8038412: Move object_iterate_careful down from Space to ContigousSpace and CFLSpace

Summary: Only declare the functions where they are actually needed.
Reviewed-by: tschatzl, stefank

src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp

@@ -907,39 +907,6 @@ void CompactibleFreeListSpace::object_iterate_mem(MemRegion mr,
   }
 }
 
-// Callers of this iterator beware: The closure application should
-// be robust in the face of uninitialized objects and should (always)
-// return a correct size so that the next addr + size below gives us a
-// valid block boundary. [See for instance,
-// ScanMarkedObjectsAgainCarefullyClosure::do_object_careful()
-// in ConcurrentMarkSweepGeneration.cpp.]
-HeapWord*
-CompactibleFreeListSpace::object_iterate_careful(ObjectClosureCareful* cl) {
-  assert_lock_strong(freelistLock());
-  HeapWord *addr, *last;
-  size_t size;
-  for (addr = bottom(), last  = end();
-       addr < last; addr += size) {
-    FreeChunk* fc = (FreeChunk*)addr;
-    if (fc->is_free()) {
-      // Since we hold the free list lock, which protects direct
-      // allocation in this generation by mutators, a free object
-      // will remain free throughout this iteration code.
-      size = fc->size();
-    } else {
-      // Note that the object need not necessarily be initialized,
-      // because (for instance) the free list lock does NOT protect
-      // object initialization. The closure application below must
-      // therefore be correct in the face of uninitialized objects.
-      size = cl->do_object_careful(oop(addr));
-      if (size == 0) {
-        // An unparsable object found. Signal early termination.
-        return addr;
-      }
-    }
-  }
-  return NULL;
-}
 
 // Callers of this iterator beware: The closure application should
 // be robust in the face of uninitialized objects and should (always)

src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.hpp

@@ -376,11 +376,8 @@ class CompactibleFreeListSpace: public CompactibleSpace {
   // terminate the iteration and return the address of the start of the
   // subregion that isn't done.  Return of "NULL" indicates that the
   // interation completed.
-  virtual HeapWord*
-       object_iterate_careful_m(MemRegion mr,
+ HeapWord* object_iterate_careful_m(MemRegion mr,
                                     ObjectClosureCareful* cl);
-  virtual HeapWord*
-       object_iterate_careful(ObjectClosureCareful* cl);
 
   // Override: provides a DCTO_CL specific to this kind of space.
   DirtyCardToOopClosure* new_dcto_cl(ExtendedOopClosure* cl,

src/share/vm/memory/space.cpp

@@ -551,17 +551,6 @@ void Space::oop_iterate(ExtendedOopClosure* blk) {
   object_iterate(&blk2);
 }
 
-HeapWord* Space::object_iterate_careful(ObjectClosureCareful* cl) {
-  guarantee(false, "NYI");
-  return bottom();
-}
-
-HeapWord* Space::object_iterate_careful_m(MemRegion mr,
-                                          ObjectClosureCareful* cl) {
-  guarantee(false, "NYI");
-  return bottom();
-}
-
 bool Space::obj_is_alive(const HeapWord* p) const {
   assert (block_is_obj(p), "The address should point to an object");
   return true;

src/share/vm/memory/space.hpp

@@ -188,17 +188,6 @@ class Space: public CHeapObj<mtGC> {
   // objects whose internal references point to objects in the space.
   virtual void safe_object_iterate(ObjectClosure* blk) = 0;
 
-  // Iterate over as many initialized objects in the space as possible,
-  // calling "cl.do_object_careful" on each. Return NULL if all objects
-  // in the space (at the start of the iteration) were iterated over.
-  // Return an address indicating the extent of the iteration in the
-  // event that the iteration had to return because of finding an
-  // uninitialized object in the space, or if the closure "cl"
-  // signalled early termination.
-  virtual HeapWord* object_iterate_careful(ObjectClosureCareful* cl);
-  virtual HeapWord* object_iterate_careful_m(MemRegion mr,
-                                             ObjectClosureCareful* cl);
-
   // Create and return a new dirty card to oop closure. Can be
   // overriden to return the appropriate type of closure
   // depending on the type of space in which the closure will
@@ -551,7 +540,14 @@ class ContiguousSpace: public CompactibleSpace {
   // For contiguous spaces this method will iterate safely over objects
   // in the space (i.e., between bottom and top) when at a safepoint.
   void safe_object_iterate(ObjectClosure* blk);
-  // iterates on objects up to the safe limit
+
+  // Iterate over as many initialized objects in the space as possible,
+  // calling "cl.do_object_careful" on each. Return NULL if all objects
+  // in the space (at the start of the iteration) were iterated over.
+  // Return an address indicating the extent of the iteration in the
+  // event that the iteration had to return because of finding an
+  // uninitialized object in the space, or if the closure "cl"
+  // signaled early termination.
   HeapWord* object_iterate_careful(ObjectClosureCareful* cl);
   HeapWord* concurrent_iteration_safe_limit() {
     assert(_concurrent_iteration_safe_limit <= top(),