Fix Initialize & Dispose for external snapshot.

src/natives-external.cc

 // Copyright 2014 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/natives.h"
 
 #include "src/base/logging.h"
 #include "src/list.h"
 #include "src/list-inl.h"
 #include "src/snapshot-source-sink.h"
@@ skipping 114 matching lines @@
 class NativesHolder {
  public:
   static NativesStore* get() {
     DCHECK(holder_);
     return holder_;
   }
   static void set(NativesStore* store) {
     DCHECK(store);
     holder_ = store;
   }
+  static bool empty() { return holder_ == NULL; }
   static void Dispose() {
-    DCHECK(holder_);
     delete holder_;
+    holder_ = NULL;
   }
 
  private:
   static NativesStore* holder_;
 };
 
 template<NativeType type>
 NativesStore* NativesHolder<type>::holder_ = NULL;
 
 
+// The natives blob. Memory is owned by caller.
+static StartupData* natives_blob_ = NULL;
+
+
 /**
- * Read the Natives (library sources) blob, as generated by js2c + the build
+ * Read the Natives blob, as previously set by SetNativesFromFile.
+ */
+void ReadNatives() {
+  if (natives_blob_ && NativesHolder<CORE>::empty()) {
+    SnapshotByteSource bytes(natives_blob_->data, natives_blob_->raw_size);
+    NativesHolder<CORE>::set(NativesStore::MakeFromScriptsSource(&bytes));
+    NativesHolder<EXPERIMENTAL>::set(
+        NativesStore::MakeFromScriptsSource(&bytes));
+    DCHECK(!bytes.HasMore());
+  }
+}
+
+
+/**
+ * Set the Natives (library sources) blob, as generated by js2c + the build
  * system.
  */
 void SetNativesFromFile(StartupData* natives_blob) {
+  DCHECK(!natives_blob_);
   DCHECK(natives_blob);
   DCHECK(natives_blob->data);
   DCHECK(natives_blob->raw_size > 0);
 
-  SnapshotByteSource bytes(natives_blob->data, natives_blob->raw_size);
-  NativesHolder<CORE>::set(NativesStore::MakeFromScriptsSource(&bytes));
-  NativesHolder<EXPERIMENTAL>::set(NativesStore::MakeFromScriptsSource(&bytes));
-  DCHECK(!bytes.HasMore());
+  natives_blob_ = natives_blob;
+  ReadNatives();
 }
 
 
 /**
  * Release memory allocated by SetNativesFromFile.
  */
 void DisposeNatives() {
   NativesHolder<CORE>::Dispose();
   NativesHolder<EXPERIMENTAL>::Dispose();
 }
@@ skipping 36 matching lines @@
 }
 
 
 // The compiler can't 'see' all uses of the static methods and hence
 // my choice to elide them. This we'll explicitly instantiate these.
 template class NativesCollection<CORE>;
 template class NativesCollection<EXPERIMENTAL>;
 
 }  // namespace v8::internal
 }  // namespace v8