view src/share/vm/oops/typeArrayKlass.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 d8ce2825b193
children 6bd680e9ea35
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/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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.
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#ifndef SHARE_VM_OOPS_TYPEARRAYKLASS_HPP
#define SHARE_VM_OOPS_TYPEARRAYKLASS_HPP

#include "classfile/classLoaderData.hpp"
#include "oops/arrayKlass.hpp"

// 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

  // Constructor
  TypeArrayKlass(BasicType type, Symbol* name);
  static TypeArrayKlass* allocate(ClassLoaderData* loader_data, BasicType type, Symbol* name, TRAPS);
 public:
  TypeArrayKlass() {} // For dummy objects.

  // 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
  static TypeArrayKlass* create_klass(BasicType type, const char* name_str,
                               TRAPS);
  static inline Klass* create_klass(BasicType type, int scale, TRAPS) {
    TypeArrayKlass* tak = create_klass(type, external_name(type), CHECK_NULL);
    assert(scale == (1 << tak->log2_element_size()), "scale must check out");
    return tak;
  }

  int oop_size(oop obj) const;

  bool compute_is_subtype_of(Klass* k);

  // Allocation
  typeArrayOop allocate_common(int length, bool do_zero, TRAPS);
  typeArrayOop allocate(int length, TRAPS) { return allocate_common(length, true, THREAD); }
  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, ExtendedOopClosure* blk);
  int oop_oop_iterate_m(oop obj, ExtendedOopClosure* 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 Klass* array_klass_impl(bool or_null, int n, TRAPS);

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

 public:
  // Casting from Klass*
  static TypeArrayKlass* cast(Klass* k) {
    assert(k->oop_is_typeArray(), "cast to TypeArrayKlass");
    return (TypeArrayKlass*) k;
  }

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

  // Sizing
  static int header_size()  { return sizeof(TypeArrayKlass)/HeapWordSize; }
  int size() const          { return ArrayKlass::static_size(header_size()); }

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

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

  void print_on(outputStream* st) const;
  void print_value_on(outputStream* st) const;

 public:
  const char* internal_name() const;
};

#endif // SHARE_VM_OOPS_TYPEARRAYKLASS_HPP