Enables clean VM shutdown.

runtime/vm/dart.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/dart.h"
 
 #include "vm/code_observers.h"
 #include "vm/cpu.h"
 #include "vm/dart_api_state.h"
 #include "vm/dart_entry.h"
@@ skipping 96 matching lines @@
   Metric::InitOnce();
   StoreBuffer::InitOnce();
 
 #if defined(USING_SIMULATOR)
   Simulator::InitOnce();
 #endif
   // Create the read-only handles area.
   ASSERT(predefined_handles_ == NULL);
   predefined_handles_ = new ReadOnlyHandles();
   // Create the VM isolate and finish the VM initialization.
-  ASSERT(thread_pool_ == NULL);
-  thread_pool_ = new ThreadPool();
   {
     ASSERT(vm_isolate_ == NULL);
     ASSERT(Flags::Initialized());
     const bool is_vm_isolate = true;
     Thread::EnsureInit();
 
     // Setup default flags for the VM isolate.
     Isolate::Flags vm_flags;
     Dart_IsolateFlags api_flags;
     vm_flags.CopyTo(&api_flags);
@@ skipping 62 matching lines @@
   Isolate::SetUnhandledExceptionCallback(unhandled);
   Isolate::SetShutdownCallback(shutdown);
 
   ServiceIsolate::Run();
 
   return NULL;
 }
 
 
 const char* Dart::Cleanup() {
-  // Shutdown the service isolate before shutting down the thread pool.
-  ServiceIsolate::Shutdown();
-#if 0
-  // Ideally we should shutdown the VM isolate here, but the thread pool
-  // shutdown does not seem to ensure that all the threads have stopped
-  // execution before it terminates, this results in racing isolates.
+  ASSERT(Isolate::Current() == NULL);
   if (vm_isolate_ == NULL) {
     return "VM already terminated.";
   }
 
-  ASSERT(Isolate::Current() == NULL);
+  // Shutdown the service isolate before shutting down the thread pool.
+  ServiceIsolate::Shutdown();
 
-  delete thread_pool_;
-  thread_pool_ = NULL;
+  // Shutdown the thread pool. On return, all thread pool threads have exited.
+  ThreadPool::Shutdown();
 
   // Set the VM isolate as current isolate.
   Thread::EnsureInit();
   Thread::EnterIsolate(vm_isolate_);
 
-  // There is a planned and known asymmetry here: We exit one scope for the VM
-  // isolate to account for the scope that was entered in Dart_InitOnce.
-  Dart_ExitScope();
-
   ShutdownIsolate();
   vm_isolate_ = NULL;
 
   TargetCPUFeatures::Cleanup();
-#endif
 
   Profiler::Shutdown();
   CodeObservers::DeleteAll();
 
   return NULL;
 }
 
 
 Isolate* Dart::CreateIsolate(const char* name_prefix,
                              const Dart_IsolateFlags& api_flags) {
@@ skipping 134 matching lines @@
   return predefined_handles_->handles_.IsValidScopedHandle(address);
 }
 
 
 bool Dart::IsReadOnlyApiHandle(Dart_Handle handle) {
   ASSERT(predefined_handles_ != NULL);
   return predefined_handles_->api_handles_.IsValidHandle(handle);
 }
 
 }  // namespace dart