--- old/src/hotspot/share/runtime/thread.inline.hpp	2019-11-22 14:30:47.189725988 -0500
+++ new/src/hotspot/share/runtime/thread.inline.hpp	2019-11-22 14:30:46.897718333 -0500
@@ -125,6 +125,8 @@
 }
 
 inline void JavaThread::set_thread_state(JavaThreadState s) {
+  assert(current_or_null() == NULL || current_or_null() == this,
+         "state change should only be called by the current thread");
 #if defined(PPC64) || defined (AARCH64)
   // Use membars when accessing volatile _thread_state. See
   // Threads::create_vm() for size checks.