Fixes for OSThread creation shutdown race.

runtime/vm/os_thread.h

 // 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.
 
 #ifndef VM_OS_THREAD_H_
 #define VM_OS_THREAD_H_
 
 #include "platform/globals.h"
 #include "vm/allocation.h"
 #include "vm/globals.h"
@@ skipping 210 matching lines @@
   TimelineEventBlock* timeline_block_;
 
   // All |Thread|s are registered in the thread list.
   OSThread* thread_list_next_;
 
   uintptr_t thread_interrupt_disabled_;
   Log* log_;
   uword stack_base_;
   Thread* thread_;
 
+  // thread_list_lock_ cannot have a static lifetime because the order in which
+  // destructors run is undefined. At the moment this lock cannot be deleted
+  // either since otherwise, if a thread only begins to run after we have
+  // started to run TLS destructors for a call to exit(), there will be a race
+  // on its deletion in CreateOSThread().
+  static Mutex* thread_list_lock_;
   static OSThread* thread_list_head_;
-  static Mutex* thread_list_lock_;
   static bool creation_enabled_;
 
   friend class OSThreadIterator;
   friend class ThreadInterrupterWin;
   friend class ThreadRegistry;
 };
 
 
 // Note that this takes the thread list lock, prohibiting threads from coming
 // on- or off-line.
@@ skipping 84 matching lines @@
 #endif  // defined(DEBUG)
 
   DISALLOW_COPY_AND_ASSIGN(Monitor);
 };
 
 
 }  // namespace dart
 
 
 #endif  // VM_OS_THREAD_H_