--- old/src/hotspot/share/runtime/thread.cpp	2018-12-09 03:18:58.402640859 -0500
+++ new/src/hotspot/share/runtime/thread.cpp	2018-12-09 03:18:58.018620523 -0500
@@ -306,15 +306,19 @@
   }
 #endif // ASSERT
 
-  // Notify the barrier set that a thread is being created. Note that some
-  // threads are created before a barrier set is available. The call to
-  // BarrierSet::on_thread_create() for these threads is therefore deferred
+  // Notify the barrier set that a thread is being created. The initial
+  // thread is created before the barrier set is available.  The call to
+  // BarrierSet::on_thread_create() for this thread is therefore deferred
   // to BarrierSet::set_barrier_set().
   BarrierSet* const barrier_set = BarrierSet::barrier_set();
   if (barrier_set != NULL) {
     barrier_set->on_thread_create(this);
   } else {
-    DEBUG_ONLY(Threads::inc_threads_before_barrier_set();)
+#ifdef ASSERT
+    static bool initial_thread_created = false;
+    assert(!initial_thread_created, "creating thread before barrier set");
+    initial_thread_created = true;
+#endif // ASSERT
   }
 }
 
@@ -3395,7 +3399,6 @@
 
 #ifdef ASSERT
 bool        Threads::_vm_complete = false;
-size_t      Threads::_threads_before_barrier_set = 0;
 #endif
 
 static inline void *prefetch_and_load_ptr(void **addr, intx prefetch_interval) {