view src/share/vm/ci/ciObjArrayKlass.hpp @ 20543:e7d0505c8a30

8059758: Footprint regressions with JDK-8038423 Summary: Changes in JDK-8038423 always initialize (zero out) virtual memory used for auxiliary data structures. This causes a footprint regression for G1 in startup benchmarks. This is because they do not touch that memory at all, so the operating system does not actually commit these pages. The fix is to, if the initialization value of the data structures matches the default value of just committed memory (=0), do not do anything. Reviewed-by: jwilhelm, brutisso
author tschatzl
date Fri, 10 Oct 2014 15:51:58 +0200
parents 55fb97c4c58d
children 4ca6dc0799b6
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/*
 * Copyright (c) 1999, 2013, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 * questions.
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 */

#ifndef SHARE_VM_CI_CIOBJARRAYKLASS_HPP
#define SHARE_VM_CI_CIOBJARRAYKLASS_HPP

#include "ci/ciArrayKlass.hpp"

// ciObjArrayKlass
//
// This class represents a Klass* in the HotSpot virtual machine
// whose Klass part is an ObjArrayKlass.
class ciObjArrayKlass : public ciArrayKlass {
  CI_PACKAGE_ACCESS
  friend class ciEnv;

private:
  ciKlass* _element_klass;
  ciKlass* _base_element_klass;

protected:
  ciObjArrayKlass(KlassHandle h_k);
  ciObjArrayKlass(ciSymbol* array_name,
                  ciKlass* base_element_klass,
                  int dimension);

  ObjArrayKlass* get_ObjArrayKlass() {
    return (ObjArrayKlass*)get_Klass();
  }

  static ciObjArrayKlass* make_impl(ciKlass* element_klass);
  static ciSymbol* construct_array_name(ciSymbol* element_name,
                                        int       dimension);

  const char* type_string() { return "ciObjArrayKlass"; }

  oop     loader()        { return _base_element_klass->loader(); }
  jobject loader_handle() { return _base_element_klass->loader_handle(); }

  oop     protection_domain()        { return _base_element_klass->protection_domain(); }
  jobject protection_domain_handle() { return _base_element_klass->protection_domain_handle(); }


public:
  // The one-level type of the array elements.
  ciKlass* element_klass();

  // The innermost type of the array elements.
  ciKlass* base_element_klass() { return _base_element_klass; }

  // What kind of ciObject is this?
  bool is_obj_array_klass() const { return true; }

  static ciObjArrayKlass* make(ciKlass* element_klass);

  virtual ciKlass* exact_klass();
};

#endif // SHARE_VM_CI_CIOBJARRAYKLASS_HPP