New approach to Crankshaft decision-making

src/runtime-profiler.h

 // 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
@@ skipping 40 matching lines @@
   }
 
   void OptimizeNow();
 
   void NotifyTick();
 
   void Setup();
   void Reset();
   void TearDown();
 
-  Object** SamplerWindowAddress();
-  int SamplerWindowSize();
+  void NotifyICChanged() {
+    any_ic_changed_ = true;
+  }
+  void NotifyCodeGenerated(int generated_code_size) {
+    code_generated_ = true;
+    total_code_generated_ += generated_code_size;
+  }
 
   // Rate limiting support.
 
   // VM thread interface.
   //
   // Called by isolates when their states change.
   static inline void IsolateEnteredJS(Isolate* isolate);
   static inline void IsolateExitedJS(Isolate* isolate);
 
   // Profiler thread interface.
   //
   // IsSomeIsolateInJS():
   // The profiler thread can query whether some isolate is currently
   // running JavaScript code.
   //
   // WaitForSomeIsolateToEnterJS():
   // When no isolates are running JavaScript code for some time the
   // profiler thread suspends itself by calling the wait function. The
   // wait function returns true after it waited or false immediately.
   // While the function was waiting the profiler may have been
   // disabled so it *must check* whether it is allowed to continue.
   static bool IsSomeIsolateInJS();
   static bool WaitForSomeIsolateToEnterJS();
 
   // Stops the runtime profiler thread when profiling support is being
   // turned off.
   static void StopRuntimeProfilerThreadBeforeShutdown(Thread* thread);
 
-  void UpdateSamplesAfterScavenge();
-  void RemoveDeadSamples();
-  void UpdateSamplesAfterCompact(ObjectVisitor* visitor);
-
  private:
-  static const int kSamplerWindowSize = 16;
-
   static void HandleWakeUp(Isolate* isolate);
 
-  void Optimize(JSFunction* function);
+  void Optimize(JSFunction* function, const char* reason);
 
   void AttemptOnStackReplacement(JSFunction* function);
 
   void ClearSampleBuffer();
 
   void ClearSampleBufferNewSpaceEntries();
 
-  int LookupSample(JSFunction* function);
-
-  void AddSample(JSFunction* function, int weight);
-
   Isolate* isolate_;
 
-  int sampler_threshold_;
-  int sampler_threshold_size_factor_;
-  int sampler_ticks_until_threshold_adjustment_;
-
-  Object* sampler_window_[kSamplerWindowSize];
-  int sampler_window_position_;
-  int sampler_window_weight_[kSamplerWindowSize];
+  bool any_ic_changed_;
+  bool code_generated_;
+  int total_code_generated_;
 
   // Possible state values:
   //   -1            => the profiler thread is waiting on the semaphore
   //   0 or positive => the number of isolates running JavaScript code.
   static Atomic32 state_;
   static Semaphore* semaphore_;
 
 #ifdef DEBUG
   static bool has_been_globally_setup_;
 #endif
@@ skipping 35 matching lines @@
 
 void RuntimeProfiler::IsolateExitedJS(Isolate* isolate) {
   Atomic32 new_state = NoBarrier_AtomicIncrement(&state_, -1);
   ASSERT(new_state >= 0);
   USE(new_state);
 }
 
 } }  // namespace v8::internal
 
 #endif  // V8_RUNTIME_PROFILER_H_