Clean VM thread shutdown:

runtime/bin/process.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 "bin/dartutils.h"
 #include "bin/io_buffer.h"
+#include "bin/log.h"
 #include "bin/platform.h"
 #include "bin/process.h"
 #include "bin/socket.h"
 #include "bin/utils.h"
 
 #include "include/dart_api.h"
 
 namespace dart {
 namespace bin {
 
@@ skipping 192 matching lines @@
   intptr_t signal = DartUtils::GetIntptrValue(Dart_GetNativeArgument(args, 1));
   bool success = Process::Kill(pid, signal);
   Dart_SetReturnValue(args, Dart_NewBoolean(success));
 }
 
 
 void FUNCTION_NAME(Process_Exit)(Dart_NativeArguments args) {
   int64_t status = 0;
   // Ignore result if passing invalid argument and just exit 0.
   DartUtils::GetInt64Value(Dart_GetNativeArgument(args, 0), &status);
-  Dart_ExitIsolate();
-  Dart_Cleanup();
+  Dart_ShutdownIsolate();
+  Process::TerminateExitCodeHandler();
+  char* error = Dart_Cleanup();
+  if (error != NULL) {
+    Log::PrintErr("VM cleanup failed: %s\n", error);
+    free(error);
+  }
   exit(static_cast<int>(status));
 }
 
 
 void FUNCTION_NAME(Process_SetExitCode)(Dart_NativeArguments args) {
   int64_t status = 0;
   // Ignore result if passing invalid argument and just set exit code to 0.
   DartUtils::GetInt64Value(Dart_GetNativeArgument(args, 0), &status);
   Process::SetGlobalExitCode(status);
 }
@@ skipping 105 matching lines @@
     free(const_cast<char*>(system_string));
     Dart_PropagateError(result);
   }
   memmove(buffer, system_string, system_len);
   free(const_cast<char*>(system_string));
   Dart_SetReturnValue(args, external_array);
 }
 
 }  // namespace bin
 }  // namespace dart