Merge up to 8597 to experimental/gc from the bleeding edge.

src/runtime-profiler.cc

Index: src/runtime-profiler.cc
===================================================================
--- src/runtime-profiler.cc	(revision 8618)
+++ src/runtime-profiler.cc	(working copy)
@@ -43,32 +43,6 @@
 namespace internal {
 
 
-class PendingListNode : public Malloced {
- public:
-  explicit PendingListNode(JSFunction* function);
-  ~PendingListNode() { Destroy(); }
-
-  PendingListNode* next() const { return next_; }
-  void set_next(PendingListNode* node) { next_ = node; }
-  Handle<JSFunction> function() { return Handle<JSFunction>::cast(function_); }
-
-  // If the function is garbage collected before we've had the chance
-  // to optimize it the weak handle will be null.
-  bool IsValid() { return !function_.is_null(); }
-
-  // Returns the number of microseconds this node has been pending.
-  int Delay() const { return static_cast<int>(OS::Ticks() - start_); }
-
- private:
-  void Destroy();
-  static void WeakCallback(v8::Persistent<v8::Value> object, void* data);
-
-  PendingListNode* next_;
-  Handle<Object> function_;  // Weak handle.
-  int64_t start_;
-};
-
-
 // Optimization sampler constants.
 static const int kSamplerFrameCount = 2;
 static const int kSamplerFrameWeight[kSamplerFrameCount] = { 2, 1 };
@@ -80,33 +54,10 @@
 static const int kSamplerThresholdDelta = 1;
 
 static const int kSamplerThresholdSizeFactorInit = 3;
-static const int kSamplerThresholdSizeFactorMin = 1;
-static const int kSamplerThresholdSizeFactorDelta = 1;
 
 static const int kSizeLimit = 1500;
 
 
-PendingListNode::PendingListNode(JSFunction* function) : next_(NULL) {
-  GlobalHandles* global_handles = Isolate::Current()->global_handles();
-  function_ = global_handles->Create(function);
-  start_ = OS::Ticks();
-  global_handles->MakeWeak(function_.location(), this, &WeakCallback);
-}
-
-
-void PendingListNode::Destroy() {
-  if (!IsValid()) return;
-  GlobalHandles* global_handles = Isolate::Current()->global_handles();
-  global_handles->Destroy(function_.location());
-  function_= Handle<Object>::null();
-}
-
-
-void PendingListNode::WeakCallback(v8::Persistent<v8::Value>, void* data) {
-  reinterpret_cast<PendingListNode*>(data)->Destroy();
-}
-
-
 Atomic32 RuntimeProfiler::state_ = 0;
 // TODO(isolates): Create the semaphore lazily and clean it up when no
 // longer required.
@@ -125,16 +76,8 @@
       sampler_threshold_(kSamplerThresholdInit),
       sampler_threshold_size_factor_(kSamplerThresholdSizeFactorInit),
       sampler_ticks_until_threshold_adjustment_(
-        kSamplerTicksBetweenThresholdAdjustment),
-      js_ratio_(0),
-      sampler_window_position_(0),
-      optimize_soon_list_(NULL),
-      state_window_position_(0),
-      state_window_ticks_(0) {
-  state_counts_[IN_NON_JS_STATE] = kStateWindowSize;
-  state_counts_[IN_JS_STATE] = 0;
-  STATIC_ASSERT(IN_NON_JS_STATE == 0);
-  memset(state_window_, 0, sizeof(state_window_));
+          kSamplerTicksBetweenThresholdAdjustment),
+      sampler_window_position_(0) {
   ClearSampleBuffer();
 }
 
@@ -148,16 +91,13 @@
 }
 
 
-void RuntimeProfiler::Optimize(JSFunction* function, bool eager, int delay) {
+void RuntimeProfiler::Optimize(JSFunction* function) {
   ASSERT(function->IsOptimizable());
   if (FLAG_trace_opt) {
-    PrintF("[marking (%s) ", eager ? "eagerly" : "lazily");
+    PrintF("[marking ");
     function->PrintName();
     PrintF(" 0x%" V8PRIxPTR, reinterpret_cast<intptr_t>(function->address()));
     PrintF(" for recompilation");
-    if (delay > 0) {
-      PrintF(" (delayed %0.3f ms)", static_cast<double>(delay) / 1000);
-    }
     PrintF("]\n");
   }
 
@@ -185,7 +125,7 @@
   // We are not prepared to do OSR for a function that already has an
   // allocated arguments object.  The optimized code would bypass it for
   // arguments accesses, which is unsound.  Don't try OSR.
-  if (shared->scope_info()->HasArgumentsShadow()) return;
+  if (shared->uses_arguments()) return;
 
   // We're using on-stack replacement: patch the unoptimized code so that
   // any back edge in any unoptimized frame will trigger on-stack
@@ -243,20 +183,6 @@
 
 void RuntimeProfiler::OptimizeNow() {
   HandleScope scope(isolate_);
-  PendingListNode* current = optimize_soon_list_;
-  while (current != NULL) {
-    PendingListNode* next = current->next();
-    if (current->IsValid()) {
-      Handle<JSFunction> function = current->function();
-      int delay = current->Delay();
-      if (function->IsOptimizable()) {
-        Optimize(*function, true, delay);
-      }
-    }
-    delete current;
-    current = next;
-  }
-  optimize_soon_list_ = NULL;
 
   // Run through the JavaScript frames and collect them. If we already
   // have a sample of the function, we mark it for optimizations
@@ -303,24 +229,9 @@
         : 1;
 
     int threshold = sampler_threshold_ * threshold_size_factor;
-    int current_js_ratio = NoBarrier_Load(&js_ratio_);
 
-    // Adjust threshold depending on the ratio of time spent
-    // in JS code.
-    if (current_js_ratio < 20) {
-      // If we spend less than 20% of the time in JS code,
-      // do not optimize.
-      continue;
-    } else if (current_js_ratio < 75) {
-      // Below 75% of time spent in JS code, only optimize very
-      // frequently used functions.
-      threshold *= 3;
-    }
-
     if (LookupSample(function) >= threshold) {
-      Optimize(function, false, 0);
-      isolate_->compilation_cache()->MarkForEagerOptimizing(
-          Handle<JSFunction>(function));
+      Optimize(function);
     }
   }
 
@@ -333,40 +244,8 @@
 }
 
 
-void RuntimeProfiler::OptimizeSoon(JSFunction* function) {
-  if (!function->IsOptimizable()) return;
-  PendingListNode* node = new PendingListNode(function);
-  node->set_next(optimize_soon_list_);
-  optimize_soon_list_ = node;
-}
-
-
-#ifdef ENABLE_LOGGING_AND_PROFILING
-void RuntimeProfiler::UpdateStateRatio(SamplerState current_state) {
-  SamplerState old_state = state_window_[state_window_position_];
-  state_counts_[old_state]--;
-  state_window_[state_window_position_] = current_state;
-  state_counts_[current_state]++;
-  ASSERT(IsPowerOf2(kStateWindowSize));
-  state_window_position_ = (state_window_position_ + 1) &
-      (kStateWindowSize - 1);
-  // Note: to calculate correct ratio we have to track how many valid
-  // ticks are actually in the state window, because on profiler
-  // startup this number can be less than the window size.
-  state_window_ticks_ = Min(kStateWindowSize, state_window_ticks_ + 1);
-  NoBarrier_Store(&js_ratio_, state_counts_[IN_JS_STATE] * 100 /
-                  state_window_ticks_);
-}
-#endif
-
-
 void RuntimeProfiler::NotifyTick() {
 #ifdef ENABLE_LOGGING_AND_PROFILING
-  // Record state sample.
-  SamplerState state = IsSomeIsolateInJS()
-      ? IN_JS_STATE
-      : IN_NON_JS_STATE;
-  UpdateStateRatio(state);
   isolate_->stack_guard()->RequestRuntimeProfilerTick();
 #endif
 }
@@ -424,7 +303,6 @@
   // to get the right count of active isolates.
   NoBarrier_AtomicIncrement(&state_, 1);
   semaphore_->Signal();
-  isolate->ResetEagerOptimizingData();
 #endif
 }
 
@@ -445,9 +323,26 @@
 }
 
 
-void RuntimeProfiler::WakeUpRuntimeProfilerThreadBeforeShutdown() {
+void RuntimeProfiler::StopRuntimeProfilerThreadBeforeShutdown(Thread* thread) {
 #ifdef ENABLE_LOGGING_AND_PROFILING
-  semaphore_->Signal();
+  // Do a fake increment. If the profiler is waiting on the semaphore,
+  // the returned state is 0, which can be left as an initial state in
+  // case profiling is restarted later. If the profiler is not
+  // waiting, the increment will prevent it from waiting, but has to
+  // be undone after the profiler is stopped.
+  Atomic32 new_state = NoBarrier_AtomicIncrement(&state_, 1);
+  ASSERT(new_state >= 0);
+  if (new_state == 0) {
+    // The profiler thread is waiting. Wake it up. It must check for
+    // stop conditions before attempting to wait again.
+    semaphore_->Signal();
+  }
+  thread->Join();
+  // The profiler thread is now stopped. Undo the increment in case it
+  // was not waiting.
+  if (new_state != 0) {
+    NoBarrier_AtomicIncrement(&state_, -1);
+  }
 #endif
 }
 
@@ -472,15 +367,8 @@
 
 bool RuntimeProfilerRateLimiter::SuspendIfNecessary() {
 #ifdef ENABLE_LOGGING_AND_PROFILING
-  static const int kNonJSTicksThreshold = 100;
-  if (RuntimeProfiler::IsSomeIsolateInJS()) {
-    non_js_ticks_ = 0;
-  } else {
-    if (non_js_ticks_ < kNonJSTicksThreshold) {
-      ++non_js_ticks_;
-    } else {
-      return RuntimeProfiler::WaitForSomeIsolateToEnterJS();
-    }
+  if (!RuntimeProfiler::IsSomeIsolateInJS()) {
+    return RuntimeProfiler::WaitForSomeIsolateToEnterJS();
   }
 #endif
   return false;