Rework service extensions to be safe

runtime/vm/dart_entry.cc

 // 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.
 
 #include "vm/dart_entry.h"
 
 #include "vm/class_finalizer.h"
 #include "vm/code_generator.h"
 #include "vm/compiler.h"
 #include "vm/debugger.h"
@@ skipping 540 matching lines @@
     // at the first location the user is interested in.
     isolate->debugger()->SetSingleStep();
   }
   const Object& result = Object::Handle(isolate,
       DartEntry::InvokeFunction(function, args));
   ASSERT(result.IsNull() || result.IsError());
   return result.raw();
 }
 
 
+RawObject* DartLibraryCalls::DrainMicrotaskQueue() {
+  Isolate* isolate = Isolate::Current();
+  Library& isolate_lib = Library::Handle(isolate, Library::IsolateLibrary());
+  ASSERT(!isolate_lib.IsNull());
+  Function& function = Function::Handle(isolate,
+      isolate_lib.LookupFunctionAllowPrivate(
+          Symbols::_runPendingImmediateCallback()));
+  const Object& result = Object::Handle(isolate,
+      DartEntry::InvokeFunction(function, Object::empty_array()));
+  ASSERT(result.IsNull() || result.IsError());
+  return result.raw();
+}
+
+
 RawObject* DartLibraryCalls::MapSetAt(const Instance& map,
                                       const Instance& key,
                                       const Instance& value) {
   const int kNumArguments = 3;
   ArgumentsDescriptor args_desc(
       Array::Handle(ArgumentsDescriptor::New(kNumArguments)));
   const Function& function = Function::Handle(
       Resolver::ResolveDynamic(map,
                                Symbols::AssignIndexToken(),
                                args_desc));
   ASSERT(!function.IsNull());
   const Array& args = Array::Handle(Array::New(kNumArguments));
   args.SetAt(0, map);
   args.SetAt(1, key);
   args.SetAt(2, value);
   const Object& result = Object::Handle(DartEntry::InvokeFunction(function,
                                                                   args));
   return result.raw();
 }
 
 }  // namespace dart