Create a thread safe version of StatsCounters and use.

src/isolate.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_ISOLATE_H_
 #define V8_ISOLATE_H_
 
 #include <memory>
 #include <queue>
 
@@ skipping 518 matching lines @@
     DCHECK(isolate != NULL);
     return isolate;
   }
 
   // Usually called by Init(), but can be called early e.g. to allow
   // testing components that require logging but not the whole
   // isolate.
   //
   // Safe to call more than once.
   void InitializeLoggingAndCounters();
+  bool InitializeCounters();  // Returns false if already initialized.
 
   bool Init(Deserializer* des);
 
   // True if at least one thread Enter'ed this isolate.
   bool IsInUse() { return entry_stack_ != NULL; }
 
   // Destroys the non-default isolates.
   // Sets default isolate into "has_been_disposed" state rather then destroying,
   // for legacy API reasons.
   void TearDown();
@@ skipping 316 matching lines @@
   NATIVE_CONTEXT_FIELDS(NATIVE_CONTEXT_FIELD_ACCESSOR)
 #undef NATIVE_CONTEXT_FIELD_ACCESSOR
 
   Bootstrapper* bootstrapper() { return bootstrapper_; }
   Counters* counters() {
     // Call InitializeLoggingAndCounters() if logging is needed before
     // the isolate is fully initialized.
     DCHECK(counters_ != NULL);
     return counters_;
   }
+  std::shared_ptr<Counters> counters_shared() { return counters_shared_; }
   RuntimeProfiler* runtime_profiler() { return runtime_profiler_; }
   CompilationCache* compilation_cache() { return compilation_cache_; }
   Logger* logger() {
     // Call InitializeLoggingAndCounters() if logging is needed before
     // the isolate is fully initialized.
     DCHECK(logger_ != NULL);
     return logger_;
   }
   StackGuard* stack_guard() { return &stack_guard_; }
   Heap* heap() { return &heap_; }
@@ skipping 535 matching lines @@
   CpuProfiler* cpu_profiler() const { return cpu_profiler_; }
 
   base::Atomic32 id_;
   EntryStackItem* entry_stack_;
   int stack_trace_nesting_level_;
   StringStream* incomplete_message_;
   Address isolate_addresses_[kIsolateAddressCount + 1];  // NOLINT
   Bootstrapper* bootstrapper_;
   RuntimeProfiler* runtime_profiler_;
   CompilationCache* compilation_cache_;
+  std::shared_ptr<Counters> counters_shared_;
   Counters* counters_;
   base::RecursiveMutex break_access_;
   Logger* logger_;
   StackGuard stack_guard_;
   StatsTable* stats_table_;
   StubCache* load_stub_cache_;
   StubCache* store_stub_cache_;
   CodeAgingHelper* code_aging_helper_;
   DeoptimizerData* deoptimizer_data_;
   bool deoptimizer_lazy_throw_;
@@ skipping 374 matching lines @@
 
   EmbeddedVector<char, 128> filename_;
   FILE* file_;
   int scope_depth_;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_ISOLATE_H_