- Add assertions in MutexLocker/MonitorLocker to ensure that the code enclosed

runtime/vm/port.cc

 // Copyright (c) 2012, 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/port.h"
 
 #include "vm/dart_entry.h"
 #include "platform/utils.h"
 #include "vm/dart_api_impl.h"
 #include "vm/isolate.h"
@@ skipping 295 matching lines @@
 void PortMap::PrintPortsForMessageHandler(MessageHandler* handler,
                                           JSONStream* stream) {
   if (!FLAG_support_service) {
     return;
   }
   JSONObject jsobj(stream);
   jsobj.AddProperty("type", "_Ports");
   Object& msg_handler = Object::Handle();
   {
     JSONArray ports(&jsobj, "ports");
-    MutexLocker ml(mutex_);
+    SafepointMutexLocker ml(mutex_);
     for (intptr_t i = 0; i < capacity_; i++) {
       if (map_[i].handler == handler) {
         if (map_[i].state == kLivePort) {
           JSONObject port(&ports);
           port.AddProperty("type", "_Port");
           port.AddPropertyF("name", "Isolate Port (%" Pd64 ")", map_[i].port);
           msg_handler = DartLibraryCalls::LookupHandler(map_[i].port);
           port.AddProperty("handler", msg_handler);
         }
       }
     }
   }
 }
 
 }  // namespace dart