- Premark vm_isolate objects to avoid having to test for them

runtime/vm/dart.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/dart.h"
 
 #include "vm/dart_api_state.h"
 #include "vm/flags.h"
 #include "vm/freelist.h"
 #include "vm/handles.h"
@@ skipping 11 matching lines @@
 namespace dart {
 
 DECLARE_FLAG(bool, print_class_table);
 DECLARE_FLAG(bool, trace_isolates);
 
 Isolate* Dart::vm_isolate_ = NULL;
 ThreadPool* Dart::thread_pool_ = NULL;
 DebugInfo* Dart::pprof_symbol_generator_ = NULL;
 FileWriterFunction Dart::flow_graph_writer_ = NULL;
 
+// An object visitor which will mark all visited objects. This is used to
+// premark all objects in the vm_isolate_ heap.
+class PremarkingVisitor : public ObjectVisitor {
+ public:
+  void VisitObject(RawObject* obj) {
+    // RawInstruction objects are premarked on allocation.
+    if (!obj->IsMarked()) {
+      obj->SetMarkBit();
+    }
+  }
+};
+
+
 // TODO(turnidge): We should add a corresponding Dart::Cleanup.
 bool Dart::InitOnce(Dart_IsolateCreateCallback create,
                     Dart_IsolateInterruptCallback interrupt) {
   // TODO(iposva): Fix race condition here.
   if (vm_isolate_ != NULL || !Flags::Initialized()) {
     return false;
   }
   OS::InitOnce();
   VirtualMemory::InitOnce();
   Isolate::InitOnce();
   PortMap::InitOnce();
   FreeListElement::InitOnce();
   Api::InitOnce();
   // Create the VM isolate and finish the VM initialization.
   ASSERT(thread_pool_ == NULL);
   thread_pool_ = new ThreadPool();
   {
     ASSERT(vm_isolate_ == NULL);
     ASSERT(Flags::Initialized());
     vm_isolate_ = Isolate::Init("vm-isolate");
     Zone zone(vm_isolate_);
     HandleScope handle_scope(vm_isolate_);
     Heap::Init(vm_isolate_);
     ObjectStore::Init(vm_isolate_);
     Object::InitOnce();
     StubCode::InitOnce();
     Scanner::InitOnce();
+    PremarkingVisitor premarker;
+    vm_isolate_->heap()->IterateOldObjects(&premarker);
   }
   Isolate::SetCurrent(NULL);  // Unregister the VM isolate from this thread.
   Isolate::SetCreateCallback(create);
   Isolate::SetInterruptCallback(interrupt);
   return true;
 }
 
 
 Isolate* Dart::CreateIsolate(const char* name_prefix) {
   // Create a new isolate.
@@ skipping 43 matching lines @@
 }
 
 
 void Dart::ShutdownIsolate() {
   Isolate* isolate = Isolate::Current();
   isolate->Shutdown();
   delete isolate;
 }
 
 }  // namespace dart