Refactor isolate startup code in preparation for making isolate spawning more truly non-blocking.

runtime/vm/object.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/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/cpu.h"
@@ skipping 18800 matching lines @@
 const char* Capability::ToCString() const {
   return "Capability";
 }
 
 
 void Capability::PrintJSONImpl(JSONStream* stream, bool ref) const {
   Instance::PrintJSONImpl(stream, ref);
 }
 
 
-RawReceivePort* ReceivePort::New(Dart_Port id, Heap::Space space) {
+RawReceivePort* ReceivePort::New(Dart_Port id,
+                                 bool is_control_port,
+                                 Heap::Space space) {
   Isolate* isolate = Isolate::Current();
   const SendPort& send_port = SendPort::Handle(isolate, SendPort::New(id));
 
   ReceivePort& result = ReceivePort::Handle(isolate);
   {
     RawObject* raw = Object::Allocate(ReceivePort::kClassId,
                                       ReceivePort::InstanceSize(),
                                       space);
     NoGCScope no_gc;
     result ^= raw;
     result.raw_ptr()->send_port_ = send_port.raw();
   }
-  PortMap::SetLive(id);
+  if (is_control_port) {
+    PortMap::SetPortState(id, PortMap::kControlPort);
+  } else {
+    PortMap::SetPortState(id, PortMap::kLivePort);
+  }
   return result.raw();
 }
 
 
 const char* ReceivePort::ToCString() const {
   return "ReceivePort";
 }
 
 
 void ReceivePort::PrintJSONImpl(JSONStream* stream, bool ref) const {
@@ skipping 638 matching lines @@
   return tag_label.ToCString();
 }
 
 
 void UserTag::PrintJSONImpl(JSONStream* stream, bool ref) const {
   Instance::PrintJSONImpl(stream, ref);
 }
 
 
 }  // namespace dart