8309306: G1: Move is_obj_dead from HeapRegion to G1CollectedHeap

Reviewed-by: tschatzl, iwalulya

Author: albertnetymk

src/hotspot/share/gc/g1/g1CollectedHeap.inline.hpp

@@ -247,13 +247,19 @@ inline bool G1CollectedHeap::is_obj_filler(const oop obj) {
 }
 
 inline bool G1CollectedHeap::is_obj_dead(const oop obj, const HeapRegion* hr) const {
-  return hr->is_obj_dead(obj, hr->parsable_bottom());
+  if (hr->is_in_parsable_area(obj)) {
+    // This object is in the parsable part of the heap, live unless scrubbed.
+    return is_obj_filler(obj);
+  } else {
+    // From Remark until a region has been concurrently scrubbed, parts of the
+    // region is not guaranteed to be parsable. Use the bitmap for liveness.
+    return !concurrent_mark()->mark_bitmap()->is_marked(obj);
+  }
 }
 
 inline bool G1CollectedHeap::is_obj_dead(const oop obj) const {
-  if (obj == nullptr) {
-    return false;
-  }
+  assert(obj != nullptr, "precondition");
+
   return is_obj_dead(obj, heap_region_containing(obj));
 }
 

src/hotspot/share/gc/g1/g1HeapVerifier.cpp

@@ -224,7 +224,7 @@ class VerifyObjsInRegionClosure: public ObjectClosure {
       }
 
       o->oop_iterate(&isLive);
-      if (_hr->obj_in_unparsable_area(o, _hr->parsable_bottom())) {
+      if (!_hr->is_in_parsable_area(o)) {
         size_t obj_size = o->size();
         _live_bytes += (obj_size * HeapWordSize);
       }

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

@@ -182,10 +182,6 @@ class HeapRegion : public CHeapObj<mtGC> {
   // All allocated blocks are occupied by objects in a HeapRegion.
   bool block_is_obj(const HeapWord* p, HeapWord* pb) const;
 
-  // Returns whether the given object is dead based on the given parsable_bottom (pb).
-  // For an object to be considered dead it must be below pb and scrubbed.
-  bool is_obj_dead(oop obj, HeapWord* pb) const;
-
   // Returns the object size for all valid block starts. If parsable_bottom (pb)
   // is given, calculates the block size based on that parsable_bottom, not the
   // current value of this HeapRegion.
@@ -524,9 +520,9 @@ class HeapRegion : public CHeapObj<mtGC> {
 
   void record_surv_words_in_group(size_t words_survived);
 
-  // Determine if an object is in the parsable or the to-be-scrubbed area.
-  inline static bool obj_in_parsable_area(const HeapWord* addr, HeapWord* pb);
-  inline static bool obj_in_unparsable_area(oop obj, HeapWord* pb);
+  // Determine if an address is in the parsable or the to-be-scrubbed area.
+  inline        bool is_in_parsable_area(const void* const addr) const;
+  inline static bool is_in_parsable_area(const void* const addr, const void* const pb);
 
   bool obj_allocated_since_marking_start(oop obj) const {
     return cast_from_oop<HeapWord*>(obj) >= top_at_mark_start();

src/hotspot/share/gc/g1/heapRegion.inline.hpp

@@ -109,11 +109,11 @@ inline HeapWord* HeapRegion::block_start(const void* addr, HeapWord* const pb) c
   return advance_to_block_containing_addr(addr, pb, first_block);
 }
 
-inline bool HeapRegion::obj_in_unparsable_area(oop obj, HeapWord* const pb) {
-  return !HeapRegion::obj_in_parsable_area(cast_from_oop<HeapWord*>(obj), pb);
+inline bool HeapRegion::is_in_parsable_area(const void* const addr) const {
+  return is_in_parsable_area(addr, parsable_bottom());
 }
 
-inline bool HeapRegion::obj_in_parsable_area(const HeapWord* addr, HeapWord* const pb) {
+inline bool HeapRegion::is_in_parsable_area(const void* const addr, const void* const pb) {
   return addr >= pb;
 }
 
@@ -125,7 +125,7 @@ inline bool HeapRegion::block_is_obj(const HeapWord* const p, HeapWord* const pb
   assert(p >= bottom() && p < top(), "precondition");
   assert(!is_continues_humongous(), "p must point to block-start");
 
-  if (obj_in_parsable_area(p, pb)) {
+  if (is_in_parsable_area(p, pb)) {
     return true;
   }
 
@@ -140,19 +140,6 @@ inline bool HeapRegion::block_is_obj(const HeapWord* const p, HeapWord* const pb
   return is_marked_in_bitmap(cast_to_oop(p));
 }
 
-inline bool HeapRegion::is_obj_dead(const oop obj, HeapWord* const pb) const {
-  assert(is_in_reserved(obj), "Object " PTR_FORMAT " must be in region", p2i(obj));
-
-  // From Remark until a region has been concurrently scrubbed, parts of the
-  // region is not guaranteed to be parsable. Use the bitmap for liveness.
-  if (obj_in_unparsable_area(obj, pb)) {
-    return !is_marked_in_bitmap(obj);
-  }
-
-  // This object is in the parsable part of the heap, live unless scrubbed.
-  return G1CollectedHeap::is_obj_filler(obj);
-}
-
 inline HeapWord* HeapRegion::next_live_in_unparsable(G1CMBitMap* const bitmap, const HeapWord* p, HeapWord* const limit) const {
   return bitmap->get_next_marked_addr(p, limit);
 }
@@ -450,7 +437,7 @@ inline HeapWord* HeapRegion::oops_on_memregion_iterate(MemRegion mr, Closure* cl
   //   safepoints.
   //
   HeapWord* cur = block_start(start, pb);
-  if (!obj_in_parsable_area(start, pb)) {
+  if (!is_in_parsable_area(start, pb)) {
     // Limit the MemRegion to the part of the area to scan to the unparsable one as using the bitmap
     // is slower than blindly iterating the objects.
     MemRegion mr_in_unparsable(mr.start(), MIN2(mr.end(), pb));