CSE2410 Fall 2014 Bounce

// Copyright 2009 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

// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#include <stdarg.h>

#include "v8.h"

#include "bootstrapper.h"

#include "log.h"

#include "macro-assembler.h"

#include "platform.h"

#include "serialize.h"

#include "string-stream.h"

namespace v8 { namespace internal {

#ifdef ENABLE_LOGGING_AND_PROFILING

//

// Sliding state window.  Updates counters to keep track of the last

// window of kBufferSize states.  This is useful to track where we

// spent our time.

//

class SlidingStateWindow {

 public:

  SlidingStateWindow();

  ~SlidingStateWindow();

  void AddState(StateTag state);

 private:

  static const int kBufferSize = 256;

  int current_index_;

  bool is_full_;

  byte buffer_[kBufferSize];

  void IncrementStateCounter(StateTag state) {

    Counters::state_counters[state].Increment();

  }

  void DecrementStateCounter(StateTag state) {

    Counters::state_counters[state].Decrement();

  }

};

//

// The Profiler samples pc and sp values for the main thread.

// Each sample is appended to a circular buffer.

// An independent thread removes data and writes it to the log.

// This design minimizes the time spent in the sampler.

//

class Profiler: public Thread {

 public:

  Profiler();

  void Engage();

  void Disengage();

  // Inserts collected profiling data into buffer.

  void Insert(TickSample* sample) {

    if (paused_)

      return;

    if (Succ(head_) == tail_) {

      overflow_ = true;

    } else {

      buffer_[head_] = *sample;

      head_ = Succ(head_);

      buffer_semaphore_->Signal();  // Tell we have an element.

    }

  }

  // Waits for a signal and removes profiling data.

  bool Remove(TickSample* sample) {

    buffer_semaphore_->Wait();  // Wait for an element.

    *sample = buffer_[tail_];

    bool result = overflow_;

    tail_ = Succ(tail_);

    overflow_ = false;

    return result;

  }

  void Run();

  // Pause and Resume TickSample data collection.

  static bool paused() { return paused_; }

  static void pause() { paused_ = true; }

  static void resume() { paused_ = false; }

 private:

  // Returns the next index in the cyclic buffer.

  int Succ(int index) { return (index + 1) % kBufferSize; }

  // Cyclic buffer for communicating profiling samples

  // between the signal handler and the worker thread.

  static const int kBufferSize = 128;

  TickSample buffer_[kBufferSize];  // Buffer storage.

  int head_;  // Index to the buffer head.

  int tail_;  // Index to the buffer tail.

  bool overflow_;  // Tell whether a buffer overflow has occurred.

  Semaphore* buffer_semaphore_;  // Sempahore used for buffer synchronization.

  // Tells whether worker thread should continue running.

  bool running_;

  // Tells whether we are currently recording tick samples.

  static bool paused_;

};

bool Profiler::paused_ = false;

//

// StackTracer implementation

//

void StackTracer::Trace(TickSample* sample) {

  if (sample->state == GC) {

    sample->frames_count = 0;

    return;

  }

  SafeStackTraceFrameIterator it(

      reinterpret_cast<Address>(sample->fp),

      reinterpret_cast<Address>(sample->sp),

      reinterpret_cast<Address>(sample->sp),

      reinterpret_cast<Address>(low_stack_bound_));

  int i = 0;

  while (!it.done() && i < TickSample::kMaxFramesCount) {

    sample->stack[i++] = it.frame()->pc();

    it.Advance();

  }

  sample->frames_count = i;

}

//

// Ticker used to provide ticks to the profiler and the sliding state

// window.

//

class Ticker: public Sampler {

 public:

  explicit Ticker(int interval, unsigned int low_stack_bound):

      Sampler(interval, FLAG_prof), window_(NULL), profiler_(NULL),

      stack_tracer_(low_stack_bound) {}

  ~Ticker() { if (IsActive()) Stop(); }

  void Tick(TickSample* sample) {

    if (IsProfiling()) stack_tracer_.Trace(sample);

    if (profiler_) profiler_->Insert(sample);

    if (window_) window_->AddState(sample->state);

  }

  void SetWindow(SlidingStateWindow* window) {

    window_ = window;

    if (!IsActive()) Start();

  }

  void ClearWindow() {

    window_ = NULL;

    if (!profiler_ && IsActive()) Stop();

  }

  void SetProfiler(Profiler* profiler) {

    profiler_ = profiler;

    if (!IsActive()) Start();

  }

  void ClearProfiler() {

    profiler_ = NULL;

    if (!window_ && IsActive()) Stop();

  }

 private:

  SlidingStateWindow* window_;

  Profiler* profiler_;

  StackTracer stack_tracer_;

};

//

// SlidingStateWindow implementation.

//

SlidingStateWindow::SlidingStateWindow(): current_index_(0), is_full_(false) {

  for (int i = 0; i < kBufferSize; i++) {

    buffer_[i] = static_cast<byte>(OTHER);

  }

  Logger::ticker_->SetWindow(this);

}

SlidingStateWindow::~SlidingStateWindow() {

  Logger::ticker_->ClearWindow();

}

void SlidingStateWindow::AddState(StateTag state) {

  if (is_full_) {

    DecrementStateCounter(static_cast<StateTag>(buffer_[current_index_]));

  } else if (current_index_ == kBufferSize - 1) {

    is_full_ = true;

  }

  buffer_[current_index_] = static_cast<byte>(state);

  IncrementStateCounter(state);

  ASSERT(IsPowerOf2(kBufferSize));

  current_index_ = (current_index_ + 1) & (kBufferSize - 1);

}

//

// Profiler implementation.

//

Profiler::Profiler() {

  buffer_semaphore_ = OS::CreateSemaphore(0);

  head_ = 0;

  tail_ = 0;

  overflow_ = false;

  running_ = false;

}

void Profiler::Engage() {

  OS::LogSharedLibraryAddresses();

  // Start thread processing the profiler buffer.

  running_ = true;

  Start();

  // Register to get ticks.

  Logger::ticker_->SetProfiler(this);

  LOG(UncheckedStringEvent("profiler", "begin"));

}

void Profiler::Disengage() {

  // Stop receiving ticks.

  Logger::ticker_->ClearProfiler();

  // Terminate the worker thread by setting running_ to false,

  // inserting a fake element in the queue and then wait for

  // the thread to terminate.

  running_ = false;

  TickSample sample;

  Insert(&sample);

  Join();

  LOG(UncheckedStringEvent("profiler", "end"));

}

void Profiler::Run() {

  TickSample sample;

  bool overflow = Logger::profiler_->Remove(&sample);

  while (running_) {

    LOG(TickEvent(&sample, overflow));

    overflow = Logger::profiler_->Remove(&sample);

  }

}

#ifdef ENABLE_LOGGING_AND_PROFILING

// Utility class for formatting log messages. It fills the message into the

// static buffer in Logger.

class LogMessageBuilder BASE_EMBEDDED {

 public:

  explicit LogMessageBuilder();

  ~LogMessageBuilder() { }

  void Append(const char* format, ...);

  void Append(const char* format, va_list args);

  void Append(const char c);

  void Append(String *str);

  void AppendDetailed(String* str, bool show_impl_info);

  void WriteToLogFile();

  void WriteCStringToLogFile(const char* str);

 private:

  ScopedLock sl;

  int pos_;

};

// Create a message builder starting from position 0. This acquires the mutex

// in the logger as well.

LogMessageBuilder::LogMessageBuilder(): sl(Logger::mutex_), pos_(0) {

  ASSERT(Logger::message_buffer_ != NULL);

}

// Append string data to the log message.

void LogMessageBuilder::Append(const char* format, ...) {

  Vector<char> buf(Logger::message_buffer_ + pos_,

                   Logger::kMessageBufferSize - pos_);

  va_list args;

  va_start(args, format);

  Append(format, args);

  va_end(args);

  ASSERT(pos_ <= Logger::kMessageBufferSize);

}

// Append string data to the log message.

void LogMessageBuilder::Append(const char* format, va_list args) {

  Vector<char> buf(Logger::message_buffer_ + pos_,

                   Logger::kMessageBufferSize - pos_);

  int result = v8::internal::OS::VSNPrintF(buf, format, args);

  // Result is -1 if output was truncated.

  if (result >= 0) {

    pos_ += result;

  } else {

    pos_ = Logger::kMessageBufferSize;

  }

  ASSERT(pos_ <= Logger::kMessageBufferSize);

}

// Append a character to the log message.

void LogMessageBuilder::Append(const char c) {

  if (pos_ < Logger::kMessageBufferSize) {

    Logger::message_buffer_[pos_++] = c;

  }

  ASSERT(pos_ <= Logger::kMessageBufferSize);

}

// Append a heap string.

void LogMessageBuilder::Append(String* str) {

  AssertNoAllocation no_heap_allocation;  // Ensure string stay valid.

  int length = str->length();

  for (int i = 0; i < length; i++) {

    Append(static_cast<char>(str->Get(i)));

  }

}

void LogMessageBuilder::AppendDetailed(String* str, bool show_impl_info) {

  AssertNoAllocation no_heap_allocation;  // Ensure string stay valid.

  int len = str->length();

  if (len > 0x1000)

    len = 0x1000;

  if (show_impl_info) {

    Append(StringShape(str).IsAsciiRepresentation() ? 'a' : '2');

    if (StringShape(str).IsExternal())

      Append('e');

    if (StringShape(str).IsSymbol())

      Append('#');

    Append(":%i:", str->length());

  }

  for (int i = 0; i < len; i++) {

    uc32 c = str->Get(i);

    if (c > 0xff) {

      Append("\\u%04x", c);

    } else if (c < 32 || c > 126) {

      Append("\\x%02x", c);

    } else if (c == ',') {

      Append("\\,");

    } else if (c == '\\') {

      Append("\\\\");

    } else {

      Append("%lc", c);

    }

  }

}

// Write the log message to the log file currently opened.

void LogMessageBuilder::WriteToLogFile() {

  ASSERT(pos_ <= Logger::kMessageBufferSize);

  size_t rv = fwrite(Logger::message_buffer_, 1, pos_, Logger::logfile_);

  ASSERT(rv == static_cast<size_t>(pos_));

  USE(rv);

}

// Write a null-terminated string to to the log file currently opened.

void LogMessageBuilder::WriteCStringToLogFile(const char* str) {

  size_t len = strlen(str);

  size_t rv = fwrite(str, 1, len, Logger::logfile_);

  ASSERT(rv == len);

  USE(rv);

}

#endif

//

// Logger class implementation.

//

Ticker* Logger::ticker_ = NULL;

char* Logger::message_buffer_ = NULL;

FILE* Logger::logfile_ = NULL;

Profiler* Logger::profiler_ = NULL;

Mutex* Logger::mutex_ = NULL;

VMState* Logger::current_state_ = NULL;

VMState Logger::bottom_state_(EXTERNAL);

SlidingStateWindow* Logger::sliding_state_window_ = NULL;

#endif  // ENABLE_LOGGING_AND_PROFILING

void Logger::Preamble(const char* content) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  if (logfile_ == NULL || !FLAG_log_code) return;

  LogMessageBuilder msg;

  msg.WriteCStringToLogFile(content);

#endif

}

void Logger::StringEvent(const char* name, const char* value) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  if (FLAG_log) UncheckedStringEvent(name, value);

#endif

}

#ifdef ENABLE_LOGGING_AND_PROFILING

void Logger::UncheckedStringEvent(const char* name, const char* value) {

  if (logfile_ == NULL) return;

  LogMessageBuilder msg;

  msg.Append("%s,\"%s\"\n", name, value);

  msg.WriteToLogFile();

}

#endif

void Logger::IntEvent(const char* name, int value) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  if (logfile_ == NULL || !FLAG_log) return;

  LogMessageBuilder msg;

  msg.Append("%s,%d\n", name, value);

  msg.WriteToLogFile();

#endif

}

void Logger::HandleEvent(const char* name, Object** location) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  if (logfile_ == NULL || !FLAG_log_handles) return;

  LogMessageBuilder msg;

  msg.Append("%s,0x%x\n", name,

             reinterpret_cast<unsigned int>(location));

  msg.WriteToLogFile();

#endif

}

#ifdef ENABLE_LOGGING_AND_PROFILING

// ApiEvent is private so all the calls come from the Logger class.  It is the

// caller's responsibility to ensure that logfile_ is not NULL and that

// FLAG_log_api is true.

void Logger::ApiEvent(const char* format, ...) {

  ASSERT(logfile_ != NULL && FLAG_log_api);

  LogMessageBuilder msg;

  va_list ap;

  va_start(ap, format);

  msg.Append(format, ap);

  va_end(ap);

  msg.WriteToLogFile();

}

#endif

void Logger::ApiNamedSecurityCheck(Object* key) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  if (logfile_ == NULL || !FLAG_log_api) return;

  if (key->IsString()) {

    SmartPointer<char> str =

        String::cast(key)->ToCString(DISALLOW_NULLS, ROBUST_STRING_TRAVERSAL);

    ApiEvent("api,check-security,\"%s\"\n", *str);

  } else if (key->IsUndefined()) {

    ApiEvent("api,check-security,undefined\n");

  } else {

    ApiEvent("api,check-security,['no-name']\n");

  }

#endif

}

void Logger::SharedLibraryEvent(const char* library_path,

                                unsigned start,

                                unsigned end) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  if (logfile_ == NULL || !FLAG_prof) return;

  LogMessageBuilder msg;

  msg.Append("shared-library,\"%s\",0x%08x,0x%08x\n", library_path,

             start, end);

  msg.WriteToLogFile();

#endif

}

void Logger::SharedLibraryEvent(const wchar_t* library_path,

                                unsigned start,

                                unsigned end) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  if (logfile_ == NULL || !FLAG_prof) return;

  LogMessageBuilder msg;

  msg.Append("shared-library,\"%ls\",0x%08x,0x%08x\n", library_path,

             start, end);

  msg.WriteToLogFile();

#endif

}

#ifdef ENABLE_LOGGING_AND_PROFILING

void Logger::LogRegExpSource(Handle<JSRegExp> regexp) {

  // Prints "/" + re.source + "/" +

  //      (re.global?"g":"") + (re.ignorecase?"i":"") + (re.multiline?"m":"")

  LogMessageBuilder msg;

  Handle<Object> source = GetProperty(regexp, "source");

  if (!source->IsString()) {

    msg.Append("no source");

    return;

  }

  switch (regexp->TypeTag()) {

    case JSRegExp::ATOM:

      msg.Append('a');

      break;

    default:

      break;

  }

  msg.Append('/');

  msg.AppendDetailed(*Handle<String>::cast(source), false);

  msg.Append('/');

  // global flag

  Handle<Object> global = GetProperty(regexp, "global");

  if (global->IsTrue()) {

    msg.Append('g');

  }

  // ignorecase flag

  Handle<Object> ignorecase = GetProperty(regexp, "ignoreCase");

  if (ignorecase->IsTrue()) {

    msg.Append('i');

  }

  // multiline flag

  Handle<Object> multiline = GetProperty(regexp, "multiline");

  if (multiline->IsTrue()) {

    msg.Append('m');

  }

  msg.WriteToLogFile();

}

#endif  // ENABLE_LOGGING_AND_PROFILING

void Logger::RegExpCompileEvent(Handle<JSRegExp> regexp, bool in_cache) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  if (logfile_ == NULL || !FLAG_log_regexp) return;

  LogMessageBuilder msg;

  msg.Append("regexp-compile,");

  LogRegExpSource(regexp);

  msg.Append(in_cache ? ",hit\n" : ",miss\n");

  msg.WriteToLogFile();

#endif

}

void Logger::LogRuntime(Vector<const char> format, JSArray* args) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  if (logfile_ == NULL || !FLAG_log_runtime) return;

  HandleScope scope;

  LogMessageBuilder msg;

  for (int i = 0; i < format.length(); i++) {

    char c = format[i];

    if (c == '%' && i <= format.length() - 2) {

      i++;

      ASSERT('0' <= format[i] && format[i] <= '9');

      Object* obj = args->GetElement(format[i] - '0');

      i++;

      switch (format[i]) {

        case 's':

          msg.AppendDetailed(String::cast(obj), false);

          break;

        case 'S':

          msg.AppendDetailed(String::cast(obj), true);

          break;

        case 'r':

          Logger::LogRegExpSource(Handle<JSRegExp>(JSRegExp::cast(obj)));

          break;

        case 'x':

          msg.Append("0x%x", Smi::cast(obj)->value());

          break;

        case 'i':

          msg.Append("%i", Smi::cast(obj)->value());

          break;

        default:

          UNREACHABLE();

      }

    } else {

      msg.Append(c);

    }

  }

  msg.Append('\n');

  msg.WriteToLogFile();

#endif

}

void Logger::ApiIndexedSecurityCheck(uint32_t index) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  if (logfile_ == NULL || !FLAG_log_api) return;

  ApiEvent("api,check-security,%u\n", index);

#endif

}

void Logger::ApiNamedPropertyAccess(const char* tag,

                                    JSObject* holder,

                                    Object* name) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  ASSERT(name->IsString());

  if (logfile_ == NULL || !FLAG_log_api) return;

  String* class_name_obj = holder->class_name();

  SmartPointer<char> class_name =

      class_name_obj->ToCString(DISALLOW_NULLS, ROBUST_STRING_TRAVERSAL);

  SmartPointer<char> property_name =

      String::cast(name)->ToCString(DISALLOW_NULLS, ROBUST_STRING_TRAVERSAL);

  Logger::ApiEvent("api,%s,\"%s\",\"%s\"\n", tag, *class_name, *property_name);

#endif

}

void Logger::ApiIndexedPropertyAccess(const char* tag,

                                      JSObject* holder,

                                      uint32_t index) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  if (logfile_ == NULL || !FLAG_log_api) return;

  String* class_name_obj = holder->class_name();

  SmartPointer<char> class_name =

      class_name_obj->ToCString(DISALLOW_NULLS, ROBUST_STRING_TRAVERSAL);

  Logger::ApiEvent("api,%s,\"%s\",%u\n", tag, *class_name, index);

#endif

}

void Logger::ApiObjectAccess(const char* tag, JSObject* object) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  if (logfile_ == NULL || !FLAG_log_api) return;

  String* class_name_obj = object->class_name();

  SmartPointer<char> class_name =

      class_name_obj->ToCString(DISALLOW_NULLS, ROBUST_STRING_TRAVERSAL);

  Logger::ApiEvent("api,%s,\"%s\"\n", tag, *class_name);

#endif

}

void Logger::ApiEntryCall(const char* name) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  if (logfile_ == NULL || !FLAG_log_api) return;

  Logger::ApiEvent("api,%s\n", name);

#endif

}

void Logger::NewEvent(const char* name, void* object, size_t size) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  if (logfile_ == NULL || !FLAG_log) return;

  LogMessageBuilder msg;

  msg.Append("new,%s,0x%x,%u\n", name,

             reinterpret_cast<unsigned int>(object),

             static_cast<unsigned int>(size));

  msg.WriteToLogFile();

#endif

}

void Logger::DeleteEvent(const char* name, void* object) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  if (logfile_ == NULL || !FLAG_log) return;

  LogMessageBuilder msg;

  msg.Append("delete,%s,0x%x\n", name,

             reinterpret_cast<unsigned int>(object));

  msg.WriteToLogFile();

#endif

}

void Logger::CodeCreateEvent(const char* tag, Code* code, const char* comment) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  if (logfile_ == NULL || !FLAG_log_code) return;

  LogMessageBuilder msg;

  msg.Append("code-creation,%s,0x%x,%d,\"", tag,

             reinterpret_cast<unsigned int>(code->address()),

             code->ExecutableSize());

  for (const char* p = comment; *p != '\0'; p++) {

    if (*p == '"') {

      msg.Append('\\');

    }

    msg.Append(*p);

  }

  msg.Append('"');

  msg.Append('\n');

  msg.WriteToLogFile();

#endif

}

void Logger::CodeCreateEvent(const char* tag, Code* code, String* name) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  if (logfile_ == NULL || !FLAG_log_code) return;

  LogMessageBuilder msg;

  SmartPointer<char> str =

      name->ToCString(DISALLOW_NULLS, ROBUST_STRING_TRAVERSAL);

  msg.Append("code-creation,%s,0x%x,%d,\"%s\"\n", tag,

             reinterpret_cast<unsigned int>(code->address()),

             code->ExecutableSize(), *str);

  msg.WriteToLogFile();

#endif

}

void Logger::CodeCreateEvent(const char* tag, Code* code, String* name,

                             String* source, int line) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  if (logfile_ == NULL || !FLAG_log_code) return;

  LogMessageBuilder msg;

  SmartPointer<char> str =

      name->ToCString(DISALLOW_NULLS, ROBUST_STRING_TRAVERSAL);

  SmartPointer<char> sourcestr =

      source->ToCString(DISALLOW_NULLS, ROBUST_STRING_TRAVERSAL);

  msg.Append("code-creation,%s,0x%x,%d,\"%s %s:%d\"\n", tag,

             reinterpret_cast<unsigned int>(code->address()),

             code->ExecutableSize(),

             *str, *sourcestr, line);

  msg.WriteToLogFile();

#endif

}

void Logger::CodeCreateEvent(const char* tag, Code* code, int args_count) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  if (logfile_ == NULL || !FLAG_log_code) return;

  LogMessageBuilder msg;

  msg.Append("code-creation,%s,0x%x,%d,\"args_count: %d\"\n", tag,

             reinterpret_cast<unsigned int>(code->address()),

             code->ExecutableSize(),

             args_count);

  msg.WriteToLogFile();

#endif

}

void Logger::RegExpCodeCreateEvent(Code* code, String* source) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  if (logfile_ == NULL || !FLAG_log_code) return;

  LogMessageBuilder msg;

  msg.Append("code-creation,%s,0x%x,%d,\"", "RegExp",

             reinterpret_cast<unsigned int>(code->address()),

             code->ExecutableSize());

  msg.AppendDetailed(source, false);

  msg.Append("\"\n");

  msg.WriteToLogFile();

#endif

}

void Logger::CodeAllocateEvent(Code* code, Assembler* assem) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  if (logfile_ == NULL || !FLAG_log_code) return;

  LogMessageBuilder msg;

  msg.Append("code-allocate,0x%x,0x%x\n",

             reinterpret_cast<unsigned int>(code->address()),

             reinterpret_cast<unsigned int>(assem));

  msg.WriteToLogFile();

#endif

}

void Logger::CodeMoveEvent(Address from, Address to) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  if (logfile_ == NULL || !FLAG_log_code) return;

  LogMessageBuilder msg;

  msg.Append("code-move,0x%x,0x%x\n",

             reinterpret_cast<unsigned int>(from),

             reinterpret_cast<unsigned int>(to));

  msg.WriteToLogFile();

#endif

}

void Logger::CodeDeleteEvent(Address from) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  if (logfile_ == NULL || !FLAG_log_code) return;

  LogMessageBuilder msg;

  msg.Append("code-delete,0x%x\n", reinterpret_cast<unsigned int>(from));

  msg.WriteToLogFile();

#endif

}

void Logger::BeginCodeRegionEvent(CodeRegion* region,

                                  Assembler* masm,

                                  const char* name) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  if (logfile_ == NULL || !FLAG_log_code) return;

  LogMessageBuilder msg;

  msg.Append("begin-code-region,0x%x,0x%x,0x%x,%s\n",

             reinterpret_cast<unsigned int>(region),

             reinterpret_cast<unsigned int>(masm),

             masm->pc_offset(),

             name);

  msg.WriteToLogFile();

#endif

}

void Logger::EndCodeRegionEvent(CodeRegion* region, Assembler* masm) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  if (logfile_ == NULL || !FLAG_log_code) return;

  LogMessageBuilder msg;

  msg.Append("end-code-region,0x%x,0x%x,0x%x\n",

             reinterpret_cast<unsigned int>(region),

             reinterpret_cast<unsigned int>(masm),

             masm->pc_offset());

  msg.WriteToLogFile();

#endif

}

void Logger::ResourceEvent(const char* name, const char* tag) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  if (logfile_ == NULL || !FLAG_log) return;

  LogMessageBuilder msg;

  msg.Append("%s,%s,", name, tag);

  uint32_t sec, usec;

  if (OS::GetUserTime(&sec, &usec) != -1) {

    msg.Append("%d,%d,", sec, usec);

  }

  msg.Append("%.0f", OS::TimeCurrentMillis());

  msg.Append('\n');

  msg.WriteToLogFile();

#endif

}

void Logger::SuspectReadEvent(String* name, Object* obj) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  if (logfile_ == NULL || !FLAG_log_suspect) return;

  LogMessageBuilder msg;

  String* class_name = obj->IsJSObject()

                       ? JSObject::cast(obj)->class_name()

                       : Heap::empty_string();

  ScopedLock sl(mutex_);

  msg.Append("suspect-read,");

  msg.Append(class_name);

  msg.Append(',');

  msg.Append('"');

  msg.Append(name);

  msg.Append('"');

  msg.Append('\n');

  msg.WriteToLogFile();

#endif

}

void Logger::HeapSampleBeginEvent(const char* space, const char* kind) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  if (logfile_ == NULL || !FLAG_log_gc) return;

  LogMessageBuilder msg;

  msg.Append("heap-sample-begin,\"%s\",\"%s\"\n", space, kind);

  msg.WriteToLogFile();

#endif

}

void Logger::HeapSampleEndEvent(const char* space, const char* kind) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  if (logfile_ == NULL || !FLAG_log_gc) return;

  LogMessageBuilder msg;

  msg.Append("heap-sample-end,\"%s\",\"%s\"\n", space, kind);

  msg.WriteToLogFile();

#endif

}

void Logger::HeapSampleItemEvent(const char* type, int number, int bytes) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  if (logfile_ == NULL || !FLAG_log_gc) return;

  LogMessageBuilder msg;

  msg.Append("heap-sample-item,%s,%d,%d\n", type, number, bytes);

  msg.WriteToLogFile();

#endif

}

void Logger::DebugTag(const char* call_site_tag) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  if (logfile_ == NULL || !FLAG_log) return;

  LogMessageBuilder msg;

  msg.Append("debug-tag,%s\n", call_site_tag);

  msg.WriteToLogFile();

#endif

}

void Logger::DebugEvent(const char* event_type, Vector<uint16_t> parameter) {

#ifdef ENABLE_LOGGING_AND_PROFILING

  if (logfile_ == NULL || !FLAG_log) return;

  StringBuilder s(parameter.length() + 1);

  for (int i = 0; i < parameter.length(); ++i) {

    s.AddCharacter(static_cast<char>(parameter[i]));

  }

  char* parameter_string = s.Finalize();

  LogMessageBuilder msg;

  msg.Append("debug-queue-event,%s,%15.3f,%s\n",

             event_type,

             OS::TimeCurrentMillis(),

             parameter_string);

  DeleteArray(parameter_string);

  msg.WriteToLogFile();

#endif

}

#ifdef ENABLE_LOGGING_AND_PROFILING

void Logger::TickEvent(TickSample* sample, bool overflow) {

  if (logfile_ == NULL || !FLAG_prof) return;

  LogMessageBuilder msg;

  msg.Append("tick,0x%x,0x%x,%d", sample->pc, sample->sp,

             static_cast<int>(sample->state));

  if (overflow) {

    msg.Append(",overflow");

  }

  for (int i = 0; i < sample->frames_count; ++i) {

    msg.Append(",0x%x", reinterpret_cast<uint32_t>(sample->stack[i]));

  }

  msg.Append('\n');

  msg.WriteToLogFile();

}

bool Logger::IsProfilerPaused() {

  return profiler_->paused();

}

void Logger::PauseProfiler() {

  profiler_->pause();

}

void Logger::ResumeProfiler() {

  profiler_->resume();

}

#endif

bool Logger::Setup() {

#ifdef ENABLE_LOGGING_AND_PROFILING

  // --log-all enables all the log flags.

  if (FLAG_log_all) {

    FLAG_log_runtime = true;

    FLAG_log_api = true;

    FLAG_log_code = true;

    FLAG_log_gc = true;

    FLAG_log_suspect = true;

    FLAG_log_handles = true;

    FLAG_log_regexp = true;

  }

  // --prof implies --log-code.

  if (FLAG_prof) FLAG_log_code = true;

  bool open_log_file = FLAG_log || FLAG_log_runtime || FLAG_log_api

      || FLAG_log_code || FLAG_log_gc || FLAG_log_handles || FLAG_log_suspect

      || FLAG_log_regexp || FLAG_log_state_changes;

  // If we're logging anything, we need to open the log file.

  if (open_log_file) {

    if (strcmp(FLAG_logfile, "-") == 0) {

      logfile_ = stdout;

    } else if (strchr(FLAG_logfile, '%') != NULL) {

      // If there's a '%' in the log file name we have to expand

      // placeholders.

      HeapStringAllocator allocator;

      StringStream stream(&allocator);

      for (const char* p = FLAG_logfile; *p; p++) {

        if (*p == '%') {

          p++;

          switch (*p) {

            case '\0':

              // If there's a % at the end of the string we back up

              // one character so we can escape the loop properly.

              p--;

              break;

            case 't': {

              // %t expands to the current time in milliseconds.

              uint32_t time = static_cast<uint32_t>(OS::TimeCurrentMillis());

              stream.Add("%u", time);

              break;

            }

            case '%':

              // %% expands (contracts really) to %.

              stream.Put('%');

              break;

            default:

              // All other %'s expand to themselves.

              stream.Put('%');

              stream.Put(*p);

              break;

          }

        } else {

          stream.Put(*p);

        }

      }

      SmartPointer<const char> expanded = stream.ToCString();

      logfile_ = OS::FOpen(*expanded, OS::LogFileOpenMode);

    } else {

      logfile_ = OS::FOpen(FLAG_logfile, OS::LogFileOpenMode);

    }

    message_buffer_ = NewArray<char>(kMessageBufferSize);

    mutex_ = OS::CreateMutex();

  }

  current_state_ = &bottom_state_;

  // as log is initialized early with V8, we can assume that JS execution

  // frames can never reach this point on stack

  int stack_var;

  ticker_ = new Ticker(1, reinterpret_cast<unsigned int>(&stack_var));

  if (FLAG_sliding_state_window && sliding_state_window_ == NULL) {

    sliding_state_window_ = new SlidingStateWindow();

  }

  if (FLAG_prof) {

    profiler_ = new Profiler();

    if (!FLAG_prof_auto)

      profiler_->pause();

    profiler_->Engage();

  }

  return true;

#else

  return false;

#endif

}

void Logger::TearDown() {

#ifdef ENABLE_LOGGING_AND_PROFILING

  // Stop the profiler before closing the file.

  if (profiler_ != NULL) {

    profiler_->Disengage();

    delete profiler_;

    profiler_ = NULL;

  }

  delete sliding_state_window_;

  delete ticker_;

  if (logfile_ != NULL) {

    fclose(logfile_);

    logfile_ = NULL;

    delete mutex_;

    mutex_ = NULL;

    DeleteArray(message_buffer_);

  }

#endif

}

void Logger::EnableSlidingStateWindow() {

#ifdef ENABLE_LOGGING_AND_PROFILING

  // If the ticker is NULL, Logger::Setup has not been called yet.  In

  // that case, we set the sliding_state_window flag so that the

  // sliding window computation will be started when Logger::Setup is

  // called.

  if (ticker_ == NULL) {

    FLAG_sliding_state_window = true;

    return;

  }

  // Otherwise, if the sliding state window computation has not been

  // started we do it now.

  if (sliding_state_window_ == NULL) {

    sliding_state_window_ = new SlidingStateWindow();

  }

#endif

}

//

// VMState class implementation.  A simple stack of VM states held by the

// logger and partially threaded through the call stack.  States are pushed by

// VMState construction and popped by destruction.

//

#ifdef ENABLE_LOGGING_AND_PROFILING

static const char* StateToString(StateTag state) {

  switch (state) {

    case JS:

      return "JS";

    case GC:

      return "GC";

    case COMPILER:

      return "COMPILER";

    case OTHER:

      return "OTHER";

    default:

      UNREACHABLE();

      return NULL;

  }

}

VMState::VMState(StateTag state) {

#if !defined(ENABLE_HEAP_PROTECTION)

  // When not protecting the heap, there is no difference between

  // EXTERNAL and OTHER.  As an optimizatin in that case, we will not

  // perform EXTERNAL->OTHER transitions through the API.  We thus

  // compress the two states into one.

  if (state == EXTERNAL) state = OTHER;

#endif

  state_ = state;

  previous_ = Logger::current_state_;

  Logger::current_state_ = this;

  if (FLAG_log_state_changes) {

    LOG(UncheckedStringEvent("Entering", StateToString(state_)));

    if (previous_ != NULL) {

      LOG(UncheckedStringEvent("From", StateToString(previous_->state_)));

    }

  }

#ifdef ENABLE_HEAP_PROTECTION

  if (FLAG_protect_heap && previous_ != NULL) {

    if (state_ == EXTERNAL) {

      // We are leaving V8.

      ASSERT(previous_->state_ != EXTERNAL);

      Heap::Protect();

    } else if (previous_->state_ == EXTERNAL) {

      // We are entering V8.

      Heap::Unprotect();

    }

  }

#endif

}

VMState::~VMState() {

  Logger::current_state_ = previous_;

  if (FLAG_log_state_changes) {

    LOG(UncheckedStringEvent("Leaving", StateToString(state_)));

    if (previous_ != NULL) {

      LOG(UncheckedStringEvent("To", StateToString(previous_->state_)));

    }

  }

#ifdef ENABLE_HEAP_PROTECTION

  if (FLAG_protect_heap && previous_ != NULL) {

    if (state_ == EXTERNAL) {

      // We are reentering V8.

      ASSERT(previous_->state_ != EXTERNAL);

      Heap::Unprotect();

    } else if (previous_->state_ == EXTERNAL) {

      // We are leaving V8.

      Heap::Protect();

    }

  }

#endif

}

#endif

} }  // namespace v8::internal