8047819: G1 HeapRegionDCTOC does not need to inherit ContiguousSpaceDCTOC

Reviewed-by: stefank, tschatzl

src/share/vm/gc_implementation/g1/heapRegion.cpp

@@ -48,7 +48,7 @@ HeapRegionDCTOC::HeapRegionDCTOC(G1CollectedHeap* g1,
                                  HeapRegion* hr, ExtendedOopClosure* cl,
                                  CardTableModRefBS::PrecisionStyle precision,
                                  FilterKind fk) :
-  ContiguousSpaceDCTOC(hr, cl, precision, NULL),
+  DirtyCardToOopClosure(hr, cl, precision, NULL),
   _hr(hr), _fk(fk), _g1(g1) { }
 
 FilterOutOfRegionClosure::FilterOutOfRegionClosure(HeapRegion* r,
@@ -77,19 +77,18 @@ HeapWord* walk_mem_region_loop(ClosureType* cl, G1CollectedHeap* g1h,
   return cur;
 }
 
-void HeapRegionDCTOC::walk_mem_region_with_cl(MemRegion mr,
-                                              HeapWord* bottom,
-                                              HeapWord* top,
-                                              ExtendedOopClosure* cl) {
+void HeapRegionDCTOC::walk_mem_region(MemRegion mr,
+                                      HeapWord* bottom,
+                                      HeapWord* top) {
   G1CollectedHeap* g1h = _g1;
   int oop_size;
   ExtendedOopClosure* cl2 = NULL;
 
-  FilterIntoCSClosure intoCSFilt(this, g1h, cl);
-  FilterOutOfRegionClosure outOfRegionFilt(_hr, cl);
+  FilterIntoCSClosure intoCSFilt(this, g1h, _cl);
+  FilterOutOfRegionClosure outOfRegionFilt(_hr, _cl);
 
   switch (_fk) {
-  case NoFilterKind:          cl2 = cl; break;
+  case NoFilterKind:          cl2 = _cl; break;
   case IntoCSFilterKind:      cl2 = &intoCSFilt; break;
   case OutOfRegionFilterKind: cl2 = &outOfRegionFilt; break;
   default:                    ShouldNotReachHere();
@@ -111,17 +110,17 @@ void HeapRegionDCTOC::walk_mem_region_with_cl(MemRegion mr,
     // We replicate the loop below for several kinds of possible filters.
     switch (_fk) {
     case NoFilterKind:
-      bottom = walk_mem_region_loop(cl, g1h, _hr, bottom, top);
+      bottom = walk_mem_region_loop(_cl, g1h, _hr, bottom, top);
       break;
 
     case IntoCSFilterKind: {
-      FilterIntoCSClosure filt(this, g1h, cl);
+      FilterIntoCSClosure filt(this, g1h, _cl);
       bottom = walk_mem_region_loop(&filt, g1h, _hr, bottom, top);
       break;
     }
 
     case OutOfRegionFilterKind: {
-      FilterOutOfRegionClosure filt(_hr, cl);
+      FilterOutOfRegionClosure filt(_hr, _cl);
       bottom = walk_mem_region_loop(&filt, g1h, _hr, bottom, top);
       break;
     }

src/share/vm/gc_implementation/g1/heapRegion.hpp

@@ -71,7 +71,7 @@ class nmethod;
 // in the concurrent marker used by G1 to filter remembered
 // sets.
 
-class HeapRegionDCTOC : public ContiguousSpaceDCTOC {
+class HeapRegionDCTOC : public DirtyCardToOopClosure {
 public:
   // Specification of possible DirtyCardToOopClosure filtering.
   enum FilterKind {
@@ -85,39 +85,13 @@ protected:
   FilterKind _fk;
   G1CollectedHeap* _g1;
 
-  void walk_mem_region_with_cl(MemRegion mr,
-                               HeapWord* bottom, HeapWord* top,
-                               ExtendedOopClosure* cl);
-
-  // We don't specialize this for FilteringClosure; filtering is handled by
-  // the "FilterKind" mechanism.  But we provide this to avoid a compiler
-  // warning.
-  void walk_mem_region_with_cl(MemRegion mr,
-                               HeapWord* bottom, HeapWord* top,
-                               FilteringClosure* cl) {
-    HeapRegionDCTOC::walk_mem_region_with_cl(mr, bottom, top,
-                                             (ExtendedOopClosure*)cl);
-  }
-
-  // Get the actual top of the area on which the closure will
-  // operate, given where the top is assumed to be (the end of the
-  // memory region passed to do_MemRegion) and where the object
-  // at the top is assumed to start. For example, an object may
-  // start at the top but actually extend past the assumed top,
-  // in which case the top becomes the end of the object.
-  HeapWord* get_actual_top(HeapWord* top, HeapWord* top_obj) {
-    return ContiguousSpaceDCTOC::get_actual_top(top, top_obj);
-  }
-
   // Walk the given memory region from bottom to (actual) top
   // looking for objects and applying the oop closure (_cl) to
   // them. The base implementation of this treats the area as
   // blocks, where a block may or may not be an object. Sub-
   // classes should override this to provide more accurate
   // or possibly more efficient walking.
-  void walk_mem_region(MemRegion mr, HeapWord* bottom, HeapWord* top) {
-    Filtering_DCTOC::walk_mem_region(mr, bottom, top);
-  }
+  void walk_mem_region(MemRegion mr, HeapWord* bottom, HeapWord* top);
 
 public:
   HeapRegionDCTOC(G1CollectedHeap* g1,