- Create isolate specific resuable handles and use them in the hot lookup paths.

runtime/vm/isolate.h

Index: runtime/vm/isolate.h
===================================================================
--- runtime/vm/isolate.h	(revision 24061)
+++ runtime/vm/isolate.h	(working copy)
@@ -11,6 +11,7 @@
 #include "vm/base_isolate.h"
 #include "vm/class_table.h"
 #include "vm/gc_callbacks.h"
+#include "vm/handles.h"
 #include "vm/megamorphic_cache_table.h"
 #include "vm/store_buffer.h"
 #include "vm/timer.h"
@@ -18,9 +19,13 @@
 namespace dart {
 
 // Forward declarations.
+class AbstractType;
 class ApiState;
+class Array;
+class Class;
 class CodeIndexTable;
 class Debugger;
+class Field;
 class Function;
 class HandleScope;
 class HandleVisitor;
@@ -30,6 +35,7 @@
 class LongJump;
 class MessageHandler;
 class Mutex;
+class Object;
 class ObjectPointerVisitor;
 class ObjectStore;
 class RawInstance;
@@ -40,12 +46,14 @@
 class RawObject;
 class RawInteger;
 class RawError;
+class RawFloat32x4;
+class RawUint32x4;
 class Simulator;
 class StackResource;
 class StackZone;
 class StubCode;
-class RawFloat32x4;
-class RawUint32x4;
+class TypeArguments;
+class TypeParameter;
 class ObjectHistogram;
 
 
@@ -218,6 +226,19 @@
 };
 
 
+#define REUSABLE_HANDLE_LIST(V)                                                \
+  V(Object)                                                                    \
+  V(Array)                                                                     \
+  V(String)                                                                    \
+  V(Instance)                                                                  \
+  V(Function)                                                                  \
+  V(Field)                                                                     \
+  V(Class)                                                                     \
+  V(AbstractType)                                                              \
+  V(TypeParameter)                                                             \
+  V(TypeArguments)                                                             \
+
+
 class Isolate : public BaseIsolate {
  public:
   ~Isolate();
@@ -581,6 +602,15 @@
   // were eliminated by AllocationSinking pass.
   void MaterializeDeferredObjects();
 
+#define REUSABLE_HANDLE_ACCESSORS(object)                                      \
+  object& object##Handle() {                                                   \
+    ASSERT(object##_handle_ != NULL);                                          \
+    return *object##_handle_;                                                  \
+  }                                                                            \
+
+  REUSABLE_HANDLE_LIST(REUSABLE_HANDLE_ACCESSORS)
+#undef REUSABLE_HANDLE_ACCESSORS
+
   static char* GetStatus(const char* request);
 
  private:
@@ -595,6 +625,7 @@
   char* GetStatusStacktrace();
   char* GetStatusStackFrame(intptr_t index);
   char* DoStacktraceInterrupt(Dart_IsolateInterruptCallback cb);
+  template<class T> T* AllocateReusableHandle();
 
   static ThreadLocalKey isolate_key;
   StoreBuffer store_buffer_;
@@ -643,6 +674,14 @@
   intptr_t stack_frame_index_;
   ObjectHistogram* object_histogram_;
 
+  // Reusable handles support.
+#define REUSABLE_HANDLE_FIELDS(object)                                         \
+  object* object##_handle_;                                                    \
+
+  REUSABLE_HANDLE_LIST(REUSABLE_HANDLE_FIELDS)
+#undef REUSABLE_HANDLE_FIELDS
+  VMHandles handles_;
+
   static Dart_IsolateCreateCallback create_callback_;
   static Dart_IsolateInterruptCallback interrupt_callback_;
   static Dart_IsolateUnhandledExceptionCallback unhandled_exception_callback_;