Set the loaded_ flag in RawLibrary when it is completely loaded. This

vm/raw_object.h

 // Copyright (c) 2011, 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.
 
 #ifndef VM_RAW_OBJECT_H_
 #define VM_RAW_OBJECT_H_
 
 #include "vm/assert.h"
 #include "vm/globals.h"
 #include "vm/snapshot.h"
@@ skipping 420 matching lines @@
   RawString* url_;
   RawString* source_;
   RawTokenStream* tokens_;
   RawObject** to() { return reinterpret_cast<RawObject**>(&ptr()->tokens_); }
 
   Kind kind_;
 };
 
 
 class RawLibrary : public RawObject {
+  enum LibraryState {
+    kAllocated,       // Initial state.
+    kLoadInProgress,  // Library is in the process of being loaded.
+    kLoaded,          // Library is loaded.
+    kLoadError,       // Error occurred during load of the Library.
+  };
+
   RAW_HEAP_OBJECT_IMPLEMENTATION(Library);
 
   RawObject** from() { return reinterpret_cast<RawObject**>(&ptr()->name_); }
   RawString* name_;
   RawString* url_;
   RawScript* script_;
   RawString* private_key_;
   RawArray* dictionary_;         // Top-level names in this library.
   RawArray* anonymous_classes_;  // Classes containing top-level elements.
   RawArray* imports_;            // List of libraries imported without prefix.
   RawArray* imported_into_;      // List of libraries where this library
                                  // is imported into without a prefix.
   RawLibrary* next_registered_;  // Linked list of registered libraries.
   RawObject** to() {
     return reinterpret_cast<RawObject**>(&ptr()->next_registered_);
   }
 
   intptr_t num_imports_;         // Number of entries in imports_.
   intptr_t num_imported_into_;   // Number of entries in imported_into_.
   intptr_t num_anonymous_;       // Number of entries in anonymous_classes_.
   Dart_NativeEntryResolver native_entry_resolver_;  // Resolves natives.
   bool corelib_imported_;
-  bool loaded_;
+  int8_t load_state_;            // Of type LibraryState.
 };
 
 
 class RawLibraryPrefix : public RawObject {
   RAW_HEAP_OBJECT_IMPLEMENTATION(LibraryPrefix);
 
   RawObject** from() { return reinterpret_cast<RawObject**>(&ptr()->name_); }
   RawString* name_;               // library prefix name.
   RawLibrary* library_;           // library imported with a prefix.
   RawObject** to() {
@@ skipping 295 matching lines @@
   intptr_t type_;  // Uninitialized, simple or complex.
   intptr_t flags_;  // Represents global/local, case insensitive, multiline.
 
   // Variable length data follows here.
   uint8_t data_[0];
 };
 
 }  // namespace dart
 
 #endif  // VM_RAW_OBJECT_H_