[Isolates] Merge crankshaft (r5922 from bleeding_edge).

src/platform.h

 // Copyright 2006-2008 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 95 matching lines @@
 // only when compiling with GCC versions affected by the bug (2.96.x - 4.0.x)
 // __GNUC_PREREQ is not defined in GCC for Mac OS X, so we define our own macro
 #if __GNUC_VERSION__ >= 29600 && __GNUC_VERSION__ < 40100
 #include <limits>
 #undef V8_INFINITY
 #define V8_INFINITY std::numeric_limits<double>::infinity()
 #endif
 
 #endif  // __GNUC__
 
+#include "atomicops.h"
+
 namespace v8 {
 namespace internal {
 
 // Use AtomicWord for a machine-sized pointer. It is assumed that
 // reads and writes of naturally aligned values of this type are atomic.
 typedef intptr_t AtomicWord;
 
 class Semaphore;
 
 double ceiling(double x);
@@ skipping 303 matching lines @@
 
   // Locks the given mutex. If the mutex is currently unlocked, it becomes
   // locked and owned by the calling thread, and immediately. If the mutex
   // is already locked by another thread, suspends the calling thread until
   // the mutex is unlocked.
   virtual int Lock() = 0;
 
   // Unlocks the given mutex. The mutex is assumed to be locked and owned by
   // the calling thread on entrance.
   virtual int Unlock() = 0;
+
+  // Tries to lock the given mutex. Returns whether the mutex was
+  // successfully locked.
+  virtual bool TryLock() = 0;
 };
 
 
 // ----------------------------------------------------------------------------
-// ScopedLock
+// ScopedLock/ScopedUnlock
 //
-// Stack-allocated ScopedLocks provide block-scoped locking and unlocking
-// of a mutex.
+// Stack-allocated ScopedLocks/ScopedUnlocks provide block-scoped
+// locking and unlocking of a mutex.
 class ScopedLock {
  public:
   explicit ScopedLock(Mutex* mutex): mutex_(mutex) {
+    ASSERT(mutex_ != NULL);
     mutex_->Lock();
   }
   ~ScopedLock() {
     mutex_->Unlock();
   }
 
  private:
   Mutex* mutex_;
   DISALLOW_COPY_AND_ASSIGN(ScopedLock);
 };
@@ skipping 90 matching lines @@
   Address function;  // The last called JS function.
   static const int kMaxFramesCount = 64;
   Address stack[kMaxFramesCount];  // Call stack.
   int frames_count;  // Number of captured frames.
 };
 
 #ifdef ENABLE_LOGGING_AND_PROFILING
 class Sampler {
  public:
   // Initialize sampler.
-  Sampler(Isolate* isolate, int interval, bool profiling);
+  Sampler(Isolate* isolate, int interval);
   virtual ~Sampler();
 
+  int interval() const { return interval_; }
+
   // Performs stack sampling.
   void SampleStack(TickSample* sample) {
     DoSampleStack(sample);
     IncSamplesTaken();
   }
 
   // This method is called for each sampling period with the current
   // program counter.
   virtual void Tick(TickSample* sample) = 0;
 
   // Start and stop sampler.
   void Start();
   void Stop();
 
   // Is the sampler used for profiling?
-  bool IsProfiling() const { return profiling_; }
-
-  // Is the sampler running in sync with the JS thread? On platforms
-  // where the sampler is implemented with a thread that wakes up
-  // every now and then, having a synchronous sampler implies
-  // suspending/resuming the JS thread.
-  bool IsSynchronous() const { return synchronous_; }
+  bool IsProfiling() const { return NoBarrier_Load(&profiling_) > 0; }
+  void IncreaseProfilingDepth() { NoBarrier_AtomicIncrement(&profiling_, 1); }
+  void DecreaseProfilingDepth() { NoBarrier_AtomicIncrement(&profiling_, -1); }
 
   // Whether the sampler is running (that is, consumes resources).
-  bool IsActive() const { return active_; }
+  bool IsActive() const { return NoBarrier_Load(&active_); }
 
   Isolate* isolate() { return isolate_; }
 
   // Used in tests to make sure that stack sampling is performed.
   int samples_taken() const { return samples_taken_; }
   void ResetSamplesTaken() { samples_taken_ = 0; }
 
   class PlatformData;
 
+  PlatformData* platform_data() { return data_; }
+
  protected:
   virtual void DoSampleStack(TickSample* sample) = 0;
 
  private:
-  Isolate* isolate_;
-
+  void SetActive(bool value) { NoBarrier_Store(&active_, value); }
   void IncSamplesTaken() { if (++samples_taken_ < 0) samples_taken_ = 0; }
 
+  Isolate* isolate_;
   const int interval_;
-  const bool synchronous_;
-  const bool profiling_;
-  bool active_;
+  Atomic32 profiling_;
+  Atomic32 active_;
   PlatformData* data_;  // Platform specific data.
   int samples_taken_;  // Counts stack samples taken.
   DISALLOW_IMPLICIT_CONSTRUCTORS(Sampler);
 };
 
+
 #endif  // ENABLE_LOGGING_AND_PROFILING
 
 } }  // namespace v8::internal
 
 #endif  // V8_PLATFORM_H_