src/share/vm/gc/g1/heapRegionManager.cpp

*** 276,285 ****
--- 276,310 ----
           err_msg("The region at the current position %u must be available or at the end of the heap.", cur));
  #endif
    return num_regions;
  }
  
+ uint HeapRegionManager::find_highest_available(bool* expanded) {
+   // Loop downwards from the highest region index, looking for an
+   // entry which is either free or not yet committed.  If not yet
+   // committed, expand_at that index, and set the 'expanded' output
+   // bool result to true.
+   uint curr = max_length() - 1;
+   while (curr != 0) {
+     HeapRegion *hr = _regions.get_by_index(curr);
+     if (hr == NULL) {
+       uint res = expand_at(curr, 1);
+       if (res == 1) {
+         *expanded = true;
+         return curr;
+       }
+     } else {
+       if (hr->is_free()) {
+         *expanded = false;
+         return curr;
+       }
+     }
+     curr--;
+   }
+   return G1_NO_HRM_INDEX;
+ }
+ 
  void HeapRegionManager::par_iterate(HeapRegionClosure* blk, uint worker_id, HeapRegionClaimer* hrclaimer, bool concurrent) const {
    const uint start_index = hrclaimer->start_region_for_worker(worker_id);
  
    // Every worker will actually look at all regions, skipping over regions that
    // are currently not committed.
*** 434,444 ****
        continue;
      }
      num_committed++;
      HeapRegion* hr = _regions.get_by_index(i);
      guarantee(hr != NULL, err_msg("invariant: i: %u", i));
!     guarantee(!prev_committed || hr->bottom() == prev_end,
                err_msg("invariant i: %u "HR_FORMAT" prev_end: "PTR_FORMAT,
                        i, HR_FORMAT_PARAMS(hr), p2i(prev_end)));
      guarantee(hr->hrm_index() == i,
                err_msg("invariant: i: %u hrm_index(): %u", i, hr->hrm_index()));
      // Asserts will fire if i is >= _length
--- 459,469 ----
        continue;
      }
      num_committed++;
      HeapRegion* hr = _regions.get_by_index(i);
      guarantee(hr != NULL, err_msg("invariant: i: %u", i));
!     guarantee(!prev_committed || hr->bottom() == prev_end || hr->is_archive(),
                err_msg("invariant i: %u "HR_FORMAT" prev_end: "PTR_FORMAT,
                        i, HR_FORMAT_PARAMS(hr), p2i(prev_end)));
      guarantee(hr->hrm_index() == i,
                err_msg("invariant: i: %u hrm_index(): %u", i, hr->hrm_index()));
      // Asserts will fire if i is >= _length