Implement safepointing of threads

runtime/lib/vmservice.cc

 // Copyright (c) 2015, 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/bootstrap_natives.h"
 #include "vm/dart_api_impl.h"
 #include "vm/datastream.h"
 #include "vm/exceptions.h"
 #include "vm/growable_array.h"
 #include "vm/message.h"
@@ skipping 324 matching lines @@
 
 
 static void FilenameFinalizer(void* peer) {
   char* filename = reinterpret_cast<char*>(peer);
   delete[] filename;
 }
 
 
 DEFINE_NATIVE_ENTRY(VMService_DecodeAssets, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(TypedData, data, arguments->NativeArgAt(0));
+  TransitionVMToNative transition(thread);
   Api::Scope scope(thread);
 
   Dart_Handle data_handle = Api::NewHandle(thread, data.raw());
 
   Dart_TypedData_Type typ;
   void* bytes;
   intptr_t length;
   Dart_Handle err = Dart_TypedDataAcquireData(
       data_handle, &typ, &bytes, &length);
   ASSERT(!Dart_IsError(err));
@@ skipping 32 matching lines @@
         thread->zone(), dart_filename));
     result_list.SetAt(idx + 1, Api::UnwrapExternalTypedDataHandle(
         thread->zone(), dart_contents));
     idx += 2;
   }
 
   return result_list.raw();
 }
 
 }  // namespace dart