view src/share/vm/oops/typeArrayOop.hpp @ 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
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/*
 * Copyright 1997-2007 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.
 *
 */

// A typeArrayOop is an array containing basic types (non oop elements).
// It is used for arrays of {characters, singles, doubles, bytes, shorts, integers, longs}
#include <limits.h>

class typeArrayOopDesc : public arrayOopDesc {
 protected:
  jchar*    char_base()   const { return (jchar*)   base(T_CHAR); }
  jboolean* bool_base()   const { return (jboolean*)base(T_BOOLEAN); }
  jbyte*    byte_base()   const { return (jbyte*)   base(T_BYTE); }
  jint*     int_base()    const { return (jint*)    base(T_INT); }
  jlong*    long_base()   const { return (jlong*)   base(T_LONG); }
  jshort*   short_base()  const { return (jshort*)  base(T_SHORT); }
  jfloat*   float_base()  const { return (jfloat*)  base(T_FLOAT); }
  jdouble*  double_base() const { return (jdouble*) base(T_DOUBLE); }

  friend class typeArrayKlass;

 public:
  jbyte* byte_at_addr(int which) const {
    assert(is_within_bounds(which), "index out of bounds");
    return &byte_base()[which];
  }

  jboolean* bool_at_addr(int which) const {
    assert(is_within_bounds(which), "index out of bounds");
    return &bool_base()[which];
  }

  jchar* char_at_addr(int which) const {
    assert(is_within_bounds(which), "index out of bounds");
    return &char_base()[which];
  }

  jint* int_at_addr(int which) const {
    assert(is_within_bounds(which), "index out of bounds");
    return &int_base()[which];
  }

  jshort* short_at_addr(int which) const {
    assert(is_within_bounds(which), "index out of bounds");
    return &short_base()[which];
  }

  jushort* ushort_at_addr(int which) const {  // for field descriptor arrays
    assert(is_within_bounds(which), "index out of bounds");
    return (jushort*) &short_base()[which];
  }

  jlong* long_at_addr(int which) const {
    assert(is_within_bounds(which), "index out of bounds");
    return &long_base()[which];
  }

  jfloat* float_at_addr(int which) const {
    assert(is_within_bounds(which), "index out of bounds");
    return &float_base()[which];
  }

  jdouble* double_at_addr(int which) const {
    assert(is_within_bounds(which), "index out of bounds");
    return &double_base()[which];
  }

  jbyte byte_at(int which) const                  { return *byte_at_addr(which); }
  void byte_at_put(int which, jbyte contents)     { *byte_at_addr(which) = contents; }

  jboolean bool_at(int which) const               { return *bool_at_addr(which); }
  void bool_at_put(int which, jboolean contents)  { *bool_at_addr(which) = contents; }

  jchar char_at(int which) const                  { return *char_at_addr(which); }
  void char_at_put(int which, jchar contents)     { *char_at_addr(which) = contents; }

  jint int_at(int which) const                    { return *int_at_addr(which); }
  void int_at_put(int which, jint contents)       { *int_at_addr(which) = contents; }

  jshort short_at(int which) const                { return *short_at_addr(which); }
  void short_at_put(int which, jshort contents)   { *short_at_addr(which) = contents; }

  jushort ushort_at(int which) const              { return *ushort_at_addr(which); }
  void ushort_at_put(int which, jushort contents) { *ushort_at_addr(which) = contents; }

  jlong long_at(int which) const                  { return *long_at_addr(which); }
  void long_at_put(int which, jlong contents)     { *long_at_addr(which) = contents; }

  jfloat float_at(int which) const                { return *float_at_addr(which); }
  void float_at_put(int which, jfloat contents)   { *float_at_addr(which) = contents; }

  jdouble double_at(int which) const              { return *double_at_addr(which); }
  void double_at_put(int which, jdouble contents) { *double_at_addr(which) = contents; }

  jbyte byte_at_acquire(int which) const              { return OrderAccess::load_acquire(byte_at_addr(which)); }
  void release_byte_at_put(int which, jbyte contents) { OrderAccess::release_store(byte_at_addr(which), contents); }

  // Sizing

  // Returns the number of words necessary to hold an array of "len"
  // elements each of the given "byte_size".
 private:
  static int object_size(int lh, int length) {
    int instance_header_size = Klass::layout_helper_header_size(lh);
    int element_shift = Klass::layout_helper_log2_element_size(lh);
    DEBUG_ONLY(BasicType etype = Klass::layout_helper_element_type(lh));
    assert(length <= arrayOopDesc::max_array_length(etype), "no overflow");

    julong size_in_bytes = length;
    size_in_bytes <<= element_shift;
    size_in_bytes += instance_header_size;
    julong size_in_words = ((size_in_bytes + (HeapWordSize-1)) >> LogHeapWordSize);
    assert(size_in_words <= (julong)max_jint, "no overflow");

    return align_object_size((intptr_t)size_in_words);
  }

 public:
  int object_size() {
    typeArrayKlass* tk = typeArrayKlass::cast(klass());
    return object_size(tk->layout_helper(), length());
  }
};