view src/share/vm/runtime/aprofiler.hpp @ 1145:e018e6884bd8

6631166: CMS: better heuristics when combatting fragmentation Summary: Autonomic per-worker free block cache sizing, tunable coalition policies, fixes to per-size block statistics, retuned gain and bandwidth of some feedback loop filters to allow quicker reactivity to abrupt changes in ambient demand, and other heuristics to reduce fragmentation of the CMS old gen. Also tightened some assertions, including those related to locking. Reviewed-by: jmasa
author ysr
date Wed, 23 Dec 2009 09:23:54 -0800
parents 37f87013dfd8
children c18cbe5936b8
line wrap: on
line source

/*
 * 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.
 *
 */

// A simple allocation profiler for Java. The profiler collects and prints
// the number and total size of instances allocated per class, including
// array classes.
//
// The profiler is currently global for all threads. It can be changed to a
// per threads profiler by keeping a more elaborate data structure and calling
// iterate_since_last_scavenge at thread switches.


class AllocationProfiler: AllStatic {
  friend class GenCollectedHeap;
  friend class G1CollectedHeap;
  friend class MarkSweep;
 private:
  static bool _active;                          // tells whether profiler is active
  static GrowableArray<klassOop>* _print_array; // temporary array for printing

  // Utility printing functions
  static void add_class_to_array(klassOop k);
  static void add_classes_to_array(klassOop k);
  static int  compare_classes(klassOop* k1, klassOop* k2);
  static int  average(size_t alloc_size, int alloc_count);
  static void sort_and_print_array(size_t cutoff);

  // Call for collecting allocation information. Called at scavenge, mark-sweep and disengage.
  static void iterate_since_last_gc();

 public:
  // Start profiler
  static void engage();
  // Stop profiler
  static void disengage();
  // Tells whether profiler is active
  static bool is_active()                   { return _active; }
  // Print profile
  static void print(size_t cutoff);   // Cutoff in total allocation size (in words)
};