view src/share/vm/oops/metadata.hpp @ 9126:bc26f978b0ce

HotSpotResolvedObjectType: implement hasFinalizeSubclass() correctly don't use the (wrong) cached value, but ask the runtime on each request. Fixes regression on xml.* benchmarks @ specjvm2008. The problem was: After the constructor of Object was deoptimized due to an assumption violation, it was recompiled again after some time. However, on recompilation, the value of hasFinalizeSubclass for the class was not updated and it was compiled again with a, now wrong, assumption, which then triggers deoptimization again. This was repeated until it hit the recompilation limit (defined by PerMethodRecompilationCutoff), and therefore only executed by the interpreter from now on, causing the performance regression.
author Bernhard Urban <bernhard.urban@jku.at>
date Mon, 15 Apr 2013 19:54:58 +0200
parents da91efe96a93
children cd6b3f1a94ff
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/*
 * Copyright (c) 2011, 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_OOPS_METADATA_HPP
#define SHARE_VM_OOPS_METADATA_HPP

#include "utilities/exceptions.hpp"
#include "utilities/globalDefinitions.hpp"
#include "utilities/ostream.hpp"

// This is the base class for an internal Class related metadata
class Metadata : public MetaspaceObj {
  // Debugging hook to check that the metadata has not been deleted.
  NOT_PRODUCT(int _valid;)
 public:
  NOT_PRODUCT(Metadata()     { _valid = 0; })
  NOT_PRODUCT(bool is_valid() const volatile { return _valid == 0; })

  int identity_hash()                { return (int)(uintptr_t)this; }

  // Rehashing support for tables containing pointers to this
  unsigned int new_hash(jint seed)   { ShouldNotReachHere();  return 0; }

  virtual bool is_klass()              const volatile { return false; }
  virtual bool is_method()             const volatile { return false; }
  virtual bool is_methodData()         const volatile { return false; }
  virtual bool is_constantPool()       const volatile { return false; }

  virtual const char* internal_name()  const = 0;

  void print()       const { print_on(tty); }
  void print_value() const { print_value_on(tty); }

  void print_maybe_null() const { print_on_maybe_null(tty); }
  void print_on_maybe_null(outputStream* st) const {
    if (this == NULL)
      st->print("NULL");
    else
      print_on(tty);
  }
  void print_value_on_maybe_null(outputStream* st) const {
    if (this == NULL)
      st->print("NULL");
    else
      print_value_on(tty);
  }

  virtual void print_on(outputStream* st) const;       // First level print
  virtual void print_value_on(outputStream* st) const = 0; // Second level print

  char* print_value_string() const;

  // Used to keep metadata alive during class redefinition
  // Can't assert because is called for delete functions (as an assert)
  virtual bool on_stack() const { return false; }
  virtual void set_on_stack(const bool value);

  // Set on_stack bit, so that the metadata is not cleared
  // during class redefinition.  This is a virtual call because only methods
  // and constant pools need to be set, but someday instanceKlasses might also.
  static void mark_on_stack(Metadata* m) { m->set_on_stack(true); }
};

#endif // SHARE_VM_OOPS_METADATA_HPP