--- old/src/hotspot/share/gc/shared/threadLocalAllocBuffer.hpp	2018-02-12 20:05:06.771759862 -0800
+++ new/src/hotspot/share/gc/shared/threadLocalAllocBuffer.hpp	2018-02-12 20:05:06.507760880 -0800
@@ -51,10 +51,9 @@
   HeapWord* _start;                              // address of TLAB
   HeapWord* _top;                                // address after last allocation
   HeapWord* _pf_top;                             // allocation prefetch watermark
-  HeapWord* _end;                                // allocation end (can be the sampling end point or
-                                                 //                 the actual TLAB end, excluding alignment_reserve)
-  HeapWord* _actual_end;                         // allocation actual_end (actual TLAB end, excluding alignment_reserve)
-  HeapWord* _slow_path_end;                      // remember the end in case a fast refill occurs.
+  HeapWord* _current_end;                        // allocation end (can be the sampling end point or _allocation_end)
+  HeapWord* _allocation_end;                     // end for allocations (actual TLAB end, excluding alignment_reserve)
+  HeapWord* _last_slow_path_end;                 // last address for slow_path_end (as opposed to _allocation_end)
 
   size_t    _desired_size;                       // desired size   (including alignment_reserve)
   size_t    _refill_waste_limit;                 // hold onto tlab if free() is larger than this
@@ -77,9 +76,9 @@
   void initialize_statistics();
 
   void set_start(HeapWord* start)                { _start = start; }
-  void set_end(HeapWord* end)                    { _end = end; }
-  void set_actual_end(HeapWord* actual_end)      { _actual_end = actual_end; }
-  void set_slow_path_end(HeapWord* slow_path_end)    { _slow_path_end = slow_path_end; }
+  void set_current_end(HeapWord* current_end)    { _current_end = current_end; }
+  void set_allocation_end(HeapWord* ptr)         { _allocation_end = ptr; }
+  void set_last_slow_path_end(HeapWord* ptr)     { _last_slow_path_end = ptr; }
   void set_top(HeapWord* top)                    { _top = top; }
   void set_pf_top(HeapWord* pf_top)              { _pf_top = pf_top; }
   void set_desired_size(size_t desired_size)     { _desired_size = desired_size; }
@@ -91,9 +90,10 @@
   static int    target_refills()                 { return _target_refills; }
   size_t initial_desired_size();
 
-  size_t remaining()                             { return end() == NULL ? 0 : pointer_delta(hard_end(), top()); }
+  size_t remaining();
 
   void set_sample_end();
+  void update_end_pointers();
 
   // Make parsable and release it.
   void reset();
@@ -101,7 +101,7 @@
   // Resize based on amount of allocation, etc.
   void resize();
 
-  void invariants() const { assert(top() >= start() && top() <= end(), "invalid tlab"); }
+  void invariants() const { assert(top() >= start() && top() <= current_end(), "invalid tlab"); }
 
   void initialize(HeapWord* start, HeapWord* top, HeapWord* end);
 
@@ -131,14 +131,14 @@
   static void set_max_size(size_t max_size)      { _max_size = max_size; }
 
   HeapWord* start() const                        { return _start; }
-  HeapWord* end() const                          { return _end; }
+  HeapWord* current_end() const                  { return _current_end; }
   HeapWord* top() const                          { return _top; }
-  HeapWord* hard_end();
+  HeapWord* reserved_end();
   HeapWord* pf_top() const                       { return _pf_top; }
   size_t desired_size() const                    { return _desired_size; }
   size_t used() const                            { return pointer_delta(top(), start()); }
   size_t used_bytes() const                      { return pointer_delta(top(), start(), 1); }
-  size_t free() const                            { return pointer_delta(end(), top()); }
+  size_t free() const                            { return pointer_delta(current_end(), top()); }
   // Don't discard tlab if remaining space is larger than this.
   size_t refill_waste_limit() const              { return _refill_waste_limit; }
 
@@ -180,15 +180,16 @@
   void initialize();
 
   void pick_next_sample(size_t diff = 0);
-  void set_back_actual_end();
-  void handle_sample(Thread* thread, HeapWord* result, size_t size);
+  void set_back_allocation_end();
+  void update_tlab_sample_point(size_t size_in_bytes);
+  void handle_sample(Thread* thread, HeapWord* result, size_t size_in_bytes);
   bool should_sample() { return _bytes_until_sample == 0; }
 
   static size_t refill_waste_limit_increment()   { return TLABWasteIncrement; }
 
   // Code generation support
   static ByteSize start_offset()                 { return byte_offset_of(ThreadLocalAllocBuffer, _start); }
-  static ByteSize end_offset()                   { return byte_offset_of(ThreadLocalAllocBuffer, _end  ); }
+  static ByteSize current_end_offset()           { return byte_offset_of(ThreadLocalAllocBuffer, _current_end  ); }
   static ByteSize top_offset()                   { return byte_offset_of(ThreadLocalAllocBuffer, _top  ); }
   static ByteSize pf_top_offset()                { return byte_offset_of(ThreadLocalAllocBuffer, _pf_top  ); }
   static ByteSize size_offset()                  { return byte_offset_of(ThreadLocalAllocBuffer, _desired_size ); }