view src/share/vm/ci/ciKlass.cpp @ 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 dd57230ba8fe
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/*
 * Copyright 1999-2007 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.
 *
 */

#include "incls/_precompiled.incl"
#include "incls/_ciKlass.cpp.incl"

// ciKlass
//
// This class represents a klassOop in the HotSpot virtual
// machine.

// ------------------------------------------------------------------
// ciKlass::ciKlass
ciKlass::ciKlass(KlassHandle h_k) : ciType(h_k) {
  assert(get_oop()->is_klass(), "wrong type");
  Klass* k = get_Klass();
  _layout_helper = k->layout_helper();
  symbolOop klass_name = k->name();
  assert(klass_name != NULL, "wrong ciKlass constructor");
  _name = CURRENT_ENV->get_object(klass_name)->as_symbol();
}

// ------------------------------------------------------------------
// ciKlass::ciKlass
//
// Nameless klass variant.
ciKlass::ciKlass(KlassHandle h_k, ciSymbol* name) : ciType(h_k) {
  assert(get_oop()->is_klass(), "wrong type");
  _name = name;
  _layout_helper = Klass::_lh_neutral_value;
}

// ------------------------------------------------------------------
// ciKlass::ciKlass
//
// Unloaded klass variant.
ciKlass::ciKlass(ciSymbol* name, ciKlass* klass) : ciType(klass) {
  _name = name;
  _layout_helper = Klass::_lh_neutral_value;
}

// ------------------------------------------------------------------
// ciKlass::is_subtype_of
bool ciKlass::is_subtype_of(ciKlass* that) {
  assert(is_loaded() && that->is_loaded(), "must be loaded");
  assert(is_java_klass() && that->is_java_klass(), "must be java klasses");
  // Check to see if the klasses are identical.
  if (this == that) {
    return true;
  }

  VM_ENTRY_MARK;
  Klass* this_klass = get_Klass();
  klassOop that_klass = that->get_klassOop();
  bool result = this_klass->is_subtype_of(that_klass);

  return result;
}

// ------------------------------------------------------------------
// ciKlass::is_subclass_of
bool ciKlass::is_subclass_of(ciKlass* that) {
  assert(is_loaded() && that->is_loaded(), "must be loaded");
  assert(is_java_klass() && that->is_java_klass(), "must be java klasses");
  // Check to see if the klasses are identical.

  VM_ENTRY_MARK;
  Klass* this_klass = get_Klass();
  klassOop that_klass = that->get_klassOop();
  bool result = this_klass->is_subclass_of(that_klass);

  return result;
}

// ------------------------------------------------------------------
// ciKlass::super_depth
juint ciKlass::super_depth() {
  assert(is_loaded(), "must be loaded");
  assert(is_java_klass(), "must be java klasses");

  VM_ENTRY_MARK;
  Klass* this_klass = get_Klass();
  return this_klass->super_depth();
}

// ------------------------------------------------------------------
// ciKlass::super_check_offset
juint ciKlass::super_check_offset() {
  assert(is_loaded(), "must be loaded");
  assert(is_java_klass(), "must be java klasses");

  VM_ENTRY_MARK;
  Klass* this_klass = get_Klass();
  return this_klass->super_check_offset();
}

// ------------------------------------------------------------------
// ciKlass::super_of_depth
ciKlass* ciKlass::super_of_depth(juint i) {
  assert(is_loaded(), "must be loaded");
  assert(is_java_klass(), "must be java klasses");

  VM_ENTRY_MARK;
  Klass* this_klass = get_Klass();
  klassOop super = this_klass->primary_super_of_depth(i);
  return (super != NULL) ? CURRENT_THREAD_ENV->get_object(super)->as_klass() : NULL;
}

// ------------------------------------------------------------------
// ciKlass::can_be_primary_super
bool ciKlass::can_be_primary_super() {
  assert(is_loaded(), "must be loaded");
  assert(is_java_klass(), "must be java klasses");

  VM_ENTRY_MARK;
  Klass* this_klass = get_Klass();
  return this_klass->can_be_primary_super();
}

// ------------------------------------------------------------------
// ciKlass::least_common_ancestor
//
// Get the shared parent of two klasses.
//
// Implementation note: this method currently goes "over the wall"
// and does all of the work on the VM side.  It could be rewritten
// to use the super() method and do all of the work (aside from the
// lazy computation of super()) in native mode.  This may be
// worthwhile if the compiler is repeatedly requesting the same lca
// computation or possibly if most of the superklasses have already
// been created as ciObjects anyway.  Something to think about...
ciKlass*
ciKlass::least_common_ancestor(ciKlass* that) {
  assert(is_loaded() && that->is_loaded(), "must be loaded");
  assert(is_java_klass() && that->is_java_klass(), "must be java klasses");
  // Check to see if the klasses are identical.
  if (this == that) {
    return this;
  }

  VM_ENTRY_MARK;
  Klass* this_klass = get_Klass();
  Klass* that_klass = that->get_Klass();
  Klass* lca        = this_klass->LCA(that_klass);

  // Many times the LCA will be either this_klass or that_klass.
  // Treat these as special cases.
  if (lca == that_klass) {
    return that;
  }
  if (this_klass == lca) {
    return this;
  }

  // Create the ciInstanceKlass for the lca.
  ciKlass* result =
    CURRENT_THREAD_ENV->get_object(lca->as_klassOop())->as_klass();

  return result;
}

// ------------------------------------------------------------------
// ciKlass::find_klass
//
// Find a klass using this klass's class loader.
ciKlass* ciKlass::find_klass(ciSymbol* klass_name) {
  assert(is_loaded(), "cannot find_klass through an unloaded klass");
  return CURRENT_ENV->get_klass_by_name(this,
                                        klass_name, false);
}

// ------------------------------------------------------------------
// ciKlass::java_mirror
ciInstance* ciKlass::java_mirror() {
  GUARDED_VM_ENTRY(
    oop java_mirror = get_Klass()->java_mirror();
    return CURRENT_ENV->get_object(java_mirror)->as_instance();
  )
}

// ------------------------------------------------------------------
// ciKlass::modifier_flags
jint ciKlass::modifier_flags() {
  assert(is_loaded(), "not loaded");
  GUARDED_VM_ENTRY(
    return get_Klass()->modifier_flags();
  )
}

// ------------------------------------------------------------------
// ciKlass::access_flags
jint ciKlass::access_flags() {
  assert(is_loaded(), "not loaded");
  GUARDED_VM_ENTRY(
    return get_Klass()->access_flags().as_int();
  )
}

// ------------------------------------------------------------------
// ciKlass::print_impl
//
// Implementation of the print method
void ciKlass::print_impl(outputStream* st) {
  st->print(" name=");
  print_name_on(st);
}

// ------------------------------------------------------------------
// ciKlass::print_name
//
// Print the name of this klass
void ciKlass::print_name_on(outputStream* st) {
  name()->print_symbol_on(st);
}