Refactor Thread lifecycle interface, add Thread::Enter/ExitIsolate.

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 128 matching lines @@
     }
 #endif
     Object::FinalizeVMIsolate(vm_isolate_);
   }
   // There is a planned and known asymmetry here: We enter one scope for the VM
   // isolate so that we can allocate the "persistent" scoped handles for the
   // predefined API values (such as Dart_True, Dart_False and Dart_Null).
   Dart_EnterScope();
   Api::InitHandles();
 
-  Isolate::SetCurrent(NULL);  // Unregister the VM isolate from this thread.
+  Thread::ExitIsolate();  // Unregister the VM isolate from this thread.
   Isolate::SetCreateCallback(create);
   Isolate::SetInterruptCallback(interrupt);
   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.
   if (vm_isolate_ == NULL) {
     return "VM already terminated.";
   }
 
   ASSERT(Isolate::Current() == NULL);
 
   delete thread_pool_;
   thread_pool_ = NULL;
 
   // Set the VM isolate as current isolate.
-  Isolate::SetCurrent(vm_isolate_);
+  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
@@ skipping 124 matching lines @@
   return predefined_handles_->handles_.AllocateScopedHandle();
 }
 
 
 bool Dart::IsReadOnlyHandle(uword address) {
   ASSERT(predefined_handles_ != NULL);
   return predefined_handles_->handles_.IsValidScopedHandle(address);
 }
 
 }  // namespace dart