Run Crankshaft on a separate thread.

src/isolate.h

Index: src/isolate.h
diff --git a/src/isolate.h b/src/isolate.h
index f1c9b3ccfaae7843cfb1be0357ce056d105a6fb3..d83950c084b2cf793620f516983899a81832e0b8 100644
--- a/src/isolate.h
+++ b/src/isolate.h
@@ -1032,6 +1032,8 @@ class Isolate {
     date_cache_ = date_cache;
   }
 
+  bool to_delete() { return to_delete_; }
+
  private:
   Isolate();
 
@@ -1128,7 +1130,10 @@ class Isolate {
   // for the thread.
   // Not thread-safe. Multiple threads should not Enter/Exit the same isolate
   // at the same time, this should be prevented using external locking.
-  void Exit();
+  // When using --concurrent_crankshaft, the Entry and Exit methods
+  // need to automatically lock and unlock the isolate, except in one
+  // edge-case, when we call Exit(false)

[danno, 2012/05/22 10:32:19]

Can you be more explicit why this case happens?

+  void Exit(bool auto_unlock = true);
 
   void PreallocatedMemoryThreadStart();
   void PreallocatedMemoryThreadStop();
@@ -1215,6 +1220,12 @@ class Isolate {
   // Time stamp at initialization.
   double time_millis_at_init_;
 
+  // The crankshaft thread should delete this isolate when it sees it
+  // next (and also not compile anything in it).
+  bool to_delete_;
+
+  List<bool> lock_history_;
+
 #if defined(V8_TARGET_ARCH_ARM) && !defined(__arm__) || \
     defined(V8_TARGET_ARCH_MIPS) && !defined(__mips__)
   bool simulator_initialized_;
@@ -1255,6 +1266,7 @@ class Isolate {
 #undef ISOLATE_FIELD_OFFSET
 #endif
 
+  friend class CrankshaftThread;
   friend class ExecutionAccess;
   friend class IsolateInitializer;
   friend class ThreadManager;