src/hotspot/share/gc/g1/g1OopClosures.hpp

rev 52316 : imported patch 8212911-unify-reference-handling-during-gc
rev 52317 : imported patch 8212911-stefanj-review
rev 52319 : imported patch 8213142-use-raii-to-set-scanning-from-young

*** 34,43 ****
--- 34,44 ----
  class G1RemSet;
  class G1ConcurrentMark;
  class DirtyCardToOopClosure;
  class G1CMBitMap;
  class G1ParScanThreadState;
+ class G1ScanEvacuatedObjClosure;
  class G1CMTask;
  class ReferenceProcessor;
  
  class G1ScanClosureBase : public BasicOopIterateClosure {
  protected:
*** 80,98 ****
    template <class T> void do_oop_work(T* p);
    virtual void do_oop(oop* p)          { do_oop_work(p); }
    virtual void do_oop(narrowOop* p)    { do_oop_work(p); }
  };
  
  // This closure is applied to the fields of the objects that have just been copied during evacuation.
  class G1ScanEvacuatedObjClosure : public G1ScanClosureBase {
!   bool _scanning_in_young;
  
  public:
    G1ScanEvacuatedObjClosure(G1CollectedHeap* g1h, G1ParScanThreadState* par_scan_state) :
!     G1ScanClosureBase(g1h, par_scan_state), _scanning_in_young(false) { }
! 
!   void set_scanning_in_young(bool scanning_in_young) { _scanning_in_young = scanning_in_young; }
  
    template <class T> void do_oop_work(T* p);
    virtual void do_oop(oop* p)          { do_oop_work(p); }
    virtual void do_oop(narrowOop* p)    { do_oop_work(p); }
  
--- 81,106 ----
    template <class T> void do_oop_work(T* p);
    virtual void do_oop(oop* p)          { do_oop_work(p); }
    virtual void do_oop(narrowOop* p)    { do_oop_work(p); }
  };
  
+ 
  // This closure is applied to the fields of the objects that have just been copied during evacuation.
  class G1ScanEvacuatedObjClosure : public G1ScanClosureBase {
!   friend class G1ScanInYoungSetter;
! 
!   enum ScanningInYoungValues {
!     False = 0,
!     True,
!     Uninitialized
!   };
! 
!   ScanningInYoungValues _scanning_in_young;
  
  public:
    G1ScanEvacuatedObjClosure(G1CollectedHeap* g1h, G1ParScanThreadState* par_scan_state) :
!     G1ScanClosureBase(g1h, par_scan_state), _scanning_in_young(Uninitialized) { }
  
    template <class T> void do_oop_work(T* p);
    virtual void do_oop(oop* p)          { do_oop_work(p); }
    virtual void do_oop(narrowOop* p)    { do_oop_work(p); }
  
*** 102,111 ****
--- 110,134 ----
    void set_ref_discoverer(ReferenceDiscoverer* rd) {
      set_ref_discoverer_internal(rd);
    }
  };
  
+ // RAII object to properly set the _scanning_in_young field in G1ScanEvacuatedObjClosure.
+ class G1ScanInYoungSetter : public StackObj {
+   G1ScanEvacuatedObjClosure* _closure;
+ 
+ public:
+   G1ScanInYoungSetter(G1ScanEvacuatedObjClosure* closure, bool new_value) : _closure(closure) {
+     assert(_closure->_scanning_in_young == G1ScanEvacuatedObjClosure::Uninitialized, "Must not be set");
+     _closure->_scanning_in_young = new_value ? G1ScanEvacuatedObjClosure::True : G1ScanEvacuatedObjClosure::False;
+   }
+ 
+   ~G1ScanInYoungSetter() {
+     DEBUG_ONLY(_closure->_scanning_in_young = G1ScanEvacuatedObjClosure::Uninitialized;)
+   }
+ };
+ 
  // Add back base class for metadata
  class G1ParCopyHelper : public OopClosure {
  protected:
    G1CollectedHeap* _g1h;
    G1ParScanThreadState* _par_scan_state;