view src/share/vm/runtime/fieldDescriptor.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 a61af66fc99e
children c18cbe5936b8
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/*
 * Copyright 1997-2005 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 fieldDescriptor describes the attributes of a single field (instance or class variable).
// It needs the class constant pool to work (because it only holds indices into the pool
// rather than the actual info).

class fieldDescriptor VALUE_OBJ_CLASS_SPEC {
 private:
  AccessFlags         _access_flags;
  int                 _name_index;
  int                 _signature_index;
  int                 _initial_value_index;
  int                 _offset;
  int                 _generic_signature_index;
  int                 _index; // index into fields() array
  constantPoolHandle  _cp;

 public:
  symbolOop name() const               { return _cp->symbol_at(_name_index); }
  symbolOop signature() const          { return _cp->symbol_at(_signature_index); }
  klassOop field_holder() const        { return _cp->pool_holder(); }
  constantPoolOop constants() const    { return _cp(); }
  AccessFlags access_flags() const     { return _access_flags; }
  oop loader() const;
  // Offset (in words) of field from start of instanceOop / klassOop
  int offset() const                   { return _offset; }
  symbolOop generic_signature() const  { return (_generic_signature_index > 0 ? _cp->symbol_at(_generic_signature_index) : (symbolOop)NULL); }
  int index() const                    { return _index; }
  typeArrayOop annotations() const;

  // Initial field value
  bool has_initial_value() const          { return _initial_value_index != 0; }
  constantTag initial_value_tag() const;  // The tag will return true on one of is_int(), is_long(), is_single(), is_double()
  jint        int_initial_value() const;
  jlong       long_initial_value() const;
  jfloat      float_initial_value() const;
  jdouble     double_initial_value() const;
  oop         string_initial_value(TRAPS) const;

  // Field signature type
  BasicType field_type() const            { return FieldType::basic_type(signature()); }

  // Access flags
  bool is_public() const                  { return _access_flags.is_public(); }
  bool is_private() const                 { return _access_flags.is_private(); }
  bool is_protected() const               { return _access_flags.is_protected(); }
  bool is_package_private() const         { return !is_public() && !is_private() && !is_protected(); }

  bool is_static() const                  { return _access_flags.is_static(); }
  bool is_final() const                   { return _access_flags.is_final(); }
  bool is_volatile() const                { return _access_flags.is_volatile(); }
  bool is_transient() const               { return _access_flags.is_transient(); }

  bool is_synthetic() const               { return _access_flags.is_synthetic(); }

  bool is_field_access_watched() const    { return _access_flags.is_field_access_watched(); }
  bool is_field_modification_watched() const
                                          { return _access_flags.is_field_modification_watched(); }
  void set_is_field_access_watched(const bool value)
                                          { _access_flags.set_is_field_access_watched(value); }
  void set_is_field_modification_watched(const bool value)
                                          { _access_flags.set_is_field_modification_watched(value); }

  // Initialization
  void initialize(klassOop k, int index);

  // Print
  void print_on(outputStream* st) const         PRODUCT_RETURN;
  void print_on_for(outputStream* st, oop obj)  PRODUCT_RETURN;
};