value());
  rec->size = code->ExecutableSize();
  rec->shared = shared->address();
  processor_->Enqueue(evt_rec);
}


void CpuProfiler::CodeCreateEvent(Logger::LogEventsAndTags tag,
                                  Code* code,
                                  int args_count) {
  if (FilterOutCodeCreateEvent(tag)) return;
  CodeEventsContainer evt_rec(CodeEventRecord::CODE_CREATION);
  CodeCreateEventRecord* rec = &evt_rec.CodeCreateEventRecord_;
  rec->start = code->address();
  rec->entry = profiles_->NewCodeEntry(
      tag,
      profiles_->GetName(args_count),
      "args_count: ");
  rec->size = code->ExecutableSize();
  rec->shared = NULL;
  processor_->Enqueue(evt_rec);
}


void CpuProfiler::CodeMoveEvent(Address from, Address to) {
  CodeEventsContainer evt_rec(CodeEventRecord::CODE_MOVE);
  CodeMoveEventRecord* rec = &evt_rec.CodeMoveEventRecord_;
  rec->from = from;
  rec->to = to;
  processor_->Enqueue(evt_rec);
}


void CpuProfiler::CodeDeleteEvent(Address from) {
}


void CpuProfiler::SharedFunctionInfoMoveEvent(Address from, Address to) {
  CodeEventsContainer evt_rec(CodeEventRecord::SHARED_FUNC_MOVE);
  SharedFunctionInfoMoveEventRecord* rec =
      &evt_rec.SharedFunctionInfoMoveEventRecord_;
  rec->from = from;
  rec->to = to;
  processor_->Enqueue(evt_rec);
}


void CpuProfiler::GetterCallbackEvent(Name* name, Address entry_point) {
  if (FilterOutCodeCreateEvent(Logger::CALLBACK_TAG)) return;
  CodeEventsContainer evt_rec(CodeEventRecord::CODE_CREATION);
  CodeCreateEventRecord* rec = &evt_rec.CodeCreateEventRecord_;
  rec->start = entry_point;
  rec->entry = profiles_->NewCodeEntry(
      Logger::CALLBACK_TAG,
      profiles_->GetName(name),
      "get ");
  rec->size = 1;
  rec->shared = NULL;
  processor_->Enqueue(evt_rec);
}


void CpuProfiler::RegExpCodeCreateEvent(Code* code, String* source) {
  if (FilterOutCodeCreateEvent(Logger::REG_EXP_TAG)) return;
  CodeEventsContainer evt_rec(CodeEventRecord::CODE_CREATION);
  CodeCreateEventRecord* rec = &evt_rec.CodeCreateEventRecord_;
  rec->start = code->address();
  rec->entry = profiles_->NewCodeEntry(
      Logger::REG_EXP_TAG,
      profiles_->GetName(source),
      "RegExp: ");
  rec->size = code->ExecutableSize();
  processor_->Enqueue(evt_rec);
}


void CpuProfiler::SetterCallbackEvent(Name* name, Address entry_point) {
  if (FilterOutCodeCreateEvent(Logger::CALLBACK_TAG)) return;
  CodeEventsContainer evt_rec(CodeEventRecord::CODE_CREATION);
  CodeCreateEventRecord* rec = &evt_rec.CodeCreateEventRecord_;
  rec->start = entry_point;
  rec->entry = profiles_->NewCodeEntry(
      Logger::CALLBACK_TAG,
      profiles_->GetName(name),
      "set ");
  rec->size = 1;
  rec->shared = NULL;
  processor_->Enqueue(evt_rec);
}


CpuProfiler::CpuProfiler(Isolate* isolate)
    : isolate_(isolate),
      profiles_(new CpuProfilesCollection()),
      next_profile_uid_(1),
      generator_(NULL),
      processor_(NULL),
      need_to_stop_sampler_(false),
      is_profiling_(false) {
}


CpuProfiler::CpuProfiler(Isolate* isolate,
                         CpuProfilesCollection* test_profiles,
                         ProfileGenerator* test_generator,
                         ProfilerEventsProcessor* test_processor)
    : isolate_(isolate),
      profiles_(test_profiles),
      next_profile_uid_(1),
      generator_(test_generator),
      processor_(test_processor),
      need_to_stop_sampler_(false),
      is_profiling_(false) {
}


CpuProfiler::~CpuProfiler() {
  ASSERT(!is_profiling_);
  delete profiles_;
}


void CpuProfiler::ResetProfiles() {
  delete profiles_;
  profiles_ = new CpuProfilesCollection();
}


void CpuProfiler::StartProfiling(const char* title, bool record_samples) {
  if (profiles_->StartProfiling(title, next_profile_uid_++, record_samples)) {
    StartProcessorIfNotStarted();
  }
  processor_->AddCurrentStack(isolate_);
}


void CpuProfiler::StartProfiling(String* title, bool record_samples) {
  StartProfiling(profiles_->GetName(title), record_samples);
}


void CpuProfiler::StartProcessorIfNotStarted() {
  if (processor_ == NULL) {
    Logger* logger = isolate_->logger();
    // Disable logging when using the new implementation.
    saved_logging_nesting_ = logger->logging_nesting_;
    logger->logging_nesting_ = 0;
    generator_ = new ProfileGenerator(profiles_);
    processor_ = new ProfilerEventsProcessor(generator_);
    is_profiling_ = true;
    processor_->StartSynchronously();
    // Enumerate stuff we already have in the heap.
    ASSERT(isolate_->heap()->HasBeenSetUp());
    if (!FLAG_prof_browser_mode) {
      logger->LogCodeObjects();
    }
    logger->LogCompiledFunctions();
    logger->LogAccessorCallbacks();
    LogBuiltins();
    // Enable stack sampling.
    Sampler* sampler = logger->sampler();
    sampler->IncreaseProfilingDepth();
    if (!sampler->IsActive()) {
      sampler->Start();
      need_to_stop_sampler_ = true;
    }
  }
}


CpuProfile* CpuProfiler::StopProfiling(const char* title) {
  if (!is_profiling_) return NULL;
  const double actual_sampling_rate = generator_->actual_sampling_rate();
  StopProcessorIfLastProfile(title);
  CpuProfile* result = profiles_->StopProfiling(title, actual_sampling_rate);
  if (result != NULL) {
    result->Print();
  }
  return result;
}


CpuProfile* CpuProfiler::StopProfiling(String* title) {
  if (!is_profiling_) return NULL;
  const double actual_sampling_rate = generator_->actual_sampling_rate();
  const char* profile_title = profiles_->GetName(title);
  StopProcessorIfLastProfile(profile_title);
  return profiles_->StopProfiling(profile_title, actual_sampling_rate);
}


void CpuProfiler::StopProcessorIfLastProfile(const char* title) {
  if (profiles_->IsLastProfile(title)) StopProcessor();
}


void CpuProfiler::StopProcessor() {
  Logger* logger = isolate_->logger();
  Sampler* sampler = reinterpret_cast<Sampler*>(logger->ticker_);
  sampler->DecreaseProfilingDepth();
  if (need_to_stop_sampler_) {
    sampler->Stop();
    need_to_stop_sampler_ = false;
  }
  is_profiling_ = false;
  processor_->StopSynchronously();
  delete processor_;
  delete generator_;
  processor_ = NULL;
  generator_ = NULL;
  logger->logging_nesting_ = saved_logging_nesting_;
}


void CpuProfiler::LogBuiltins() {
  Builtins* builtins = isolate_->builtins();
  ASSERT(builtins->is_initialized());
  for (int i = 0; i < Builtins::builtin_count; i++) {
    CodeEventsContainer evt_rec(CodeEventRecord::REPORT_BUILTIN);
    ReportBuiltinEventRecord* rec = &evt_rec.ReportBuiltinEventRecord_;
    Builtins::Name id = static_cast<Builtins::Name>(i);
    rec->start = builtins->builtin(id)->address();
    rec->builtin_id = id;
    processor_->Enqueue(evt_rec);
  }
}


} }  // namespace v8::internal