view src/share/vm/utilities/elfStringTable.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 b9a9ed0f8eeb
children e7cbc95179c4
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/*
 * Copyright (c) 1997, 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
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#ifndef SHARE_VM_UTILITIES_ELF_STRING_TABLE_HPP
#define SHARE_VM_UTILITIES_ELF_STRING_TABLE_HPP

#if !defined(_WINDOWS) && !defined(__APPLE__)

#include "memory/allocation.hpp"
#include "utilities/decoder.hpp"
#include "utilities/elfFile.hpp"


// The string table represents a string table section in an elf file.
// Whenever there is enough memory, it will load whole string table as
// one blob. Otherwise, it will load string from file when requested.
class ElfStringTable: CHeapObj<mtInternal> {
  friend class ElfFile;
 public:
  ElfStringTable(FILE* file, Elf_Shdr shdr, int index);
  ~ElfStringTable();

  // section index
  int index() { return m_index; };

  // get string at specified offset
  bool string_at(int offset, char* buf, int buflen);

  // get status code
  NullDecoder::decoder_status get_status() { return m_status; };

 protected:
  ElfStringTable*        m_next;

  // section index
  int                      m_index;

  // holds complete string table if can
  // allocate enough memory
  const char*              m_table;

  // file contains string table
  FILE*                    m_file;

  // section header
  Elf_Shdr                 m_shdr;

  // error code
  NullDecoder::decoder_status  m_status;
};

#endif // _WINDOWS and _APPLE

#endif // SHARE_VM_UTILITIES_ELF_STRING_TABLE_HPP