view src/share/vm/oops/constMethodOop.cpp @ 452:00b023ae2d78

6722113: CMS: Incorrect overflow handling during precleaning of Reference lists Summary: When we encounter marking stack overflow during precleaning of Reference lists, we were using the overflow list mechanism, which can cause problems on account of mutating the mark word of the header because of conflicts with mutator accesses and updates of that field. Instead we should use the usual mechanism for overflow handling in concurrent phases, namely dirtying of the card on which the overflowed object lies. Since precleaning effectively does a form of discovered list processing, albeit with discovery enabled, we needed to adjust some code to be correct in the face of interleaved processing and discovery. Reviewed-by: apetrusenko, jcoomes
author ysr
date Thu, 20 Nov 2008 12:27:41 -0800
parents a61af66fc99e
children c18cbe5936b8
line wrap: on
line source

/*
 * Copyright 2003-2006 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/_constMethodOop.cpp.incl"

// Static initialization
const u2 constMethodOopDesc::MAX_IDNUM   = 0xFFFE;
const u2 constMethodOopDesc::UNSET_IDNUM = 0xFFFF;

// How big must this constMethodObject be?

int constMethodOopDesc::object_size(int code_size,
                                    int compressed_line_number_size,
                                    int local_variable_table_length,
                                    int checked_exceptions_length) {
  int extra_bytes = code_size;
  if (compressed_line_number_size > 0) {
    extra_bytes += compressed_line_number_size;
  }
  if (checked_exceptions_length > 0) {
    extra_bytes += sizeof(u2);
    extra_bytes += checked_exceptions_length * sizeof(CheckedExceptionElement);
  }
  if (local_variable_table_length > 0) {
    extra_bytes += sizeof(u2);
    extra_bytes +=
              local_variable_table_length * sizeof(LocalVariableTableElement);
  }
  int extra_words = align_size_up(extra_bytes, BytesPerWord) / BytesPerWord;
  return align_object_size(header_size() + extra_words);
}


// linenumber table - note that length is unknown until decompression,
// see class CompressedLineNumberReadStream.

u_char* constMethodOopDesc::compressed_linenumber_table() const {
  // Located immediately following the bytecodes.
  assert(has_linenumber_table(), "called only if table is present");
  return code_end();
}

u2* constMethodOopDesc::checked_exceptions_length_addr() const {
  // Located at the end of the constMethod.
  assert(has_checked_exceptions(), "called only if table is present");
  return last_u2_element();
}

u2* constMethodOopDesc::localvariable_table_length_addr() const {
  assert(has_localvariable_table(), "called only if table is present");
  if (has_checked_exceptions()) {
    // If checked_exception present, locate immediately before them.
    return (u2*) checked_exceptions_start() - 1;
  } else {
    // Else, the linenumber table is at the end of the constMethod.
    return last_u2_element();
  }
}


// Update the flags to indicate the presence of these optional fields.
void constMethodOopDesc::set_inlined_tables_length(
                                              int checked_exceptions_len,
                                              int compressed_line_number_size,
                                              int localvariable_table_len) {
  // Must be done in the order below, otherwise length_addr accessors
  // will not work. Only set bit in header if length is positive.
  assert(_flags == 0, "Error");
  if (compressed_line_number_size > 0) {
    _flags |= _has_linenumber_table;
  }
  if (checked_exceptions_len > 0) {
    _flags |= _has_checked_exceptions;
    *(checked_exceptions_length_addr()) = checked_exceptions_len;
  }
  if (localvariable_table_len > 0) {
    _flags |= _has_localvariable_table;
    *(localvariable_table_length_addr()) = localvariable_table_len;
  }
}


int constMethodOopDesc::checked_exceptions_length() const {
  return has_checked_exceptions() ? *(checked_exceptions_length_addr()) : 0;
}


CheckedExceptionElement* constMethodOopDesc::checked_exceptions_start() const {
  u2* addr = checked_exceptions_length_addr();
  u2 length = *addr;
  assert(length > 0, "should only be called if table is present");
  addr -= length * sizeof(CheckedExceptionElement) / sizeof(u2);
  return (CheckedExceptionElement*) addr;
}


int constMethodOopDesc::localvariable_table_length() const {
  return has_localvariable_table() ? *(localvariable_table_length_addr()) : 0;
}


LocalVariableTableElement* constMethodOopDesc::localvariable_table_start() const {
  u2* addr = localvariable_table_length_addr();
  u2 length = *addr;
  assert(length > 0, "should only be called if table is present");
  addr -= length * sizeof(LocalVariableTableElement) / sizeof(u2);
  return (LocalVariableTableElement*) addr;
}