Run Crankshaft on a separate thread.

src/api.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 655 matching lines @@
   LOG_API(isolate, "DisposeGlobal");
   if (!isolate->IsInitialized()) return;
   isolate->global_handles()->Destroy(obj);
 }
 
 // --- H a n d l e s ---
 
 
 HandleScope::HandleScope() {
   i::Isolate* isolate = i::Isolate::Current();
+  if (i::FLAG_optimize_in_parallel &&
+      !isolate->thread_manager()->IsLockedByCurrentThread()) {
+    has_isolate_lock_ = true;
+    isolate->thread_manager()->Lock();
+  } else {
+    has_isolate_lock_ = false;
+  }
+
   API_ENTRY_CHECK(isolate, "HandleScope::HandleScope");
   v8::ImplementationUtilities::HandleScopeData* current =
       isolate->handle_scope_data();
   isolate_ = isolate;
   prev_next_ = current->next;
   prev_limit_ = current->limit;
   is_closed_ = false;
   current->level++;
 }
 
 
 HandleScope::~HandleScope() {
   if (!is_closed_) {
     Leave();
   }
+  if (has_isolate_lock_) {
+    isolate_->thread_manager()->Unlock();
+  }
 }
 
 
 void HandleScope::Leave() {
   ASSERT(isolate_ == i::Isolate::Current());
   v8::ImplementationUtilities::HandleScopeData* current =
       isolate_->handle_scope_data();
   current->level--;
   ASSERT(current->level >= 0);
   current->next = prev_next_;
@@ skipping 5710 matching lines @@
 
 
 char* HandleScopeImplementer::Iterate(ObjectVisitor* v, char* storage) {
   HandleScopeImplementer* scope_implementer =
       reinterpret_cast<HandleScopeImplementer*>(storage);
   scope_implementer->IterateThis(v);
   return storage + ArchiveSpacePerThread();
 }
 
 } }  // namespace v8::internal