--- old/src/hotspot/share/gc/shared/owstTaskTerminator.cpp	2020-01-30 17:09:51.617442727 +0100
+++ new/src/hotspot/share/gc/shared/owstTaskTerminator.cpp	2020-01-30 17:09:50.465426224 +0100
@@ -26,6 +26,7 @@
 #include "precompiled.hpp"
 
 #include "gc/shared/owstTaskTerminator.hpp"
+#include "gc/shared/taskqueue.hpp"
 #include "logging/log.hpp"
 
 #ifdef TRACESPINNING
@@ -40,16 +41,16 @@
   _offered_termination(0),
   _spin_master(NULL) {
 
-    _blocker = new Monitor(Mutex::leaf, "OWSTTaskTerminator", false, Monitor::_safepoint_check_never);
+  _blocker = new Monitor(Mutex::leaf, "OWSTTaskTerminator", false, Monitor::_safepoint_check_never);
 }
 
 OWSTTaskTerminator::~OWSTTaskTerminator() {
+  assert(_offered_termination == 0 || !peek_in_queue_set(), "Precondition");
+  assert(_offered_termination == 0 || _offered_termination == _n_threads, "Terminated or aborted" );
+
   assert(_spin_master == NULL, "Should have been reset");
   assert(_blocker != NULL, "Can not be NULL");
   delete _blocker;
-
-  assert(_offered_termination == 0 || !peek_in_queue_set(), "Precondition");
-  assert(_offered_termination == 0 || _offered_termination == _n_threads, "Terminated or aborted" );
 }
 
 #ifdef ASSERT
@@ -65,11 +66,8 @@
 
 #ifdef TRACESPINNING
 void OWSTTaskTerminator::print_termination_counts() {
-  log_trace(gc, task)("ParallelTaskTerminator Total yields: %u"
-    " Total spins: %u Total peeks: %u",
-    total_yields(),
-    total_spins(),
-    total_peeks());
+  log_trace(gc, task)("TaskTerminator Yields: %u Spins: %u Peeks: %u",
+                      total_yields(), total_spins(), total_peeks());
 }
 #endif
 
@@ -90,6 +88,10 @@
   return tasks > 0 || (terminator != NULL && terminator->should_exit_termination());
 }
 
+size_t OWSTTaskTerminator::tasks_in_queue_set() const {
+  return _queue_set->tasks();
+}
+
 bool OWSTTaskTerminator::offer_termination(TerminatorTerminator* terminator) {
   assert(_n_threads > 0, "Initialization is incorrect");
   assert(_offered_termination < _n_threads, "Invariant");
@@ -222,7 +224,7 @@
     }
 
 #ifdef TRACESPINNING
-      _total_peeks++;
+    _total_peeks++;
 #endif
     size_t tasks = tasks_in_queue_set();
     bool exit = exit_termination(tasks, terminator);
--- old/src/hotspot/share/gc/shared/owstTaskTerminator.hpp	2020-01-30 17:09:56.113507138 +0100
+++ new/src/hotspot/share/gc/shared/owstTaskTerminator.hpp	2020-01-30 17:09:54.929490177 +0100
@@ -25,7 +25,6 @@
 #ifndef SHARE_GC_SHARED_OWSTTASKTERMINATOR_HPP
 #define SHARE_GC_SHARED_OWSTTASKTERMINATOR_HPP
 
-#include "gc/shared/taskqueue.hpp"
 #include "memory/allocation.hpp"
 #include "runtime/mutex.hpp"
 #include "runtime/thread.hpp"
@@ -33,6 +32,9 @@
 // Define this to enable additional tracing probes.
 #undef TRACESPINNING
 
+class TaskQueueSetSuper;
+class TerminatorTerminator;
+
 /*
  * Provides a task termination protocol. OWST stands for Optimized Work Stealing Threads
  *
@@ -73,7 +75,7 @@
   // If we should exit current termination protocol
   bool exit_termination(size_t tasks, TerminatorTerminator* terminator);
 
-  size_t tasks_in_queue_set() { return _queue_set->tasks(); }
+  size_t tasks_in_queue_set() const;
 
   // Perform spin-master task.
   // Return true if termination condition is detected, otherwise return false