--- old/src/share/vm/runtime/thread.hpp	2017-04-18 10:46:13.186546982 -0700
+++ new/src/share/vm/runtime/thread.hpp	2017-04-18 10:46:13.070547435 -0700
@@ -815,6 +815,9 @@
 
   JavaFrameAnchor _anchor;                       // Encapsulation of current java frame and it state
 
+  size_t _bytes_until_sample;                    // Thread local counter to determine when to sample
+                                                 // allocations.
+
   ThreadFunction _entry_point;
 
   JNIEnv        _jni_environment;
@@ -1102,6 +1105,9 @@
 
   address last_Java_pc(void)                     { return _anchor.last_Java_pc(); }
 
+  // Bytes until next heap sample.
+  size_t* bytes_until_sample()                   { return &_bytes_until_sample; }
+
   // Safepoint support
 #if !(defined(PPC64) || defined(AARCH64))
   JavaThreadState thread_state() const           { return _thread_state; }
@@ -1554,6 +1560,7 @@
   static ByteSize frame_anchor_offset() {
     return byte_offset_of(JavaThread, _anchor);
   }
+  static ByteSize bytes_until_sample_offset()    { return byte_offset_of(JavaThread, _bytes_until_sample); }
   static ByteSize callee_target_offset()         { return byte_offset_of(JavaThread, _callee_target); }
   static ByteSize vm_result_offset()             { return byte_offset_of(JavaThread, _vm_result); }
   static ByteSize vm_result_2_offset()           { return byte_offset_of(JavaThread, _vm_result_2); }