--- old/src/hotspot/share/gc/g1/g1CollectedHeap.hpp	2020-02-19 11:43:06.759410682 +0100
+++ new/src/hotspot/share/gc/g1/g1CollectedHeap.hpp	2020-02-19 11:43:06.353397998 +0100
@@ -76,6 +76,7 @@
 class Space;
 class G1CardTableEntryClosure;
 class G1CollectionSet;
+class G1HeapSizingPolicy;
 class G1Policy;
 class G1HotCardCache;
 class G1RemSet;
@@ -565,7 +566,7 @@
     return _g1mm;
   }
 
-  void resize_heap_if_necessary();
+  void resize_heap_after_full_gc();
 
   G1NUMA* numa() const { return _numa; }
 
@@ -782,13 +783,17 @@
   // Evacuate the next set of optional regions.
   void evacuate_next_optional_regions(G1ParScanThreadStateSet* per_thread_states);
 
+  bool expand_heap_after_young_collection();
+  void shrink_heap_after_young_collection();
+
 public:
   void pre_evacuate_collection_set(G1EvacuationInfo& evacuation_info, G1ParScanThreadStateSet* pss);
   void post_evacuate_collection_set(G1EvacuationInfo& evacuation_info,
                                     G1RedirtyCardsQueueSet* rdcqs,
                                     G1ParScanThreadStateSet* pss);
 
-  void expand_heap_after_young_collection();
+  void resize_heap_after_young_collection();
+
   // Update object copying statistics.
   void record_obj_copy_mem_stats();
 
@@ -990,6 +995,7 @@
   const G1CollectorState* collector_state() const { return &_collector_state; }
   G1CollectorState* collector_state() { return &_collector_state; }
 
+  G1HeapSizingPolicy* heap_sizing_policy() const { return _heap_sizing_policy; }
   // The current policy object for the collector.
   G1Policy* policy() const { return _policy; }
   // The remembered set.
@@ -1085,7 +1091,7 @@
 
   inline void archive_set_add(HeapRegion* hr);
 
-  size_t non_young_capacity_bytes() {
+  size_t non_young_capacity_bytes() const {
     return (old_regions_count() + _archive_set.length() + humongous_regions_count()) * HeapRegion::GrainBytes;
   }
 
@@ -1287,6 +1293,9 @@
   // Return the size of reserved memory. Returns different value than max_capacity() when AllocateOldGenAt is used.
   virtual size_t max_reserved_capacity() const;
 
+  // Print the soft maximum heap capacity.
+  size_t soft_max_capacity() const;
+
   virtual jlong millis_since_last_gc();