Fix data races and leaks related to v8::Lockers

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 "include/v8-debug.h"
 #include "src/allocation.h"
 #include "src/assert-scope.h"
@@ skipping 161 matching lines @@
   C(Context, context)                                   \
   C(PendingException, pending_exception)                \
   C(ExternalCaughtException, external_caught_exception) \
   C(JSEntrySP, js_entry_sp)
 
 
 // Platform-independent, reliable thread identifier.
 class ThreadId {
  public:
   // Creates an invalid ThreadId.
-  ThreadId() : id_(kInvalidId) {}
+  ThreadId() { base::NoBarrier_Store(&id_, kInvalidId); }
+
+  ThreadId& operator=(const ThreadId& other) {
+    base::NoBarrier_Store(&id_, base::NoBarrier_Load(&other.id_));
+    return *this;
+  }
 
   // Returns ThreadId for current thread.
   static ThreadId Current() { return ThreadId(GetCurrentThreadId()); }
 
   // Returns invalid ThreadId (guaranteed not to be equal to any thread).
   static ThreadId Invalid() { return ThreadId(kInvalidId); }
 
   // Compares ThreadIds for equality.
   INLINE(bool Equals(const ThreadId& other) const) {
-    return id_ == other.id_;
+    return base::NoBarrier_Load(&id_) == base::NoBarrier_Load(&other.id_);
   }
 
   // Checks whether this ThreadId refers to any thread.
   INLINE(bool IsValid() const) {
-    return id_ != kInvalidId;
+    return base::NoBarrier_Load(&id_) != kInvalidId;
   }
 
   // Converts ThreadId to an integer representation
   // (required for public API: V8::V8::GetCurrentThreadId).
-  int ToInteger() const { return id_; }
+  int ToInteger() const { return static_cast<int>(base::NoBarrier_Load(&id_)); }
 
   // Converts ThreadId to an integer representation
   // (required for public API: V8::V8::TerminateExecution).
   static ThreadId FromInteger(int id) { return ThreadId(id); }
 
  private:
   static const int kInvalidId = -1;
 
-  explicit ThreadId(int id) : id_(id) {}
+  explicit ThreadId(int id) { base::NoBarrier_Store(&id_, id); }
 
   static int AllocateThreadId();
 
   static int GetCurrentThreadId();
 
-  int id_;
+  base::Atomic32 id_;
 
   static base::Atomic32 highest_thread_id_;
 
   friend class Isolate;
 };
 
 
 #define FIELD_ACCESSOR(type, name)                 \
   inline void set_##name(type v) { name##_ = v; }  \
   inline type name() const { return name##_; }
@@ skipping 1324 matching lines @@
   }
 
   EmbeddedVector<char, 128> filename_;
   FILE* file_;
   int scope_depth_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_ISOLATE_H_