210   static size_t MaxTLABSizeBytes;
 211   static size_t MaxTLABSizeWords;
 212 
 213   // Global allocation counter, increased for each allocation under Shenandoah heap lock.
 214   // Padded to avoid false sharing with the read-only fields above.
 215   struct PaddedAllocSeqNum {
 216     DEFINE_PAD_MINUS_SIZE(0, DEFAULT_CACHE_LINE_SIZE, sizeof(uint64_t));
 217     uint64_t value;
 218     DEFINE_PAD_MINUS_SIZE(1, DEFAULT_CACHE_LINE_SIZE, 0);
 219 
 220     PaddedAllocSeqNum() {
 221       // start with 1, reserve 0 for uninitialized value
 222       value = 1;
 223     }
 224   };
 225 
 226   static PaddedAllocSeqNum _alloc_seq_num;
 227 
 228   // Never updated fields
 229   ShenandoahHeap* _heap;
 230   ShenandoahPacer* _pacer;
 231   MemRegion _reserved;
 232   size_t _region_number;
 233 
 234   // Rarely updated fields
 235   HeapWord* _new_top;
 236   size_t _critical_pins;
 237   double _empty_time;
 238 
 239   // Seldom updated fields
 240   RegionState _state;
 241 
 242   // Frequently updated fields
 243   size_t _tlab_allocs;
 244   size_t _gclab_allocs;
 245   size_t _shared_allocs;
 246 
 247   uint64_t _seqnum_first_alloc_mutator;
 248   uint64_t _seqnum_first_alloc_gc;
 249   uint64_t _seqnum_last_alloc_mutator;
 250   uint64_t _seqnum_last_alloc_gc;

 210   static size_t MaxTLABSizeBytes;
 211   static size_t MaxTLABSizeWords;
 212 
 213   // Global allocation counter, increased for each allocation under Shenandoah heap lock.
 214   // Padded to avoid false sharing with the read-only fields above.
 215   struct PaddedAllocSeqNum {
 216     DEFINE_PAD_MINUS_SIZE(0, DEFAULT_CACHE_LINE_SIZE, sizeof(uint64_t));
 217     uint64_t value;
 218     DEFINE_PAD_MINUS_SIZE(1, DEFAULT_CACHE_LINE_SIZE, 0);
 219 
 220     PaddedAllocSeqNum() {
 221       // start with 1, reserve 0 for uninitialized value
 222       value = 1;
 223     }
 224   };
 225 
 226   static PaddedAllocSeqNum _alloc_seq_num;
 227 
 228   // Never updated fields
 229   ShenandoahHeap* _heap;

 230   MemRegion _reserved;
 231   size_t _region_number;
 232 
 233   // Rarely updated fields
 234   HeapWord* _new_top;
 235   size_t _critical_pins;
 236   double _empty_time;
 237 
 238   // Seldom updated fields
 239   RegionState _state;
 240 
 241   // Frequently updated fields
 242   size_t _tlab_allocs;
 243   size_t _gclab_allocs;
 244   size_t _shared_allocs;
 245 
 246   uint64_t _seqnum_first_alloc_mutator;
 247   uint64_t _seqnum_first_alloc_gc;
 248   uint64_t _seqnum_last_alloc_mutator;
 249   uint64_t _seqnum_last_alloc_gc;