--- old/src/hotspot/share/oops/markOop.hpp	2018-12-07 12:57:46.000000000 -0800
+++ new/src/hotspot/share/oops/markOop.hpp	2018-12-07 12:57:45.000000000 -0800
@@ -108,6 +108,10 @@
 //
 //    [ <unused> |1| epoch | age | 1 | 01]       permanently locked
 //
+//    A private buffered value can be in a larval state.  It's a value instance
+//    and hence always locked.  "epoch" is unused.  We use the same bit as "epoch"
+//    to set the larval state.
+//
 
 class BasicLock;
 class ObjectMonitor;
@@ -126,7 +130,8 @@
          max_hash_bits            = BitsPerWord - age_bits - lock_bits - biased_lock_bits,
          hash_bits                = max_hash_bits > 31 ? 31 : max_hash_bits,
          cms_bits                 = LP64_ONLY(1) NOT_LP64(0),
-         epoch_bits               = 2
+         epoch_bits               = 2,
+         larval_bits              = 1
   };
 
   // The biased locking code currently requires that the age bits be
@@ -137,7 +142,8 @@
          cms_shift                = age_shift + age_bits,
          hash_shift               = cms_shift + cms_bits,
          epoch_shift              = hash_shift,
-         thread_shift             = epoch_shift + epoch_bits
+         larval_shift             = hash_shift,
+         thread_shift             = epoch_shift + epoch_bits,
   };
 
   enum { lock_mask                = right_n_bits(lock_bits),
@@ -150,11 +156,13 @@
          epoch_mask               = right_n_bits(epoch_bits),
          epoch_mask_in_place      = epoch_mask << epoch_shift,
          cms_mask                 = right_n_bits(cms_bits),
-         cms_mask_in_place        = cms_mask << cms_shift
+         cms_mask_in_place        = cms_mask << cms_shift,
 #ifndef _WIN64
-         ,hash_mask               = right_n_bits(hash_bits),
-         hash_mask_in_place       = (address_word)hash_mask << hash_shift
+         hash_mask                = right_n_bits(hash_bits),
+         hash_mask_in_place       = (address_word)hash_mask << hash_shift,
 #endif
+         larval_mask              = right_n_bits(larval_bits),
+         larval_mask_in_place     = larval_mask << larval_shift
   };
 
   // Alignment of JavaThread pointers encoded in object header required by biased locking
@@ -186,6 +194,10 @@
 
   enum { max_bias_epoch           = epoch_mask };
 
+  enum { normal_value             = 0,
+         larval_value             = 1
+  };
+
   static markOop always_locked_prototype() {
     return markOop(always_locked_pattern);
   }
@@ -371,6 +383,17 @@
     return hash() == no_hash;
   }
 
+  // value private buffer operations
+  markOop enter_larval_state() const {
+    return markOop((value() & ~larval_mask_in_place) | larval_value); 
+  }
+  markOop exit_larval_state() const {
+    return markOop((value() & ~larval_mask_in_place) | normal_value); 
+  }
+  bool is_larval_state() const {
+    return ((value() & larval_mask_in_place) == larval_value);
+  }
+
   // Prototype mark for initialization
   static markOop prototype() {
     return markOop( no_hash_in_place | no_lock_in_place );