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

*** 59,69 ****
      HeapWord* obj = top();
      size_t available = pointer_delta(end(), obj);
      size_t want_to_allocate = MIN2(available, desired_word_size);
      if (want_to_allocate >= min_word_size) {
        HeapWord* new_top = obj + want_to_allocate;
!       HeapWord* result = Atomic::cmpxchg(new_top, &_top, obj);
        // result can be one of two:
        //  the old top value: the exchange succeeded
        //  otherwise: the new value of the top is returned.
        if (result == obj) {
          assert(is_object_aligned(obj) && is_object_aligned(new_top), "checking alignment");
--- 59,69 ----
      HeapWord* obj = top();
      size_t available = pointer_delta(end(), obj);
      size_t want_to_allocate = MIN2(available, desired_word_size);
      if (want_to_allocate >= min_word_size) {
        HeapWord* new_top = obj + want_to_allocate;
!       HeapWord* result = Atomic::cmpxchg(&_top, obj, new_top);
        // result can be one of two:
        //  the old top value: the exchange succeeded
        //  otherwise: the new value of the top is returned.
        if (result == obj) {
          assert(is_object_aligned(obj) && is_object_aligned(new_top), "checking alignment");