view src/share/vm/ci/ciKlass.hpp @ 3602:da91efe96a93

6964458: Reimplement class meta-data storage to use native memory Summary: Remove PermGen, allocate meta-data in metaspace linked to class loaders, rewrite GC walking, rewrite and rename metadata to be C++ classes Reviewed-by: jmasa, stefank, never, coleenp, kvn, brutisso, mgerdin, dholmes, jrose, twisti, roland Contributed-by: jmasa <jon.masamitsu@oracle.com>, stefank <stefan.karlsson@oracle.com>, mgerdin <mikael.gerdin@oracle.com>, never <tom.rodriguez@oracle.com>
author coleenp
date Sat, 01 Sep 2012 13:25:18 -0400
parents f95d63e2154a
children d8ce2825b193
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/*
 * Copyright (c) 1999, 2012, 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
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 *
 */

#ifndef SHARE_VM_CI_CIKLASS_HPP
#define SHARE_VM_CI_CIKLASS_HPP

#include "ci/ciType.hpp"

// ciKlass
//
// This class and its subclasses represent Klass*s in the
// HotSpot virtual machine.  In the vm, each Klass* contains an
// embedded Klass object.  ciKlass is subclassed to explicitly
// represent the kind of Klass embedded in the Klass*.  For
// example, a Klass* with an embedded objArrayKlass object is
// represented in the ciObject hierarchy by the class
// ciObjArrayKlass.
class ciKlass : public ciType {
  CI_PACKAGE_ACCESS
  friend class ciEnv;
  friend class ciField;
  friend class ciMethod;
  friend class ciObjArrayKlass;

private:
  ciSymbol* _name;
  jint _layout_helper;

protected:
  ciKlass(KlassHandle k_h, ciSymbol* name);
  ciKlass(ciSymbol* name, BasicType bt);

  Klass* get_Klass() const {
    Klass* k = (Klass*)_metadata;
    assert(k != NULL, "illegal use of unloaded klass");
    return k;
  }

  // Certain subklasses have an associated class loader.
  virtual oop loader()             { return NULL; }
  virtual jobject loader_handle()  { return NULL; }

  virtual oop protection_domain()             { return NULL; }
  virtual jobject protection_domain_handle()  { return NULL; }

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

  void print_impl(outputStream* st);

public:
  ciKlass(KlassHandle k_h);

  // What is the name of this klass?
  ciSymbol* name() const { return _name; }

  // What is its layout helper value?
  jint layout_helper() { return _layout_helper; }

  bool is_subtype_of(ciKlass* klass);
  bool is_subclass_of(ciKlass* klass);
  juint super_depth();
  juint super_check_offset();
  ciKlass* super_of_depth(juint i);
  bool can_be_primary_super();
  static juint primary_super_limit() { return Klass::primary_super_limit(); }

  // Is this ciObject the ciInstanceKlass representing java.lang.Object()?
  virtual bool is_java_lang_Object() const  { return false; }

  // Get the shared parent of two klasses.
  ciKlass* least_common_ancestor(ciKlass* k);

  virtual bool is_interface() {
    return false;
  }

  virtual bool is_abstract() {
    return false;
  }

  // Does this type (array, class, interface) have no subtypes?
  virtual bool is_leaf_type() {
    return false;
  }

  // Attempt to get a klass using this ciKlass's loader.
  ciKlass* find_klass(ciSymbol* klass_name);
  // Note:  To find a class from its name string, use ciSymbol::make,
  // but consider adding to vmSymbols.hpp instead.

  // Get the instance of java.lang.Class corresponding to this klass.
  ciInstance*            java_mirror();

  // Fetch Klass::modifier_flags.
  jint                   modifier_flags();

  // Fetch Klass::access_flags.
  jint                   access_flags();

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

  void print_name_on(outputStream* st);
};

#endif // SHARE_VM_CI_CIKLASS_HPP