Add option to disable MirrorCache.

src/debug.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/api.h"
 #include "src/arguments.h"
 #include "src/bootstrapper.h"
 #include "src/code-stubs.h"
@@ skipping 2441 matching lines @@
 
 bool Debug::IsDebugGlobal(GlobalObject* global) {
   return is_loaded() && global == debug_context()->global_object();
 }
 
 
 void Debug::ClearMirrorCache() {
   PostponeInterruptsScope postpone(isolate_);
   HandleScope scope(isolate_);
   ASSERT(isolate_->context() == *Debug::debug_context());
-
-  // Clear the mirror cache.
-  Handle<Object> fun = Object::GetProperty(
-      isolate_,
-      isolate_->global_object(),
-      "ClearMirrorCache").ToHandleChecked();
-  ASSERT(fun->IsJSFunction());
-  Execution::TryCall(Handle<JSFunction>::cast(fun),
-                     Handle<JSObject>(Debug::debug_context()->global_object()),
-                     0,
-                     NULL);
+  Factory* factory = isolate_->factory();

[yurys, 2014/06/03 13:27:18]

Just curious why is the advantage of this implementation compared to
ClearMirrorCache call?

[Yang, 2014/06/03 14:22:05]

Less overhead, and I think that two SetProperty is nicer than a GetProperty +
TryCall.

+  JSObject::SetProperty(isolate_->global_object(),
+      factory->NewStringFromAsciiChecked("next_handle_"),
+      handle(Smi::FromInt(0), isolate_),
+      NONE,
+      SLOPPY);
+  JSObject::SetProperty(isolate_->global_object(),
+      factory->NewStringFromAsciiChecked("mirror_cache_"),
+      factory->NewJSArray(0, FAST_ELEMENTS),
+      NONE,
+      SLOPPY);
 }
 
 
 Handle<FixedArray> Debug::GetLoadedScripts() {
   // Create and fill the script cache when the loaded scripts is requested for
   // the first time.
   if (script_cache_ == NULL) script_cache_ = new ScriptCache(isolate_);
 
   // Perform GC to get unreferenced scripts evicted from the cache before
   // returning the content.
@@ skipping 928 matching lines @@
   logger_->DebugEvent("Put", message.text());
 }
 
 
 void LockingCommandMessageQueue::Clear() {
   LockGuard<Mutex> lock_guard(&mutex_);
   queue_.Clear();
 }
 
 } }  // namespace v8::internal