Fix Shutdown race.

runtime/vm/service_isolate.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/service_isolate.h"
 
 #include "vm/compiler.h"
 #include "vm/dart_api_impl.h"
 #include "vm/dart_entry.h"
 #include "vm/isolate.h"
@@ skipping 326 matching lines @@
                                     ShutdownIsolate,
                                     reinterpret_cast<uword>(isolate));
   }
 
  protected:
   static void ShutdownIsolate(uword parameter) {
     Isolate* I = reinterpret_cast<Isolate*>(parameter);
     ASSERT(ServiceIsolate::IsServiceIsolate(I));
     ServiceIsolate::SetServiceIsolate(NULL);
     ServiceIsolate::SetServicePort(ILLEGAL_PORT);
+    I->WaitForOutstandingSpawns();
     {
       // Print the error if there is one.  This may execute dart code to
       // print the exception object, so we need to use a StartIsolateScope.
       ASSERT(Isolate::Current() == NULL);
       StartIsolateScope start_scope(I);
       Thread* T = Thread::Current();
       ASSERT(I == T->isolate());
       StackZone zone(T);
       HandleScope handle_scope(T);
       Error& error = Error::Handle(Z);
@@ skipping 127 matching lines @@
   ASSERT(!result.IsNull());
   Dart_Port port = ILLEGAL_PORT;
   if (result.IsReceivePort()) {
     port = ReceivePort::Cast(result).Id();
   }
   ASSERT(port != ILLEGAL_PORT);
   ServiceIsolate::SetServicePort(port);
 }
 
 }  // namespace dart