- Add and enable concurrent sweeper.

runtime/vm/isolate.h

Index: runtime/vm/isolate.h
===================================================================
--- runtime/vm/isolate.h	(revision 39568)
+++ runtime/vm/isolate.h	(working copy)
@@ -120,6 +120,8 @@
   static Isolate* Init(const char* name_prefix);
   void Shutdown();
 
+  Isolate* ShallowCopy();

[koda, 2014/08/26 23:34:48]

Briefly specify what is available in a shallow copy:
* class table (without stats)
* ...
and preferably also why it's useful.

[Ivan Posva, 2014/08/27 01:00:22]

For now we are leaving this alone after discussion. Some major refactoring will
be needed for the use of isolate/classtable.

+
   // Register a newly introduced class.
   void RegisterClass(const Class& cls);
   void RegisterClassAt(intptr_t index, const Class& cls);
@@ -602,6 +604,7 @@
 
  private:
   Isolate();
+  explicit Isolate(Isolate* original);
 
   void BuildName(const char* name_prefix);
   void PrintInvokedFunctions();