--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc_implementation/shared/ageTable.hpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,65 @@
+/*
+ * Copyright 1997-2003 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+/* Copyright 1992 Sun Microsystems, Inc. and Stanford University.
+   See the LICENSE file for license information. */
+
+// Age table for adaptive feedback-mediated tenuring (scavenging)
+//
+// Note: all sizes are in oops
+
+class ageTable VALUE_OBJ_CLASS_SPEC {
+  friend class VMStructs;
+
+ public:
+  // constants
+  enum { table_size = markOopDesc::max_age + 1 };
+
+  // instance variables
+  size_t sizes[table_size];
+
+  // constructor.  "global" indicates that this is the global age table
+  // (as opposed to gc-thread-local)
+  ageTable(bool global = true);
+
+  // clear table
+  void clear();
+
+  // add entry
+  void add(oop p, size_t oop_size) {
+    int age = p->age();
+    assert(age > 0 && age < table_size, "invalid age of object");
+    sizes[age] += oop_size;
+  }
+
+  // Merge another age table with the current one.  Used
+  // for parallel young generation gc.
+  void merge(ageTable* subTable);
+
+  // calculate new tenuring threshold based on age information
+  int compute_tenuring_threshold(size_t survivor_capacity);
+
+ private:
+  PerfVariable* _perf_sizes[table_size];
+};