Fix data race on CpuProfiler::running_

src/cpu-profiler.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_CPU_PROFILER_H_
 #define V8_CPU_PROFILER_H_
 
 #include "src/allocation.h"
 #include "src/base/atomicops.h"
 #include "src/base/platform/time.h"
@@ skipping 114 matching lines @@
 class ProfilerEventsProcessor : public base::Thread {
  public:
   ProfilerEventsProcessor(ProfileGenerator* generator,
                           Sampler* sampler,
                           base::TimeDelta period);
   virtual ~ProfilerEventsProcessor() {}
 
   // Thread control.
   virtual void Run();
   void StopSynchronously();
-  INLINE(bool running()) { return running_; }
+  INLINE(bool running()) { return !!base::NoBarrier_Load(&running_); }
   void Enqueue(const CodeEventsContainer& event);
 
   // Puts current stack into tick sample events buffer.
   void AddCurrentStack(Isolate* isolate);
 
   // Tick sample events are filled directly in the buffer of the circular
   // queue (because the structure is of fixed width, but usually not all
   // stack frame entries are filled.) This method returns a pointer to the
   // next record of the buffer.
   inline TickSample* StartTickSample();
@@ skipping 10 matching lines @@
 
   enum SampleProcessingResult {
     OneSampleProcessed,
     FoundSampleForNextCodeEvent,
     NoSamplesInQueue
   };
   SampleProcessingResult ProcessOneSample();
 
   ProfileGenerator* generator_;
   Sampler* sampler_;
-  bool running_;
+  base::Atomic32 running_;
   // Sampling period in microseconds.
   const base::TimeDelta period_;
   UnboundQueue<CodeEventsContainer> events_buffer_;
   static const size_t kTickSampleBufferSize = 1 * MB;
   static const size_t kTickSampleQueueLength =
       kTickSampleBufferSize / sizeof(TickSampleEventRecord);
   SamplingCircularQueue<TickSampleEventRecord,
                         kTickSampleQueueLength> ticks_buffer_;
   UnboundQueue<TickSampleEventRecord> ticks_from_vm_buffer_;
   unsigned last_code_event_id_;
@@ skipping 86 matching lines @@
   bool saved_is_logging_;
   bool is_profiling_;
 
   DISALLOW_COPY_AND_ASSIGN(CpuProfiler);
 };
 
 } }  // namespace v8::internal
 
 
 #endif  // V8_CPU_PROFILER_H_