src/share/vm/code/nmethod.hpp

@@ -200,15 +200,22 @@
   // event processing needs to be done.
   jint  _lock_count;
 
   // not_entrant method removal. Each mark_sweep pass will update
   // this mark to current sweep invocation count if it is seen on the
-  // stack.  An not_entrant method can be removed when there is no
+  // stack.  An not_entrant method can be removed when there are no
   // more activations, i.e., when the _stack_traversal_mark is less than
   // current sweep traversal index.
   long _stack_traversal_mark;
 
+  // The _hotness_counter indicates the hotness of a method. The higher
+  // the value the hotter the method. The hotness counter of a nmethod is
+  // set to [(ReservedCodeCacheSize / (1024 * 1024)) * 2] each time the method
+  // is active while stack scanning (mark_active_nmethods()). The hotness
+  // counter is decreased (by 1) while sweeping.
+  int _hotness_counter;
+
   ExceptionCache *_exception_cache;
   PcDescCache     _pc_desc_cache;
 
   // These are used for compiled synchronized native methods to
   // locate the owner and stack slot for the BasicLock so that we can

@@ -380,10 +387,15 @@
   int handler_table_size() const                  { return            handler_table_end() -            handler_table_begin(); }
   int nul_chk_table_size() const                  { return            nul_chk_table_end() -            nul_chk_table_begin(); }
 
   int total_size        () const;
 
+  // Hotness counter accessor methods
+  void dec_hotness_counter(int val) { _hotness_counter-= val;  }
+  void set_hotness_counter(int val) { _hotness_counter = val;  }
+  int  get_hotness_counter() const  { return _hotness_counter; }
+
   // Containment
   bool consts_contains       (address addr) const { return consts_begin       () <= addr && addr < consts_end       (); }
   bool insts_contains        (address addr) const { return insts_begin        () <= addr && addr < insts_end        (); }
   bool stub_contains         (address addr) const { return stub_begin         () <= addr && addr < stub_end         (); }
   bool oops_contains         (oop*    addr) const { return oops_begin         () <= addr && addr < oops_end         (); }