8047821: G1 Does not use the save_marks functionality as intended

Summary: Rename save_marks to record_top_and_timestamp and remove som unused but related methods
Reviewed-by: stefank, ehelin

src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp

@@ -4361,7 +4361,7 @@ void G1CollectedHeap::init_gc_alloc_regions(EvacuationInfo& evacuation_info) {
       !(retained_region->top() == retained_region->end()) &&
       !retained_region->is_empty() &&
       !retained_region->isHumongous()) {
-    retained_region->set_saved_mark();
+    retained_region->record_top_and_timestamp();
     // The retained region was added to the old region set when it was
     // retired. We have to remove it now, since we don't allow regions
     // we allocate to in the region sets. We'll re-add it later, when
@@ -6304,7 +6304,7 @@ HeapRegion* G1CollectedHeap::new_gc_alloc_region(size_t word_size,
       // We really only need to do this for old regions given that we
       // should never scan survivors. But it doesn't hurt to do it
       // for survivors too.
-      new_alloc_region->set_saved_mark();
+      new_alloc_region->record_top_and_timestamp();
       if (survivor) {
         new_alloc_region->set_survivor();
         _hr_printer.alloc(new_alloc_region, G1HRPrinter::Survivor);

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

@@ -373,7 +373,7 @@ HeapRegion::HeapRegion(uint hrs_index,
   // region.
   hr_clear(false /*par*/, false /*clear_space*/);
   set_top(bottom());
-  set_saved_mark();
+  record_top_and_timestamp();
 
   assert(HeapRegionRemSet::num_par_rem_sets() > 0, "Invariant.");
 }
@@ -393,32 +393,6 @@ CompactibleSpace* HeapRegion::next_compaction_space() const {
   return NULL;
 }
 
-void HeapRegion::save_marks() {
-  set_saved_mark();
-}
-
-void HeapRegion::oops_in_mr_iterate(MemRegion mr, ExtendedOopClosure* cl) {
-  HeapWord* p = mr.start();
-  HeapWord* e = mr.end();
-  oop obj;
-  while (p < e) {
-    obj = oop(p);
-    p += obj->oop_iterate(cl);
-  }
-  assert(p == e, "bad memregion: doesn't end on obj boundary");
-}
-
-#define HeapRegion_OOP_SINCE_SAVE_MARKS_DEFN(OopClosureType, nv_suffix) \
-void HeapRegion::oop_since_save_marks_iterate##nv_suffix(OopClosureType* cl) { \
-  ContiguousSpace::oop_since_save_marks_iterate##nv_suffix(cl);              \
-}
-SPECIALIZED_SINCE_SAVE_MARKS_CLOSURES(HeapRegion_OOP_SINCE_SAVE_MARKS_DEFN)
-
-
-void HeapRegion::oop_before_save_marks_iterate(ExtendedOopClosure* cl) {
-  oops_in_mr_iterate(MemRegion(bottom(), saved_mark_word()), cl);
-}
-
 void HeapRegion::note_self_forwarding_removal_start(bool during_initial_mark,
                                                     bool during_conc_mark) {
   // We always recreate the prev marking info and we'll explicitly
@@ -1107,7 +1081,7 @@ HeapWord* G1OffsetTableContigSpace::saved_mark_word() const {
     return ContiguousSpace::saved_mark_word();
 }
 
-void G1OffsetTableContigSpace::set_saved_mark() {
+void G1OffsetTableContigSpace::record_top_and_timestamp() {
   G1CollectedHeap* g1h = G1CollectedHeap::heap();
   unsigned curr_gc_time_stamp = g1h->get_gc_time_stamp();
 

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

@@ -148,7 +148,7 @@ class G1OffsetTableContigSpace: public ContiguousSpace {
   void set_end(HeapWord* value);
 
   virtual HeapWord* saved_mark_word() const;
-  virtual void set_saved_mark();
+  void record_top_and_timestamp();
   void reset_gc_time_stamp() { _gc_time_stamp = 0; }
   unsigned get_gc_time_stamp() { return _gc_time_stamp; }
 
@@ -202,10 +202,6 @@ class HeapRegion: public G1OffsetTableContigSpace {
     ContinuesHumongous
   };
 
-  // Requires that the region "mr" be dense with objects, and begin and end
-  // with an object.
-  void oops_in_mr_iterate(MemRegion mr, ExtendedOopClosure* cl);
-
   // The remembered set for this region.
   // (Might want to make this "inline" later, to avoid some alloc failure
   // issues.)
@@ -569,9 +565,6 @@ class HeapRegion: public G1OffsetTableContigSpace {
 
   HeapWord* orig_end() { return _orig_end; }
 
-  // Allows logical separation between objects allocated before and after.
-  void save_marks();
-
   // Reset HR stuff to default values.
   void hr_clear(bool par, bool clear_space, bool locked = false);
   void par_clear();
@@ -580,10 +573,6 @@ class HeapRegion: public G1OffsetTableContigSpace {
   HeapWord* prev_top_at_mark_start() const { return _prev_top_at_mark_start; }
   HeapWord* next_top_at_mark_start() const { return _next_top_at_mark_start; }
 
-  // Apply "cl->do_oop" to (the addresses of) all reference fields in objects
-  // allocated in the current region before the last call to "save_mark".
-  void oop_before_save_marks_iterate(ExtendedOopClosure* cl);
-
   // Note the start or end of marking. This tells the heap region
   // that the collector is about to start or has finished (concurrently)
   // marking the heap.
@@ -769,10 +758,6 @@ class HeapRegion: public G1OffsetTableContigSpace {
     _predicted_bytes_to_copy = bytes;
   }
 
-#define HeapRegion_OOP_SINCE_SAVE_MARKS_DECL(OopClosureType, nv_suffix)  \
-  virtual void oop_since_save_marks_iterate##nv_suffix(OopClosureType* cl);
-  SPECIALIZED_SINCE_SAVE_MARKS_CLOSURES(HeapRegion_OOP_SINCE_SAVE_MARKS_DECL)
-
   virtual CompactibleSpace* next_compaction_space() const;
 
   virtual void reset_after_compaction();