8324636: Serial: Remove Generation::block_is_obj

Reviewed-by: stefank, ysr

src/hotspot/share/gc/serial/defNewGeneration.cpp

@@ -723,6 +723,12 @@ void DefNewGeneration::adjust_desired_tenuring_threshold() {
   age_table()->print_age_table(_tenuring_threshold);
 }
 
+bool DefNewGeneration::block_is_obj(const HeapWord* addr) const {
+  return eden()->is_in(addr)
+      || from()->is_in(addr)
+      || to()  ->is_in(addr);
+}
+
 void DefNewGeneration::collect(bool   full,
                                bool   clear_all_soft_refs,
                                size_t size,

src/hotspot/share/gc/serial/defNewGeneration.hpp

@@ -257,6 +257,10 @@ class DefNewGeneration: public Generation {
   // at some additional cost.
   bool collection_attempt_is_safe();
 
+  // Requires "addr" to be the start of a block, and returns "TRUE" iff
+  // the block is an object.
+  bool block_is_obj(const HeapWord* addr) const;
+
   virtual void collect(bool   full,
                        bool   clear_all_soft_refs,
                        size_t size,

src/hotspot/share/gc/serial/generation.cpp

@@ -164,22 +164,3 @@ HeapWord* Generation::block_start(const void* p) const {
   ((Generation*)this)->space_iterate(&blk);
   return blk._start;
 }
-
-class GenerationBlockIsObjClosure : public SpaceClosure {
- public:
-  const HeapWord* _p;
-  bool is_obj;
-  virtual void do_space(Space* s) {
-    if (!is_obj && s->is_in_reserved(_p)) {
-      is_obj |= s->block_is_obj(_p);
-    }
-  }
-  GenerationBlockIsObjClosure(const HeapWord* p) { _p = p; is_obj = false; }
-};
-
-bool Generation::block_is_obj(const HeapWord* p) const {
-  GenerationBlockIsObjClosure blk(p);
-  // Cast away const
-  ((Generation*)this)->space_iterate(&blk);
-  return blk.is_obj;
-}

src/hotspot/share/gc/serial/generation.hpp

@@ -234,10 +234,6 @@ class Generation: public CHeapObj<mtGC> {
   // non-object.
   virtual HeapWord* block_start(const void* addr) const;
 
-  // Requires "addr" to be the start of a block, and returns "TRUE" iff
-  // the block is an object.
-  virtual bool block_is_obj(const HeapWord* addr) const;
-
   virtual void print() const;
   virtual void print_on(outputStream* st) const;
 

src/hotspot/share/gc/serial/tenuredGeneration.hpp

@@ -129,6 +129,8 @@ class TenuredGeneration: public Generation {
 
   bool no_allocs_since_save_marks();
 
+  // Requires "addr" to be the start of a block, and returns "TRUE" iff
+  // the block is an object.
   inline bool block_is_obj(const HeapWord* addr) const;
 
   virtual void collect(bool full,

src/hotspot/share/gc/serial/tenuredGeneration.inline.hpp

@@ -62,7 +62,7 @@ HeapWord* TenuredGeneration::par_allocate(size_t word_size,
 }
 
 bool TenuredGeneration::block_is_obj(const HeapWord* addr) const {
-  return addr < _the_space  ->top();
+  return addr < _the_space->top();
 }
 
 template <typename OopClosureType>