src/hotspot/share/gc/shenandoah/shenandoahTraversalGC.cpp

*** 194,207 ****
          ShenandoahWorkerTimingsTracker timer(worker_times, ShenandoahPhaseTimings::CodeCacheRoots, worker_id);
          _cset_coderoots->possibly_parallel_blobs_do(&code_cl);
        } else {
          _rp->process_all_roots(&roots_cl, &cld_cl, &code_cl, NULL, worker_id);
        }
-       if (ShenandoahStringDedup::is_enabled()) {
-         AlwaysTrueClosure is_alive;
-         ShenandoahStringDedup::parallel_oops_do(&is_alive, &roots_cl, worker_id);
-       }
      }
    }
  };
  
  class ShenandoahConcurrentTraversalCollectionTask : public AbstractGangTask {
--- 194,203 ----
*** 597,610 ****
    if (!_heap->cancelled_gc() && _heap->process_references()) {
      weak_refs_work();
    }
  
    if (!_heap->cancelled_gc()) {
-     fixup_roots();
      if (_heap->unload_classes()) {
        _heap->unload_classes_and_cleanup_tables(false);
      }
    }
  
    if (!_heap->cancelled_gc()) {
      assert(_task_queues->is_empty(), "queues must be empty after traversal GC");
      TASKQUEUE_STATS_ONLY(_task_queues->print_taskqueue_stats());
--- 593,607 ----
    if (!_heap->cancelled_gc() && _heap->process_references()) {
      weak_refs_work();
    }
  
    if (!_heap->cancelled_gc()) {
      if (_heap->unload_classes()) {
        _heap->unload_classes_and_cleanup_tables(false);
      }
+ 
+     fixup_roots();
    }
  
    if (!_heap->cancelled_gc()) {
      assert(_task_queues->is_empty(), "queues must be empty after traversal GC");
      TASKQUEUE_STATS_ONLY(_task_queues->print_taskqueue_stats());
*** 770,779 ****
--- 767,799 ----
  
    void do_oop(narrowOop* p) { do_oop_work(p); }
    void do_oop(oop* p)       { do_oop_work(p); }
  };
  
+ class ShenandoahTraversalWeakUpdateClosure : public OopClosure {
+ private:
+   template <class T>
+   inline void do_oop_work(T* p) {
+     // Cannot call maybe_update_with_forwarded, because on traversal-degen
+     // path the collection set is already dropped. Instead, do the unguarded store.
+     // TODO: This can be fixed after degen-traversal stops dropping cset.
+     T o = RawAccess<>::oop_load(p);
+     if (!CompressedOops::is_null(o)) {
+       oop obj = CompressedOops::decode_not_null(o);
+       obj = ShenandoahBarrierSet::resolve_forwarded_not_null(obj);
+       shenandoah_assert_marked(p, obj);
+       RawAccess<IS_NOT_NULL>::oop_store(p, obj);
+     }
+   }
+ 
+ public:
+   ShenandoahTraversalWeakUpdateClosure() {}
+ 
+   void do_oop(narrowOop* p) { do_oop_work(p); }
+   void do_oop(oop* p)       { do_oop_work(p); }
+ };
+ 
  class ShenandoahTraversalKeepAliveUpdateDegenClosure : public OopClosure {
  private:
    ShenandoahObjToScanQueue* _queue;
    Thread* _thread;
    ShenandoahTraversalGC* _traversal_gc;
*** 1082,1089 ****
--- 1102,1119 ----
      rp->process_discovered_references(&is_alive, &keep_alive,
                                        &complete_gc, &executor,
                                        &pt);
    }
  
+   {
+     ShenandoahGCPhase phase(phase_process);
+     ShenandoahTerminationTracker termination(ShenandoahPhaseTimings::weakrefs_termination);
+ 
+     // Process leftover weak oops (using parallel version)
+     ShenandoahTraversalWeakUpdateClosure cl;
+     WeakProcessor::weak_oops_do(workers, &is_alive, &cl, 1);
+ 
      pt.print_all_references();
+ 
      assert(task_queues()->is_empty() || _heap->cancelled_gc(), "Should be empty");
+   }
  }