365       obj = initialize(mem);
366     } else {
367       // The unhandled oop detector will poison local variable obj,
368       // so reset it to NULL if mem is NULL.
369       obj = NULL;
370     }
371   }
372   return obj;
373 }
374 
375 void MemAllocator::mem_clear(HeapWord* mem) const {
376   assert(mem != NULL, "cannot initialize NULL object");
377   const size_t hs = oopDesc::header_size();
378   assert(_word_size >= hs, "unexpected object size");
379   oopDesc::set_klass_gap(mem, 0);
380   Copy::fill_to_aligned_words(mem + hs, _word_size - hs);
381 }
382 
383 oop MemAllocator::finish(HeapWord* mem) const {
384   assert(mem != NULL, "NULL object pointer");
385   // May be bootstrapping
386   oopDesc::set_mark(mem, markWord::prototype());
387   // Need a release store to ensure array/class length, mark word, and
388   // object zeroing are visible before setting the klass non-NULL, for
389   // concurrent collectors.
390   oopDesc::release_set_klass(mem, _klass);
391   return cast_to_oop(mem);
392 }
393 
394 oop ObjAllocator::initialize(HeapWord* mem) const {
395   mem_clear(mem);
396   return finish(mem);
397 }
398 
399 MemRegion ObjArrayAllocator::obj_memory_range(oop obj) const {
400   if (_do_zero) {
401     return MemAllocator::obj_memory_range(obj);
402   }
403   ArrayKlass* array_klass = ArrayKlass::cast(_klass);
404   const size_t hs = arrayOopDesc::header_size(array_klass->element_type());
405   return MemRegion(cast_from_oop<HeapWord*>(obj) + hs, _word_size - hs);
406 }

365       obj = initialize(mem);
366     } else {
367       // The unhandled oop detector will poison local variable obj,
368       // so reset it to NULL if mem is NULL.
369       obj = NULL;
370     }
371   }
372   return obj;
373 }
374 
375 void MemAllocator::mem_clear(HeapWord* mem) const {
376   assert(mem != NULL, "cannot initialize NULL object");
377   const size_t hs = oopDesc::header_size();
378   assert(_word_size >= hs, "unexpected object size");
379   oopDesc::set_klass_gap(mem, 0);
380   Copy::fill_to_aligned_words(mem + hs, _word_size - hs);
381 }
382 
383 oop MemAllocator::finish(HeapWord* mem) const {
384   assert(mem != NULL, "NULL object pointer");
385   oopDesc::set_mark(mem, _klass->prototype_header());

386   // Need a release store to ensure array/class length, mark word, and
387   // object zeroing are visible before setting the klass non-NULL, for
388   // concurrent collectors.
389   oopDesc::release_set_klass(mem, _klass);
390   return cast_to_oop(mem);
391 }
392 
393 oop ObjAllocator::initialize(HeapWord* mem) const {
394   mem_clear(mem);
395   return finish(mem);
396 }
397 
398 MemRegion ObjArrayAllocator::obj_memory_range(oop obj) const {
399   if (_do_zero) {
400     return MemAllocator::obj_memory_range(obj);
401   }
402   ArrayKlass* array_klass = ArrayKlass::cast(_klass);
403   const size_t hs = arrayOopDesc::header_size(array_klass->element_type());
404   return MemRegion(cast_from_oop<HeapWord*>(obj) + hs, _word_size - hs);
405 }