--- old/src/hotspot/share/gc/g1/g1CollectedHeap.hpp	2020-05-14 07:47:44.753868612 -0400
+++ new/src/hotspot/share/gc/g1/g1CollectedHeap.hpp	2020-05-14 07:47:44.357855464 -0400
@@ -54,6 +54,7 @@
 #include "gc/shared/plab.hpp"
 #include "gc/shared/preservedMarks.hpp"
 #include "gc/shared/softRefPolicy.hpp"
+#include "gc/shared/taskqueue.hpp"
 #include "memory/memRegion.hpp"
 #include "utilities/stack.hpp"
 
@@ -97,8 +98,8 @@
 class G1HeapSummary;
 class G1EvacSummary;
 
-typedef OverflowTaskQueue<StarTask, mtGC>         RefToScanQueue;
-typedef GenericTaskQueueSet<RefToScanQueue, mtGC> RefToScanQueueSet;
+typedef OverflowTaskQueue<ScannerTask, mtGC>         ScannerTasksQueue;
+typedef GenericTaskQueueSet<ScannerTasksQueue, mtGC> ScannerTasksQueueSet;
 
 typedef int RegionIdx_t;   // needs to hold [ 0..max_regions() )
 typedef int CardIdx_t;     // needs to hold [ 0..CardsPerRegion )
@@ -814,7 +815,7 @@
   G1ConcurrentRefine* _cr;
 
   // The parallel task queues
-  RefToScanQueueSet *_task_queues;
+  ScannerTasksQueueSet *_task_queues;
 
   // True iff a evacuation has failed in the current collection.
   bool _evacuation_failed;
@@ -951,7 +952,7 @@
   G1CMSubjectToDiscoveryClosure _is_subject_to_discovery_cm;
 public:
 
-  RefToScanQueue *task_queue(uint i) const;
+  ScannerTasksQueue* task_queue(uint i) const;
 
   uint num_task_queues() const;
 
@@ -1478,18 +1479,18 @@
 protected:
   G1CollectedHeap*              _g1h;
   G1ParScanThreadState*         _par_scan_state;
-  RefToScanQueueSet*            _queues;
+  ScannerTasksQueueSet*         _queues;
   TaskTerminator*               _terminator;
   G1GCPhaseTimes::GCParPhases   _phase;
 
   G1ParScanThreadState*   par_scan_state() { return _par_scan_state; }
-  RefToScanQueueSet*      queues()         { return _queues; }
+  ScannerTasksQueueSet*   queues()         { return _queues; }
   TaskTerminator*         terminator()     { return _terminator; }
 
 public:
   G1ParEvacuateFollowersClosure(G1CollectedHeap* g1h,
                                 G1ParScanThreadState* par_scan_state,
-                                RefToScanQueueSet* queues,
+                                ScannerTasksQueueSet* queues,
                                 TaskTerminator* terminator,
                                 G1GCPhaseTimes::GCParPhases phase)
     : _start_term(0.0), _term_time(0.0), _term_attempts(0),