Remove SlidingStateWindow and related code.

src/log.cc

Index: src/log.cc
diff --git a/src/log.cc b/src/log.cc
index 9a3c54d0432b72ec54887615fc0f679a6c561623..88527ca6b304d67b6fdd7d317988877da06568d0 100644
--- a/src/log.cc
+++ b/src/log.cc
@@ -44,37 +44,6 @@
 namespace v8 {
 namespace internal {
 
-//
-// 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:
-  explicit SlidingStateWindow(Isolate* isolate);
-  ~SlidingStateWindow();
-  void AddState(StateTag state);
-
- private:
-  static const int kBufferSize = 256;
-  Counters* counters_;
-  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.
@@ -189,24 +158,12 @@ class Ticker: public Sampler {
  public:
   Ticker(Isolate* isolate, int interval):
       Sampler(isolate, interval),
-      window_(NULL),
       profiler_(NULL) {}
 
   ~Ticker() { if (IsActive()) Stop(); }
 
   virtual void Tick(TickSample* 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() && !RuntimeProfiler::IsEnabled()) Stop();
   }
 
   void SetProfiler(Profiler* profiler) {
@@ -219,7 +176,7 @@ class Ticker: public Sampler {
   void ClearProfiler() {
     DecreaseProfilingDepth();
     profiler_ = NULL;
-    if (!window_ && IsActive() && !RuntimeProfiler::IsEnabled()) Stop();
+    if (IsActive()) Stop();
   }
 
  protected:
@@ -228,42 +185,11 @@ class Ticker: public Sampler {
   }
 
  private:
-  SlidingStateWindow* window_;
   Profiler* profiler_;
 };
 
 
 //
-// SlidingStateWindow implementation.
-//
-SlidingStateWindow::SlidingStateWindow(Isolate* isolate)
-    : counters_(isolate->counters()), current_index_(0), is_full_(false) {
-  for (int i = 0; i < kBufferSize; i++) {
-    buffer_[i] = static_cast<byte>(OTHER);
-  }
-  isolate->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(Isolate* isolate)
@@ -518,7 +444,6 @@ class Logger::NameBuffer {
 Logger::Logger()
   : ticker_(NULL),
     profiler_(NULL),
-    sliding_state_window_(NULL),
     log_events_(NULL),
     logging_nesting_(0),
     cpu_profiler_nesting_(0),
@@ -1412,9 +1337,7 @@ void Logger::PauseProfiler() {
     if (--cpu_profiler_nesting_ == 0) {
       profiler_->pause();
       if (FLAG_prof_lazy) {
-        if (!FLAG_sliding_state_window && !RuntimeProfiler::IsEnabled()) {
-          ticker_->Stop();
-        }
+        ticker_->Stop();
         FLAG_log_code = false;
         LOG(ISOLATE, UncheckedStringEvent("profiler", "pause"));
       }
@@ -1435,9 +1358,7 @@ void Logger::ResumeProfiler() {
         FLAG_log_code = true;
         LogCompiledFunctions();
         LogAccessorCallbacks();
-        if (!FLAG_sliding_state_window && !ticker_->IsActive()) {
-          ticker_->Start();
-        }
+        if (!ticker_->IsActive()) ticker_->Start();
       }
       profiler_->resume();
     }
@@ -1781,10 +1702,6 @@ bool Logger::SetUp() {
   Isolate* isolate = Isolate::Current();
   ticker_ = new Ticker(isolate, kSamplingIntervalMs);
 
-  if (FLAG_sliding_state_window && sliding_state_window_ == NULL) {
-    sliding_state_window_ = new SlidingStateWindow(isolate);
-  }
-
   bool start_logging = 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 || FLAG_ll_prof
@@ -1851,9 +1768,6 @@ FILE* Logger::TearDown() {
     profiler_ = NULL;
   }
 
-  delete sliding_state_window_;
-  sliding_state_window_ = NULL;
-
   delete ticker_;
   ticker_ = NULL;
 
@@ -1861,22 +1775,6 @@ FILE* Logger::TearDown() {
 }
 
 
-void Logger::EnableSlidingStateWindow() {
-  // 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(Isolate::Current());
-  }
-}
-
 // Protects the state below.
 static Mutex* active_samplers_mutex = NULL;