Clean VM thread shutdown:

runtime/vm/isolate.h

 // 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.
 
 #ifndef VM_ISOLATE_H_
 #define VM_ISOLATE_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/base_isolate.h"
@@ skipping 724 matching lines @@
   // to using the mutator thread (which must also be the current thread).
   Zone* current_zone() const {
     ASSERT(Thread::Current() == mutator_thread_);
     return mutator_thread_->zone();
   }
   void set_current_zone(Zone* zone) {
     ASSERT(Thread::Current() == mutator_thread_);
     mutator_thread_->set_zone(zone);
   }
 
+  static void KillIsolate(Isolate* isolate);
+  static void KillAllIsolates();
+
+  static void DisableIsolateCreation();
+  static void EnableIsolateCreation();
+
  private:
   friend class Dart;  // Init, InitOnce, Shutdown.
 
   explicit Isolate(const Dart_IsolateFlags& api_flags);
 
   static void InitOnce();
   static Isolate* Init(const char* name_prefix,
                        const Dart_IsolateFlags& api_flags,
                        bool is_vm_isolate = false);
+  void LowLevelShutdown();
   void Shutdown();
 
   void BuildName(const char* name_prefix);
   void PrintInvokedFunctions();
 
   void ProfileIdle();
 
   // Visit all object pointers. Caller must ensure concurrent sweeper is not
   // running, and the visitor must not allocate.
   void VisitObjectPointers(ObjectPointerVisitor* visitor,
@@ skipping 146 matching lines @@
   static Dart_FileOpenCallback file_open_callback_;
   static Dart_FileReadCallback file_read_callback_;
   static Dart_FileWriteCallback file_write_callback_;
   static Dart_FileCloseCallback file_close_callback_;
   static Dart_EntropySource entropy_source_callback_;
   static Dart_IsolateInterruptCallback vmstats_callback_;
 
   static void WakePauseEventHandler(Dart_Isolate isolate);
 
   // Manage list of existing isolates.
-  static void AddIsolateTolist(Isolate* isolate);
+  static bool AddIsolateToList(Isolate* isolate);
   static void RemoveIsolateFromList(Isolate* isolate);
   static void CheckForDuplicateThreadState(InterruptableThreadState* state);
 
-  static Monitor* isolates_list_monitor_;  // Protects isolates_list_head_
+  // This monitor protects isolates_list_head_, and creation_enabled_.
+  static Monitor* isolates_list_monitor_;
   static Isolate* isolates_list_head_;
+  static bool creation_enabled_;
 
 #define REUSABLE_FRIEND_DECLARATION(name)                                      \
   friend class Reusable##name##HandleScope;
 REUSABLE_HANDLE_LIST(REUSABLE_FRIEND_DECLARATION)
 #undef REUSABLE_FRIEND_DECLARATION
 
   friend class GCMarker;  // VisitObjectPointers
   friend class Scavenger;  // VisitObjectPointers
   friend class ServiceIsolate;
   friend class Thread;
@@ skipping 141 matching lines @@
   uint8_t* serialized_message_;
   intptr_t serialized_message_len_;
   Isolate::Flags isolate_flags_;
   bool paused_;
   bool errors_are_fatal_;
 };
 
 }  // namespace dart
 
 #endif  // VM_ISOLATE_H_