view src/share/vm/oops/typeArrayKlass.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 7d7a7c599c17
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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 typeArrayKlass is the klass of a typeArray
// It contains the type and size of the elements

class typeArrayKlass : public arrayKlass {
  friend class VMStructs;
 private:
  jint _max_length;            // maximum number of elements allowed in an array
 public:
  // instance variables
  jint max_length()                     { return _max_length; }
  void set_max_length(jint m)           { _max_length = m;    }

  // testers
  bool oop_is_typeArray_slow() const    { return true; }

  // klass allocation
  DEFINE_ALLOCATE_PERMANENT(typeArrayKlass);
  static klassOop create_klass(BasicType type, int scale, TRAPS);

  int oop_size(oop obj) const;
  int klass_oop_size() const  { return object_size(); }

  bool compute_is_subtype_of(klassOop k);

  // Allocation
  typeArrayOop allocate(int length, TRAPS);
  typeArrayOop allocate_permanent(int length, TRAPS);  // used for class file structures
  oop multi_allocate(int rank, jint* sizes, TRAPS);

  // Copying
  void  copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS);

  // Iteration
  int oop_oop_iterate(oop obj, OopClosure* blk);
  int oop_oop_iterate_m(oop obj, OopClosure* blk, MemRegion mr);

  // Garbage collection
  void oop_follow_contents(oop obj);
  int  oop_adjust_pointers(oop obj);

  // Parallel Scavenge and Parallel Old
  PARALLEL_GC_DECLS

 protected:
  // Find n'th dimensional array
  virtual klassOop array_klass_impl(bool or_null, int n, TRAPS);

  // Returns the array class with this class as element type
  virtual klassOop array_klass_impl(bool or_null, TRAPS);

 public:
  // Casting from klassOop
  static typeArrayKlass* cast(klassOop k) {
    assert(k->klass_part()->oop_is_typeArray_slow(), "cast to typeArrayKlass");
    return (typeArrayKlass*) k->klass_part();
  }

  // Naming
  static const char* external_name(BasicType type);

  // Sizing
  static int header_size()  { return oopDesc::header_size() + sizeof(typeArrayKlass)/HeapWordSize; }
  int object_size() const   { return arrayKlass::object_size(header_size()); }

  // Initialization (virtual from Klass)
  void initialize(TRAPS);

 private:
   // Helpers
   static klassOop array_klass_impl(typeArrayKlassHandle h_this, bool or_null, int n, TRAPS);

#ifndef PRODUCT
 public:
  // Printing
  void oop_print_on(oop obj, outputStream* st);
#endif
 public:
  const char* internal_name() const;
};