Update VM service to new isolate API

runtime/vm/isolate.cc

 // Copyright (c) 2013, 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/isolate.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/json.h"
 #include "lib/mirrors.h"
@@ skipping 261 matching lines @@
 
 #define REUSABLE_HANDLE_INITIALIZERS(object)                                   \
   object##_handle_(NULL),
 
 Isolate::Isolate()
     : store_buffer_(),
       message_notify_callback_(NULL),
       name_(NULL),
       start_time_(OS::GetCurrentTimeMicros()),
       main_port_(0),
+      service_port_(0),
       heap_(NULL),
       object_store_(NULL),
       top_context_(Context::null()),
       top_exit_frame_info_(0),
       init_callback_data_(NULL),
       library_tag_handler_(NULL),
       api_state_(NULL),
       stub_code_(NULL),
       debugger_(NULL),
       single_step_(false),
@@ skipping 86 matching lines @@
   ApiState* state = new ApiState();
   ASSERT(state != NULL);
   result->set_api_state(state);
 
   // Initialize stack top and limit in case we are running the isolate in the
   // main thread.
   // TODO(5411455): Need to figure out how to set the stack limit for the
   // main thread.
   result->SetStackLimitFromCurrentTOS(reinterpret_cast<uword>(&result));
   result->set_main_port(PortMap::CreatePort(result->message_handler()));
+  result->set_service_port(PortMap::CreatePort(result->message_handler()));

[Ivan Posva, 2013/10/25 00:30:27]

What is this service port used for? How does the VM account for the additional
open port when determining to terminate an isolate?

[Cutch, 2013/10/25 01:21:57]

(Florian is closing the main port from Dart code as part of his port/cleanup,
this was stopping the VM service from communicating with the isolate).

Using a separate port allows for Dart code to close the main port but still have
service messages delivered to isolates. 

The service port is only ever used as a SendPort (vm service sends OOB messages
over the SendPort) so it does not increment the live port count (except
momentarily when a service message is in flight and we allocate a ReceivePort)
and does not interfere with isolate shutdown.

   result->BuildName(name_prefix);
 
   result->debugger_ = new Debugger();
   result->debugger_->Initialize(result);
   if (FLAG_trace_isolates) {
     if (name_prefix == NULL || strcmp(name_prefix, "vm-isolate") != 0) {
       OS::Print("[+] Starting isolate:\n"
                 "\tisolate:    %s\n", result->name());
     }
   }
@@ skipping 653 matching lines @@
   return func.raw();
 }
 
 
 void IsolateSpawnState::Cleanup() {
   SwitchIsolateScope switch_scope(isolate());
   Dart::ShutdownIsolate();
 }
 
 }  // namespace dart