Fix for 3303 MultithreadedParallelIsolates has a race condition.

src/codegen.h

Index: src/codegen.h
diff --git a/src/codegen.h b/src/codegen.h
index 1e87a1b9e7654feddd63ab869ad43a055733b609..65f1a6dcd66a7049725e362bc7a2ae785140ab84 100644
--- a/src/codegen.h
+++ b/src/codegen.h
@@ -120,6 +120,22 @@ class ElementsTransitionGenerator : public AllStatic {
 static const int kNumberDictionaryProbes = 4;
 
 
+class NoCodeAgeSequence {
+ public:
+  NoCodeAgeSequence();
+
+  uint32_t length() const { return sequence_.length(); }
+  bool Match(byte* candidate) const {

[Sven Panne, 2014/05/05 07:54:14]

"IsPrefixOf" describes the intent more closely.

[mvstanton, 2014/05/06 09:55:45]

I ended up generalizing the class, and the notion of "IsYoung()" and "IsOld()"
worked nicely.

+    return memcmp(candidate, sequence_.start(), sequence_.length()) == 0;
+  }
+  void CopyTo(byte* new_buffer) const {
+    CopyBytes(new_buffer, sequence_.start(), sequence_.length());
+  }
+
+ protected:
+  const EmbeddedVector<byte, kNoCodeAgeSequenceLength> sequence_;
+};
+
 } }  // namespace v8::internal
 
 #endif  // V8_CODEGEN_H_