src/share/vm/gc/g1/g1CollectorPolicy.cpp

*** 324,339 ****
    size_t free_bytes = (base_free_regions - young_length) * HeapRegion::GrainBytes;
  
    // When copying, we will likely need more bytes free than is live in the region.
    // Add some safety margin to factor in the confidence of our guess, and the
    // natural expected waste.
!   // (100.0 / G1ConfidencePercent) is a scale factor that expresses the uncertainty
!   // of the calculation: the lower the confidence, the more headroom.
!   // (100 + TargetPLABWastePct) represents the increase in expected bytes during
!   // copying due to anticipated waste in the PLABs.
!   double safety_factor = (100.0 / G1ConfidencePercent) * (100 + TargetPLABWastePct) / 100.0;
!   size_t expected_bytes_to_copy = (size_t)(safety_factor * bytes_to_copy);
  
    if (expected_bytes_to_copy > free_bytes) {
      // end condition 3: out-of-space
      return false;
    }
--- 324,334 ----
    size_t free_bytes = (base_free_regions - young_length) * HeapRegion::GrainBytes;
  
    // When copying, we will likely need more bytes free than is live in the region.
    // Add some safety margin to factor in the confidence of our guess, and the
    // natural expected waste.
!   size_t expected_bytes_to_copy = (size_t)(bytes_to_copy * safety_factor());
  
    if (expected_bytes_to_copy > free_bytes) {
      // end condition 3: out-of-space
      return false;
    }
*** 695,704 ****
--- 690,700 ----
  
    phase_times()->record_cur_collection_start_sec(start_time_sec);
    _pending_cards = _g1->pending_card_num();
  
    _collection_set->reset_bytes_used_before();
+   _collection_set->reset_bytes_live_before();
    _bytes_copied_during_gc = 0;
  
    collector_state()->set_last_gc_was_young(false);
  
    // do that for any other surv rate groups
*** 1726,1735 ****
--- 1722,1740 ----
      result += 1;
    }
    return (uint) result;
  }
  
+ size_t G1CollectorPolicy::available_bytes_estimate() {
+   size_t estimated_available_bytes = 0;
+   if (_free_regions_at_end_of_collection > _reserve_regions) {
+     uint available_regions = _free_regions_at_end_of_collection - _reserve_regions;
+     estimated_available_bytes = (size_t)((available_regions * HeapRegion::GrainBytes) / safety_factor());
+   }
+   return estimated_available_bytes;
+ }
+ 
  void G1CollectorPolicy::finalize_collection_set(double target_pause_time_ms) {
    double time_remaining_ms = _collection_set->finalize_young_part(target_pause_time_ms);
    _collection_set->finalize_old_part(time_remaining_ms);
  }